MARGetuximab Or Trastuzumab (MARGOT): A Phase II Study Comparing Neoadjuvant Paclitaxel/Margetuximab/Pertuzumab to Paclitaxel/Trastuzumab/Pertuzumab in Patients With Stage II-III HER2-positive Breast Cancer
Phase: PHASE2
Conditions: Breast Cancer, Stage II Breast Cancer, Stage III Breast Cancer, HER2-positive Breast Cancer
Sponsor: Dana-Farber Cancer Institute

1 
 
 
 
 
MARGetuximab Or Trastuzumab (MARGOT): 
A phase II study comparing neoadjuvant paclitaxel/margetuximab/pertuzumab to 
paclitaxel/trastuzumab/pertuzumab in patients with Stage II-III HER2-positive breast cancer 
 
TBCRC #: 
TBCRC-052 
 
DF/HCC Protocol #: 
20-068 
 
Coordinating Center: 
Dana-Farber Cancer Institute 
 
Principal Investigator (PI): 
Adrienne Gropper Waks, MD 
Dana-Farber Cancer Institute 
450 Brookline Ave, Y1250 
Boston, MA 02215 
Tel: 617-632-6973 
awaks@partners.org 
 
Other Investigators: 
 
Elizabeth Mittendorf, MD, PhD 
Dana-Farber Cancer Institute 
emittendorf@bwh.harvard.edu 
 
Biostatistician: 
Nabihah Tayob 
Dana-Farber Cancer Institute 
Nabihah_Tayob@dfci.harvard.edu 
 
Project Manager: 
Emma Kelly 
Dana-Farber Cancer Institute 
CTOPM@dfci.harvard.edu 
 
Supporters: 
TerSera Therapeutics LLC (formerly supported by 
MacroGenics), Johns Hopkins University on behalf of the 
Translational Breast Cancer Research Consortium (TBCRC) 
 
IND Agent: Margetuximab (Margenza™) supplied by TerSera Therapeutics LLC (formerly 
supplied by MacroGenics) 
Other Agents: paclitaxel, nab-paclitaxel, trastuzumab, pertuzumab, trastuzumab and 
pertuzumab FDC (PHESGO) commercially supplied 
 
IND #: 145981 
IND Sponsor: Adrienne Gropper Waks, MD 
Protocol Version # / Version Date: Sponsor Amendment 08/Version 9/ July 24, 2025 

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THP x 12 weeks 
Paclitaxel 
Trastuzumab 
Pertuzumab 
TMP x 12 weeks 
Paclitaxel 
Margetuximab 
Pertuzumab 
Definitive 
surgery 
OR, if clinical 
residual disease: 
biopsy → 
additional pre-op 
chemo 
If pCR* (breast 
and nodes), 
complete 52 
wks MP/HP** 
SCHEMA 
 
 
 
Eligibility: 
• Anatomic stage II- 
III HER2+ breast 
cancer 
• Breast tumor >1.5 
cm 
• ER/PR pos or 
negative 
• CD16A Genotype 
FF or FV 
 
 
 
2:1 randomization 
 
 
 
 
*pCR defined as: RCB 0 
**concurrent endocrine tx allowed if HR+ 
Adjuvant radiation per standard institutional procedure 
Biopsy x2 
Baseline 
On-treatment 
Surgical 
tissue 
collection 
If no pCR, 
standard 
therapy per 
investigator 
discretion, 
and T-DM1 
Follow-up for recurrence/survival 
REGISTRATION 
N=171 
Research blood collection (plasma + PBMCs) 

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TABLE OF CONTENTS 
SCHEMA ......................................................................................................................................... 2 
1. 
OBJECTIVES ...................................................................................................................... 7 
1.1 
Study Design ............................................................................................................ 7 
1.2 
Primary Objectives ................................................................................................... 7 
1.3 
Secondary Objectives ............................................................................................... 8 
1.4 
Correlative, Patient-Reported Outcomes, and Exploratory Objectives .................... 8 
2. 
BACKGROUND .................................................................................................................. 9 
2.1 
Study Disease: HER2-positive breast cancer and neoadjuvant therapy ................... 9 
2.2 
Mechanism of action of trastuzumab ..................................................................... 10 
2.3 
IND Agent: Margetuximab .................................................................................... 11 
2.4 
Other Agents .......................................................................................................... 14 
2.5 
Rationale ................................................................................................................ 15 
2.6 
Correlative Studies Background ............................................................................. 17 
3. 
PARTICIPANT SELECTION ........................................................................................... 20 
3.1 
Eligibility Criteria .................................................................................................. 20 
3.2 
Exclusion Criteria ................................................................................................... 21 
3.3 
Inclusion of Women and Minorities ....................................................................... 22 
3.4 
Central Testing for CD16 Genotype ...................................................................... 22 
4. 
REGISTRATION And Randomization PROCEDURES ................................................... 22 
4.1 
General Guidelines for DF/HCC Institutions ......................................................... 22 
4.2 
Registration Process for DF/HCC Institutions ....................................................... 23 
4.3 
General Guidelines for Other Investigative Sites ................................................... 23 
4.4 
Registration Process for Other Investigative Sites ................................................. 23 
5. 
TREATMENT PLAN ........................................................................................................ 24 
5.1 
Treatment Regimen ................................................................................................ 24 
5.2 
Pre-Treatment Criteria ........................................................................................... 26 
5.3 
Agent Administration ............................................................................................. 26 
5.4 
Dose-Limiting Toxicity (DLT) .............................................................................. 28 
5.5 
Additional Pre-Surgical Therapy ........................................................................... 29 
5.6 
Physical Examinations ........................................................................................... 30 
5.7 
Tumor Staging ........................................................................................................ 30 
5.8 
Surgical Assessment ............................................................................................... 31 
5.9 
Axillary Assessment and Axillary Surgery ............................................................ 31 
5.10 
General Concomitant Medication and Supportive Care Guidelines ...................... 32 
5.11 
Definitive Breast Surgery ....................................................................................... 34 
5.12 
Post-operative Radiotherapy .................................................................................. 34 
5.13 
Post-operative Adjuvant Systemic Therapy ........................................................... 34 
5.14 
End of Treatment Visit ........................................................................................... 35 
5.15 
Criteria for Taking a Participant Off Protocol Therapy ......................................... 36 

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5.16 
Duration of Follow-Up ........................................................................................... 36 
5.17 
Criteria for Taking a Participant Off Study ............................................................ 37 
6. 
DOSING DELAYS/DOSE MODIFICATIONS ................................................................ 37 
6.1 
Paclitaxel and nab-paclitaxel Dose Modifications ................................................. 39 
6.2 
Management of Infusion-Related Reactions .......................................................... 39 
6.3 
Management of Neuropathy, Hepatotoxicity, and Neutropenia............................. 41 
6.4 
Management of Cardiotoxicity ............................................................................... 43 
6.5 
Toxicity Attributed to Pertuzumab ......................................................................... 44 
7. 
ADVERSE EVENTS: LIST AND REPORTING REQUIREMENTS ............................. 44 
7.1 
Expected Toxicities ................................................................................................ 44 
7.2 
Adverse Event Characteristics ................................................................................ 48 
7.3 
Serious Adverse Event Reporting .......................................................................... 49 
7.4 
DF/HCC Adverse Event Expedited Reporting Guidelines .................................... 49 
7.5 
Reporting to the Food and Drug Administration (FDA) and TerSera 
Therapeutics LLC ................................................................................................... 50 
7.6 
Reporting to Hospital Risk Management ............................................................... 50 
7.7 
Routine Adverse Event Reporting.......................................................................... 50 
8. 
PHARMACEUTICAL INFORMATION .......................................................................... 50 
8.1 
Margetuximab ........................................................................................................ 50 
8.2 
Trastuzumab and Biosimilars ................................................................................. 52 
8.3 
Paclitaxel ................................................................................................................ 55 
8.4 
Pertuzumab ............................................................................................................. 57 
8.5 
Trastuzumab + Pertuzumab SC FDC (PHESGO) .................................................. 58 
8.6 
Nab-Paclitaxel ........................................................................................................ 59 
9. 
CORRELATIVE AND SPECIAL STUDIES .................................................................... 61 
9.1 
Correlative Science Background ............................................................................ 61 
9.2 
Specimen Collection Requirements ....................................................................... 61 
9.3 
Research Tumor Biopsies....................................................................................... 63 
9.4 
Overview of blood collection protocols ................................................................. 64 
9.5 
Archival Tissue Collection ..................................................................................... 65 
9.6 
Stool Sample Collection ......................................................................................... 65 
9.7 
Hypotheses ............................................................................................................. 65 
9.8 
Translational Research: Planned Assays ................................................................ 66 
9.9 
Diet and Physical Activity Assessments ................................................................ 67 
9.10 
Genetic Testing ...................................................................................................... 67 
9.11 
Additional Information ........................................................................................... 68 
9.12 
Specimen Banking ................................................................................................. 68 
9.13 
Assessment of Adjuvant Therapy Decision-Making ............................................. 68 
9.14 
Patient-Reported Outcomes ................................................................................... 70 
10. 
STUDY CALENDAR ........................................................................................................ 72 
11. 
MEASUREMENT OF EFFECT ........................................................................................ 75 

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11.1 
Antitumor Effect – Solid Tumors .......................................................................... 75 
11.2 
Radiographic assessment ........................................................................................ 75 
11.3 
Clinical assessments ............................................................................................... 75 
11.4 
Pathologic Response .............................................................................................. 75 
12. 
DATA REPORTING / REGULATORY REQUIREMENTS ............................................ 76 
12.1 
Data Reporting ....................................................................................................... 76 
12.2 
Data Safety Monitoring .......................................................................................... 76 
12.3 
Multi-Center Guidelines ......................................................................................... 77 
12.4 
Collaborative Research and Future Use of Data and Samples ............................... 77 
13. REGULATORY CONSIDERATIONS and multicenter guidelines ........................................ 78 
13.1 
Protocol Review and Amendments ........................................................................ 78 
13.2 
Informed Consent ................................................................................................... 78 
13.3 
Ethics and GCP ...................................................................................................... 78 
13.4 
Compliance with Trial Registration and Results Posting Requirements................ 79 
13.5 
Study Documentation ............................................................................................. 79 
13.6 
Records Retention .................................................................................................. 79 
14. 
STATISTICAL CONSIDERATIONS. .............................................................................. 79 
14.1 
Study Design/Endpoints ......................................................................................... 79 
14.2 
Endpoints ................................................................................................................ 80 
14.3 
Sample Size and Analysis of Primary Endpoint .................................................... 80 
14.4 
Stratification Factors .............................................................................................. 81 
14.5 
Interim Monitoring Plan for pCR ........................................................................... 81 
14.6 
Interim Monitoring Plan for Post-Operative Outcomes ......................................... 81 
14.7 
Supplemental Interim Monitoring of Safety .......................................................... 82 
14.8 
Analysis of Secondary Endpoints........................................................................... 83 
14.9 
Reporting and Exclusions ....................................................................................... 83 
15. 
PUBLICATION PLAN ...................................................................................................... 84 
REFERENCES ............................................................................................................................... 85 
APPENDIX A 
PERFORMANCE STATUS CRITERIA ................................................... 89 
APPENDIX B 
DF/HCC Data-Safety Monitoring Plan ...................................................... 90 
1 
INTRODUCTION .............................................................................................................. 90 
1.1 
Purpose ................................................................................................................... 90 
2 
GENERAL ROLES AND RESPONSIBILITIES .............................................................. 90 
2.1 
Coordinating Center ............................................................................................... 90 
2.2 
External Site ........................................................................................................... 91 
3 
DF/HCC REQUIREMENTS FOR MULTI-CENTER PROTOCOLS .............................. 91 
3.1 
Protocol Revisions and Closures ............................................................................ 91 
3.2 
Informed Consent Requirements ............................................................................ 92 

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3.3 
IRB Re-Approval ................................................................................................... 92 
3.4. 
DF/HCC Multi-Center Protocol Confidentiality .................................................... 92 
3.5. 
Data Management .................................................................................................. 93 
3.6. 
Protocol Reporting Requirements .......................................................................... 94 
4. 
MONITORING: QUALITY CONTROL .......................................................................... 94 
4.4. 
Ongoing Monitoring of Protocol Compliance ....................................................... 94 
4.5. 
Monitoring Reports ................................................................................................ 95 
4.6. 
Accrual Monitoring ................................................................................................ 95 
5. 
AUDITING: QUALITY ASSURANCE ............................................................................ 95 
5.4. 
DF/HCC Internal Audits ........................................................................................ 95 
5.5. 
Audit Notifications ................................................................................................. 95 
5.6. 
Audit Reports ......................................................................................................... 96 
5.7. 
External Site Performance ...................................................................................... 96 
APPENDIX C 
DIET AND PHYSICAL ACTIVITY ASSESSMENTS ............................ 97 
APPENDIX D 
DIET AND PHYSICAL ACTIVITY ASSESSMENTS .......................... 101 
APPENDIX E 
STOOL QUESTIONNAIRE .................................................................... 102 

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1. OBJECTIVES 
 
1.1 
Study Design 
 
This is a randomized open-label phase II trial comparing paclitaxel/margetuximab/pertuzumab 
(TMP) to paclitaxel/trastuzumab/pertuzumab (THP) in patients with anatomic stage II-III 
HER2+ breast cancer who have the CD16A low affinity genotype (FF or FV). Eligible patients 
will have anatomic stage II-III (according to AJCC 8th edition anatomic staging table) HER2+ 
breast cancer. Patients may have any hormone receptor status, may be either pre- or post- 
menopausal, and must be treatment-naïve for this cancer. The FF or FV CD16A genotype will be 
confirmed by central testing in all patients. 
At least 171 eligible patients will be randomized 2:1 to neoadjuvant TMP (Arm A, approximately 
114 patients) or THP (Arm B: approximately 57 patients). All patients will receive 4 cycles of 
neoadjuvant therapy (1 cycle=21 days). Patients will be stratified by ER status (<10% vs >10%) 
and clinical anatomic stage (II vs III). 
 
Arm A (n=114) 
• paclitaxel 80 mg/m2 IV D1, D8, D15 
• pertuzumab 840 mg initial, 420 mg subsequent IV D1 
• margetuximab 15 mg/kg IV D1 
Arm B (n=57) 
• paclitaxel 80 mg/m2 IV D1, D8, D15 
• pertuzumab 840 mg initial, 420 mg subsequent IV D1 
• trastuzumab 8mg/kg initial, 6 mg/kg subsequent IV D1 
 
Pathologic response will be assessed at surgery, per standard clinical practice. Patients with pCR 
(defined as Residual Cancer Burden (RCB) = 0) will complete one year of their assigned MP or 
HP therapy in the adjuvant setting, and additional chemotherapy is not recommended. Patients 
who do not achieve pCR will receive additional/alternative adjuvant therapy of the investigator’s 
choice (four cycles of adjuvant adriamycin/cyclophosphamide (AC) chemotherapy followed by 
14 cycles of adjuvant trastuzumab-emtansine (T-DM1) or 14 cycles of adjuvant T-DM1 alone, 
depending on extent of residual disease are recommended, but not mandated). In all patients with 
hormone receptor-positive (HR+) disease, any adjuvant hormonal therapy may be given at the 
investigator’s discretion. All patients will be followed for recurrence and survival events. 
 
Given that Margetuximab has not been previously combined with Paclitaxel or Pertuzumab, the 
first 6 patients randomized to TMP will be monitored and assessed for safety. Should ≥ 4 of the 
6 patients experience a dose limiting toxicity (DLT) the TMP treatment regimen will be modified 
or discontinued. See Section 5.3 for more information. 
 
1.2 
Primary Objectives 
 
To compare rate of pathologic complete response (pCR, defined as RCB 0) in patients with the 

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FF or FV CD16A genotype and anatomic stage II-III HER2+ breast cancer treated with 4 cycles 
of neoadjuvant TMP or THP 
 
1.3 
Secondary Objectives 
 
• To compare rate of pCR (RCB 0) in patients treated with TMP or THP, according to 
hormone receptor-positive (HR+) or hormone receptor-negative (HR-) status. 
• To assess Residual Cancer Burden (RCB) scores1 in patients treated with TMP or THP, 
overall and according to HR+ or HR- status. 
• To assess safety and tolerability of THP and TMP in the neoadjuvant and adjuvant 
setting. 
• To measure event-free survival (EFS), recurrence-free interval (RFI), and overall survival 
(OS) in the overall study population. 
• To compare EFS, RFI, and OS in the following subgroups: 
o Patients with pCR versus patients without pCR 
o Patients with RCB 0 or 1, versus patients with RCB 2 or 3 
o Patients randomized to neoadjuvant TMP, versus patients randomized to 
neoadjuvant THP 
1.4 
Correlative, Patient-Reported Outcomes, and Exploratory Objectives 
 
• To describe patient and physician considerations and decisions in choice of adjuvant 
therapy following preoperative treatment with THP or TMP. 
• To assess use of protocol-specified antibody doublet therapy only (MP or HP) without 
further cytotoxic chemotherapy in the adjuvant setting, among patients with stage II-III 
HER2+ breast cancer who achieve pCR following neoadjuvant TMP or THP. 
• To assess humoral and cellular immune responses to TMP versus THP, in both tissue and 
blood. 
• To assess radiographic response to neoadjuvant therapy in patients treated with TMP or 
THP, overall and according to HR+ or HR- status. 
• To compare rate of pCR (RCB 0) in patients treated with TMP or THP, according to FF 
genotype or FV genotype. 
• To determine the feasibility of sentinel lymph node mapping and biopsy after 
preoperative therapy in this cohort. 
• To determine the incidence of additional nodal disease among patients in this cohort with 
positive sentinel lymph node(s), overall and stratified by size of largest sentinel lymph 
node metastasis. 
• To describe symptoms and quality of life (both physical and mental health) during 
neoadjuvant TMP and THP. 
• To compare mean changes in physical health, mental health and fatigue from baseline to 
the pre-operative visit at the end of neoadjuvant therapy with TMP or THP. 
• To describe symptoms and QOL over time during therapy with TMP and THP. 
• To explore the structure and function of the gut microbiome 

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2. BACKGROUND 
 
2.1 
Study Disease: HER2-positive breast cancer and neoadjuvant therapy 
 
HER2, also known as neu and c-erbB-2, is an oncogene encoding a tyrosine kinase growth factor 
receptor in the family of the epidermal growth factor receptor (EGFR) and is amplified in 
approximately 20% of all human breast cancers. It is an independent predictor of time to relapse 
and overall survival in multivariable models, and is a marker of poor prognosis.2 The functional 
significance of HER2 amplification in breast cancer prompted development of trastuzumab, a 
monoclonal anti-HER2 antibody that was the first agent developed to target the HER2 pathway. 
Addition of trastuzumab to standard chemotherapy produces an overall survival benefit in HER2- 
amplified metastatic breast cancer.3 Similarly, trastuzumab plus chemotherapy is superior to 
chemotherapy alone in multiple large, randomized trials of adjuvant therapy in HER2-positive 
disease, resulting in a striking reduction in the risk of relapse and death by 50% and 30%, 
respectively.4-7 These results led to the approval of trastuzumab for use in the early stage disease 
setting. 
In addition to large registrational studies, clinical trials conducted in the preoperative setting have 
contributed to the understanding of the activity of anti-HER2 therapies with the ability to provide 
an early read-out of drug efficacy. In the “first generation” of neoadjuvant anti-HER2 trials, 
patients were randomized to receive chemotherapy with or without trastuzumab.8-10 These seminal 
studies confirmed the superiority of neoadjuvant trastuzumab in combination with chemotherapy, 
showing pCR rates at least two times higher in the trastuzumab containing arms (summarized in 
Table 1). In the “second generation” of neoadjuvant anti-HER2 trials, patients were randomized 
to receive one of two different anti-HER2 agents or to receive trastuzumab with or without another 
anti-HER2 agent in an effort to further improve the clinical benefit achieved with trastuzumab 
alone (Table)11-13. 
Table: Representative first and second generation neoadjuvant trials of HER2-targeted 
therapies 
Studies and 
sample size 
Study design 
pCR * rates, p values 
 
NOAH 9 
N = 235 
 
NeoALTTO 
14 
 
 
N = 455 
1) AT→T→CMF 
2) AT +H→T+ H→CMF +H 
1) H → T + H → surgery → FEC → H until w 52 
 
2) L → T → surgery → FEC → L until w 52 
 
3) H + L → T + H + L → surgery → FEC → H + L until w 52 
19 
38 (P = 0.001) 
29.5 
24.7 (2 vs. 1; P = 0.34 ) 
51.3 (3 vs. 1; P = 0.0001) 
 
 
MD 
Anderson 8 
N = 64 
1) T→FEC 
26.3 
2) T + H→FEC + H 
60 (P = NR) 

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NSABP B41 
N = 529 
16 
1) AC → T + H → surgery → H until w 52 
2) AC → T + L → surgery → H until w 52 
3) AC → T + H+ L → surgery → H until w 52 
52.5 
53.2 (2 vs. 1; P = 0.99) 
62.0 (3 vs. 1; P = 0.09) 
 
1) T + H → surgery → ddAC → H until w 52 
46.0 
CALGB 
40601 
2) T + L → surgery → ddAC → H until w 52 
37.0 (2 vs. 1; P =0.12) 
N = 301 
17 
56.0 (3 vs. 1; P = 0.12) 
3) T + H + L → surgery → ddAC → H until w 52 
GeparQuinto 
18 
1) EC + H → D + H → surgery 
31.3 
N = 620 
2) EC + L → D + L → surgery 
21.7 
P < 0.05 
Abbreviations: A = doxorubicin; C = cyclophosphamide; D= docetaxel; E = epirubicin; F = fluorouracil; H = 
trastuzumab; L = lapatinib; NR = not reported; PZ = pertuzumab; pCR = pathologic complete response; T = 
paclitaxel; X = capecitabine. Comments: MD Anderson and NOAH studies have chemotherapy-only arms 
compared with chemotherapy plus trastuzumab (first generation studies). NeoALTTO, NeoSphere, GeparQuinto, 
NSABP-B41 and CALGB 40601 represent the second generation of neoadjuvant studies with anti-HER2 
regimens in all study arms. pCR definitions: MD Anderson – No evidence of invasive cancer in breast or axilla; 
NOAH – Total pCR in breast and axillary nodes; NeoALTTO – non invasive cancer in the breast or only non 
invasive in situ cancer; NeoSphere – pathologic complete response in the breast GeparQuinto – no microscopic 
evidence of residual viable cells in any specimen. 
While these second-generation neoadjuvant studies hold considerable promise, it must be 
acknowledged that the pCR definitions used across these trials were not homogeneous (pCR 
definitions are described in the Table), limiting cross-trial analysis. 
Over the past years there have been significant improvements in our understanding of the biology 
of HER2-positive disease and several novel anti-HER2 drugs have been approved for the treatment 
of HER2-positive breast cancer. 
Pertuzumab, another HER2-targeted humanized monoclonal antibody, represents the first of a 
novel class of drugs that have the ability to block the heterodimerization of HER2 with other 
members of the HER family (e.g., HER1, HER3). The resulting complementary and enhanced 
efficacy of HER2 blockade that is provided by the combination of trastuzumab plus pertuzumab 
has been demonstrated in both the preoperative, adjuvant, and metastatic settings where this 
combination of antibodies along with chemotherapy leads to improved outcomes compared with 
trastuzumab and chemotherapy.19-21 
 
2.2 
Mechanism of action of trastuzumab 
 
Multiple mechanisms of action have been proposed for trastuzumab including activation of both 
innate and adaptive cellular immunity.35 In vivo models have confirmed antibody-dependent 
1) H + D → surgery → FEC → H until w 52 
29.0 
NeoSphere 
15 
2) H + PZ + D → surgery → FEC → H until w 52 
45.8 (2 vs. 1; P = 0.0141) 
N = 417 
3) H + PZ → surgery → H + D → FEC → H until w 52 
16.8 (3 vs. 1; P = 0.019) 
4) PZ + D → surgery → FEC → H until w 52 
24.0 (4 vs. 2; P = 0.03) 

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cell-mediated cytotoxicity (ADCC) as one mechanism of action with efficacy correlating with 
the presence of NK cells. 36,37 ADCC involves the Fc-gamma receptor (FcγR) on NK cells or 
macrophages cross-linking cell-bound antibodies (i.e. trastuzumab) leading to release of 
granzyme and perforin into the synapse, promoting apoptosis. 
 
The Fc-gamma RIIIA (CD16) stimulatory receptor is encoded by two alleles that differ at amino 
acid 158: a V allele (valine; higher affinity) and an F allele (phenylalanine; lower affinity).22 A 
retrospective analysis of the NSABP-B31 trial of adjuvant AC-T +/- trastuzumab demonstrated 
greater benefit for trastuzumab in patients with at least one high affinity (V) CD16A allele, 
compared to patients homozygous for the low affinity (F) allele.39 This result suggests that those 
patients with at least one low affinity CD16A allele, which make up approximately 85% of the 
population, may not receive maximal efficacy from trastuzumab-based therapy and that they may 
benefit from use of an alternative agent. 
 
2.3 
IND Agent: Margetuximab 
 
2.3.1 Background on margetuximab 
 
Margetuximab is a monoclonal anti-HER2 antibody similar to trastuzumab but with five amino 
acid substitutions engineered into the IgG1 Fc domain to allow increased ADCC and decreased 
inhibition of immune effector cells, thereby optimizing tumor cell killing.22 
 
Margetuximab is a mouse-human chimeric IgG1 anti-HER2 antibody based on the precursor to 
trastuzumab (mouse clone 4D5).23 It was engineered to maintain the antigen-binding 
properties of the original antibody (4D5 V region), while optimizing its interactions with Fcγ 
receptors (FcγRs), important mediators of antibody function in vivo. MGFc0264, the 
engineered human IgG1 Fc domain of margetuximab, differs from that of wild type human 
IgG1 at 5 amino acid residues. The biochemical properties imparted by the engineered Fc 
domain have translated into favorable biological improvements compared with trastuzumab 
in terms of enhanced antitumor activity against HER2-expressing tumor cell lines in vitro 
and in mouse xenograft models. 
 
The biochemical and biological properties of margetuximab were compared with those of 
RES120, a chimeric anti-HER2 mAb that is identical to margetuximab except for containing 
a wild type human IgG1 Fc domain, used here as a surrogate for trastuzumab. In selected in 
vitro studies, margetuximab was also compared to trastuzumab and pertuzumab. 
In vitro studies were conducted to assess binding to recombinant human HER2 protein and to 
recombinant human, cynomolgus monkey, and murine Fcγ receptors. Studies were conducted 
with HER2-expressing tumor cell lines to assess margetuximab’s ability to mediate Fc- 
independent activities (inhibition of proliferation; inhibition of HER2 extracellular domain 
(ECD) shedding) and Fc-dependent activities (ADCC activity; natural killer (NK) cell 
activation). Studies with human peripheral-blood mononuclear cells (PBMC) were also 
conducted to assess the potential for cytokine release. 

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As noted above, the Fc-gamma RIIIA (CD16) stimulatory receptor is encoded by two alleles that 
differ at amino acid 158: a V allele (valine; higher affinity) and an F allele (phenylalanine; lower 
affinity).22 In vivo efficacy studies were conducted in a mouse xenograft model that utilized 
HER2-expressing tumor cells implanted in mCD16-/- (murine CD16 knockout) mice that 
were transgenic (Tg) for human CD16A-158F, which encodes the lower affinity allotype. The 
mCD16-/- hCD16A Tg mouse model was developed to overcome an inconsistency in 
differential binding between the wild type and engineered Fc domains to murine CD16 
compared to human CD16A, and thus provide a setting for the enhanced properties of the 
engineered Fc domain of margetuximab, optimized for human FcγR interaction, to be 
assessed. 
 
Single-dose and multi-dose toxicology/toxicokinetic (TK) studies were conducted in 
cynomolgus monkeys, which express both target antigen and FcγRs that are relevant for 
modeling margetuximab. The multi-dose studies were conducted under Good Laboratory 
Practice (GLP) compliance. These studies included TK parameters, assessments of subsets of 
circulating blood cells by flow cytometry, measurements of natural killer (NK) cell activity, 
and determination of serum cytokine levels. 
 
Cross reactivity studies, conducted under GLP compliance, were performed with panels of 
human and cynomolgus monkey tissues. A study directly comparing the cross-reactivity of 
margetuximab and trastuzumab was included. The nonclinical pharmacology, TK, and toxicology 
data support the clinical development of margetuximab for the treatment of HER2-positive 
cancers. The antitumor activity and toxicokinetics analysis of margetuximab is summarized in a 
paper by Nordstrom et al.24 
 
2.3.2 Clinical studies of margetuximab 
 
As of a data cut-off date of 23 February 2019, margetuximab has been, or is currently 
being, evaluated in 4 TerSera-sponsored clinical studies (2 ongoing, 2 completed) and 
an ongoing Expanded Access Program (EAP) of individually approved, single-patient IND 
studies providing margetuximab in single, individually approved patients. Brief overviews of 
these studies and of the EAP are provided in the table, below. 

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2.3.3 Phase III study of margetuximab in HER2+ breast cancer 
 
The SOPHIA study, MacroGenics study CP-MGAH22-04, is a Phase 3 randomized, comparator- 
controlled study of margetuximab plus chemotherapy for the treatment of patients with HER2+ 
metastatic breast cancer who had received at least 2 prior lines of anti-HER2 directed therapy in 
the metastatic setting, or in case of having received (neo)adjuvant pertuzumab, at least 1 prior 
line of anti-HER2 directed therapy in the metastatic setting, and who had received at least 1,and 
no more than 3, lines of therapy overall in the metastatic setting. Eligible patients were 
randomized 1:1 to receive either margetuximab (15.0 mg/kg IV Q3W) or trastuzumab (8 mg/kg 
loading dose, 6 mg/kg subsequent doses, IV Q3W) to be administered in combination with 
chemotherapy (capecitabine, eribulin, gemcitabine, or vinorelbine) of the investigator’s choice 
and as allowable per local regulations. Patients received treatment until disease progression, 
death, withdrawal of consent, or request by the treating physician to discontinue treatment. 
Following completion of (or discontinuation from) treatment, patients are followed for survival. 
 
Primary results from the SOPHIA study were reported at the American Society for Clinical 
Oncology Annual Meeting in June 2019.25 The study met its primary endpoint of progression-free 
survival (PFS) in the intention to treat population, with PFS 5.8 months in the margetuximab + 
chemotherapy arm versus 4.9 months in the trastuzumab + chemotherapy arm (hazard ratio 0.76, 
p=0.033). Of note, the benefit of margetuximab appeared confined to the patients with the low- 
affinity CD16 allele; the hazard ratio was 0.68 (95% CI, 0.52–0.90) in the 86% of patients with 
either a FF or FV genotype, and 1.78 (95% CI, 0.87–3.62) in the 14% of patients with the VV 
genotype. Similar allele-based differences in margetuximab benefit were apparently observed in 
an interim analysis of overall survival, although these results are not yet publicly available. This 
differential activity is consistent with the preclinical data suggesting that superiority of 
margetuximab over trastuzumab is most apparent in the context of low affinity Fc receptors that 
do not bind trastuzumab well. 
 
In the SOPHIA study, the toxicity of margetuximab was acceptable, and generally similar to 
trastuzumab, with an increased incidence of low-grade infusion-related reactions in patients 
receiving margetuximab (though notably, all patients in the trial had previously received 
trastuzumab). 
 
2.4 
Other Agents 
 
2.4.1 Trastuzumab and Biosimilars 
Refer to the Full Prescribing Information for trastuzumab or biosimilars for complete 
safety information: http://www.accessdata.fda.gov/scripts/cder/drugsatfda/ in addition to 
information provided in Sections 5 and 8 of the protocol. 
 
2.4.2 Paclitaxel 
Paclitaxel is a chemotherapy agent in the taxane class. 
Refer to the Full Prescribing Information for paclitaxel for complete safety information: 
http://www.accessdata.fda.gov/scripts/cder/drugsatfda/ in addition to information 
provided in Sections 5 and 8 of the protocol. 

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2.4.3 Pertuzumab 
Pertuzumab (Perjeta ®) is a recombinant monoclonal antibody that binds to the 
dimerization domain of HER2. 
Refer to the Full Prescribing Information for Pertuzumab for complete safety 
information: http://www.accessdata.fda.gov/scripts/cder/drugsatfda/ in addition to 
information provided in Sections 5 and 8 of the protocol. 
 
2.4.4 Trastuzumab and pertuzumab FDC SC (PHESGO) 
A subcutaneous fixed dose combination of trastuzumab and pertuzumab (PHESGO) may 
be used instead of intravenous HP in the adjuvant setting for Arm B patients who achieve 
pCR at time of surgery. 
Refer to the Full Prescribing Information for pertuzumab, trastuzumab, and hyaluronidase- 
zzxf injection (PHESGO) for complete safety information: 
http://www.accessdata.fda.gov/scripts/cder/drugsatfda/ in addition to information provided 
in Sections 5 and 8 of the protocol 
 
2.4.5 Nab-paclitaxel (Abraxane) 
Protein-bound paclitaxel is paclitaxel bonded to albumin as a delivery vehicle. 
Refer to the Full Prescribing Information for abraxane for complete safety information: 
http://www.accessdata.fda.gov/scripts/cder/drugsatfda/ in addition to information provided 
in Sections 5 and 8 of the protocol. 
 
 
 
2.5 
Rationale 
 
2.5.1 Use of margetuximab in the neoadjuvant setting 
 
Margetuximab is a monoclonal anti-HER2 antibody similar to trastuzumab but with five 
amino acid substitutions engineered into the IgG1 Fc domain to allow increased antibody- 
dependent cell-mediated cytotoxicity (ADCC) and decreased inhibition of immune effector 
cells, thereby optimizing tumor cell killing.22 Recent results from the randomized phase III 
SOPHIA study (NCT02492711) of margetuximab plus chemotherapy versus trastuzumab 
plus chemotherapy for patients with refractory metastatic HER2+ breast cancer 
demonstrated a significant improvement in progression-free survival for patients receiving 
margetuximab (see protocol Section 2.2.3 for more details).25 The improved clinical 
activity of margetuximab compared to trastuzumab in patients with metastatic HER2+ 
breast cancer raises the question of whether margetuximab will also demonstrate improved 
activity in non-metastatic HER2+ breast cancer. This possibility is of particular interest 
given that other agents acting through immunologic mechanisms appear to generally have 
greater activity in earlier stages of disease. 
 
2.5.2 De-escalation of adjuvant therapy following pathologic complete response in HER2+ 
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In this protocol, we plan to examine de-escalation of therapy from a multi-agent to a single- 
agent chemotherapy backbone plus HP or MP in patients with stage II-III HER2+ breast 
cancer, based on pCR as a prognostic biomarker. At present, standard-of-care neo/adjuvant 
therapy for stage II-III HER2+ breast cancer involves either adriamycin/cyclophosphamide 
followed by taxane plus trastuzumab (AC-TH) or taxane/carboplatin/trastuzumab 
concurrently (TCH), with consideration of pertuzumab in all patients.26 These multi-agent 
chemotherapy regimens are associated with multiple short-and long-term toxicities 
including alopecia, fatigue, neuropathy, cytopenias, cardiomyopathy, and secondary 
leukemia,6 with impacts ranging from common but temporary reduction in quality of life 
to rare and life-threatening conditions. 
Though HER2+ breast cancer was historically associated with a worse prognosis than other 
types of breast cancer,2 in recent years there has been explosive development and FDA 
approval of numerous effective HER2-targeted therapies. In 2017 the large majority of 
patients with non-metastatic HER2+ disease is cured with modern regimens incorporating 
chemotherapy plus HER2-directed therapy. In the recently published APHINITY trial of 
adjuvant multi-agent chemotherapy plus trastuzumab with or without pertuzumab, 3-year 
invasive-disease-free survival was 93-94% for all patients, and 90-92% in patients with 
node-positive disease.21 Clearly, ongoing efforts must strive to understand the patients for 
whom HER2+ breast cancer recurs despite these highly active regimens, and additional 
treatment options are needed for those patients. At the same time, the excellent long-term 
outcomes of most patients treated with modern regimens for non-metastatic HER2+ disease 
mean that we must begin to thoughtfully identify patients who can be cured with less toxic, 
less intensive therapy. 
We plan to investigate pCR-based de-escalation: selecting patients who are likely to have 
excellent long-term outcomes with less treatment, on the basis of pCR following an 
effective neoadjuvant regimen. De-escalating therapy on the basis of pCR makes sense for 
a number of reasons: Pathologic complete response at surgery provides real-time, concrete 
evidence of response to a given therapy for a given patient; and it is widely recognized as 
a positive prognostic biomarker in breast cancer.27-29 If pCR-based de-escalation is found 
to be a feasible strategy that maintains excellent long-term outcomes for patients with 
HER2+ breast cancer, it has the potential to spare a select group of breast cancer patients 
the short- and long-term toxicities of multi-agent chemotherapy, without compromising 
their long-term survival. 
Supporting the safety of a de-escalation strategy for patients who achieve pCR on this trial, 
prior evidence demonstrates excellent outcomes following pCR to neoadjuvant therapy in 
HER2+ breast cancer, regardless of neoadjuvant regimen received. For example, in the 
phase III KRISTINE study of neoadjuvant T-DM1 plus P for HER2+ breast cancer (a non- 
standard and entirely chemotherapy-sparing regimen), the 3-year IDFS event rate was 
similar and excellent among patients who achieved pCR following neoadjuvant T-DM1/P 
(96.7% 3 year IDFS) versus those patients who achieved pCR following neoadjuvant 
TCHP (docetaxel/carboplatin/HP—a standard, chemotherapy-based regimen; 3 year IDFS 
97.5%). These excellent outcomes post-pCR were seen in the chemotherapy-sparing 
regimen despite the fact that only a small minority (9.1%) of those patients who achieved 
pCR after T-DM1+P received additional adjuvant chemotherapy.30 Similarly, in the I- 
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3 year distant disease-free survival was 98% among patients who achieved pCR following 
neoadjuvant therapy, in a combined analysis that incorporated many heterogeneous 
chemotherapy-sparing neoadjuvant regimens.31 
 
2.5.3 Choice of regimen: neoadjuvant paclitaxel/trastuzumab/pertuzumab (THP) or 
paclitaxel/margetuximab/pertuzumab (TMP) 
 
On this prospective protocol, de-escalated therapy patients (i.e. those that achieve pCR) 
will receive only single-agent chemotherapy with paclitaxel (T) in addition to 
trastuzumab/pertuzumab or margetuximab/pertuzumab. The rationale for incorporation of 
margetuximab into the experimental arm is addressed above. THP is an optimal de- 
escalated regimen for a number of reasons. First, regimens incorporating doublet HER2- 
directed monoclonal antibodies (trastuzumab plus pertuzumab) show high levels of activity 
in both metastatic and non-metastatic HER2+ breast cancer, and improved outcomes 
compared to H alone.20,21,32 Indeed, in the phase II NeoSphere trial, 16.8% of patients 
treated with HP alone in the neoadjuvant setting had pathologic complete response (pCR) 
at surgery.20 Second, in stage I HER2+ breast cancer, long-term outcomes are very 
favorable with paclitaxel plus trastuzumab, and this single-agent chemotherapy backbone 
is now standard-of-care in that setting.33 
Although the taxane chemotherapy backbone used with HP in the NeoSphere and 
TRYPHAENA studies (both evaluating neoadjuvant taxane plus HP) was docetaxel, 
national guidelines support the use of paclitaxel over docetaxel.26 Safety data from a 
prospective clinical trial of metastatic HER2+ breast cancer patients treated with paclitaxel 
plus HP suggest that it is associated with less toxicity than a docetaxel-based regimen.34 
 
2.5.4 Screening for CD16 genotype and restricting study to those patients with the low affinity 
allele (FF or FV) 
As noted above, subgroup analysis of the clinical data from the phase 3 SOPHIA trial 
suggest that the superiority of margetuximab over trastuzumab is restricted to those 
patients who have a low affinity CD16 genotype (FF or FV), and that margetuximab may 
even be inferior to trastuzumab in those patients with the high affinity genotype (VV). 
While this differential activity of margetuximab based on genotype has not been 
validated yet in another study and may be spurious, given that this trial will enroll a 
population in which trastuzumab has clear benefit, it is felt prudent to only include 
patients in whom the available data suggests margetuximab is most effective. Therefore, 
in this study, all patients will be assessed for CD16 genotype during screening, and only 
those with the low affinity genotype (FF or FV) will be enrolled. 
 
2.6 
Correlative Studies Background 
 
2.6.1 Examining tissue and blood markers of ADCC during neoadjuvant therapy with TMP or 
THP 

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Multiple mechanisms of action have been proposed for trastuzumab or biosimilars 
including ADCC as well as activation of adaptive cellular immunity.35 Small pilot studies 
evaluating patients with HER2+ operable breast cancer have confirmed ADCC as a likely 
mechanism of trastuzumab therapy and have suggested a correlation between the 
presence of Fc receptors (CD16+) on the surface of NK cells and macrophages with 
efficacy. To date, limited work has been done to determine the role of peripheral NK cell 
activity (i.e. function vs. phenotype) or the presence of NK cells in the tumor 
microenvironment on the response to trastuzumab therapy. And while ADCC has been 
demonstrated as a mechanism of action of pertuzumab in in vivo models38, less is known 
regarding the impact of NK cell presence and activity on response to pertuzumab (or the 
combination of trastuzumab and pertuzumab) in patients. Furthermore, margetuximab is a 
monoclonal anti-HER2 antibody similar to trastuzumab but with five amino acid 
substitutions engineered into the IgG1 Fc domain to allow increased ADCC and 
decreased inhibition of immune effector cells, thereby optimizing tumor cell killing.22 
Thus, studies in human tumors exploring the effects of these HER2-directed antibodies, 
particularly margetuximab, are of significant clinical relevance. 
 
2.6.2 Rationale for on-study tumor biopsy 
 
Currently, there are limited data available on the ability of margetuximab (and limited 
data with trastuzumab) to activate ADCC or other immune mechanisms in human 
cancers. This study thus provides a unique opportunity to obtain mechanistic data on the 
immune effects of margetuximab and trastuzumab in human tumor tissue. Because a 
substantial percentage of patients will have a pCR, and these patients’ cancers will 
undoubtedly be biologically distinct from those who do not have a pCR, it is necessary to 
obtain a biopsy at Cycle 2, rather than rely solely on the surgical sample, in order to 
ensure there is tissue available from all patients. 
 
2.6.3 Microbiome Analysis 
 
The gut microbiome modulates immune system development,49 but the microbial 
populations of healthy individuals vary markedly in composition.50,51 The diversity of 
intestinal microbiota represents a careful balance between immune tolerance of beneficial 
microbes and inflammatory responses against pathogens. Alterations in the gut microbiota 
and their resulting interactions with intestinal epithelium and the host immune system are 
associated with many diseases, including cancer.52 Preclinical studies have provided strong 
evidence for the role of gut microbiota in modulating response and resistance to immune 
checkpoint inhibitors, raising the possibility that stool microbiota could be used as a 
response biomarker for immunotherapy.53,54 Interestingly, postmenopausal women with 
breast cancer have altered composition and low diversity of their gut microbiota compared 
to healthy controls, as measured by the Shannon index.55 
 
Emerging evidence suggests that the gut microbiome may influence response to checkpoint 
inhibitors in a number of malignancies.56-59 Preclinical studies in murine models have 
demonstrated that microbiome composition is associated with response to PD-L1 
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responding to treatment as compared to mice with an “unfavorable” microbiome. Studies 
also demonstrate that transplanting feces from mice with favorable microbiota to those with 
unfavorable microbiota increases response rates, suggesting that modification of the 
microbiome could have a therapeutic effect in patients receiving checkpoint inhibitors.60 
Translational work demonstrates that fecal transplants from patients responding to 
checkpoint inhibitors to nude mice increases the likelihood of response to immunotherapy 
in these animals, whereas transplants from human non-responders leads to a lower 
likelihood of response.57.58 The evidence linking the gut microbiome to checkpoint 
inhibitor efficacy in humans has been relatively limited to date, but a number of recent 
publications have demonstrated a relationship between composition of the microbiome and 
response to immunotherapy in melanoma, non-small cell lung carcinoma and renal cell 
cancer.56-59 Notably, the bacterial species associated with a favorable response to treatment 
have differed across disease sites and studies.56,59 
 
Microbiome composition is influenced by many factors, including age, genetics, and use 
of antibiotics and probiotics.60-62 Studies demonstrate that dietary composition is one of the 
primary drivers of microbiome diversity and taxa.60,61 Other factors related to energy 
balance, the balance of calories ingested versus expended, such as physical activity and 
body weight also impact microbiome composition.61,62 Limited data in humans suggest that 
factors impacting microbiome composition may also be related to checkpoint inhibitor 
response. An analysis of 113 patients with metastatic melanoma found significant 
associations between dietary factors (ingestion of red meat [p=0.006], sugar-sweetened 
beverages [p=0.048] and fruits/vegetables [p=0.049]) and microbiome composition.63 Use 
of antibiotics (p=0.05) and probiotics (p=0.02) was also associated with lower microbiome 
-diversity. Exploratory analyses of 46 of these patients who were initiating treatment with 
anti-PD-1 therapy suggested that individuals in this cohort with a higher consumption of 
dietary fiber had a 5-fold likelihood of response to anti-PD-1 therapy as compared to 
individuals with low fiber consumption (personal communication, Wargo). These findings 
are provocative but were based on a dietary screening tool that provides a relative crude 
assessment of dietary intake. The study also did not assess other modifiable factors that can 
influence microbiome composition, such as physical activity, precluding identification of 
an optimal strategy of lifestyle modification to enhance immunotherapy response. 
 
The identification of bacterial species associated with response to therapy could open new 
strategies to maximize the clinical benefit of cancer treatments through the modulation of 
gut microbiota. 
 
In an effort to identify characterize the microbiome in patients with newly diagnosed breast 
cancer and correlate with response to therapy, stool samples will be collected to determine 
baseline characteristics of the structure of the gut microbiome. Additionally, to identify 
potentially modifiable drivers of microbiome diversity and composition, participants will 
undergo assessment of dietary composition, physical activity and body mass index at the 
same timepoints. 

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3. 
PARTICIPANT SELECTION 
 
3.1 
Eligibility Criteria 
 
3.1.1 Stage II or III (according to AJCC cancer staging manual anatomic staging table, 8th 
edition) histologically confirmed invasive carcinoma of the breast. A minimum tumor 
size of 1.5 cm (in breast mass or axillary lymph node) determined by physical exam or 
imaging (whichever is larger) is required. Patients with inflammatory breast carcinoma 
(T4d) are NOT eligible. 
3.1.2 Centrally confirmed to have a low affinity CD16 germline genotype (FF or FV) 
3.1.3 HER-2 positive by 2018 American Society of Clinical Oncology/College of American 
Pathologists criteria, as assessed by standard institutional guidelines (central testing is not 
required). 
3.1.4 ER/PR determination is required. ER- and PR-assays should be performed by 
immunohistochemical methods according to standard institutional guidelines 
3.1.5 Bilateral breast cancers are allowed as long as both cancers are HER2-positive (as 
defined in 3.1.2), or the contralateral cancer is a <1 cm, ER+ tumor. 
3.1.6 Patients with multifocal or multicentric disease are eligible if the treating investigator has 
determined the patient should be treated as HER2-positive. 
3.1.7 Breast imaging should include dedicated ultrasound of the ipsilateral axilla. For subjects 
with a clinically positive axilla based on exam or imaging, a fine needle aspiration or core 
biopsy procedure will be performed to determine the presence of metastatic disease in the 
lymph nodes (though lymph node sampling procedure need not be resulted prior to 
patient’s registration on trial, as long as all other eligibility are met). 
 
3.1.8 Men and women (with any menopausal status)  18 years of age are eligible. 
 
3.1.9 ECOG performance status 0 or 1 
 
3.1.10 Required laboratory values demonstrating adequate organ function: 
• ANC  1000/mm3 
• Hemoglobin  9 g/dl 
• Platelets  100,000/mm3 
• Serum creatinine < 1.5 x ULN (institutional) OR calculated GFR 60mL/min 
• Total bilirubin  1.5 x ULN (institutional). For patients with Gilbert Syndrome, the 
direct bilirubin should be within the institutional normal range OR total bilirubin  

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2.0 mg/dL. 
• AST and ALT  2.5x ULN (institutional) 
3.1.11 Left ventricular ejection fraction (LVEF)  50%. 
3.1.12 Women of childbearing potential must have a negative serum pregnancy test within 14 
days of treatment start. Childbearing potential is defined as: those who have not been 
surgically sterilized and/or have had a menstrual period in the past 12 months 
3.1.13 Women of childbearing potential and men with partners of childbearing potential must be 
willing to use one highly effective form of non-hormonal contraception or two effective 
forms of non-hormonal contraception by the patient and/or partner and continue its use 
for the duration of the study treatment and for 7 months after the last dose of study 
treatment (See Section 5.10.1). 
3.1.14 Patients with a history of ipsilateral or contralateral DCIS or LCIS are eligible 
3.1.15 Patients undergoing breast conservation therapy (i.e. lumpectomy) must not have any 
contraindications to radiation therapy. 
3.1.16 Non-English-speaking patients are eligible but will be exempt from patient-completed 
questionnaires. 
3.1.17 Willing and able to sign informed consent. 
3.1.18 Willing to undergo breast biopsy for research purposes. 
 
3.2 
Exclusion Criteria 
3.2.1 Pregnant or nursing women due to the teratogenic potential of the study drugs. 
3.2.2 Active, unresolved infection requiring intervention 
3.2.3 Receipt of intravenous antibiotics for infection within 7 days prior to registration. 
3.2.4 Uncontrolled hypertension (systolic >180 mm Hg and/or diastolic >100 mm Hg) or 
clinically significant (i.e. active) cardiovascular disease: cerebrovascular accident/stroke 
or myocardial infarction within 6 months prior to first study medication, unstable angina, 
congestive heart failure (CHF) of New York Heart Association (NYHA) Class II or 
higher, or serious cardiac arrhythmia requiring medication. 
3.2.5 Significant symptoms (Grade ≥ 2) from peripheral neuropathy. 
3.2.6 Other concurrent serious diseases that may interfere with planned treatment, including 
severe pulmonary conditions/illness, uncontrolled infections, uncontrolled diabetes. 
3.2.7 Any prior treatment for the current breast cancer, including chemotherapy, hormonal 
therapy, radiation, or experimental therapy. 
3.2.8 Patients with any prior history of invasive breast cancer within the past 5 years are not 
eligible. Non-metastatic invasive breast cancers diagnosed more than 5 years ago and any 
other type of prior non-metastatic cancer is allowed. 

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3.3 
Inclusion of Women and Minorities 
 
Both men and women of all races and ethnic groups are eligible for this trial. 
 
3.4 
Central Testing for CD16 Genotype 
 
Central Testing for the CD16 genotype will be performed by Flagship Biosciences, Inc. 
(formerly Cancer Genetics Incorporated and formerly Interpace Pharma Solutions). The CD16 
genotype will be assessed using a validated PCR based assay. Participants with samples 
determined to have low affinity for CD16 genotype (FF or FV) will be eligible for registration. 
 
Flagship Biosciences, Inc. will supply kits containing sample collection (EDTA) tubes and all 
necessary supplies and instructions to submit samples for central testing. This will include: 
sample submission forms (with a unique barcode for each site), shipping box, gel packs, sleeves, 
appropriate labels for shipment and a pre-printed FedEx label. 
 
Submit the following: 
• 
One 10 mL EDTA tube 
• Completed sample submission form 
Label tubes appropriately according to the instructions in the lab manual with patient name 
with the Protocol Number, Specimen ID, and collection date (preferably all on a printed label). 
Documentation of the patient ID, site, and contact info at the site should be included with the 
shipment. Ship using the shippers provided in the kit to: 
Flagship Biosciences, Inc. 
133 Southcenter Court 
Suite 400, Bay 2 
Morrisville, NC 27560 
 
Notify Flagship Biosciences, Inc. Sample Management Team when samples have been submitted 
by emailing the air bill/tracking number, Study ID, Sample ID, and Site ID to 
samplenotification-rtp@flagshipbio.com and cc ctopm@dfci.harvard.edu. Results of central 
review will be provided directly by email to sites in approximately 7 business days after receipt 
of sample. 
 
Kit reorder/resupply information is found in the Flagship Biosciences, Inc. Lab Manual. Please 
contact the DFCI Project Management team at ctopm@dfci.harvard.edu if additional assistance 
is needed beyond the instructions in the lab manual. 
 
4. REGISTRATION AND RANDOMIZATION PROCEDURES 
 
4.1 
General Guidelines for DF/HCC Institutions 
 
DF/HCC institutions will register eligible participants in the Clinical Trials Management System 
(CTMS) OnCore. Registrations must occur prior to the initiation of any protocol-specific therapy 

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or intervention. Any participant not registered to the protocol before protocol-specific therapy or 
intervention begins will be considered ineligible and registration will be denied. 
 
An investigator will confirm eligibility criteria and a member of the study team will complete the 
protocol-specific eligibility checklist. 
 
The eligibility checklist(s) and all pages of the consent form(s) will be faxed to the ODQ at 617- 
632-2295. The ODQ will (a) review the eligibility checklist, (b) register the participant on the 
protocol, and (c) randomize the participant. 
 
Randomization can only occur during ODQ business hours (8:30am - 5pm Eastern Time, 
Monday through Friday excluding holidays). 
 
An email confirmation of the registration and/or randomization will be sent to the study 
coordinator(s) from the registering Site, treating investigator and registering person immediately 
following the registration and/or randomization. 
 
Following registration, participants may begin protocol-specific therapy and/or intervention. 
Issues that would cause treatment delays should be discussed with the DF/HCC Sponsor- 
Investigator. If the subject does not receive protocol therapy following registration, the subject 
must be taken off study in the CTMS (OnCore) with an appropriate date and reason entered. 
 
4.2 
Registration Process for DF/HCC Institutions 
 
Applicable DF/HCC policy (REGIST-101) must be followed. 
 
4.3 
General Guidelines for Other Investigative Sites 
 
Eligible participants will be entered on study centrally at Dana-Farber Cancer Institute by the 
Project Manager. To verify slot availability, participating sites may email or call the Project 
Manager. The required forms in section 4.4 should be emailed to the Project Manager. 
 
Following registration, participants should begin protocol therapy within 7 business days. Issues 
that would cause treatment delays should be discussed with the DF/HCC Sponsor-Investigator. 
If the subject does not receive protocol therapy following registration, the subject must be taken 
off study in the CTMS (OnCore) with an appropriate date and reason entered. 
 
4.4 
Registration Process for Other Investigative Sites 
 
To register/randomize a participant, the following documents should be completed by the 
research nurse or data manager and emailed to CTOPM@dfci.harvard.edu: 
• Completed and signed DF/HCC Eligibility Checklist 
• Signed participant consent form 
• HIPAA authorization form 

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• Required laboratory test results including: Hematology (CBC with differential), 
serum chemistries (creatinine and/or creatinine clearance, bilirubin, ALT, and AST), 
and pregnancy test (if applicable) 
• Baseline imaging reports with tumor measurements (MRI/Mammogram/Ultrasound) 
• CT (chest/abdomen/pelvis) scan report for patients with Stage III disease 
• Pathology report confirming diagnosis and ER/PR/HER2 status 
• Results of central testing demonstrating low affinity for CD16 genotype (FF or FV) 
• Clinic visit note with medical history, physical exam, vital signs and ECOG 
To complete the registration process, the Project Manager will 
• follow DF/HCC policy (REGIST-101) and register the participant on the protocol 
• Email the study team at the participating site with the participant study number, treatment 
assignment and to confirm registration 
NOTE: Participants MUST be registered prior to the start of protocol treatment. Registration 
can only be conducted during the business hours of 8:00 AM and 5:00 PM Eastern Time Monday 
through Friday. Same day treatment registrations will only be accepted with prior notice and 
discussion with the DF/HCC Project Manager. 
5. TREATMENT PLAN 
Data will be collected and maintained on study specific case report forms (CRFs). See Section 10 
Study Calendar for additional details. Reported adverse events and potential risks are described in 
Section 7. Appropriate dose modifications are described in Section 6. No investigational or 
commercial agents of therapies other than those described below may be administered with the 
intent to treat the participant’s malignancy. 
 
5.1 
Treatment Regimen 
In this study, patients will be randomized to treatment on one of two arms 
(paclitaxel/margetuximab/pertuzumab, TMP, or paclitaxel/trastuzumab/pertuzumab, THP). On 
both arms, one cycle is defined as 3 weeks, and study treatment will be administered in 21-day (3- 
week) cycles. Treatment and study visits will be administered within a +/- 3 day window. 
Biosimilars may be used for trastuzumab on Arm B of this study. 
 
Treatment will typically be administered on an outpatient basis. Sites may use their institutional 
standards (e.g., the Dubois formula) for calculating the doses of paclitaxel and 
trastuzumab/biosimilar. 
 
Arm A Regimen Description** 
Agent* 
Pre-Medications 
Dose 
Route 
Schedule 
Cycle 
Length 
Paclitaxel 
The following 
premedication regimen is 
recommended, but may be 
80 mg/m2 
IV per local 
standard 
Days 1, 8, 
and 15 of 
21 days 
(3 weeks) 

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altered per institutional 
standards and/or physician 
discretion: 
• Prior to 1st and 2nd 
paclitaxel infusion: 12 mg 
dexamethasone, 50 mg IV 
diphenhydramine, 20 mg 
IV famotidine 
• Prior to subsequent doses 
of paclitaxel: Steroid 
should be eliminated if no 
infusion-related reaction 
during 1st and 2nd infusion. 
Other premeds per 
investigator 
discretion/institutional 
standard. 
operating 
procedures 
each 21- 
day cycle 
Pertuzumab 
No routine pre- 
medications 
recommended 
840 mg for 
initial 
dose; 420 
mg for 
subsequent 
doses 
IV per local 
standard 
operating 
procedures 
Day 1 of 
each 21- 
day cycle 
Margetuximab 
No routine pre- 
medications 
recommended 
15 mg/kg 
IV over 120 
minutes for first 
infusion; IV 
over 30 minutes 
for subsequent 
infusions, if 
first is well 
tolerated 
Day 1 of 
each 21- 
day cycle 
*Required order of infusion for the three medications is as follows: (1) Paclitaxel, then (2) 
Pertuzumab, then (3) Margetuximab. Alterations to order of drug administration are not 
permitted. 
**Further administration details follow in Section 5.3. 
 
Arm B Regimen Description** 
Agent* 
Pre-Medications 
Dose 
Route 
Schedule 
Cycle 
Length 
Paclitaxel 
The following 
premedication regimen is 
recommended, but may be 
altered per institutional 
standards and/or physician 
discretion: 
• Prior to 1st and 2nd 
paclitaxel infusion: 12 mg 
dexamethasone, 50 mg IV 
diphenhydramine, 20 mg 
IV famotidine 
80 mg/m2 
IV per local 
standard 
operating 
procedures 
Days 1, 8, 
and 15 of 
each 21- 
day cycle 
21 days 
(3 weeks) 

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• Prior to subsequent doses 
of paclitaxel: Steroid 
should be eliminated if no 
infusion-related reaction 
during 1st and 2nd infusion. 
Other premeds per 
investigator 
discretion/institutional 
standard. 
Pertuzumab 
No routine pre- 
medications 
recommended 
840 mg for 
initial 
dose; 420 
mg for 
subsequent 
doses 
IV per local 
standard 
operating 
procedures 
Day 1 of 
each 21- 
day cycle 
Trastuzumab 
or biosimilar 
No routine pre- 
medications 
recommended 
8 mg/kg 
for initial 
dose; 6 
mg/kg for 
subsequent 
doses 
IV per local 
standard 
operating 
procedures 
Day 1 of 
each 21- 
day cycle 
*Required order of infusion for the three medications in each regimen is as follows: (1) 
Paclitaxel, then (2) Pertuzumab, then (3) Trastuzumab. Alterations to order of drug 
administration are not permitted. 
**Further administration details follow in Section 5.3. 
 
5.2 
Pre-Treatment Criteria 
 
The following laboratory criteria should be met prior to proceeding with treatment at cycle 1 day 
1 and on Day 1 of each subsequent cycle. Eligibility criteria do not need to be re-met at cycle 1 
day 1. 
 
Guideline criteria to treat at cycle 1 day 1, and subsequent cycle day 1 treatment days: 
• Absolute neutrophil count >1000/mm3 
• Platelets >100,000/mm3 
• Total bilirubin  1.5 x ULN (institutional). 
• AST and ALT <2.5 x ULN (institutional) 
• Serum creatinine < 1.5 x ULN (institutional) OR calculated GFR 60mL/min 
 
5.3 
Agent Administration 
 
5.3.1 Paclitaxel 
 
Paclitaxel will be administered in clinic on Days 1, 8, and 15 of each 21-day cycle (with 
window of +/- 3 days, see Section 5.1) per local standard operating procedures. The dose 
for the initial treatment with paclitaxel is 80mg/m2 IV per week. Treatment will typically 
be administered on an outpatient basis. It is permissible for day 8 and/or day 15 infusions 

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to occur locally along with appropriate laboratory assessments, per local standard 
operating procedures. Dose modifications and toxicity management for paclitaxel are 
described in Section 6. 
Paclitaxel will be administered first of the three drugs in the regimen. 
Preparation and administration of paclitaxel, including pre-medications (e.g. 
dexamethasone), should follow institutional guidelines; suggested pre-medications are 
found in Section 5.1 Table. Anti-emetics typically should not be administered 
prophylactically before initial treatment with paclitaxel, though this may be modified 
based on the investigator’s discretion for a given patient. 
 
Protocol therapy will consist of 12 doses (4 cycles) of paclitaxel delivered in the 
neoadjuvant setting. Following surgery, it is not expected that patients will receive 
additional paclitaxel in the adjuvant setting. 
 
For patients who experience a hypersensitivity reaction to paclitaxel, nab-paclitaxel 
(Abraxane) may be administered for subsequent doses, at the discretion of the treating 
investigator. The starting dose of nab-paclitaxel should be 125 mg/m2 weekly (if an 
investigator wishes to use an alternative starting dose based on tolerability of prior 
weekly paclitaxel doses, this will require approval of the principal investigator). 
 
5.3.2 Trastuzumab or Biosimilar 
 
Trastuzumab (or biosimilar) will be administered on Day 1 of each 21-day cycle (with 
window of +/- 3 days, see Section 5.1), per institutional guidelines. The loading dose for 
the initial treatment with trastuzumab (or biosimilar) is 8 mg/kg IV. All subsequent doses 
are 6 mg/kg IV every 3 weeks. For delayed or missed doses, if the time between 2 
sequential infusions is less than 6 weeks, the 6 mg/kg IV dose may be administered. If the 
time between 2 sequential infusions is 6 weeks or more, the initial dose of 8 mg/kg may be 
re-administered followed every 3 weeks thereafter by a dose of 6 mg/kg. 
 
Premedication for nausea and infusion reactions are not commonly required but may be 
given at the investigator’s discretion. 
 
Protocol therapy for patients randomized to trastuzumab will consist of 4 doses of 
trastuzumab (4 cycles) or biosimilar delivered in the neoadjuvant setting. Following 
surgery, patients who achieved pCR and received THP in the neoadjuvant setting will 
receive 13 doses of additional trastuzumab (or biosimilar), for a total of 17 doses. 
Subcutaneous HP (PHESGO) may be administered in the adjuvant setting in patients who 
achieve pCR on THP. 
 
5.3.3 Pertuzumab 
 
Pertuzumab will be administered on Day 1 of each 21-day cycle (with window of +/- 3 
days, see Section 5.1), per institutional guidelines. The initial loading dose of 

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Pertuzumab is 840 mg. The pertuzumab dose in subsequent cycles is 420 mg. For delayed 
or missed doses of Pertuzumab, if the time between 2 sequential infusions is less than 6 
weeks, the 420 mg IV dose of Pertuzumab may be administered. If the time between 2 
sequential infusions is 6 weeks or more, the initial dose of 840 mg Pertuzumab may be 
re-administered followed every 3 weeks thereafter by a dose of 420 mg IV. 
 
Premedication for nausea and infusion reactions are not commonly required but may be 
given at the investigator’s discretion. 
 
Protocol therapy will consist of 4 doses of pertuzumab (4 cycles) delivered in the 
neoadjuvant setting. Following surgery, patients who achieved pCR will receive 13 doses 
of additional pertuzumab, for a total of 17 doses. Subcutaneous HP (PHESGO) may be 
administered in the adjuvant setting in patients who achieve pCR on THP. 
 
5.3.4 Margetuximab 
 
Margetuximab will be administered on Day 1 of each 21-day cycle (with window of +/- 3 
days, see Section 5.1). The dose of margetuximab is 15 mg/kg. 
 
Premedication for nausea is not commonly required but may be given at the investigator’s 
discretion. 
 
Protocol therapy for patients randomized to margetuximab will consist of 4 doses of 
margetuximab (4 cycles) delivered in the neoadjuvant setting. Following surgery, patients 
who achieved pCR and received TMP in the neoadjuvant setting will receive 13 doses of 
additional margetuximab, for a total of 17 doses. However, if a patient decides to receive 
standard of care trastuzumab instead of margetuximab in the adjuvant setting, it will not 
be considered a protocol violation. 
 
5.4 
Dose-Limiting Toxicity (DLT) 
 
The phase III SOPHIA study25 suggested that the safety profile of margetuximab is globally 
acceptable and similar to the safety profile of trastuzumab. However, as margetuximab has not 
been previously combined with paclitaxel or pertuzumab in a prospective trial, dose limiting 
toxicity (DLT) will be closely monitored. 
 
A DLT monitoring plan for the first 6 patients enrolled to the TMP arm of the trial follows below, 
and additional information on supplemental DLT monitoring for the first one third (N=40) of 
patients enrolled to the TMP arm follows in Section 14 (Statistical Considerations). 
 
Once 6 patients assigned to the experimental arm (TMP) have received at least one cycle of 
assigned treatment, a safety review will be conducted before additional patients are enrolled. Based 
on the monitoring criteria, if ≥4 of 6 patients (or before 6, if 3/3, ≥3/4, ≥4/5 patients) experience 
DLT within the first cycle of treatment, then the treatment regimen will be modified or 
discontinued. The review will include a per-patient listing of all reported AEs to date, including 

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actions required for dosing, to more fully review the nature, frequency, severity and timing of the 
events. This information combined with fewer DLTs may also result in modification of the 
experimental treatment regimen. 
 
A DLT is defined as an adverse event or abnormal laboratory, enumerated (1) through (8) below, 
value assessed as suspected to be trial treatment related (possible, probable or definite) and occurs 
within the first cycle of treatment. Toxicities and lab values will be categorized and graded 
according to CTCAE v5.0. See Section 6 for guidance on dose holds and modifications. 
 
1. Any grade ≥ 3 non-hematologic, non-hepatic adverse event with the following 
exceptions: 
• Grade 3 nausea that resolves in ≤ 3 days, 
• Grade 3 fatigue that resolves to ≤ grade 2 in ≤ 5 days, 
• Grade 3 fever (>40C for ≤ 24 hrs), 
• Grade 3/4 lab values deemed by the investigator to be clinically insignificant, 
• Grade 3 rash that resolves to ≤ grade 2 in ≤ 7 days with therapy equivalent to 
prednisolone 10 mg/day or less, 
• Grade 3 arthralgia that can be managed with supportive care that resolves to ≤ grade 2 
within 7 days, 
2. Grade ≥ 4 neutropenia (ANC < 500uL) lasting > 7 days. 
3. Grade ≥ 3 febrile neutropenia. 
4. Grade ≥ 4 anemia. 
5. Grade ≥ 4 thrombocytopenia or grade 3 with clinically significant bleeding. 
6. Grade ≥ 3 or more elevation of serum hepatic transaminase (ALT or AST) lasting > 7 
days. 
7. > Grade 3 elevation in AST or ALT AND total bilirubin > 2 x ULN 
8. Grade ≥ 2 (symptomatic) heart failure. 
 
5.5 
Additional Pre-Surgical Therapy 
 
In participants with evidence of disease progression on neoadjuvant THP or TMP, additional pre- 
surgical therapy is allowed (and constitutes a reason for taking a patient off of the treatment 
protocol, see Section 5.14). The selected additional treatment regimen will be at the discretion of 
the treating investigator. It would also be acceptable for a patient with disease progression on 
THP or TMP to proceed directly to surgery, if deemed to be in the patient’s best interest per 
investigator discretion. 
 
In participants with obvious residual disease as determined by physical examination or imaging, 
if performed, following completion of neoadjuvant THP or TMP, additional systemic therapy 
may be given in the neoadjuvant setting at the investigator’s discretion (and, if given, should be 
recorded in the CRF); four cycles of adriamycin and cyclophosphamide is the recommended 

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regimen in this case. In this case, a biopsy of the presumed residual disease is required both for 
clinical purposes (to confirm presence of malignant cells) and for research purposes (see Section 
9). Participants who receive additional pre-surgery therapy will continue to be followed, as 
described in Section 5.16. All patients who receive additional pre-surgery therapy will be 
considered as non-pCR for purposes of the primary endpoint, regardless of whether they had a 
biopsy to confirm the presence of residual disease. 
 
5.6 
Physical Examinations 
 
At the initial study visit, physical examination should include examination of breast and local- 
regional lymphatics. Clinical T and N staging according to AJCC cancer staging manual 
anatomic staging table 8th edition should be documented. At subsequent visits with medical or 
surgical providers (or more frequently, if clinically indicated), breast examination and evaluation 
of local-regional lymphatics should be performed, with breast tumor measurements performed 
and documented in the medical record or research chart (for examinations performed prior to 
surgery). Additional physical examinations should be focused on organ systems related to 
adverse events. Physical examinations will occur at least approximately once every 3 weeks (i.e. 
at day 1 of each cycle). Weight is to be measured at Pre-Study (≤ 28 days of registration) and on 
Day 1 of the specified cycles. Vital signs will include measurements of pulse rate, systolic and 
diastolic blood pressures, and temperature. 
 
5.7 
Tumor Staging 
 
5.7.1 Breast mammogram, ultrasound, MRI 
All subjects are required to have a mammogram and diagnostic breast ultrasound (with or 
without breast MRI*) performed at screening (with at least one of these imaging studies 
falling within 42 days of registration) and closely preceding or following the last dose of 
neoadjuvant therapy (from up to one week before to a maximum of up to 4 weeks after 
the last dose of neoadjuvant therapy, which is C4D15 paclitaxel), to facilitate surgical 
planning. Baseline breast imaging should include imaging of the ipsilateral axilla. The 
same imaging modality must be used at screening and prior to surgery to assess tumor 
response (with the exception that breast MRI, if performed at screening, is strongly 
recommended but not required to be repeated prior to surgery). 
 
* Breast MRI is strongly recommended in patients in whom breast conserving therapy is 
under consideration, although not required if practical or financial considerations 
preclude MRI, as long as the target lesion can be adequately measured by mammogram 
and/or ultrasound. 
 
5.7.2 CT scans 
 
Subjects with Stage III disease according to AJCC Staging Manual anatomic staging 
table, Edition 8, will have CT scans of chest, abdomen and pelvis with or without a bone 
scan (PET scan as an alternative is allowed but not preferred) performed during screening 
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5.8 
Surgical Assessment 
 
All subjects will be seen and examined by the treating surgeon during screening and at the Pre- 
Operative Visit. Each visit will include a clinical breast and lymph node examination and review 
of the imaging studies (mammogram, MRI, and any other radiographic method) of the breast. After 
examining the subject and reviewing the pertinent radiographic studies at the screening and pre- 
operative visits, the surgeon will determine whether the subject is eligible for breast conserving 
surgery. If the subject is not a breast conservation candidate, the reason(s) will be documented in 
the CRF (multicentric tumor, tumor location, extensive calcifications on imaging, other). 
 
5.9 
Axillary Assessment and Axillary Surgery 
 
An axillary assessment will be performed as part of screening. Ipsilateral axillary lymph nodes 
will be assessed as clinically normal or clinically suspicious by physical examination. In all 
patients, ipsilateral axillary lymph nodes will also be assessed as normal or suspicious 
independently by dedicated axillary ultrasound. Axillary ultrasound and/or biopsy do not need to 
be repeated if performed prior to the screening period. 
 
For patients with clinically node negative disease both at baseline and following preoperative 
therapy, sentinel lymph node (SLN) biopsy will be performed after neoadjuvant systemic 
therapy. Mapping technique (i.e. single versus dual tracer) will be at the discretion of the 
attending surgeon. 
 
For patients with clinically node positive disease at presentation who become clinically node 
negative by physical examination following completion of their neoadjuvant systemic therapy, 
SLN biopsy will be performed after preoperative therapy, and the following procedures will 
apply: 
• Dual tracer with both radioisotope and blue dye will be employed. 
• For any patient in whom mapping fails, an axillary lymph node dissection (ALND) will 
be performed at the time of the initial operation. 
• For patients without a clipped positive node in whom fewer than 3 SLNs are retrieved, an 
ALND will be performed at the time of the initial operation. 
• For patients with a clipped positive node, the clipped positive node plus at least 2 
additional SLNs must be retrieved. Otherwise, an ALND will be performed at the time of 
the initial operation. 
o The clip may be localized with a radioactive seed at surgeon discretion. Other 
types of localization are also allowable per surgeon discretion. 
• Identified SLNs from any patient eligible for omission of ALND at the time of the initial 
operation, based on the above criteria, will be sent for intraoperative frozen section 
evaluation. 
o If the SLN(s) are positive on this intraoperative frozen section evaluation, then a 
completion ALND will be performed. 
• Pathologic evaluation of SLN(s) by immunohistochemistry (IHC) staining for cytokeratin 
is required in any patient who has not undergone ALND. 
• If the SLN(s) are positive by either hematoxylin & eosin (H&E) staining or by IHC 
staining for cytokeratin, then a completion ALND will be performed. 

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o Note that positivity on final pathologic evaluation will include the finding of any 
amount of nodal disease (isolated tumor cells, micromet, or macromet), regardless 
of how detected, and will warrant completion ALND. 
 
For patients with clinically node positive disease at presentation who remain clinically node 
positive by physical examination following completion of their neoadjuvant systemic therapy, or 
for any patient who becomes clinically node-positive by physical examination following 
completion of their neoadjuvant systemic therapy, an ALND will be performed. 
 
Deviation from this algorithm will be considered a protocol violation. 
 
5.10 General Concomitant Medication and Supportive Care Guidelines 
 
Concomitant therapy includes any medication (e.g., prescription drugs, over-the-counter drugs, 
herbal/homeopathic remedies, nutritional supplements) used by a patient from 7 days prior to 
registration through the end of treatment. All concomitant medications should be reviewed by the 
study staff and recorded in the medical record. 
 
The following treatments are permitted throughout the duration of the study treatment phase and 
during follow-up: 
• Standard therapies for pre-existing medical conditions unless listed as prohibited therapy 
in section below. Any medication intended solely for supportive care (e.g., analgesics, 
anti-diarrheal, anti-depressants) may be used at the investigator’s discretion. 
• Hematopoietic growth factors (e.g., G-CSF, granulocyte macrophage colony stimulating 
factor) may be used at investigator’s discretion for the primary prophylaxis and/or 
management of treatment-emergent neutropenia and/or for secondary prophylaxis as per 
NCCN/European Society for Medical Oncology guidelines42,43 or local standard practice. 
• Bisphosphonate or denosumab therapy to be used in accordance with the approved 
labeled indication and/or nationally recognized treatment guidelines. 
 
Explicitly prohibited therapies prior to the end of treatment visit include: 
• Anti-cancer therapies other than those administered in this study, including cytotoxic 
chemotherapy, radiotherapy (except for adjuvant radiotherapy for breast cancer after 
completion of chemotherapy), immunotherapy, biological, hormonal (except for adjuvant 
hormonal therapy for breast cancer after completion of chemotherapy) or targeted (e.g., 
lapatinib, neratinib) anti-cancer therapy. GnRH agonist used for purposes of fertility 
preservation is allowed. 
• Any systemically active oral, injected, or implanted hormonal method of contraception 
except for progesterone coated intrauterine devices (IUDs) that had been previously 
implanted 
• Estrogen-replacement therapy 
• Any investigational agent, except those used for this study 

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5.10.1 Timing and Use of Contraception 
 
The agents used on this study may have teratogenic effects on a developing fetus. If, for any 
reason, a woman should become pregnant or suspect that she is pregnant while participating in 
this study, she should inform her treating physician immediately. 
 
Women of childbearing potential and men with partners of childbearing potential must be willing 
to use one highly effective form of non-hormonal contraception or two effective forms of non- 
hormonal contraception by the patient and/or partner and continue its use for the duration of the 
study treatment and for 7 months after the last dose of study treatment 
 
Highly Effective Non-Hormonal Contraception 
Methods of birth control which result in a low failure rate (i.e., less than 1% per year) when used 
consistently and correctly are considered highly-effective forms of contraception. 
The following non-hormonal methods of contraception are acceptable: 
• True abstinence when this is in line with the preferred and usual lifestyle of the 
participant. [Periodic abstinence (e.g., calendar, ovulation, symptothermal post-ovulation 
methods) and withdrawal are not acceptable methods of contraception]. 
• Male sterilization (with appropriate post-vasectomy documentation of the absence of 
sperm in the ejaculate). For female participants, the vasectomized male partner should be 
the sole partner (partner’s post-vasectomy documentation of the absence of sperm in the 
ejaculate is not required). 
Effective Non-Hormonal Contraception 
Alternatively two of the following effective forms of contraception may be used instead: 
• Placement of non-hormonal intrauterine device (IUD) or intrauterine system (IUS). 
Consideration should be given to the type of device being used, as there is higher failure 
rates quoted for certain types, e.g., steel or copper wire. 
• Condom with spermicidal foam/gel/film/cream/suppository. 
• Occlusive cap (diaphragm or cervical/vault caps) with spermicidal 
foam/gel/film/cream/suppository. 
• The use of barrier contraceptives should always be supplemented with the use of 
spermicide. The following should be noted: 
• Failure rates indicate that, when used alone, the diaphragm and condom are not highly 
effective forms of contraception. Therefore, the use of additional spermicides does confer 
additional theoretical contraceptive protection. 
• However, spermicides alone are ineffective at preventing pregnancy when the whole 
ejaculate is spilled. Therefore, spermicides are not a barrier method of contraception and 
should not be used alone. 
It should be noted that two forms of effective contraception are required. A double barrier 
method is acceptable, which is defined as condom and occlusive cap (diaphragm or 
cervical/vault caps) with spermicidal foam/gel/film/cream /suppository. 

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5.11 Definitive Breast Surgery 
 
Definitive breast surgery (lumpectomy and/or mastectomy) can be performed as soon as 14 days 
but no later than 42 days following administration of the last dose of protocol therapy i.e. C4D15 
paclitaxel administration (unless an additional preoperative systemic therapy regimen is 
administered, as described in Section 5.4). If contralateral mastectomy is performed concurrently, 
the pathology report from the contralateral breast must be recorded in the CRF if invasive disease 
is identified. 
 
For guidance regarding axillary surgery, see Section 5.8 above. 
 
5.12 Post-operative Radiotherapy 
 
Decisions regarding post-surgical radiotherapy will be made by the treating team and should be 
recorded in the CRF. 
 
5.13 Post-operative Adjuvant Systemic Therapy 
 
Note that assessment of pCR must occur after the final breast cancer surgery is performed (i.e. if 
patient returns to the operating room for ALND, pCR status cannot be ascertained until ALND 
pathology is reviewed). 
 
5.13.1 Patients who achieve pCR at the time of surgery (defined as RCB 0): These patients 
should go on to receive antibody-only therapy with trastuzumab (or biosimilar) and 
pertuzumab (IV or FDC SC HP) if that was their preoperative regimen, or margetuximab 
and pertuzumab (MP) if that was their preoperative regimen, for 13 doses in the post- 
operative setting, for a total of 17 doses of HP/MP overall (4 doses pre-operatively and 
13 doses post-operatively). However, if a patient decides to receive standard of care 
trastuzumab instead of margetuximab in the adjuvant setting, it will not be considered a 
protocol violation. For patients with HR+ disease, any regimen of adjuvant hormonal 
therapy may be given at the investigator’s discretion. Receipt of adjuvant bone modifying 
agents is allowed and will not be considered in the assessment of escalated or de- 
escalated adjuvant therapy. Receipt of additional adjuvant chemotherapy is not 
recommended but will not be considered a protocol violation if administered. If a patient 
achieves pCR with less than the intended regimen (e.g. less than 11 paclitaxel doses 
and/or less than 4 HP or MP doses), they may still be treated in accordance with the 
above adjuvant therapy guidelines, or alternative therapy may be offered at the discretion 
of the treating investigator with input from sponsor. 
 
5.13.2 Patients who do not achieve pCR at the time of surgery: All patients who do not achieve 
pCR are recommended to receive therapy with trastuzumab emtansine (T-DM1) for 14 
doses in the post-operative setting. Patients with substantial residual disease (i.e. RCB 
III) or particularly high risk should also receive additional adjuvant chemotherapy prior 
to T-DM1. In this case, four cycles of adjuvant adriamycin/cyclophosphamide (AC) is 
recommended as a preferred adjuvant chemotherapy regimen. Patients with a small to 
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additional adjuvant chemotherapy can also be used. For patients with HR+ disease, any 
regimen of adjuvant hormonal therapy may be given at the investigator’s discretion. 
Receipt of adjuvant bone modifying agents is allowed and will not be considered in the 
assessment of escalated or de-escalated adjuvant therapy. 
 
5.13.3 Post-operative hormonal therapy: Specific regimen and duration of post-operative 
hormonal therapy should be delivered at the investigator’s discretion. 
 
5.13.4 Recording of systemic adjuvant chemotherapy planned: At the post-operative visit, all 
efforts should be made for the patient and provider to review surgical pathology results 
and discuss a plan for adjuvant chemotherapy. pCR status and planned adjuvant 
chemotherapy (or lack thereof) should be recorded in the CRF and the questionnaire 
regarding planned adjuvant chemotherapy (see Questionnaire Packet) must be completed 
by a member of the study team and signed by the investigator. If for any reason the 
discussion of planned adjuvant chemotherapy is not completed at the post-operative visit, 
CRF recording of planned non-hormonal adjuvant systemic therapy and completion of 
the questionnaire may be delayed until a final decision is made regarding planned 
adjuvant chemotherapy, though it is strongly encouraged that this decision be made 
within 28 days (and as soon as possible) after the post-operative visit. Every effort must 
be made to complete adjuvant chemotherapy decision-making at an in-person visit. This 
determination of planned adjuvant chemotherapy is necessary for real-time 
administration of patient questionnaires. Additional information regarding assessment 
and questionnaires around adjuvant systemic therapy decision-making can be found in 
Section 9. 
 
5.13.5 Recording of all systemic adjuvant therapy received: Over the course of adjuvant 
systemic therapy, the patient record should be regularly reviewed and adjuvant systemic 
therapy received (including hormonal therapy, targeted therapy, and bone modifying 
agents) should be recorded and updated as of the most recent review timepoint. As in 
Section 5.16 “Duration of Follow-up,” follow-up assessments should occur at least yearly 
until 10 years after surgery, or until patient death (if occurring sooner than 10 years). 
 
5.14 End of Treatment Visit 
 
For patients who DO NOT achieve pCR following neoadjuvant THP or TMP, the post-surgery 
follow-up visit at which a final decision is made about whether or not the patient will receive 
further adjuvant chemotherapy will be considered the end of treatment visit (regardless of 
whether or not the patient goes to surgery immediately following protocol therapy or receives 
additional preoperative therapy). It is expected that this will constitute the first post-surgery 
follow-up visit for the vast majority of patients (see Section 5.12.2). If breast surgery is not 
performed the participant’s end of treatment visit should be within 28 days after the last dose of 
protocol-specified therapy. 
 
For patients who achieve pCR following neoadjuvant THP or TMP, and therefore go on to 
receive additional HP or MP in the adjuvant setting, the end of treatment visit will occur with the 
final infusion of adjuvant antibody therapy. Patients who achieve pCR following neoadjuvant 

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THP or TMP + additional neoadjuvant therapy may also stay on study to receive HP or MP in 
the adjuvant setting, and the end of treatment visit for such patients will occur with the final 
infusion of antibody therapy. However, if such patients (who received additional neoadjuvant 
therapy) choose to make the post-operative visit be their end of treatment visit on-study, that will 
not be considered a protocol violation. 
 
 
5.15 Criteria for Taking a Participant Off Protocol Therapy 
 
Participants will be removed from the protocol therapy when one of the following criteria 
applies: 
• 
Completion of protocol-mandated therapy 
• 
Disease progression 
• 
Intercurrent illness that prevents further administration of treatment 
• 
Unacceptable adverse event(s) 
• 
Participant demonstrates an inability or unwillingness to comply with the medication 
regimen and/or documentation requirements 
• 
Participant decides to withdraw from the protocol therapy 
• 
General or specific changes in the participant's condition render the participant 
unacceptable for further treatment in the judgment of the treating investigator 
 
The reason for removal from protocol therapy, and the date the participant was removed, must be 
documented in the case report form (CRF). 
In the event of unusual or life-threatening complications, treating investigators must immediately 
notify the PI. 
When a participant is removed from protocol therapy and/or is off of the study, the participant’s 
status must be updated in OnCore in accordance with REGIST-OP-1. 
 
5.16 Duration of Follow-Up 
 
Follow-up assessments should occur at least yearly (+/-2 months) until 10 years after surgery (with 
time measured from the date of protocol registration), or until patient death (if occurring sooner 
than 10 years). 
 
Comprehensive information about adjuvant therapy received must be recorded for all patients 
regardless of whether or not they receive adjuvant antibody therapy on study. 
 
Event-free survival (EFS) will be defined from the time of registration until the occurrence of the 
first of the following events: 
• 
Local/regional recurrence: a recurrent or new invasive ipsilateral breast cancer, invasive 
breast cancer in the axilla, regional lymph nodes, chest wall, or skin of the ipsilateral 
breast. 
• 
Contralateral invasive breast cancer, 
• 
Distant recurrence: metastatic disease that has either been biopsy confirmed or clinically 

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diagnosed as recurrent invasive breast cancer. A single new lesion on a bone scan without 
evidence of lytic disease on x-ray and without symptoms does not in and of itself 
constitute distant recurrence, but multiple new bone lesions, or increased isotope uptake 
associated with new bone symptoms are more likely due to metastases. Bone metastases 
may also be documented with x-rays and clinical description. 
• 
Death from any cause 
 
In situ cancer is not included as EFS event. If a patient has in situ breast cancer (on the ipsilateral 
or contralateral side) diagnosed during follow-up before any of the EFS events above, then the 
patient should continue to be followed for EFS on study (even if she is given hormonal therapy 
or undergoes additional surgery after the in-situ diagnosis). These patients will be followed for 
survival. 
 
If a patient is diagnosed with a non-melanoma skin cancer or a vaginal carcinoma in situ, she 
will continue on this study and continue to be followed for EFS. 
 
Disease-free survival (DFS) will be defined for patients who undergo surgery for breast cancer as 
the interval from the time of surgery until the occurrence of EFS events noted above. 
Recurrence-free interval will be defined for patients who undergo surgery for breast cancer as the 
interval from the time of surgery until the occurrence of invasive local/regional recurrence (as 
defined in EFS events, above), distant recurrence (as defined in EFS events, above), or death from 
breast cancer. 
It is recommended that any disease-free survival event is biopsied to confirm recurrent disease. 
Every effort will be made to collect information on breast cancer status, new anti-cancer therapy, 
and new onset malignancy diagnoses via simplified CRFs. Following a DFS event, survival 
information (i.e., date and cause of death or last known alive date if not deceased and new onset 
malignancy information) should be collected until the completion of 10 years of follow-up. 
 
5.17 Criteria for Taking a Participant Off Study 
 
Participants will be removed from study when any of the following criteria apply: 
• 
Completion of follow-up 
• 
Lost to follow-up 
• 
Withdrawal of consent 
• 
Death 
The reason for taking a participant off study, and the date the participant was removed, must be 
documented in the case report form (CRF). In addition, the study team will ensure the participant’s 
status is updated in OnCore in accordance with REGIST-OP-1 
 
 
6. DOSING DELAYS/DOSE MODIFICATIONS 
 
Dose delays and modifications will be made as indicated in the following section. The 
descriptions and grading scales found in the revised NCI Common Terminology Criteria for 

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Adverse Events (CTCAE) version 5.0 will be utilized for dose delays and dose modifications. A 
copy of the CTCAE version 5.0 can be downloaded from the CTEP website 
http://ctep.cancer.gov/protocolDevelopment/electronic_applications/ctc.htm. 
 
Patients will be assessed for toxicity prior to each dose. Patients will be instructed to notify their 
physician immediately for any and all toxicities. Assessment of causality (chronology, 
confounding factors, concomitant medications, medical history, diagnostic tests, and previous 
experience with the study treatment) should be conducted by the investigator prior to dose 
modification and/or delay whenever possible. 
 
As a general approach, it is suggested that all AEs be managed with supportive care when 
possible at the earliest signs of toxicity. If supportive care is ineffective, a dose delay or dose 
reduction may be considered to avoid worsening toxicity. Dosing will occur only if the clinical 
assessment and laboratory test values are acceptable. 
 
If there are dosing delays for any reason, all study assessments are to be delayed in the same 
fashion, such that planned assessments occur in conjunction with cycles of treatment. 
 
During study treatment, a given toxicity may be attributable to any one, or a combination, of the 
study drugs. It is important to evaluate the possible cause of toxicity and weigh risk versus 
benefit for each agent to determine the schema of dose delays/modifications (e.g., which agent to 
prioritize for maintaining dose timing/level). Determination of attribution is up to investigator 
discretion. 
 
General guidelines are provided in the following subsections based on the known safety profile 
of study drugs. Toxicity management is organized by most likely causative agents but guidelines 
may be applied to management of toxicity regardless of causative agent. General guidelines for 
dose delay and dose reduction are outlined below. The dose delay and reduction instructions 
provided in these sections are intended to serve as guidelines to allow ongoing treatment for 
patients without signs or symptoms of progression while ensuring patient safety. In addition to 
the guidelines provided below, drug holds and dose reductions for the management of adverse 
events are permitted at the discretion of the treating physician. 
 
Though the standard neoadjuvant regimen as written in this protocol has a 12-week duration, it 
will be acceptable to make up infusion of missed doses of any component of the regimen through 
14 weeks from cycle 1 day 1 (meaning, up to 3 weeks of delay from what was intended to be the 
final infusion date is acceptable). 
 
In the event that any of the individual study drug(s) in the regimen is delayed as a result of 
toxicity, the administration of other agent(s) may be continued based on the following 
guidelines: 
• If pertuzumab alone is held, all other agents may continue. Do not make up missed 
pertuzumab dose if pertuzumab alone is held (i.e. pertuzumab is only to be administered 
in combination with trastuzumab or margetuximab). 
• If trastuzumab or margetuximab is held, pertuzumab should be held as well. Paclitaxel 
may continue as per investigator discretion. 

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• If paclitaxel is held, other agents (HP or MP) should continue on schedule. 
Trastuzumab, margetuximab, and pertuzumab may be delayed as a result of toxicities (no dose 
reductions are allowed for these agents). Paclitaxel doses may be delayed and/or reduced for 
toxicities. 
 
6.1 
Paclitaxel and nab-paclitaxel Dose Modifications 
 
If a patient requires a dose reduction for paclitaxel, dosing will be reduced by one dose level 
per Table below. Dose re-escalation is not allowed after a dose reduction. 
 
Table: Dose reductions for Paclitaxel 
Dose Level 
Dose 
Starting dose 
80mg/m2 
First reduction 
64mg/m2 
Second reduction 
48mg/m2 
Indication for further dose reduction 
Off Study treatment 
For patients receiving nab-paclitaxel on trial who require dose modifications, dosing will be 
reduced by one dose level per Table below. Dose re-escalation is not allowed after a dose 
reduction. 
 
Table: Nab-paclitaxel dose reduction levels 
Dose Level 
Nab-paclitaxel Dose 
Starting dose 
125 mg/m2 weekly 
First reduction 
100 mg/m2 weekly 
Second reduction 
75 mg/m2 weekly 
Indication for further dose reduction 
Off study treatment 
 
 
6.2 
Management of Infusion-Related Reactions 
Infusion-related reactions are known to occur with the administration of monoclonal antibodies 
as well as with paclitaxel, and may be seen with trastuzumab, margetuximab, pertuzumab, or 
paclitaxel on this protocol. 
Guidelines for management of infusion-related reactions are below. Institutional standard 
protocols for initial management of infusion-related reactions may also be applied. If an 
infusion-related reaction occurs to an agent other than margetuximab at its first infusion on 
protocol, investigator discretion may be used regarding premedication for subsequent doses of 
the agent (though it should be noted that given the potential importance of immunologic 
mechanisms to the efficacy of trial therapy, steroids should be minimized if deemed safe per 
investigator). 
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guidance must be followed regarding subsequent dosing: 
• Grade 1 infusion reaction at initial margetuximab infusion: no premedication 
recommended prior to second margetuximab infusion 
• Grade 2 infusion reaction at initial margetuximab infusion: premedication is 
recommended prior to second margetuximab infusion. Specific premedication regimen is 
up to investigator discretion. 
• Grade 3 infusion reaction at initial margetuximab infusion: Premedication is required 
prior to second margetuximab infusion. For additional guidance, see table below. 

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Event 
Intervention 
Action to be Taken 
Infusion-related symptoms 
Grades 1−2. 
Supportive care with 
oxygen, -agonists, 
antihistamines, antipyretics, 
or corticosteroids may be 
used as appropriate at the 
investigator's discretion. 
Premedication with 
corticosteroids, 
antihistamines, and 
antipyretics may be used 
before subsequent infusions 
at the investigator’s 
discretion (exception: 
specific premedication 
requirements for 
margetuximab, as above). 
Patients should be 
monitored until complete 
resolution of symptoms. 
Decrease infusion rate by 
50% or interrupt infusion 
for patients who experience 
any other infusion-related 
symptoms (e.g., chills, 
fever). 
When symptoms have 
completely resolved, 
infusion may be restarted 
at  50% of prior rate and 
increased in 50% increments 
every 30 minutes as 
tolerated. Infusions may be 
restarted at the full rate at 
the next cycle, with 
appropriate monitoring. 
Grade  3 
allergic/hypersensitivity 
reaction 
Supportive care with 
oxygen, -agonists, 
antihistamines, antipyretics, 
or corticosteroids may be 
used, as appropriate, at the 
investigator's discretion. 
Patients should be 
monitored until complete 
resolution of symptoms. 
Stop infusion; the causative 
agent (trastuzumab, 
margetuximab, pertuzumab, 
or paclitaxel) should be 
permanently discontinued 
or, if continued, it is 
suggested that this be done 
in the context of close 
observation and/or co- 
management with allergy 
specialist colleagues. If 
continued, it is also 
suggested that infusion is 
started at  50% of prior 
rate and increased in 50% 
increments every 30 minutes 
as tolerated. Alternatively, 
for a grade >3 infusion 
reaction to margetuximab, 
subsequent use of 
trastuzumab in place of 
margetuximab is allowed. 
 
6.3 
Management of Neuropathy, Hepatotoxicity, and Neutropenia 
 
Neuropathy can occur associated with paclitaxel. Guidance for paclitaxel dose reductions in case 
of neuropathy is in the Table below. As paclitaxel is a standard of care drug being administered 
in standard fashion, investigator discretion or institutional standards may also be used in 
management of paclitaxel-associated neuropathy. 

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Paresthesia/Dysesthesia 
Paclitaxel: Action to be 
Taken 
(If persistent for  7 Days or Causing the Next Cycle to be Delayed) 
Grade 1 paresthesias/dysesthesias that do not interfere with 
function 
Maintain dose 
Grade 2 paresthesias/dysesthesias that interfere with function, 
but not activities of daily living 
Maintain dose 
Grade 3 paresthesias/dysesthesias with pain or with function 
impairment that interfere with activities of daily living 
Withhold therapy dose until 
neuropathy Grade 2 
Reduce one dose level 
Grade 4 Persistent paresthesias/dysesthesias that are disabling 
or life-threatening 
Discontinue therapy 
 
Hepatic toxicity manifesting as elevated transaminases may be observed with paclitaxel. 
Guidelines for management are below. As paclitaxel is a standard of care drug being 
administered in standard fashion, investigator discretion or institutional standards may also be 
used. 
 
Hepatic Toxicity 
Grade 
Paclitaxel: 
Action 
to 
Be 
Taken 
AST/ALT elevated 
Grade 3 (>5.0-20.0 x ULN) on 
the laboratory evaluation for 
the planned day of dosing. 
Hold paclitaxel until recovered 
to  Grade 1. Resume with 
dose reduction by one level. 
Grade 4 (>20.0 x ULN) 
Discontinue paclitaxel. Repeat 
lab evaluation (within 24 
hours) may be done to exclude 
lab error prior to discontinuing 
study treatment. 

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Hematologic Toxicity 
Grade 
Paclitaxel: Action to Be 
Taken 
Cytopenias, particularly neutropenia, may be observed with paclitaxel. Guidelines for management are 
below. As paclitaxel is a standard of care drug being administered in standard fashion, investigator 
discretion or institutional standards may also be used. 
Neutrophil count 
decreased 
Grade 3/4 (ANC <1000) on the 
laboratory evaluation for the 
planned day of dosing. 
Hold paclitaxel until ANC 
>1000, and restart paclitaxel at 
same dose. If dose held more 
than 2 times for grade 3/4 
neutropenia, dose reduce 
paclitaxel by one level or add 
growth factor, per investigator 
discretion. 
 
 
6.4 
Management of Cardiotoxicity 
Decreased ejection fraction (EF) may be seen in association with trastuzumab, margetuximab, or 
pertuzumab. Management of decreased EF with or without heart failure symptoms is addressed 
below. 
Ejection fraction 
decreased 
Asymptomatic 
decrease in 
LVEF 
See Figure for dose modifications 
Grade 3 or 4 
Discontinue all HER2-directed treatment. 
Heart Failure 
Grade 3 or 4 
Discontinue all HER2-directed treatment. 
Heart Failure 
Accompanied by LVEF 
<45% 
Grade 2-4 
Discontinue all HER2-directed treatment. 

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LVEF = left ventricular ejection fraction; EF = ejection fraction % points 
Note: Baseline refers to the screening LVEF. Study treatment refers to trastuzumab, margetuximab, or pertuzumab; 
paclitaxel may be continued at investigator’s discretion. 
a Three intermittent holds of study treatment will lead to discontinuation. 
 
6.5 
Toxicity Attributed to Pertuzumab 
 
Diarrhea and rash are considered EGFR-related risks based on the mechanism of action of 
pertuzumab. To prevent dehydration, early treatment of diarrhea with anti-diarrheal medication 
should be considered, and patients should be treated with fluids and electrolyte replacement, as 
clinically indicated. Treatment recommendations for EGFR-associated rash include topical or 
oral antibiotics, topical pimecrolimus, and topical or (for severe reactions) systemic steroids. 
These agents may be used in patients experiencing pertuzumab-related rash, as clinically 
indicated; although, they have not been studied in this context. 
 
7. ADVERSE EVENTS: LIST AND REPORTING REQUIREMENTS 
 
Adverse event (AE) monitoring and reporting is a routine part of every clinical trial. The 
following list of reported and/or potential AEs (Section 7.1) and the characteristics of an 
observed AE (Section 7.2) will determine whether the event requires expedited reporting in 
addition to routine reporting. 
 
7.1 
Expected Toxicities 
 
7.1.1 Adverse Event List for Margetuximab 

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Sixty of 91 (65.9%) patients treated with single-agent margetuximab in clinical studies 
have experienced at least one AE considered to have possible, probably, or definite 
relationship to margetuximab treatment. The most frequently reported treatment-related 
AEs, regardless of severity, included infusion related reaction (n=17 [18.7%]), nausea 
(n=14 [15.4%]), and fatigue (n=12 [13.2%]). Including the term CRS (n=4), treatment- 
related infusion-related reactions have occurred in a total of 21 (23.1%) patients 
administered single-agent margetuximab. 
 
The majority of treatment-related AEs occurring among patients administered single- 
agent margetuximab were Grade ≤2 in severity. Treatment-related AEs with a maximum 
severity of Grade ≥3 were experienced by 8 (8.8%) of 91 patients and included the 
following: 
• Grade 3: blood amylase increased (n=2 [2.2%]); and vomiting, infusion related 
reaction, lymphocyte count decreased, blood alkaline phosphatase increased, 
ejection fraction decreased, and hypertension (n=1 [1.1%] each) 
• Grade 4: lymphocyte count decreased and lipase increased (n=1 [1.1%] each) 
• Grade 5: none. 
Treatment-related AEs (regardless of severity) occurring in ≥5% of all patients participating in 
single-agent studies of margetuximab are presented by decreasing frequency for all patients overall 
and by dose/regimen and study in the table below. 
 
 
Additional details regarding margetuximab adverse events can be found in the 
Package Insert. 
 
7.1.1.1 
Adverse Event List for Trastuzumab (or biosimilar) 

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The following information is from the package insert for trastuzumab (Herceptin®; 
Genentech, Inc.). This is a list of those adverse events most likely to occur to this study; 
please refer to the trastuzumab package insert for the comprehensive list of adverse 
events that have occurred with trastuzumab administration. The side effect profile for 
trastuzumab biosimilars is the same as trastuzumab. 
 
Cardiac Failure/Dysfunction: Signs and symptoms of cardiac dysfunction, such as 
dyspnea, increased cough, paroxysmal nocturnal dyspnea, peripheral edema, S3 gallop, 
or reduced ejection fraction, have been observed in participants treated with 
trastuzumab. Congestive heart failure associated with trastuzumab therapy may be 
severe and has been associated with disabling cardiac failure, death, and mural 
thrombosis leading to stroke. The probability of cardiac dysfunction was highest in 
participants who received trastuzumab concurrently with anthracyclines. The data 
suggest that advanced age may increase the probability of cardiac dysfunction. Subjects 
entering this study will undergo a baseline cardiac assessment including history, 
physical exam and an echocardiogram or MUGA scan. 
 
Anemia and Leukopenia: An increased incidence of anemia and leukopenia was 
observed in the treatment group receiving trastuzumab and chemotherapy, especially 
in the trastuzumab and adriamycin/cytoxan subgroup, compared with the treatment 
group receiving chemotherapy alone. The majority of these cytopenic events were mild 
or moderate in intensity, reversible, and none resulted in discontinuation of therapy 
with trastuzumab. Hematologic toxicity is infrequent following the administration of 
trastuzumab as a single agent, with an incidence of Grade III toxicities for WBC, 
platelets, hemoglobin all <1%. No Grade IV toxicities were observed. 
 
Diarrhea: Of participants treated with trastuzumab as a single agent, 25% experienced 
diarrhea. An increased incidence of diarrhea, primarily mild to moderate in severity, 
was observed in participants receiving trastuzumab in combination with chemotherapy. 
 
Infection: An increased incidence of infections, primarily mild upper respiratory 
infections of minor clinical significance or catheter infections was observed in 
participants receiving trastuzumab in combination with chemotherapy. 
 
Infusion Reactions: During the first infusion with trastuzumab, a symptom complex 
most commonly consisting of chills and/or fever was observed in about 40% of 
participants in clinical trials. The symptoms were usually mild to moderate in severity 
and were treated with acetaminophen, diphenhydramine, and meperidine (with or 
without reduction in the rate of trastuzumab infusion). Trastuzumab discontinuation 
was infrequent. Other signs and/or symptoms may include nausea, vomiting, pain (in 
some cases at tumor sites), rigors, headache, dizziness, dyspnea, hypotension, rash and 
asthenia. The symptoms occurred infrequently with subsequent trastuzumab infusions. 

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7.1.1.2 
Adverse Event List for Pertuzumab 
 
Overall, data indicate that pertuzumab is well-tolerated as monotherapy and that it 
can be given in combination with trastuzumab and a range of other therapeutic agents 
with manageable additional toxicity. No new or unexpected toxicities have been 
encountered other than those that are known for agents that target the HER family of 
receptors. Serious or severe infusion-associated symptoms have been rarely observed 
in patients receiving pertuzumab. A low level of cardiac toxicities, predominantly 
asymptomatic declines in left ventricular ejection fraction (LVEF), has been reported. 
In the pivotal Phase III trial WO20698/TOC4129g the rates of symptomatic and 
asymptomatic left ventricular systolic dysfunction (LVSD) were not higher in patients 
receiving pertuzumab, trastuzumab and docetaxel than in those receiving placebo, 
trastuzumab and docetaxel. 
 
No fetal studies in humans have been performed but pertuzumab caused 
oligohydramnios, delayed renal development and embryo-fetal deaths in pregnant 
cynomolgus monkeys. Moreover, in the post-marketing setting, cases of 
oligohydramnios, some associated with fatal pulmonary hypoplasia of the fetus, have 
been reported in pregnant women receiving trastuzumab. Therefore, pertuzumab 
should not be used in pregnant women. Protocols for ongoing pertuzumab studies 
indicate that one highly effective or two effective contraceptive measures must be 
used; continuous pregnancy monitoring must be performed during the trials and for 
six months after the last dose of pertuzumab is administered. Because of the long 
half-life of pertuzumab women should be warned not to become pregnant for at least 
seven months after completion of treatment. 
 
7.1.1.3 
Adverse Event List for Paclitaxel 
 
The following information is from the package insert for paclitaxel. This is a list of 
those adverse events most likely to occur to this study; please refer to the paclitaxel 
package insert for the comprehensive list of adverse events that have occurred with 
paclitaxel administration. 
 
Myelosuppression 
Myelosuppression occurs in the majority of patients (neutropenia, leukopenia, 
thrombocytopenia, and anemia). Myelosuppression is dose related, schedule related, 
and infusion-rate dependent and, in general, rapidly reversible upon discontinuation. 
 
Anaphylactic-Like Reactions 
Hypersensitivity is thought to be caused by the Cremophor vehicle. Minor symptoms 
include hypotension, flushing, chest pain, abdominal or extremity pain, skin reactions, 
pruritus, dyspnea, and tachycardia. More severe reactions include hypotension 
requiring treatment, dyspnea with bronchospasm, generalized urticaria, and 
angioedema. The majority (53%) of the reported reactions occurred within 2-3 minutes 
of initiation of treatment and 78% occurred within the first 10 minutes. Reactions 
usually occurred with the first and second doses. 

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Cardiovascular toxicity 
Atrial arrhythmia (sinus bradycardia [usually transient and asymptomatic], sinus 
tachycardia, and premature beats); significant events include syncope, hypotension, 
other rhythm abnormalities (including ventricular tachycardia, bigeminy, and complete 
heart block requiring pacemaker placement), and myocardial infarction. Hypertension 
(possibly related to concomitant medication - Dexamethasone) may also occur. 
 
Neurotoxicity 
Sensory (taste changes); peripheral neuropathy; arthralgia and myalgia (dose-related, 
more common when colony-stimulating factors are also administered); seizures; mood 
alterations; neuroencephalopathy; hepatic encephalopathy; motor neuropathy; and 
autonomic neuropathy (paralytic ileus and symptomatic hypotension) 
 
Dermatologic toxicity 
Alopecia (universal, complete and often sudden, between days 14- 21); injection site 
reactions (erythema, induration, tenderness, skin discoloration); infiltration (phlebitis, 
cellulitis, ulceration, and necrosis, rare); radiation recall; and rash. 
 
Gastrointestinal toxicity 
Nausea, vomiting, diarrhea, stomatitis, mucositis, pharyngitis, typhlitis (neutropenic 
enterocolitis), ischemic colitis, and pancreatitis. 
Hepatic: Increased AST, ALT, bilirubin, alkaline phosphatase; hepatic failure, and 
hepatic necrosis. 
 
Other 
Fatigue, headache, light-headedness, myopathy, elevated serum creatinine, elevated 
serum triglycerides, and visual abnormalities (sensation of flashing lights, blurred 
vision). 
 
7.2 
Adverse Event Characteristics 
 
• CTCAE term (AE description) and grade: The descriptions and grading scales found 
in the revised NCI Common Terminology Criteria for Adverse Events (CTCAE) version 
5.0 will be utilized for AE reporting. All appropriate treatment areas should have access 
to a copy of the CTCAE version 5.0. A copy of the CTCAE version 5.0 can be 
downloaded from the CTEP web site 
http://ctep.cancer.gov/protocolDevelopment/electronic_applications/ctc.htm. 
• Expectedness: 
• Expected adverse events are those adverse events that are listed or characterized in 
the current adverse event list, the Package Insert, or is included in the informed 
consent document as a potential risk. 
• Unexpected adverse events are those not listed in the Package Insert (P.I.) or not 

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identified. This includes adverse events for which the specificity or severity is not 
consistent with the description in the P.I. or I.B. For example, under this definition, 
hepatic necrosis would be unexpected 
 
• Attribution of the AE: 
- 
Definite – The AE is clearly related to the study treatment. 
- 
Probable – The AE is likely related to the study treatment. 
- 
Possible – The AE may be related to the study treatment. 
- 
Unlikely – The AE is doubtfully related to the study treatment. 
- 
Unrelated – The AE is clearly NOT related to the study treatment. 
 
7.3 
Serious Adverse Event Reporting 
 
7.3.1 In the event of an unanticipated problem or life-threatening complications treating 
investigators must immediately notify the DF/HCC Sponsor-Investigator. 
 
7.3.2 Investigators must report to the DF/HCC Sponsor-Investigator any serious adverse event 
(SAE) that occurs after the initial dose of study treatment, during treatment, or within 30 
days of the last dose of treatment on the local institutional SAE form. 
 
7.3.3 For Multi-Center Trials where a DF/HCC investigator is serving as the Sponsor- 
Investigator, each participating institution must abide by the reporting requirements set 
by the DF/HCC (listed in section 7.4). The Sponsor-Investigator and Coordinating Center 
should be notified of SAEs within 1 working day of learning of the event. 
 
7.4 
DF/HCC Adverse Event Expedited Reporting Guidelines 
 
The following adverse events must be reported to the DFCI IRB according to the expedited 
reporting guidelines: 
• All locally occurring Adverse Events that are Serious, Unexpected, and there is a 
Reasonable Possibility the Adverse Event is related to the study intervention should be 
reported to the IRB. 
Investigative sites within DF/HCC will report SAEs directly to the DFCI Office for Human 
Research Studies (OHRS) per the DFCI IRB reporting policy. 
1. 
All life threatening and fatal Serious Adverse Events (grade 4 and 5) considered serious, 
unexpected, and related, must be submitted via a written adverse event report to OHRS 
within 5 working days from notification of the event. 
2. 
For all other Serious Adverse Events considered serious, unexpected, and related, a full 
written adverse event report must be submitted to OHRS within 10 working days from 
notification of the event. 
3. 
Any unrelated adverse event does not require reporting to OHRS except grade 5 events 
which must be reported at the time of continuing review. 
 
Other investigative sites will report SAEs to their respective IRB according to their local IRB’s 
policies and procedures for reporting adverse events. A copy of the submitted institutional AE 

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form will be forwarded to the Coordinating Center. 
 
The Coordinating Center will submit AE reports from outside institutions to the DFCI IRB 
according to DFCI IRB policies and procedures in reporting adverse events. 
 
7.5 
Reporting to the Food and Drug Administration (FDA) and TerSera Therapeutics 
LLC 
 
The PI, as study sponsor, will be responsible for all communications with the FDA. The PI will 
report to the FDA, regardless of the site of occurrence, any serious adverse event that meets the 
FDA’s criteria for expedited reporting following the reporting requirements and timelines set by 
the FDA. 
 
As required by 21 C.F.R. 312, Institution shall be responsible for reporting all necessary adverse 
events associated with the Study to the FDA. Institution shall notify FDA and TerSera of any 
unexpected fatal or life-threatening experience associated with the use of the Study Drug as soon 
as possible but in no event later than twenty-four (24) hours after the Institution’s or 
Investigator’s initial receipt of the information. Additionally, Institution shall promptly report all 
other adverse events, regardless of expectedness or causality, to TerSera (via email to 
drugsafety@tersera.com or fax to 844-697-5227) within one (1) business day after the 
Institution’s or Investigator’s initial receipt of the information, and, when necessary, to FDA and 
the applicable IRB. Institution will promptly make available such records as TerSera may deem 
necessary to investigate and/or report on an adverse event associated with the use of the Study 
Drug. 
 
7.6 
Reporting to Hospital Risk Management 
 
Participating investigators will report to their local Risk Management office any participant 
safety reports, sentinel events or unanticipated problems that require reporting per institutional 
policy. 
 
7.7 
Routine Adverse Event Reporting 
 
All Grade 2 or higher adverse events must be reported in routine study data submissions to the 
PI on the toxicity case report forms. Abnormal laboratory results are only reported as adverse 
events in the case report forms if deemed to be clinically significant by a treating investigator. 
ALL AEs reported through expedited processes (e.g., reported to the IRB, FDA, etc.) must 
be reported in routine study data submissions. 
 
8. PHARMACEUTICAL INFORMATION 
 
A list of the adverse events and potential risks associated with the agents administered in this 
study can be found in Section 7.1. 
 
8.1 
Margetuximab 

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8.1.1 Description and Form 
 
Margetuximab (MGAH22) is a sterile, clear-to-slightly-opalescent, colorless-to-pale- 
yellow or pale brown, preservative-free solution for IV administration. Some visible, 
translucent, 
proteinaceous, margetuximab particles may be present. Margetuximab is supplied in 
single use, 10-mL clear glass vials with FluroTec® coated gray butyl rubber serum 
stoppers and aluminum seals with plastic overseals. Each vial contains 250 mg 
margetuximab (25 mg/mL) in 10 mL solution. The product is formulated in a buffer 
containing 1.1 mg/mL sodium phosphate monobasic, monohydrate, 0.58 mg/mL sodium 
phosphate dibasic, heptahydrate, 2.9 mg/mL sodium chloride, 11 mg/mL L-arginine 
hydrochloride, 30 mg/mL sucrose, and 0.1 mg/mL Polysorbate 80, in Sterile Water for 
Injection, pH 6.1. 
 
8.1.2 Storage, Stability, and Handling 
 
Vials containing margetuximab should be stored under refrigeration at 2°–8°C (36°– 
46°F) in an appropriate location. Margetuximab must not be frozen. Protect from 
light during storage. DO NOT SHAKE. Vials are single-use containers and contain no 
preservatives; therefore, once margetuximab is diluted in normal saline, administration 
should begin immediately after preparation. Any partially used vials or diluted dosing 
solutions should be discarded using appropriate drug disposal procedures. 
 
Qualified personnel, familiar with procedures that minimize undue exposure to 
themselves and the environment, should undertake the preparation, handling, and safe 
disposal of the chemotherapeutic agent in a self-contained and protective environment. 
 
8.1.3 Compatibility 
 
There are no known incompatibles with margetuximab. Margetuximab should not be 
mixed or infused with any other agents. 
 
8.1.4 Availability 
 
Margetuximab will be supplied free of charge by TerSera in vials for intravenous 
administration. 
 
8.1.5 Preparation 
 
Preparation for Intravenous Infusion 
 
Prepare solution for infusion, using aseptic technique, as follows: 
• 
Parenteral drug products should be inspected visually for particulate matter and discoloration 
prior to administration, whenever solution and container permit. The solution is clear to 
slightly opalescent, colorless to pale yellow or pale brown. Some visible, translucent, 
inherent proteinaceous particles may be present. 
• 
Swirl the vial(s) gently. Do not shake the vial(s). 

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• 
Calculate the required volume of MARGENZA needed to obtain the appropriate dose 
according to patient’s body weight. The calculated total dose volume should be rounded to 
the nearest 0.1 mL. 
• 
Withdraw appropriate volume of MARGENZA solution from the vial(s) using a syringe. 
• 
Transfer MARGENZA into an intravenous bag containing 100 mL or 250 mL 0.9% Sodium 
Chloride Injection, USP. Polyvinyl chloride (PVC) intravenous bags or intravenous bags 
made with polyolefins (polyethylene and polypropylene) and polyamide or polyolefins only 
or copolymer of olefins may be used. Do not use 5% Dextrose Injection, USP solution. 
• 
The final concentration of the diluted solution should be between 0.5 mg/mL to 7.2 mg/mL. 
• 
Gently invert the intravenous bag to mix the diluted solution. Do not shake the 
intravenous bag. 
• 
Discard any unused portion left in the vial(s). 
Do not administer as an intravenous push or bolus. Do not mix MARGENZA with other drugs. 
Storage of Diluted Solution 
• 
The product does not contain a preservative. If diluted infusion solution is not used 
immediately, it can be stored at room temperature up to 4 hours or stored refrigerated at 2°C 
to 8°C (36°F to 46°F) up to 24 hours. If refrigerated, allow the diluted solution to come to 
room temperature prior to administration. Do not freeze. 
 
8.1.6 Administration 
 
Margetuximab should not be administered as an IV push or bolus and should not be 
mixed or diluted with other drugs. 
 
Administer diluted infusion solution intravenously over 120 minutes for the initial dose, then 
over a minimum of 30 minutes every 3 weeks for all subsequent doses. Administer through 
an intravenous line containing a sterile, non-pyrogenic, low-protein binding polyethersulfone 
(PES) 0.2 micron in-line or add-on filter. 
 
 
8.1.7 Ordering 
 
Margetuximab will be provided to participating institutions by TerSera. Sites will order 
directly from TerSera. 
 
8.1.8 Accountability 
 
The investigator, or a responsible party designated by the investigator, should maintain a 
careful record of the inventory and disposition of the agent using the NCI Drug 
Accountability Record Form (DARF) or another comparable drug accountability form. 
 
8.1.9 Destruction and Return 
 
Unused and expired supplies of margetuximab should be destroyed according to 
institutional policies. 

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8.2 
Trastuzumab and Biosimilars 
 
8.2.1 Description and Form 
 
This study will use trastuzumab from commercial supply. Trastuzumab is a sterile, white 
to pale yellow, preservative free lyophilized powder for intravenous (IV) administration. 
 
150 mg single-dose vial: 
Each single-dose vial of Herceptin delivers 150 mg trastuzumab, 136.2 mg α,α-trehalose 
dihydrate, 3.4 mg L-histidine HCl monohydrate, 2.2 mg L-histidine, and 0.6 mg 
polysorbate 20. 
Use appropriate aseptic technique. Reconstitute each 150 mg vial of single-dose 
Trastuzumab with 7.4 mL of sterile water for injection (SWFI) to yield a solution 
containing 21mg/mL trastuzumab that delivers 7.15 mL (150 mg trastuzumab), at a pH of 
approximately 6. 
Use the trastuzumab solution immediately following reconstitution with SWFI, as it 
contains no preservative and is intended for single-dose only. If not used immediately, 
store the reconstituted trastuzumab solution for up to 24 hours at 2○C to 8○C (36○F to 
46○F); discard any unused trastuzumab after 24 hours. 
 
Use of other reconstitution diluents should be avoided. Determine the dose of trastuzumab 
needed, based on a loading dose of 8 mg trastuzumab/kg body weight for q3wk dosing 
schedules or a maintenance dose of 6 mg/kg trastuzumab/kg body weight for q3w dosing 
schedules. Calculate the correct dose using 21 mg/mL trastuzumab solution. Withdraw this 
amount from the vial and add it to an infusion bag containing 250 mL of 0.9% sodium 
chloride, USP. DEXTROSE (5%) SOLUTION SHOULD NOT BE USED. Gently 
invert the bag to mix the solution. The reconstituted preparation results in a colorless to 
pale yellow transparent solution. Parenteral drug products should be inspected visually for 
particulates and discoloration prior to administration. 
 
Trastuzumab should not be mixed or diluted with other drugs. Trastuzumab infusions 
should not be administered or mixed with Dextrose solutions. Trastuzumab should not be 
filtered during administration. 
 
Refer to the FDA-approved package insert for more information. 
If a trastuzumab biosimilar is used, please refer to the manufacturer’s prescribing 
information/ package insert for information about dosage and administration. 
 
8.2.2 Storage and Stability 
 
Vials of trastuzumab are stable at 2ºC–8ºC (36ºF–46ºF) prior to reconstitution. Do not use 
beyond the expiration date stamped on the vial. A vial of 440 mg trastuzumab reconstituted 
with BWFI is stable for 28 days after reconstitution when stored refrigerated at 2ºC–8ºC 
(36ºF–46ºF), and the solution is preserved for multiple use. Discard any remaining multi 
dose reconstituted solution after 28 days. If unpreserved SWFI (not supplied) is used, the 

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reconstituted trastuzumab solution should be used immediately and any unused portion 
must be discarded. A vial of 150 mg trastuzumab once reconstituted with SWFI should be 
used immediately, as it contains no preservative and is intended for single-dose only. If 
not used immediately, store the reconstituted trastuzumab solution for up to 24 hours at 
2C–8C; discard any unused trastuzumab after 24 hours. 
 
DO NOT FREEZE TRASTUZUMAB THAT HAS BEEN RECONSTITUTED. 
 
The solution of trastuzumab for infusion diluted in polyvinylchloride or polyethylene bags 
containing 0.9% sodium chloride for injection, USP, may be stored at 2ºC–8ºC (36ºF–46ºF) 
for up to 24 hours prior to use. Diluted trastuzumab has been shown to be stable for up to 
24 hours at room temperature 15ºC–25ºC; however, since diluted trastuzumab contains no 
effective preservative the reconstituted and diluted solution should be stored refrigerated 
(2ºC–8ºC). 
 
If a trastuzumab biosimilar is used, please refer to the manufacturer’s prescribing 
information/ package insert for information about storage conditions. 
 
 
 
 
8.2.3 Compatibility 
 
No incompatibilities between trastuzumab and polyvinylchloride, polyolefin or 
polypropylene bags have been observed. Dextrose 5% solution should not be used since it 
causes aggregation of the protein. Trastuzumab should not be mixed or diluted with other 
drugs. 
 
If a trastuzumab biosimilar is used, please refer to the manufacturer’s prescribing 
information/package insert for information about drug compatibility. 
 
8.2.4 Handling 
 
Qualified personnel, familiar with procedures that minimize undue exposure to 
themselves and the environment, should undertake the preparation, handling, and safe 
disposal of the chemotherapeutic agent in a self-contained and protective environment. 
 
If a trastuzumab biosimilar is used, please refer to the manufacturer’s prescribing 
information/package insert for information about handling of the agent. 
 
8.2.5 Availability 
 
Trastuzumab is a commercially available agent. The cost of trastuzumab will be charged 
to the patient and/or his/her insurance company since its use is considered standard of care 
for neoadjuvant treatment of HER2-positive breast cancer. 

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A biosimilar for trastuzumab may be used on this study according to the standard of care 
at the participating institution and/or the insurance company of the participant. 
 
8.2.6 Administration 
 
Trastuzumab (or biosimilar) will be administered per local institutional guidelines. Patients 
should be observed for fever and chills or other infusion-associated symptoms per local 
institutional guidelines. Documentation of observation is not required. Refer to Section 5.1 
and Section 5.3 for more details. 
 
If a biosimilar for trastuzumab is used, the administration of the agent should be 
according to the participating site’s institutional policy/standard of care. 
 
8.2.7 Ordering 
 
As trastuzumab will be used as a commercially-supplied agent, ordering will be at the 
discretion of each local institution pharmacy’s standard practices. 
 
If a biosimilar for trastuzumab is used, the agent should be ordered according to the 
participating site’s institutional policy/standard of care. 
 
8.2.8 Accountability 
 
As commercial supply of trastuzumab will be used, inventory will be kept according to 
local institutional pharmacy practices. 
 
If a biosimilar for trastuzumab is used, accountability of the agent should be according to 
the participating site’s institutional policy/standard of care. 
 
8.2.9 Destruction and Return 
 
Unused supplies of trastuzumab should be destroyed according to institutional 
policies. 
 
8.3 
Paclitaxel 
 
8.3.1 Description and Form 
 
Other Names 
Taxol (NSC 125973) 
 
Classification 
Antimicrotubule agent. 
 
Mode of Action 
Promotes microtubule assembly and stabilizes tubulin polymers by preventing their 

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depolarization, resulting in the formation of extremely stable and nonfunctional 
microtubules, and consequently inhibition of many cell functions. 
 
Refer to the FDA-approved package insert for more information. 
 
8.3.2 Storage and Stability 
 
Intact vials should be stored between 20 - 25 C (68 - 77 F) in the original package to 
protect from light and remain stable until the expiration date on the label. Neither 
freezing nor refrigeration adversely affects stability. Upon refrigeration components in 
the paclitaxel vial may precipitate but will re-dissolve upon reaching room temperature 
with little or no agitation. There is no impact on product quality under these 
circumstances. If the solution remains cloudy or if an insoluble precipitate is noted, the 
vial should be discarded. Solutions for infusion prepared as recommended are stable at 
ambient temperature (approximately 25 C) and lighting conditions for up to 27 hours. 
 
8.3.3 Compatibility 
 
Avoid the use of PVC bags and infusion sets due to leaching of DEHP (plasticizer). 
Ketoconazole may inhibit paclitaxel metabolism, based on in vitro data. Prescription of 
concomitant drugs should address the Launch Lexi-Interact™ Drug Interactions Program. 
 
8.3.4 Handling 
 
Qualified personnel, familiar with procedures that minimize undue exposure to 
themselves and the environment, should undertake the preparation, handling, and safe 
disposal of the chemotherapeutic agent in a self-contained and protective environment. 
 
8.3.5 Availability 
 
Paclitaxel is commercially available agent. Each institutional pharmacy should assure 
availability for the study. 
 
8.3.6 Preparation 
 
Preparation of paclitaxel should follow institutional guidelines and may slightly deviate 
from the suggested preparations guidelines in the remainder of this paragraph to 
accommodate different institutional guidelines. Paclitaxel may be diluted in 0.9% sodium 
chloride injection, USP or 5% dextrose injection, USP. Paclitaxel must be prepared in 
glass, plypropylene or plyolefin containers and non-PVC containing (nitroglycerin) 
infusion sets. In-line filtration with a 0.22-micron filter is required. 
 
8.3.7 Administration 
 
Paclitaxel will be administered over 30-180 minutes, or as per local institutional guidelines. 
Refer to Section 5.1 and Section 5.3 for more details. 

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8.3.8 Ordering 
 
As paclitaxel will be used as a commercially supplied agent, ordering will be at the 
discretion of each local institution pharmacy’s standard practices. 
 
8.3.9 Accountability 
 
As commercial supply of paclitaxel will be used, inventory will be kept according to 
local institutional pharmacy practices. 
 
8.3.10 Destruction and Return 
 
Unused supplies of paclitaxel should be destroyed according to institutional policies. 
 
8.4 
Pertuzumab 
 
8.4.1 Description, Form, Preparation 
 
Pertuzumab drug product is provided as a single use formulation containing 30 mg/mL 
pertuzumab in 20 mM L-histidine acetate (pH 6.0), 120 mM sucrose and 0.02% 
polysorbate 20. Each 20 mL vial contains 420 mg of Pertuzumab (14.0 mL/vial). 
DEXTROSE (5%) SOLUTION SHOULD NOT BE USED. The preparation of 
pertuzumab solution for infusion, using aseptic technique, should be as follows: 
 
• Parenteral drug products should be inspected visually for particulates and discoloration 
prior to administration. 
• Withdraw the appropriate volume of pertuzumab liquid concentrate from the vial(s). 
• Dilute into the 250 mL 0.9% sodium chloride PVC or non PVC polyolefin infusion 
bags. Do not withdraw saline out of the infusion bag. 
• Mix diluted solution by gentle inversion. Do not shake. 
• Administer immediately once prepared. 
Refer to the FDA-approved package insert for more information. 
8.4.2 Storage and Stability 
Upon receipt, pertuzumab vials are to be refrigerated at 2°C–8°C (36°F–46°F) until use. 
Pertuzumab vials should not be used beyond the expiration date provided by the 
manufacturer. Because the formulation does not contain a preservative, the vial seal may 
only be punctured once. Any remaining solution should be discarded. Vial contents should 
be protected from light and should not be frozen or shaken. The solution of pertuzumab for 
infusion, diluted in PVC or non-PVC polyolefin bags containing 0.9% Sodium Chloride 
Injection, USP, may be stored at 2°C–8°C for up to 24 hours prior to use. Diluted 
pertuzumab has been shown to be stable for up to 24 hours (up to 30°C). However, since 
diluted pertuzumab contains no preservative, the diluted solution should be stored 

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refrigerated (2°C–8°C). 
 
8.4.3 Compatibility 
 
No incompatibilities between pertuzumab and polyvinylchloride, polyethylene or non- 
PVC polyolefin bags have been observed. Dextrose (5%) in water (D5W) solution 
should not be used to dilute pertuzumab since it was chemically and physically unstable 
in such solutions (dilute formulations of pertuzumab liquid formulations in D5W IV bags 
did not maintain stable pH after storage at room temperature (27-33°C) for 24 hours 
followed by 24 hours at refrigerator temperature [2-8°C]). Pertuzumab should not be 
mixed or diluted with other drugs. 
 
8.4.4 Handling 
 
Qualified personnel, familiar with procedures that minimize undue exposure to 
themselves and the environment, should undertake the preparation, handling, and safe 
disposal of the chemotherapeutic agent in a self-contained and protective environment. 
 
 
8.4.5 Availability 
 
Pertuzumab is a commercially available agent. The cost of pertuzumab will be charged to 
the patient and/or his/her insurance company since its use is considered standard of care 
for neoadjuvant treatment of HER2-positive breast cancer. 
 
8.4.6 Administration 
 
Pertuzumab will be administered over 30-60 minutes, or as per local institutional 
guidelines. Patients should be observed for fever and chills or other infusion-associated 
symptoms for at least 60 minutes after the initial dose and for 30 minutes after subsequent 
doses, or as per local institutional guidelines. Refer to Section 5.1 and Section 5.3 for more 
details. 
 
8.4.7 Ordering 
 
As pertuzumab will be used as a commercially-supplied agent, ordering will be at the 
discretion of each local institution pharmacy’s standard practices. 
 
8.4.8 Accountability 
 
As commercial supply of pertuzumab will be used, it will be supplied, and the inventory 
kept according to local institutional pharmacy practices. 
 
8.4.9 Destruction and Return 
 
Unused supplies of pertuzumab should be destroyed according to institutional 

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policies. 
 
8.5 
Trastuzumab + Pertuzumab SC FDC (PHESGO) 
 
8.5.1 Description, Form, and Preparation 
 
FDC of pertuzumab and trastuzumab is available in two different forms: 
• 1,200 mg pertuzumab, 600 mg trastuzumab, and 30,000 units hyaluronidase/15 
mL (80 mg, 40 mg, and 2,000 units/mL) of solution in a single-dose vial. (3) 
• 600 mg pertuzumab, 600 mg trastuzumab, and 20,000 units hyaluronidase/10 mL 
(60 mg, 60 mg, and 2,000 units/mL) of solution in a single-dose vial 
Refer to the FDA-approved package insert for more information. 
 
8.5.2 Storage and Stability 
The recommended storage conditions for the drug product are between 2°C - 8°C, 
protected from light. The drug product must not be frozen. For batch-specific instructions 
and information on shelf-life, see the packaging. 
Trastuzumab + pertuzumab SC FDC loading and maintenance doses are ready-to-use 
solutions and must be prepared for dosing under appropriate aseptic conditions, as they 
do not contain antimicrobial preservatives. The dose solution should be used 
immediately. If not used immediately, the total storage time of the dose solution prior to 
administration should not exceed 24 hours to limit the risk of microbial growth in case of 
accidental contamination. The recommended storage condition for the dose solution is 
2°C - 8°C, but dose solutions may be stored at room temperature for up to a maximum of 
4 hours. 
 
8.5.3 Handling 
Qualified personnel, familiar with procedures that minimize undue exposure to 
themselves and the environment, should undertake the preparation, handling, and safe 
disposal of the chemotherapeutic agent in a self-contained and protective environment. 
 
8.5.4 Availability 
Trastuzumab + pertuzumab SC FDC is commercially available agent. Each institutional 
pharmacy should assure availability for the study. 
 
8.5.5 Administration 
Administration of trastuzumab + pertuzumab SC FDC will be according to the FDA 
approved package insert. 
8.5.6 Ordering 
As trastuzumab + pertuzumab SC FDC will be used as a commercially supplied agent, 
ordering will be at the discretion of each local institution pharmacy’s standard practices. 

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8.5.7 Accountability 
As trastuzumab + pertuzumab SC FDC will be used as a commercially supplied agent on 
this study, accountability will be at the discretion of each local institution pharmacy’s 
standard practices. 
 
8.5.8 Destruction and Return 
As trastuzumab + pertuzumab SC FDC will be used as a commercially supplied agent on 
this study, destruction will be at the discretion of each local institution pharmacy’s 
standard practices. 
 
8.6 
Nab-Paclitaxel 
 
Please refer to the FDA-approved package insert for nab-paclitaxel for product information, 
extensive preparation instructions, and a comprehensive list of adverse events. 
 
8.6.1 Description 
ABRAXANE® for Injectable Suspension (paclitaxel protein-bound particles for injectable 
suspension) (albumin-bound) is an albumin- bound form of paclitaxel with a mean particle 
size of approximately 130 nanometers. Paclitaxel exists in the particles in a non crystalline, 
amorphous state. ABRAXANE® is free of solvents. 
 
The active agent in ABRAXANE® is paclitaxel, a microtubule inhibitor. The chemical 
name for paclitaxel is 5β,20-Epoxy 1,2α,4,7β,10β,13α-hexahydroxytax-11-en-9-one 4,10- 
diacetate 2-benzoate 13-ester with (2R,3S)-N-benzoyl-3-phenylisoserine. 
 
8.6.2 Storage and Stability 
Store vials in original cartons at room temperature (20°C-25°C; 68°F-77°F). Retain the 
original package to protect from bright light. Unopened vials of albumin-bound paclitaxel 
are stable until the date indicated on the package when stored at the above temperature in 
the original package. 
 
Reconstituted vials of nab-paclitaxel may be refrigerated at (2°C-8°C; 38°F-46°F) for a 
maximum of 8 hours and should be protected from bright light. 
 
8.6.3 Handling 
Qualified personnel, familiar with procedures that minimize undue exposure to themselves 
and the environment, should undertake the preparation, handling, and safe disposal of the 
chemotherapeutic agent in a self-contained and protective environment. 
 
8.6.4 Availability 
Nab-paclitaxel is commercially available and will be obtained according to the local institution 
pharmacy’s standard practices. 
 
8.6.5 Preparation 
Nab-paclitaxel will be prepared according to the local institution pharmacy’s standard practices. 

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8.6.6 Administration 
Nab-paclitaxel will be administered according to the local institution pharmacy’s standard 
practices. 
 
8.6.7 Ordering 
Nab-paclitaxel will be ordered per the local institution pharmacy’s standard practices. 
 
8.6.8 Accountability 
Accountability will be per the local institution pharmacy’s standard practices. 
 
8.6.9 Destruction and Return 
Destruction and return will be per the local institution pharmacy’s standard practices. 
 
 
9. CORRELATIVE AND SPECIAL STUDIES 
 
9.1 
Correlative Science Background 
 
The following outline provides a brief overview of the correlative studies. Additional exploratory 
studies not listed here may be pursued in the future if deemed relevant to the study. A 
comprehensive collection of biological materials is requested in order to be able to understand the 
immune microenvironment and assess immune responses to THP vs. TMP. The goals of the 
translational research will be to determine mechanisms and biomarkers for efficacy and resistance. 
Determining the variation in patients who respond well and those who respond poorly to treatment 
may further aid in defining the most appropriate group of patients to benefit from the given anti- 
HER2 therapy. 
 
Breast tumor tissue sampling is required at baseline, on-treatment, at time of surgery, and (if 
applicable) at time of recurrence for all patients enrolled on this trial. For patients with obvious 
residual disease following completion of neoadjuvant THP or TMP, additional systemic therapy 
may be given in the neoadjuvant setting (see Section 5.5). In this case, a biopsy of the presumed 
residual disease is required both for clinical purposes (to confirm presence of malignant cells) and 
for research purposes (see Section 9). 
 
Blood collections will be performed at 5 timepoints on trial (one baseline timepoint plus 4 on- 
treatment timepoints) as detailed below (and at a 6th timepoint for patients who experience 
recurrence). Blood will be used for profiling of peripheral blood mononuclear cells (PBMCs) and 
banked for future sequencing of circulating tumor DNA (ctDNA), assessment of anti-HER2 
antibody responses, and/or other future assays of interest. 
 
Stool will be collected at baseline, during cycle 2 and pre-surgery to explore the structure and 
function of the gut microbiome. Samples will be processed and then stored at BTIL at Dana-Farber 
Cancer Institute. 

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9.2 
Specimen Collection Requirements 
 
The following specimens are to be submitted to the indicated lab. Refer to the separate 
Operations Manual for additional processing and shipping instructions. 
 
 
 
Specimen 
Type 
Collection Time Point 
Shipping 
Condition 
Ship to 
(Pre- 
Treatment)1 
Day 1 of 
Cycle 2 
and 4 
Cycle 2 
(Within 7 
days prior to 
C2D1) 
End of 
THP or 
TMP 
Surgery/ 
After 
Surgery 
End of 
Adjuvant 
Therapy 
Recurrence 
Paraffin 
block (or 15 
unstained 
slides) 
X 
X 
X 
Ambient 
temperature 
DFCI study 
team 
1 H&E 
stained slide 
X 
X 
X 
Ambient 
temperature 
DFCI study 
team 
PBMCs + 
plasma 
(three or 
four 10mL 
CPT tubes)2 
X 
X 
X 
X7 
X6 
-80 degrees 
Celsius 
(batch 
shipping 
after local 
processing) 
DFCI 
Translational 
Hub 
Research 
Biopsy/ 
Fresh tumor 
sample 
X 
X 
X3 
X 
OCT & 
FFPE 
DFCI 
Translational 
Hub 
Stool 
Collection 
X 
X4 
X5 
Ambient 
temperature 
DFCI 
Translational 
Hub 
1. Baseline/Pre-Treatment samples to be collected after registration/randomization but prior to initiation of therapy 
for participating sites outside of DF/HCC (may be collected at C1D1 pre-treatment) 
2. Four blood collection tubes for PBMCs + plasma will be drawn pre-treatment. Three tubes will be drawn at all 
other timepoints. 
3. For patients with residual disease at the completion of neoadjuvant THP or TMP a biopsy is required prior to 
initiation of additional neoadjuvant systemic therapy 
4. Cycle 2 stool sample to be collected (any time from C2D1- C3D1) 
5. Pre-surgery stool sample to be collected any time after completion of THP/TMP but prior to surgery or initiation 
of additional non-protocol neoadjuvant systemic therapy 
6. Blood draw at recurrence is strongly recommended but not required 
7. Missed blood draw at end of adjuvant therapy will not be considered a protocol violation 
 
Additional details regarding samples to be collected at each timepoint are further summarized in 
table below. 
 
Research Sampling 
Timepoint (more details follow) 
Contents 
Fresh tissue 
Baseline (<14 days before cycle 1 
day 1) 
5-7 cores 
C2D1 (prior to C2D1 drug 
administration; details below) 
5-7 cores 
Prior to neoadjuvant therapy 
switch* 
5-7 cores 

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Surgery 
4 core-sized pieces of tissue 
from residual tumor or tumor 
bed 
Archival Tissue 
Baseline and Surgical Tissue 
FFPE Block and 1 H&E OR 
15 unstained slides cut at 4- 
5um and 1 H&E 
Breast Cancer Recurrence 
FFPE Block and 1 H&E OR 
15 unstained slides cut at 4- 
5um and 1 H&E 
Blood 
Baseline (<14 days prior to C1D1) 
4 – 10 mL CPT tubes (plasma 
+ PBMCs) 
Day 1, cycle 2 and 4 
3 – 10 mL CPT tubes (plasma 
+ PBMCs) 
Postoperative (≤6 weeks post- 
surgery) 
3 – 10 mL CPT tubes (plasma 
+ PBMCs) 
Completion of HER2-directed 
adjuvant therapy +/- 3 months for 
ALL patients, regardless of 
adjuvant therapy regimen (MP, HP, 
T-DM1, etc.) 
3 – 10 mL CPT tubes (plasma 
+ PBMCs) 
Breast Cancer Recurrence 
3 – 10 mL CPT tubes (plasma 
+ PBMCs) 
Stool 
Baseline 
Home Collection Kit and 
questionnaires 
Cycle 2 
Pre-Surgery 
* ONLY for patients with obvious residual disease at the completion of neoadjuvant THP or 
TMP, for whom additional neoadjuvant systemic therapy is planned. 
 
9.3 
Research Tumor Biopsies 
 
Tumor biopsy will be performed at the following time-points: 
• Mandatory Pre-Treatment: should be performed within 14 days prior to treatment 
initiation 
• Mandatory Pre-Cycle 2: To be performed at or up to 7 days before C2D1, after drug 
administration on C1D15 and prior to drug administration on C2D1. Ideally as close to 
C2D1 as possible. 
• Mandatory at time of treatment change: For patients with residual disease at the 
completion of neoadjuvant THP or TMP a biopsy is required (unless waived by the PI) 
prior to initiation of additional neoadjuvant systemic therapy both for clinical purposes 
(to confirm presence of malignant cells) and for research purposes 
Ideally five, and at most seven, core biopsies will be collected at each timepoint. 
 
Collection supplies for research biopsy samples will be in the research sample collection kit. 
Please see the Operations Manual for detailed instructions for collection, processing, labeling 
and shipping of research biopsy samples. 

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It is mandatory that core biopsies be image-guided. A clip should be placed in the biopsy site 
at the time of the research biopsy if a clip was not placed during diagnostic biopsy. Pre- and 
post-procedure 90-degree lateral and craniocaudal mammogram is recommended to ensure 
that the correct lesion has been biopsied and to determine the relationship of the clip to the 
lesion that was visualized prebiopsy. Clip migration following biopsy has been reported and 
the distance from the original biopsy cavity can be measured.44 If sufficiently far away from 
the biopsy cavity, then an addendum should be made to the report documenting that the clip 
should NOT be used to guide post-treatment tumor sampling. Experience with NeoALTTO 
and I-SPY1 suggest that taking four core biopsy samples from one area is feasible and 
acceptable to participants and ethics committees.45 
 
Collection of fresh tissue from surgical specimens 
At the time of definitive surgery, the pathologist or pathology assistant will take core-sized 
pieces of tissue from the tumor or residual tumor bed in the breast (goal is at least four core- 
sized pieces of tissue; more or less are allowable per protocol, though a minimum of four is 
strongly preferred). Every effort should be made to obtain the sample as soon as possible 
after the time of resection. Processing of the fresh surgical specimens after they are obtained 
is described in the Study Operations Manual accompanying this protocol. 
 
If surgery is taking place at a location where there is insufficient research infrastructure for the 
described tissue collection at the surgical timepoint, surgical specimens should not be 
collected. Instead, the FFPE surgical tissue may substitute, as described in Section 9.5. Surgical 
specimens will be collected on all participants regardless of receipt of additional non-protocol 
neoadjuvant systemic therapy. 
 
9.4 
Overview of blood collection protocols 
 
Research blood will be collected at the following timepoints: 
Baseline (<14 days prior to C1D1) 
• 4-10mL CPT tubes for whole blood 
 
Day 1 of cycles 2 and 4 
• 3-10mL CPT tubes for whole blood 
Postoperative timepoint (<6 weeks post-surgery): 
• 3-10mL CPT tubes for whole blood 
At final cycle of adjuvant HP/MP/T-DM1 (note: blood draw timeframe should be kept 
constant, even if patient does not complete HP/MP/T-DM1 therapy) 
• 3-10mL CPT tubes for whole blood 
Breast Cancer Recurrence 
• 3-10mL CPT tubes for whole blood at time of biopsy-proven recurrence event 
Collection supplies for research blood samples will be in the research sample collection kit. 

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Please see the Operations Manual for detailed instructions for collection, processing, labeling 
and shipping of research blood samples. 
 
Of note, every effort will be made to coordinate research blood draws with clinically-indicated 
blood tests to minimize additional venipuncture. Research coordinators will track participants 
closely and make every effort to collect blood at required timepoints. However, if research 
blood draws are missed or fall outside window due unanticipated changes in 
treatment/scheduling issues, the sample will be collected at the subject’s next clinic appointment 
with a blood draw and this will not be considered a violation of the protocol. These cases should 
be discussed with the coordinating center. 
 
9.5 
Archival Tissue Collection 
 
Archival tumor tissue specimens will be submitted from following surgical procedures: 
• Diagnostic biopsy (from time of first diagnosis) 
• Surgery (after completion of neoadjuvant chemotherapy) 
• Disease Progression/Recurrence (if applicable) 
Either 1 paraffin block or 15 unstained slides and an H&E slide 4-5μm thick will be submitted. 
 
Archival tissue is shipped ambient in conventional paraffin block or slide shipper with the 
Specimen Requisition form found in the Operations Manual. The Operations Manual contains 
additional information on labeling and shipment of archival tissue to DFCI. Paraffin blocks will 
be returned after completion of correlative research. Unstained slides will not be returned. 
 
9.6 
Stool Sample Collection 
 
All stool samples will be collected by each patient at home using a home-based, self-collection 
and mail method for stool that has been proven to provide nearly equivalent metagenomic and 
meta-transcriptomic data as the state-of-the-art, fresh-frozen sample collection protocol. 
 
Samples will be collected at the below timepoints: 
• Baseline 
• Cycle 2 (any time from C2D1-C3D1 is allowed) 
• Pre-Surgery (any time after completion of THP/TMP but prior to surgery or receipt of 
additional non-protocol neoadjuvant systemic therapy) 
A patient questionnaire is included in the kits (Appendix E). The questionnaire should be 
completed at the time of stool collection and mailed back along with the sample. Stool samples 
and questionnaires that are not collected at the protocol-specified collection time points will not 
be protocol violations. 
 
Handling and shipping of stool specimens 
 
All kits will be provided to the patients at a clinic visit. Patients will also be provided with a mailer 
in which to return the sample. All samples will be shipped within 24 hours of collection at ambient 

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temperature to the Breast Tumor Immunology Lab (BTIL), where they will be processed and 
stored (see Lab Manual). Samples will be stored until shipped out to an external lab vendor, such 
as Microbiome Dx, who will perform the analysis of the samples. 
 
 
9.7 
Hypotheses 
 
We hypothesize that immune activation will be detected in both tissue and blood following 
treatment with THP and TMP, and features of this immune activation may differ between the two 
regimens. In particular, we hypothesize that ADCC activity will increase on treatment with both 
THP and TMP. We hypothesize that there will be evidence of greater ADCC activity in patients 
treated with TMP versus THP. 
 
9.8 
Translational Research: Planned Assays 
 
The below-mentioned analyses may be altered or added based on updated best practices and 
major questions of interest in immuno-oncology and breast cancer biology in general at the time 
that correlative analyses are performed. Alternative technologies (based on evolving scientific 
knowledge or techniques) may be used. Some of the assays also may be eliminated if they are 
no longer deemed relevant at the time that correlative science is performed. 
 
9.8.1 Tissue-based assays: characterization of the immune microenvironment 
 
Assays will be performed to characterize immunologic aspects of the tumor microenvironment 
and immunologic responses to THP versus TMP. Potential assays include: (1) single and/or 
multiplex immunohistochemistry (IHC) or immunofluorescence (IF) performed on FFPE tissue 
to identify various lymphocyte and myeloid populations (e.g. NK cells, T cells, B cells, 
macrophages, dendritic cells) and their spatial relationships; (2) gene expression analysis or 
other genomic tests; (3) antigen-specific T-cell receptor (TCR) spectrotyping; (4) flow 
cytometry analyses performed on single cell suspensions evaluating immune markers 
characterizing of various immune cell populations (e.g. CD56+Ki67+ to identify proliferating 
NK cells). 
 
9.8.2 Blood-based assays: Fc-gamma receptor genotyping, and characterization of the 
circulating immune response 
 
CD16A (Fc-gamma RIII) receptor genotype will be determined in all patients via germline 
sequencing from PBMCs. 
 
Assays will be performed to assess the presence and functional activity of various circulating 
immune cell populations. Potential assays include: (1) flow cytometry to characterize PBMCs; 
(2) cytokine analysis, to assess PBMC effector functions; (3) ELISA and/or ELISPOT to assess 
HER2-specific antibody responses. 
 
Circulating tumor DNA (ctDNA) may undergo sequencing analysis at the timepoints outlined, 
and may be used to explore (1) the correlation between ctDNA at the preoperative timepoint and 

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presence of pCR versus residual disease; (2) the correlation between ctDNA at a postoperative 
timepoint and long-term breast cancer outcomes; (3) mechanisms of response and resistance to 
HER2-directed therapy. 
 
9.8.3 Analysis of intestinal microbiome 
 
We will quantify microbiome features from amplicon, metagenome, and metatranscriptome using 
established pipelines to identify strain-level taxonomic, functional, transcriptional, and 
microbially-mediated metabolite profiles. 
 
Microbial DNA is extracted using the Mag-Bind Universal Pathogen DNA Kit (Omega Bio- 
Tek). Briefly, 250 mg of the specimen is transferred to a deep-well plate for bead beating 
followed by DNA precipitation and purification following the manufacturer’s instructions. 
Finally, DNA is eluted in 100 uls of Elution Buffer and stored at -80°C until further use. 16S 
sequencing libraries are generated by amplifying the v3-v4 hypervariable regions of the 16S 
gene in a polymerase chain reaction using primers F341and R785. Resulting amplicons are 
tagged with unique molecular barcodes that are later used to demultiplex sequencing reads into 
individual sample buckets. Libraries are loaded on a MiSeq flow cell and sequenced following 
Illumina’s loading instructions. Sequence data are retrieved from the instrument by converting 
base call format files into fastq files for data processing purposes. 
 
9.8.4 Sites Performing Correlative Analysis 
 
De-identified biospecimens and data may be shared with the following external entities for the 
purposes described above: 
 
Broad Institute 
Memorial Sloan Kettering Cancer Center 
 
9.9 
Diet and Physical Activity Assessments 
 
Dietary composition will be assessed through the Block Fat/Sugar/Fruit/Vegetable Screener, 
supplemented with 3 additional questions about fiber intake from the Block Vegetable/Fruit/Fiber 
Screener. The dietary assessment contains 58 total questions and takes about 10-12 minutes to 
complete. Analysis produces estimates of saturated fat, trans fat, total sugars, "added sugars" (in 
sweetened cereals, soft drinks, and sweets), fruit and fruit juice, vegetable intake, glycemic load, 
glycemic index and fiber intake. 
 
Physical activity patterns will be assessed with the Leisure Score Index of Godin Leisure-Time 
Exercise Questionnaire (LSI). The LSI is a short instrument which asks participants to quantify 
the number of minutes spent in the last week engaging in vigorous, moderate, and light/mild 
physical activity. The LSI has undergone extensive reliability and validity testing in a number of 
cancer and general populations. We will be using a modified form of the instrument which includes 
not only frequency of activity but also exercise duration. Weekly minutes of moderate and 
vigorous physical activity will be calculated at each time point using standard scoring algorithms. 
 
Please refer to Appendices C and D for the Diet and Physical Activity Assessments. 
 

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Assessments will be conducted at the below timepoints (in conjunction with collection of stool 
samples): 
• Baseline 
• Cycle 2 (any time from C2D1-C3D1 is allowed) 
• Pre-Surgery (any time after completion of THP/TMP but prior to surgery or receipt of 
additional non-protocol neoadjuvant therapy) 

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The assessments should be completed at the time of stool collection and mailed back along with 
the sample and stool questionnaire. Diet and physical activity assessments that are not collected at 
the protocol-specified collection time points will not be protocol violations. 
 
 
9.10 Genetic Testing 
 
Participants will be given information as part of the informed consent process that samples will 
be used for research tests that will include genetic studies and testing. The intent is not to give 
participants (or his/her medical providers) the results of any testing done for research purposes; 
however, incidental germline (heritable) mutations may be identified of which a participant may 
or may not already be aware. In the case that an incidental genetic finding is identified, the 
Protocol Chair of this project will be notified. The possible decisions for handling incidental 
findings may include notification of the participant (and provider); recommendation for genetic 
counseling, which may or may not include genetic testing (e.g., if the finding was not done in a 
CLIA certified laboratory); or, neither. In general, a member of the participant’s treating team 
will be given the information to help with notification. In all cases, the current policy of the 
Dana Farber Cancer Institute and local/participating site IRB, as applicable, will be followed and 
any additional approvals that may be required prior to participant notification will be secured in 
advance. 
 
9.11 Additional Information 
 
Submission of data for Genome Wide Association Studies (GWAS) is not currently planned; 
however, subjects will be asked for permission in the informed consent process. A revision to the 
protocol and/or any regulatory approvals will be secured prior to any GWAS submission or 
inclusions in the future, if applicable. 
 
9.12 Specimen Banking 
 
The Protocol Chair and collaborators have approval by the TBCRC to use all research bio- 
specimens collected during the conduct of this trial to address the research questions described in 
the protocol document. All future use of residual or repository specimens collected in this trial 
for purposes not prospectively defined will require review and approval by the TBCRC 
according to its established policies, whether the specimens are stored in a central site or at a 
local institution in a virtual repository. 
Secondary use of biospecimens for new endpoints must be submitted to the TBCRC Central 
Office for possible review by the TBCRC Correlative Science Review Committee. 
 
9.13 Assessment of Adjuvant Therapy Decision-Making 
 
9.13.1 Designation of adjuvant systemic therapy status 
 
Based on pCR status (yes/no) plus systemic adjuvant therapy planned, a, patients will be 

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designated as belonging to one of three categories: (1) non-de-escalator; (2) unplanned- 
de-escalator; (3) protocol-consistent adjuvant therapy. Of note, in all patients with HR+ 
disease, any regimen of adjuvant hormonal therapy may be given at the investigator’s 
discretion (and will not be considered in the assessment of escalation/de-escalation). 
Adjuvant bone-modifying agent use will also not be considered in the assessment of 
escalation/de-escalation. 
pCR: Yes 
pCR: No 
Plan adjuvant HP/MP* or T- 
DM1 alone 
(+/- hormonal therapy) 
Protocol-consistent 
adjuvant therapy 
Unplanned-de-escalator 
Plan adjuvant HP/MP* or T- 
DM1 + additional adjuvant 
chemotherapy 
(+/- hormonal therapy) 
Non-de-escalator 
Protocol-consistent 
adjuvant therapy 
* In the adjuvant setting, patients should receive either HP or MP according to maintaining 
the regimen they received in the neoadjuvant setting, if it led to pCR. I.e. patients who 
achieved pCR after neoadjuvant HP-containing regimen should go on to receive adjuvant 
HP, patients who achieved pCR after neoadjuvant MP-containing regimen should go on to 
receive adjuvant MP. 
This designation will be established at the time of the post-operative medical oncology 
visit and recorded in the CRF. The planned adjuvant chemotherapy questionnaire 
(Questionnaire Packet; to be completed by a study team member) will also be completed 
at that time. If for any reason the discussion of planned adjuvant chemotherapy is not 
completed at the post-operative visit, CRF recording of planned adjuvant chemotherapy 
may be delayed until a final decision is made regarding planned adjuvant chemotherapy, 
though it is strongly encouraged that this decision be made within 28 days (and as soon as 
possible) after the post-operative visit. 
9.13.2 Patient questionnaire completion for non-de-escalator patients and unplanned-de- 
escalator patients 
For patients designated to fall in the non-de-escalator and unplanned-de-escalator groups, 
a questionnaire should be administered at the timepoint at which this designation is made. 
The goal of these questionnaires is to assess the rationale behind planning for non- 
protocol-consistent adjuvant therapy. 
Questionnaire for non-de-escalator patients, see Appendix A of the Questionnaire Packet. 
Questionnaire for unplanned-de-escalator patients, see Appendix B of the Questionnaire 
Packet. 
Of note, while it is strongly preferred that patients complete the questionnaire in person, 
phone, email, or mail completion/return of the questionnaire is allowed as a back-up. 
 
9.13.3 Patient questionnaire completion for protocol-consistent adjuvant therapy patients 

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For patients designated to fall in the protocol-consistent adjuvant therapy group, a 
questionnaire should be administered at the timepoint at which this designation is made. 
 
This questionnaire can be found in Appendix E of the Questionnaire Packet. 
 
Of note, while it is strongly preferred that patients complete the questionnaire in person, 
phone, email, or mail completion/return of the questionnaire is allowed as a back-up. 
 
9.13.4 Structured physician medical record review for non-de-escalator patients and unplanned- 
de-escalator patients 
 
Following patient designation into the non-de-escalator or unplanned-de-escalator 
groups, medical record review of all notes relating to adjuvant chemotherapy decision- 
making (meaning notes filed prior to the final, recorded decision being made) will be 
performed by at least one physician member of the study team. Every effort will be made 
for the same physician study team member to review all charts, for consistency. External 
sites must submit a printed copy of a patient’s post-operative visit note to 
ctopm@dfci.harvard.edu. The physician study team member will record, using the same 
structure of responses as provided on patient questionnaires, their interpretation of the 
reasons for planning a non-protocol-consistent adjuvant therapy regimen. For each case, 
this will be recorded on a structured physician review form. Every effort will be made for 
each record to be independently reviewed and questionnaire completed by two 
physicians, in order to ensure validity of results as much as possible. 
 
Structured physician review form for non-de-escalator patients, see Appendix C of the 
Questionnaire Packet. This form will be completed by DFCI principal investigator during 
central review at the end of the study. 
 
Structured physician review form for unplanned-de-escalator patients, see Appendix D of 
the Questionnaire Packet. This form will be completed by DFCI principal investigator 
during central review at the end of the study. 
 
9.14 Patient-Reported Outcomes 
 
9.14.1 Overview and rationale 
 
Patient-reported outcomes (PROs) will be assessed via questionnaires in order to capture 
a comprehensive picture of the patient experience and quality of life on TMP versus THP 
in the early-stage breast cancer setting. No data yet exist regarding PROs in patients 
receiving margetuximab in the early-stage breast cancer setting, or for patients receiving 
margetuximab in combination with paclitaxel and pertuzumab. Quality of life (QOL) data 
from the phase III SOPHIA trial of margetuximab plus chemotherapy in the setting of 
metastatic HER2+ breast cancer is not yet reported. Based on toxicity reporting by 
standard CTCAE (non-PRO) in the SOPHIA trial,25 any grade infusion reactions and 
fatigue were both numerically slightly worse with margetuximab plus chemotherapy 
versus trastuzumab plus chemotherapy, however, any grade nausea, anemia, diarrhea and 

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neutropenic fever were numerically less frequent in the margetuximab arm. Notably, 
toxicities were not statistically compared between the two arms in the SOPHIA trial and 
overall safety profiles for both arms were thought to be similar. GI symptoms were 
reported in both arms of the trial. PROs were also not included in earlier phase studies of 
margetuximab in the advanced breast cancer setting. Notable toxicities observed in these 
studies included fatigue, infusion reaction, nausea, vomiting, diarrhea, anorexia, upper 
respiratory infection, laboratory abnormalities and headache.22 
 
9.14.2 Objectives 
 
Objectives related to PROs are detailed in Section 1.4 
 
9.14.3 Assessment items and timepoints 
 
PRO measures, number of questions, recall period and time points are listed below. 
PROs will be completed by patients on paper questionnaires or tablet. 
 
Quality of life assessments that are not collected at the protocol-specified collection time 
points will not be protocol violations. 
 
PRO Questionnaire is Appendix G of the Questionnaire Packet. 
 
Domain 
Measure 
# of 
questions 
Recall 
period 
Time points 
Fatigue 
PROMIS v 1.0 short form 7a 
7 
7 days 
- Day 1 of neoadjuvant 
cycle 1 through 4 (all 
patients) 
- Pre-operative visit (all 
patients) 
- Day 1 of adjuvant 
cycle 1, 4, 7, and 13 
(only patients who 
continue on adjuvant 
HP or MP on study) 
Fatigue 
PROCTCAE questions for 
severity and interference 
2 
7 days 
Nausea 
PROCTCAE questions for 
frequency and severity 
2 
7 days 
Vomiting 
PROCTCAE questions for 
frequency and severity 
2 
7 days 
Diarrhea 
PROCTCAE question for 
frequency 
1 
7 days 
Decreased 
appetite 
PROCTCAE questions for 
severity and interference 
2 
7 days 
Abdominal 
pain 
PROCTCAE questions for 
frequency, severity, 
interference 
3 
7 days 
Rash 
PROCTCAE question for rash 
(yes/no) 
1 
7 days 
Cough 
PROCTCAE questions for 
severity and interference 
2 
7 days 
Shortness 
of breath 
PROCTCAE questions for 
severity and interference 
2 
7 days 

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Headache 
PROCTCAE questions for 
frequency, severity, 
interference 
3 
7 days 
QOL 
PROMIS Global Health Scale 
v1.2 
*2 scores (physical health and 
mental health) 
10 
7 days 
Infusion 
Reaction 
Self-report of severity of 
infusion reaction (0-10) 
1 
0 days 
Day 1 of neoadjuvant 
cycle 1 through 4 
immediately after 
infusion 
 
 
9.14.4 PRO eligibility 
Patients must be English-speaking in order to complete PRO questionnaires. Otherwise, 
eligibility will be identical to overall trial eligibility. Inability or unwillingness to 
complete PRO questionnaires will not exclude a patient from participating in the trial. 
10. STUDY CALENDAR 
All screening tests must be completed within 28 days of registration, with the exception of breast 
and axillary imaging, which may be completed up to 42 days prior to registration, pregnancy test 
(only required in specified patients), which should be completed within 14 days of treatment 
start, and LVEF assessment which should be completed within 3 months prior to registration. 
Axillary ultrasound and/or biopsy do not need to be repeated if performed prior to the screening 
period. 
Assessments must be performed prior to administration of any study agent. Study assessments 
and agents should be administered within + 3 days of the protocol-specified date, unless 
otherwise noted. 

74 
 
 
 
 
Assessment 
Pre-Study 
Cycle 1-4 (+/- 3 days) 
Pre-Op 
Visit 
Post-Op 
Visitq 
Adjuvant therapym, s 
Follow-up 
≤ 28 days of 
registrationa 
≤ 14 days of 
tx start 
D1 
D8l 
D15l 
Q3Wks 
Q9Wks 
(+/- 3 
weeks) 
Medical history 
X 
Physical exama 
X 
X 
X 
X 
X 
ECOG PS 
X 
Vital signs, weight, (& height 
at screening only) 
X 
X 
X 
Breast imagingb 
X 
X 
Axillary assessmentc 
X 
Whole-body stagingd 
X 
Chemistry and hematologye 
X 
X 
X 
X 
X 
Serum B-HCGf 
X 
LVEF Assessment (Echo or 
MUGA)g 
X 
Xg, r 
X (Q12wks) g 
Concomitant medication 
review 
X 
X 
X 
X 
X 
X 
Adverse Event evaluation 
X 
X 
X 
X 
Visit with breast surgeon 
X 
Xh 
planned adjuvant therapy 
questionnairei 
X 
Research Blood 
X 
X 
(D1 of 
C2& C4) 
X 
X (C13D1 only) 
Xo 
Research Biopsyk 
X 
X (C2D1) 
Xk 
Tissue collection 
X 
Xn 
Xo 
Stool sample collection and 
questionnairep 
X 
X 
(anytime 
During 
Cycle 2) 
X 
PROs 
X 
X 
Xj 
a: All physical examinations should include examination of breast and loco-regional lymphatics, with breast tumor measurements recorded in the medical record 
if tumor is still in place (i.e. preoperatively). Additional components of the examination should be focused on organ system(s) related to adverse events. See 
Physical exam should be collected at either post-op visit or C1D1 of adjuvant therapy and then q9wks (+/- 3 weeks) during adjuvant tx. Section 5.6 for further 
details if necessary. 

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b: See Section 5.7 for further details regarding breast imaging requirements. 
c: See Section 5.9 for further details regarding axillary assessment. 
d: Whole-body staging recommended only in patients with stage III disease according to AJCC staging manual edition 8, anatomic staging table. CT 
chest/abdomen/pelvis with or without bone scan is preferred, but PET CT scan is allowed per investigator discretion. 
e: See patient eligibility for lab values that must be verified at the time of screening. Thereafter, comprehensive metabolic panel and complete blood count with 
differential should be drawn at day 1,8, and 15 of each neoadjuvant cycle, and at day 1 of each adjuvant cycle. 
f: Pregnancy test only required in women of childbearing potential (within 14 days of treatment start). 
g: For patients who receive adjuvant HP or MP on study, another echo or MUGA should be performed in the post-operative period prior to receipt of additional 
anti-HER2 therapy, and every 12 weeks (+/- 3 weeks) thereafter from the start of adjuvant therapy. Q12 week Echo/MUGA assessments in the adjuvant setting 
do not need to be performed prior to treatment administration. 
h: Pre-op visit with surgeon is recommended to occur any time on or after C4D8, but can be performed earlier at the discretion of the surgeon. 
i: See Section 9.11 for further details regarding administration of adjuvant systemic therapy decision-making questionnaire 
j: In the adjuvant setting, PROs will be administered on day 1 of cycles 1, 4, 7, and 13 (only in patients who continue on adjuvant HP or MP on study). 
k: Pre-Treatment and Pre- Cycle 2 biopsies are mandatory for all participants. For patients with residual disease at the completion of neoadjuvant THP or TMP a 
biopsy is required prior to initiation of additional neoadjuvant systemic therapy. (See Section 9) 
l: Day 8 and Day 15 may occur at a local facility on either arm 
m: Adjuvant therapy with 13 cycles of HP or MP (matched to neoadjuvant regimen) will only be administered on trial in patients who achieve pCR following 4 
cycles of THP or TMP. 
n: see section 9 for guidance on collection of surgical tissue (fresh or FFPE for sites unable to collect fresh tissue) 
o: Blood and tissue only collected during follow-up at time of recurrence 
p: Stool samples to be collect pre-treatment, during cycle 2 (any time from C2D1-C3D1) and pre-surgery (any time after completion of THP/TMP treatment but 
prior to surgery (or prior to any additional non-protocol neoadjuvant chemotherapy)). 
q: Post-operative visits are recommended to occur within 6 weeks (42 days) from breast surgery. 
r: If clinically indicated, the post-operative LVEF assessment can occur pre-operatively. 
s: Adjuvant treatment and assessments outside of these designated windows will not result in a violation. 

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11. MEASUREMENT OF EFFECT 
 
11.1 Antitumor Effect – Solid Tumors 
 
A baseline and presurgical radiographic study of the breast is required; MRI is recommended. The same 
radiographic modality should be used consistently if at all possible. The baseline scan must be obtained 
within 42 days prior to registration. The presurgical scan should occur a maximum of 4 weeks after the last 
neoadjuvant therapy. If the participant clinically progresses, repeat imaging is required. If there is 
discordance (clinical progression, but radiographic stable disease or response), and further input is desired, 
contact the overall study PI. 
 
11.2 Radiographic assessment 
 
Each participant will have pre- and post-therapy radiographic tumor measurements, preferably by MRI, 
however if logistic or practical issues preclude MRI use, mammogram or ultrasound may be substituted. 
The longest diameter (LD) of the target lesion at the time of study initiation will be reported as the baseline 
LD. The baseline LD of the target lesion may be used as reference to further characterize the objective 
tumor response of the measurable dimension of the disease. 
 
Response criteria are based on the RECIST 1.1 criteria: 
 
Radiographic Complete Response (CR): Complete disappearance of the target lesion 
 
Radiographic Partial Response (PR): Greater than or equal to 30% decrease in the longest diameter (LD) 
of the target lesion taking as reference the baseline LD. 
 
Radiographic Progressive Disease (PD): Greater than or equal to 20% increase in the LD of target lesion 
taking as reference the baseline LD or the appearance of one or more new lesions 
. 
Radiographic Stable Disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to 
qualify for PD taking as reference the baseline LD 
 
11.3 Clinical assessments 
 
Both target and, in the event of multifocal or multicentric invasive cancer, nontarget lesions should be 
followed clinically and their clinical size recorded at baseline. Measurements thereafter are required; these 
lesions should be categorized at subsequent visits regarding whether there is evidence of progression. If 
“yes”, the study chair may be notified in order to determine whether the participant should come off 
protocol treatment. 
 
11.4 Pathologic Response 
 
For the purpose of this study pCR will be defined as RCB 0. 
 
Pathologic response will also be reported using the Residual Cancer Burden calculator 1 from M.D 

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Anderson: http://www.mdanderson.org/breastcancer_RCB. 
 
The following parameters are required from pathologic examination in order to calculate Residual Cancer 
Burden (RCB) after neoadjuvant treatment: 
 
• The largest two dimensions (mms) of the residual tumor bed in the breast (largest tumor bed if 
multicentric disease) 
• Histologic assessment of the percentage of the tumor bed area that contains carcinoma (all 
carcinoma, i.e. invasive and in situ), select one of the following: 0%, 1%, 5%, 10%, 20%, 30%, 40%, 
50%, 60%, 70%, 80%, 90% 
• To assess cellularity it is helpful to scan across the sections of tumor bed and then estimate the 
average cellularity from the different microscopic fields. 
• When estimating percentage cancer cellularity in any microscopic field, compare the involved area 
with obvious standards, e.g. more or less than half, one quarter, one fifth, one tenth, one twentieth, 
etc. 
• Expect there to be variable cellularity within the cross section of any tumor bed, but estimate the 
overall cellularity from the average of the estimates in different microscopic fields of the tumor bed. 
E.g., if cellularity in different fields of the tumor bed were estimated as 20%, 10%, 20%, 0%, 20%, 
30%, then an average estimate of overall cellularity would be 20%. 
• Histologic estimate of the percentage of the carcinoma in the tumor bed that is in situ, select one of 
the following: 0%, 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100% 
• The number of positive (metastatic) lymph nodes 
• The largest diameter (mm) of the largest nodal metastasis 
 
12. DATA REPORTING / REGULATORY REQUIREMENTS 
 
Adverse event lists, guidelines, and instructions for AE reporting can be found in Section 7.0 (Adverse 
Events: List and Reporting Requirements). 
 
12.1 Data Reporting 
 
12.1.1 Method 
 
The Office of Data Quality (ODQ) will collect, manage, and perform quality checks on the data for this 
study. 
 
12.1.2 Responsibility for Data Submission 
 
Investigative sites are responsible for submitting data and/or data forms to the Office of Data Quality 
(ODQ) in accordance with DF/HCC policies. 
 
12.2 Data Safety Monitoring 
 
The DF/HCC Data and Safety Monitoring Board (DSMB) will review and monitor study progress, toxicity, 

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safety and other data from this study. The board is chaired by a medical oncologist from outside of DF/HCC 
and has external and internal representation. Information that raises any questions about participant safety or 
protocol performance will be addressed by the Overall PI, statistician and study team. Should any major 
concerns arise, the DSMB will offer recommendations regarding whether or not to suspend the study. 
 
The DSMB will meet twice a year to review accrual, toxicity, response and reporting information. 
Information to be provided to the DSMB may include: participant accrual; treatment regimen information; 
adverse events and serious adverse events reported by category; summary of any deaths on study; audit 
results; and a summary provided by the study team. Other information (e.g. scans, laboratory values) will be 
provided upon request. 
 
12.3 Multi-Center Guidelines 
 
This protocol will adhere to DF/HCC Policy MULTI-100 and the requirements of the DF/HCC Multi- 
Center Data and Safety Monitoring Plan. The specific responsibilities of the O PI, Coordinating Center, and 
Participating Institutions and the procedures for auditing are presented in Appendix B. 
 
• The PI/Coordinating Center is responsible for distributing all IND Action Letters or Safety Reports 
to all participating institutions for submission to their individual IRBs for action as required. 
• Mechanisms will be in place to ensure quality assurance, protocol compliance, and adverse event 
reporting at each site. 
12.4 
Collaborative Research and Future Use of Data and Samples 
 
Tissue, blood, bodily fluids, and other materials derived from these will be collected in this study to analyze 
genes, DNA, RNA, proteins and cells for the study’s correlative endpoints and potential future research, 
utilizing new types of biomarker testing as it becomes available. 
 
These samples and any data generated as a part of these clinical trials may be used for future research studies 
and may be provided to collaborating investigators both within and outside of the DF/HCC for either 
correlative endpoints or secondary use. Samples and data may be shared with outside non-profit academic 
investigators, as well as with for-profit pharmaceutical investigators or commercial entities, with whom we 
collaborate. When samples or data are sent to collaborators and when any research is performed on them, all 
information will be identified with a code, and will not contain any PHI, such as name, date of birth, or MRNs. 
 
These samples may be used for future research studies and may be provided to collaborating investigators 
both within and outside of DF/HCC. Samples and data may be shared with outside non-profit academic 
investigators as well as with for-profit pharmaceutical investigators or commercial entities, with whom we 
collaborate. When samples are sent to investigators, and when any research is performed on samples, the 
samples will be identified with a code, but will not contain patient identification information such as name, 
birthdate, or medical record numbers. 
 
In order to allow the greatest amount of research to be performed on the specimens and information generated 
as a part of this trial, researchers in this study may share results of genetic sequencing with other scientists. 
De-identified specimen or genetic data may be placed into one of more publicly-accessible scientific 
databases, such as the National Institutes of Health’s Database for Genotypes and Phenotypes (dbGaP). The 

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results from the correlative research on this study will be shared with these public databases. Through such 
databases, researchers from around the world will have access to de-identified samples or data for future 
research. More detailed information, beyond the public database, may only be accessed by scientists at other 
research centers who have received special permission to review de-identified data. 
 
13. REGULATORY CONSIDERATIONS AND MULTICENTER GUIDELINES 
 
13.1 
Protocol Review and Amendments 
 
Unless otherwise specified, each participating institution must obtain its own IRB approval. It is expected that 
the IRB will have the proper representation and function in accordance with federally mandated regulations. 
The IRB should approve the consent form and protocol. 
 
Information regarding study conduct and progress will be reported to the Institutional Review Board (IRB) 
per the current institutional standards of each participating center. 
 
Any changes to the protocol will be made in the form of an amendment and must be approved by the IRB of 
each institution prior to implementation. IRB approval at each participating site is required within 90 days of 
receipt of amended documents. 
 
The Protocol Chair (or designee) is responsible for the coordination and development of all protocol 
amendments and will disseminate this information to the participating centers. 
 
13.2 
Informed Consent 
The physician- investigator will explain to each subject the nature of the study, its purpose, the procedures 
involved, the expected duration, the potential risks and benefits involved and any discomfort it may entail. 
Each subject will be informed that participation in the study is voluntary, that s/he may withdraw from the 
study at any time, and that withdrawal of consent will not affect her subsequent medical treatment or 
relationship with the treating physician(s) or institution. The informed consent will be given by means of a 
standard written statement, written in non-technical language, which will be IRB approved. The subject 
should read and consider the statement before signing and dating it and will be given a copy of the 
document. No subject will enter the study or have study-specific procedures done before his/her informed 
consent has been obtained. 
 
In accordance with the Health Information Portability and Accountability Act (HIPAA), the written 
informed consent document (or a separate document to be given in conjunction with the consent document) 
will include a subject authorization to release medical information to the study sponsor and supporting 
agencies and/or allow these bodies, a regulatory authority, or Institutional Review Board access to subjects’ 
medical information that includes all hospital records relevant to the study, including subjects’ medical 
history. 
 
13.3 
Ethics and GCP 
This study will be carried out in compliance with the protocol and Good Clinical Practice, as described in: 
 
1. ICH Harmonized Tripartite Guidelines for Good Clinical Practice 1996. 

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2. US 21 Code of Federal Regulations dealing with clinical studies (including parts 50 and 56 
concerning informed consent and IRB regulations). 
3. Declaration of Helsinki, concerning medical research in humans (Recommendations Guiding 
Physicians in Biomedical Research Involving Human Subjects, Helsinki 1964, amended Tokyo 
1975, Venice 1983, Hong Kong 1989, Somerset West 1996). 
 
The investigator agrees to adhere to the instructions and procedures described in it and thereby to adhere to 
the principles of Good Clinical Practice that it conforms to. 
 
13.4 
Compliance with Trial Registration and Results Posting Requirements 
Under the terms of the Food and Drug Administration Modernization Act (FDAMA) and the Food and Drug 
Administration Amendments Act (FDAAA), the sponsor-investigator of the trial is solely responsible for 
determining whether the trial and its results are subject to the requirements for submission to the Clinical 
Trials Data Bank, http://www.clinicaltrials.gov. The Sponsor-Investigator has delegated responsibility to the 
Coordinating Center for registering the trial and posting the results on clinicaltrials.gov. Information posted 
will allow subjects to identify potentially appropriate trials for their disease conditions and pursue 
participation by calling a central contact number for further information on appropriate trial locations and 
study site contact information. 
 
13.5 
Study Documentation 
Each participating site is responsible for submitting copies of all relevant regulatory documentation to the 
Coordinating Center. The required documents include but are not limited to the following: local IRB 
approvals (i.e., protocol, consent form, amendments, patient brochures and recruitment material, etc.), IRB 
membership rosters, summary of unanticipated problems or protocol deviations, and documentation of 
expertise of the investigators. The Coordinating Center will provide each participating site with a 
comprehensive list of the necessary documents. It is the responsibility of the participating sites to maintain 
copies of all documentation submitted to the Coordinating Center. 
 
13.6 
Records Retention 
Following closure of the study, each participating center will maintain a copy of all site study records in a 
safe and secure location. The Coordinating Center will inform the investigator at each site at such time that 
the records may be destroyed. 
 
14. STATISTICAL CONSIDERATIONS 
 
14.1 Study Design/Endpoints 
 
This is a 2:1 randomized open-label phase II trial of paclitaxel/margetuximab/pertuzumab (TMP) compared 
to paclitaxel/trastuzumab/pertuzumab (THP) in patients with anatomic stage II-III HER2+ breast cancer. We 
hypothesize that patients with stage II-III HER2+ breast cancer will have improved pCR rates to 
neoadjuvant TMP compared to THP. Eligible patients will have anatomic stage II-III (according to AJCC 
8th edition anatomic staging table) HER2+ breast cancer. Patients may have any hormone receptor status, 
may be either pre- or post-menopausal, and must be treatment-naïve for this cancer. Following registration, 
all patients will be randomized 2:1 to neoadjuvant TMP or THP, respectively. All patients will receive 4 
cycles of neoadjuvant therapy (1 cycle=21 days), with paclitaxel delivered days 1, 8, and 15 of each 21-day 
cycle for all patients, and MP or HP delivered on day 1 of each 21-day cycle according to randomization. 

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Pathologic response will be assessed at surgery per standard clinical practice. Patients with pCR (defined as 
RCB 0) will complete one year of their assigned MP or HP therapy in the adjuvant setting, without 
additional chemotherapy. Patients who do not achieve pCR will receive additional/alternative adjuvant 
therapy of the investigator’s choice (four cycles of adjuvant adriamycin/cyclophosphamide (AC) 
chemotherapy followed by 14 cycles of adjuvant trastuzumab-emtansine (T-DM1) or 14 cycles of adjuvant 
T-DM1 alone, depending on extent of residual disease are recommended, but not mandated). In all patients 
with hormone receptor-positive (HR+) disease, any adjuvant hormonal therapy may be given at the 
investigator’s discretion. 
 
Of note, all patients who receive additional pre-surgery therapy will be considered as non-pCR for purposes 
of the primary endpoint, regardless of whether they had a biopsy to confirm the presence of residual disease 
 
All patients will be followed for recurrence and survival events for up to 10 years from definitive surgery. 
 
14.2 Endpoints 
 
Primary endpoint: Rate of pCR (defined as RCB 0). 
 
Secondary endpoints: 
• Rate of pCR (RCB) in patients treated with TMP or THP, by HR status (positive/negative). 
• RCB scores in in patients treated with TMP or THP, overall and by HR status (positive/negative). 
• Radiographic response to neoadjuvant therapy in patients treated with TMP or THP, overall and by 
HR status (positive/negative) 
• Safety and tolerability profile 
o Assessment of DLTs on Arm A during the first 21 days of treatment 
o Maximum grade of all treatment-related adverse events according to CTCAE v5.0 
o Patient-reported outcomes 
• All adjuvant therapies administered in all patients. 
• Feasibility of sentinel lymph node mapping and biopsy (defined by ability to identify at least three 
sentinel lymph nodes, or the clipped node plus two sentinel lymph nodes). 
• Pathologic outcomes of axillary lymph node dissection after sentinel lymph node biopsy among 
patients with positive sentinel lymph node(s). 
• EFS, RFI, and OS. 
 
Correlative, patient-related outcomes, and exploratory endpoints: 
• Patient/physician considerations in choice of adjuvant therapy regimen. 
• Humoral and cellular immune response measured serially in both tissue and blood. 
• Symptoms and quality of life (both physical and mental health) during neoadjuvant TMP and THP. 
14.3 Sample Size and Analysis of Primary Endpoint 
 
Target accrual is 171 patients. The primary endpoint is pCR. The expected pCR rate for the THP control 
arm is 45% based on the previously published NeoSphere and CALGB 40601 trials of neoadjuvant taxane 
plus dual HER2-directed therapy.20,46 We assume that an improvement in pCR rate from 45% to 65% would 
make neoadjuvant TMP (experimental regimen) worthy of further investigation. The planned sample size of 

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171 patients, with improvement in pCR rate from 45% to 65% and a 2:1 randomization 
(experimental:control) corresponds to 80% power (chi squared test, single side testing, type I error 0.05) 
accounting for interim analysis. 
 
14.4 Stratification Factors 
 
Patients will be randomized using block stratified randomization. Patients will be stratified according to ER 
status (>10% or <10%) and clinical anatomic stage (II vs III). 
 
14.5 Interim Monitoring Plan for pCR 
 
The interim analysis of pCR will compare pCR rates of TMP and THP. The analysis will use the first 90 
outcomes (pCR-status). Enrollment is terminated if (i) the TMP pCR estimate at interim analysis is inferior 
compared to THP and (ii) a final inferiority result—assuming study continuation—is predicted with high 
probability >80%. Prediction probability will be computed based on a standard Beta-Binomial model. 
14.6 Interim Monitoring Plan for Post-Operative Outcomes 
 
We anticipate a low rate of recurrence during the time patients are receiving de-escalated adjuvant HP or 
MP. Continuous monitoring of unacceptable levels of recurrence will use Pocock-style boundaries 
constructed following the method of Ivanova, et al (2005).47 Simulation based evaluation of the sensitivity 
of design operating characteristics to the enrollment rate--which determine follow up times—have 
revealed power variations of 
2% (range: 2 to 10 patients per month). An event rate of 5% or less would be accepted (where only a 
biopsy-proven recurrence of metastatic breast cancer is considered an event), and the desired probability of 
stopping in the anticipated pCR population (N=90 calculated from 45% of THP patients and 65% of TMP 
patients) is 0.1, leading to the following stopping rules. 
 
The thresholds tabled below can determine early termination of the study, and the will be 
operationalized with quarterly interim analyses: 
Number de-escalated 
1-20 20 - 
50 
51 -80 81 - 
120 
121 - 
160 
Event (biopsy-proven 
recurrence of metastatic 
breast cancer) 
4 
6 
8 
11 
14 
 
The probabilities of stopping the trial early are presented below: 
 
True rate 
Probability of 
stopping early 
--- 
--- 
0.05 
0.097 
0.10 
0.8 
0.20 
0.99 
0.30 
>0.99 

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14.7 Supplemental Interim Monitoring of Safety 
 
Several measures will be taken to ensure the safety of patients participating in this study. The phase III 
SOPHIA study25 suggested that the safety profile of margetuximab is globally acceptable and similar to the 
safety profile of trastuzumab. However, as margetuximab has not been previously combined with paclitaxel 
or pertuzumab in a prospective trial, DLTs will be closely monitored. Safety monitoring reported to the 
DSMB will be supplemented by 1) a formal, prespecified safety monitoring guidance for pausing study 
accrual to more fully evaluate safety in case of unexpectedly high dose-limiting toxicities; 2) a pause of 
study accrual after the first 6 patients in the investigational treatment group to more fully review safety, 
regardless of the number of dose-limiting toxicities observed. 
 
14.7.1 Monitoring of dose-limiting toxicity (DLT) 
 
During enrollment of the first one third (N=40) of patients to the investigational TMP arm, DLTs will be 
summarized with pre-specified criteria based on sequential boundaries to pause enrollment to more fully 
review safety if excessive numbers of DLTs are observed. The criteria are such that the probability of 
pausing is at most 0.05 if the true DLT rate is equal to 15%, and the probabilities of pausing will be 0.66 or 
0.95 if the true DLT rate is equal to 30% or 40% 48. 
 
The cumulative number of patients (X) experiencing DLT will be compared with the number of safety- 
evaluable patients (N), i.e., in the safety population (defined in Section 14.9.1, at that time, and an 
associated cutoff of safety-evaluable patients (Nx). If the number of patients N is greater than Nx then 
enrollment will continue; if the number of patients N is less than or equal to Nx then enrollment will pause 
in order to more fully review the nature, frequency, severity and timing of the events. The Table gives the 
criteria for pausing enrollment to more fully evaluate safety. 
 
Criteria for pausing enrollment because of DLTs to more fully review safety, for sample size 
up 
to 40 patients, with probability of pausing of 0.05 when the true toxicity rate is 15%. 
Number of patients 
for whom DLT is 
reported 
X 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
Pause enrollment if 
safety-evaluable 
patients N is ≤Nx 
Nx 
- 
- 
≤4 
≤7 
≤10 
≤14 
≤18 
≤23 
≤27 
≤32 
≤36 
≤40 
Continue enrollment 
if safety-evaluable 
patients N is ≥ Nx 
Nx 
≥1 
≥2 
≥5 
≥8 
≥11 
≥15 
≥19 
≥24 
≥28 
≥33 
≥37 
- 
 
14.7.2 Assessment of first 6 patients in the TMP (investigational) treatment group 
Once 6 patients assigned to the experimental arm (TMP) have received at least one cycle of assigned 
treatment, a safety review will be conducted before additional patients are enrolled. Based on the monitoring 
criteria, if ≥4 of 6 patients (or before 6, if 3/3, ≥3/4, ≥4/5 patients) experience DLT within the first cycle of 
treatment, then the treatment regimen will be modified or discontinued. The review will include a per- 
patient listing of all reported AEs to date, including actions required for dosing, to more fully review the 
nature, frequency, severity and timing of the events. This information combined with fewer DLTs may also 
result in modification of the experimental treatment regimen. See Section 5.3 regarding DLTs for more 

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information. 
 
14.8 Analysis of Secondary Endpoints 
 
Descriptive statistics will be used to summarize patient and disease characteristics and for secondary 
endpoints related to adjuvant treatments received, adherence, and reported reasons for off-protocol treatment 
decisions. 
 
The observed rates of pCR and RCB will be reported with exact binomial two-sided 90% confidence 
intervals. The distribution of the survival function and cumulative incidence function for EFS, RFI, and OS 
will be summarized using the Kaplan Meier product limit estimator and 90% confidence interval (CI) using 
Greenwood’s formula for the standard error. 
 
Clinical outcomes will be evaluated in the entire study population—including those patients who are 
evaluable for the primary endpoint and those who are not—and in the subgroups defined by HR+ and HR- 
breast cancer. Contrasts in the long-term outcomes (EFS, RFI, and OS) in patient subgroups according to 
endpoints at time of surgery will use landmark survival analyses to avoid guarantee time bias. Contrasts 
will be estimation-only and reported as ratios (odds ratios and hazard ratios) with two-sided 95% confidence 
intervals. 
 
Analyses of correlative endpoints will be exploratory, and will use logistic regression and Cox proportional 
hazard models to evaluate the association between molecular phenotypes and clinical outcomes: binomial 
and time-to-event endpoints, respectively. For assessments at the time of surgery, landmark survival 
analyses will be performed. For post-baseline and serial assessments, including circulating tumor DNA, 
time-varying covariates will be used in survival analysis to infer the association. 
 
Descriptive statistics will describe the PRO outcomes over time. With 114 participants receiving TMP and 
57 participants receiving THP, we will have 80% power to find a standardized effect size of 0.45 (i.e. 
standard deviation units; considered a moderate effect size) in the change in physical health scores from 
baseline to pre-operative visit between the two intervention groups assuming a two-sided type I error of 5%. 
For PROMIS measures, we will describe mean and median T score, SD and range at each time point for 
each arm. We are primarily interested in the difference in change scores from baseline to the pre-operative 
visit between treatment groups and we will compare these differences between the TMP and THP groups 
using two sample t-tests. For PRO-CTCAE measures we will describe proportions who report each answer 
for each question at each time point for each arm. We will further model the trajectory over time for each 
PRO outcome using linear mixed effects models. Normalizing transformations will be used if necessary to 
ensure accurate model fit. Random effects include random intercept for participants and random slope for 
follow-up time. Treatment arm will be included as a covariate and interactions between treatment and time 
will be explored. 
 
14.9 Reporting and Exclusions 
 
14.9.1 Evaluation of Toxicity 
 
All participants will be evaluable for toxicity from the time of their first treatment. 

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14.9.2 Evaluation of the Primary Efficacy Endpoint 
 
Analysis of the primary endpoint will be by a modified intention-to-treat of all patients who initiate 
therapy. Of note, all patients who receive additional pre-surgery therapy will be considered as non- 
pCR for purposes of the primary endpoint, regardless of whether they had a biopsy to confirm the 
presence of residual disease 
 
15. PUBLICATION PLAN 
 
It is understood that any manuscript or releases resulting from the collaborative research must be approved by 
the Protocol Chair and will be circulated to applicable participating sites/investigators prior to submission for 
publication or presentation. 
 
Additionally, any publication of study data and results must conform to the publications policy as stated the 
Translational Breast Cancer Research Consortium’s (TBCRC) “Policies and Procedures”. 

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antitumor activity of trastuzumab and pertuzumab combination treatment on HER2-positive human 
xenograft tumor models. Cancer research. 2009;69(24):9330-9336. 
39. 
Gavin PG, Song N, Kim SR, et al. Association of Polymorphisms in FCGR2A and FCGR3A With 
Degree of Trastuzumab Benefit in the Adjuvant Treatment of ERBB2/HER2-Positive Breast Cancer: 
Analysis of the NSABP B-31 Trial. JAMA oncology. 2017;3(3):335-341. 
40. 
Norton N, Olson RM, Pegram M, et al. Association studies of Fcgamma receptor polymorphisms 
with outcome in HER2+ breast cancer patients treated with trastuzumab 
in NCCTG (Alliance) Trial N9831. Cancer immunology research. 2014;2(10):962-969. 
41. 
Hurvitz SA, Betting DJ, Stern HM, et al. Analysis of Fcgamma receptor IIIa and IIa polymorphisms: 
lack of correlation with outcome in trastuzumab-treated breast cancer patients. Clinical cancer 
research : an official journal of the American Association for Cancer Research. 2012;18(12):3478- 
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42. 
Crawford J, Caserta C, Roila F, Group EGW. Hematopoietic growth factors: ESMO Clinical 
Practice Guidelines for the applications. Ann Oncol. 2010;21 Suppl 5:v248-251. 
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Crawford J, Armitage J, Balducci L, et al. Myeloid growth factors. J Natl Compr Canc Netw. 
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45. 
Loi S, Symmans WF, Bartlett JM, et al. Proposals for uniform collection of biospecimens from 
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46. 
Carey LA, Berry DA, Cirrincione CT, et al. Molecular Heterogeneity and Response to Neoadjuvant 
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48. 
Ivanova A, Qaqish BF, Schell MJ. Continuous toxicity monitoring in phase II trials in oncology. 
Biometrics. 2005;61:540-545. 
49. 
Trinchieri, G. Cancer Immunity: Lessons From Infectious Diseases. J Infect Dis 212 Suppl 1, S67-73 
(2015). 
50. 
Human Microbiome Project, C. Structure, function and diversity of the healthy human microbiome. 
Nature 486, 207-214 (2012). 
51. 
Qin, J., et al. A human gut microbial gene catalogue established by metagenomic sequencing. 
Nature 464, 59-65 (2010). 
52. 
Roy, S. & Trinchieri, G. Microbiota: a key orchestrator of cancer therapy. Nat Rev Cancer (2017). 
53. 
Sivan, A., et al. Commensal Bifidobacterium promotes antitumor immunity and facilitates anti-PD- 
L1 efficacy. Science 350, 1084-1089 (2015). 
54. 
Vetizou, M., et al. Anticancer immunotherapy by CTLA-4 blockade relies on the gut microbiota. 
Science 350, 1079-1084 (2015). 
55. 
Goedert, J.J., et al. Investigation of the association between the fecal microbiota and breast cancer in 
postmenopausal women: a population-based case-control pilot study. J Natl Cancer Inst 107(2015). 
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Liu, K. & Lu, C. Gut microbes modulate host response to immune checkpoint inhibitor cancer 
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57. 
Gopalakrishnan, V., et al. Gut microbiome modulates response to anti-PD-1 immunotherapy in 
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58. 
Matson, V., et al. The commensal microbiome is associated with anti-PD-1 efficacy in metastatic 
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59. 
Routy, B., et al. Gut microbiome influences efficacy of PD-1-based immunotherapy against 
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60. 
Alvarez-Mercado, A.I., et al. Microbial Population Changes and Their Relationship with Human 
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Fayfman, M., Flint, K. & Srinivasan, S. Obesity, Motility, Diet, and Intestinal Microbiota- 
Connecting the Dots. Curr Gastroenterol Rep 21, 15 (2019). 
62. 
Ticinesi, A., et al. Exercise and immune system as modulators of intestinal microbiome: 
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Gopalakrishnan, V., C, S., J, M. & al, e. The gut microbiome of metastatic melanoma patients 
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in Society for Immunotherapy of Cancer (Washington, DC, 2018). 

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APPENDIX A 
PERFORMANCE STATUS CRITERIA 
 
ECOG Performance Status Scale 
Karnofsky Performance Scale 
Grade 
Descriptions 
Percent 
Description 
0 
Normal activity. Fully active, able 
to carry on all pre-disease 
performance without restriction. 
100 
Normal, no complaints, no evidence 
of disease. 
90 
Able to carry on normal activity; 
minor signs or symptoms of disease. 
1 
Symptoms, but ambulatory. 
Restricted in physically strenuous 
activity, but ambulatory and able 
to carry out work of a light or 
sedentary nature (e.g., light 
housework, office work). 
80 
Normal activity with effort; some 
signs or symptoms of disease. 
70 
Cares for self, unable to carry on 
normal activity or to do active work. 
2 
In bed <50% of the time. 
Ambulatory and capable of all 
self-care, but unable to carry out 
any work activities. Up and about 
more than 50% of waking hours. 
60 
Requires occasional assistance, but 
is able to care for most of his/her 
needs. 
50 
Requires considerable assistance and 
frequent medical care. 
3 
In bed >50% of the time. Capable 
of only limited self-care, confined 
to bed or chair more than 50% of 
waking hours. 
40 
Disabled, requires special care and 
assistance. 
30 
Severely disabled, hospitalization 
indicated. Death not imminent. 
4 
100% bedridden. Completely 
disabled. Cannot carry on any 
self-care. Totally confined to bed 
or chair. 
20 
Very sick, hospitalization indicated. 
Death not imminent. 
10 
Moribund, fatal processes 
progressing rapidly. 
5 
Dead. 
0 
Dead. 

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APPENDIX B 
DF/HCC DATA-SAFETY MONITORING PLAN 
 
1 INTRODUCTION 
 
The Dana-Farber/Harvard Cancer Center Multi-Center Data and Safety Monitoring Plan (DF/HCC 
DSMP) outlines the procedures for conducting a DF/HCC Multi-Center research protocol. The DF/HCC 
DSMP serves as a reference for any sites external to DF/HCC that are participating in a DF/HCC clinical 
trial. 
 
1.1 
Purpose 
 
To establish standards that will ensure that a Dana-Farber/Harvard Cancer Center Multi-Center 
protocol will comply with Federal Regulations, Health Insurance Portability and Accountability Act 
(HIPAA) requirements and applicable DF/HCC Policies and Operations. 
 
2 GENERAL ROLES AND RESPONSIBILITIES 
 
For DF/HCC Multi-Center Protocols, the following general responsibilities apply, in addition to those 
outlined in DF/HCC Policies for Sponsor-Investigators: 
 
2.1 
Coordinating Center 
 
The general responsibilities of the Coordinating Center may include but are not limited to: 
• Assist in protocol development. 
• Maintain CTEP, FDA or OBA correspondence, as applicable. 
• Review registration materials for eligibility and register participants from Participating 
Institutions in the DF/HCC clinical trial management system (CTMS). 
• Distribute protocol and informed consent document updates to External Sites as needed. 
• Oversee the data collection process from External Sites. 
• Maintain documentation of Serious Adverse Event (SAE) reports and deviations/violation 
submitted by External Sites and provide to the DF/HCC Sponsor for timely review and 
submission to the IRB of record, as necessary. 
• Distribute serious adverse events reported to the DF/HCC Sponsor that fall under the reporting 
requirements for the IRB of record to all External Sites. 
• Provide External Sites with information regarding DF/HCC requirements that they will be 
expected to comply with. 
• Carry out plan to monitor External Sites either by on-site or remote monitoring. 
• Maintain Regulatory documents of all External Sites which includes but is not limited to the 
following: local IRB approvals/notifications from all External Sites, confirmation of 
Federalwide Assurances (FWAs) for all sites, all SAE submissions, Screening Logs for all 
sites, IRB approved consents for all sites 
• Conduct regular communications with all External Sites (conference calls, emails, etc) and 
maintain documentation all relevant communications. 

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2.2 
External Site 
 
An External Site is an institution that is outside the DF/HCC and DF/PCC consortium that is 
collaborating with DF/HCC on a protocol where the sponsor is a DF/HCC investigator. The External 
Site acknowledges the DF/HCC Sponsor as having the ultimate authority and responsibility for the 
overall conduct of the study. 
 
Each External Site is expected to comply with all applicable DF/HCC requirements stated within this 
Data and Safety Monitoring Plan and/or the protocol document. 
 
The general responsibilities for each External Site may include but are not limited to: 
• Document the delegation of research specific activities to study personnel. 
• Commit to the accrual of participants to the protocol. 
• Submit protocol and/or amendments to their IRB of record. For studies under a single IRB, the 
Coordinating Center will facilitate any study-wide submissions.. 
• Maintain regulatory files as per ICH GCP and federal requirements. 
• Provide the Coordinating Center with regulatory documents or source documents as requested. 
• Participate in protocol training prior to enrolling participants and throughout the trial as 
required. 
• Update Coordinating Center with research staff changes on a timely basis. 
• Register participants through the Coordinating Center prior to beginning research related 
activities when required by the sponsor. 
• Submit Serious Adverse Event (SAE) reports to sponsor, Coordinating Center, and IRB of 
record as applicable, in accordance with DF/HCC requirements. 
• Submit protocol deviations and violations to the Sponsor, Coordinating Center, and IRB of 
record as applicable. 
• Order, store and dispense investigational agents and/or other protocol mandated drugs per 
federal guidelines and protocol requirements. 
• Participate in any quality assurance activities and meet with monitors or auditors at the 
conclusion of a visit to review findings. 
• Promptly provide follow-up and/or corrective action plans for any monitoring queries or audit 
findings. 
• Notify the sponsor immediately of any regulatory authority inspection of this protocol at the 
External Site. 
3 DF/HCC REQUIREMENTS FOR MULTI-CENTER PROTOCOLS 
 
Certain DF/HCC Policy requirements apply to External Sites participating in DF/HCC research. The 
following section will clarify DF/HCC requirements and further detail the expectations for participating 
in a DF/HCC Multi-Center protocol. 
 
3.1 
Protocol Revisions and Closures 
 
The External Sites will receive notification of protocol revisions and closures from the Coordinating 
Center. When under a separate IRB, it is the individual External Site’s responsibility to notify its IRB 
of these revisions. 

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• Protocol revisions: External Sites will receive written notification of protocol revisions from 
the Coordinating Center. All protocol revisions should be IRB approved and implemented 
within a timely manner from receipt of the notification. 
• Protocol closures and temporary holds: External Sites will receive notification of protocol 
closures and temporary holds from the Coordinating Center. Closures and holds will be 
effective immediately. In addition, the Coordinating Center, will update the External Sites on 
an ongoing basis about protocol accrual data so that they will be aware of imminent protocol 
closures. 
3.2 
Informed Consent Requirements 
 
The DF/HCC approved informed consent document will serve as a template for the informed consent 
for External Sites. The External Site consent form must follow the consent template as closely as 
possible and should adhere to specifications outlined in the DF/HCC Guidance Document on Model 
Consent Language for Investigator-Sponsored Multi-Center Trials. This document will be provided 
separately to each External Site upon request. 
 
External Sites must send their version of the informed consent document to the Coordinating Center 
for sponsor review and approval. If the HIPAA authorization is a separate document, please submit to 
the sponsor for the study record. Once sponsor approval is obtained, the External site may submit to 
their IRB of record, as applicable. In these cases, the approved consent form must also be submitted to 
the Coordinating Center after approval by the local IRB for all consent versions. 
 
The Principal Investigator (PI) at each External Site will identify the appropriate members of the study 
team who will be obtaining consent and signing the consent form for protocols. External Sites must 
follow the DF/HCC requirement that for all interventional drug, biologic, or device research, only 
attending physicians may obtain initial informed consent and any re-consent that requires a full revised 
consent form. 
 
3.3 
IRB Re-Approval 
 
Verification of IRB re-approval for the External Sites is required in order to continue research activities. 
There is no grace period for continuing approvals. 
 
The Coordinating Center will not register participants if a re-approval letter is not received for the 
External Site on or before the anniversary of the previous approval date. 
 
3.4. 
DF/HCC Multi-Center Protocol Confidentiality 
 
All documents, investigative reports, or information relating to the participant are strictly confidential. 
Whenever reasonably feasible, any participant specific reports (i.e. Pathology Reports, MRI Reports, 
Operative Reports, etc.) submitted to the Coordinating Center should be de-identified. It is 
recommended that the assigned protocol case number be used for all participant specific documents. 
Participant initials may be included or retained for cross verification of identification. 

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3.5. 
Participant Registration and Randomization 
 
Refer to Protocol Section 4 for participant registration information. Treatment cannot begin until site 
has received confirmation that participant has been registered with DF/HCC CTMS. 
 
Registration can only occur during normal business hours, Monday through Friday from 8:00 AM to 
5:00 PM Eastern Standard Time. 
 
At the time of registration, the following identifiers are required for all subjects: initials, date of birth, 
gender, race and ethnicity. Once eligibility has been established and the participant successfully 
registered, the participant is assigned a unique protocol case number. Participating Institutions should 
submit all de-identified subsequent communication and documents to the Coordinating Center, using 
this case number to identify the subject. 
 
 
3.3.1 
Initiation of Therapy 
 
Participants must be registered with the DF/HCC CTMS before the initiation of treatment or other 
protocol-specific interventions. Treatment and other protocol-specific interventions may not be 
initiated until the External Site receives confirmation of the participant’s registration from the 
Coordinating Center. The DF/HCC Sponsor and IRB of record must be notified of any violations to 
this policy. 
 
3.3.2 
Eligibility Exceptions 
 
No exceptions to the eligibility requirements for a protocol without IRB approval will be permitted. All 
External Sites are required to fully comply with this requirement. The process for requesting an 
eligibility exception is defined below. 
 
3.5. 
Data Management 
DF/HCC develops case report forms (CRF/eCRFs), for use with the protocol. These forms are 
designed to collect data for each study. DF/HCC provides a web based training for all eCRF users. 
 
3.5.1. Data Forms Review 
 
Data submissions are monitored for timeliness and completeness of submission. If study forms are 
received with missing or questionable data, the submitting institution will receive a written or electronic 
query from the DF/HCC Office of Data Quality, Coordinating Center, or designee. 
 
Responses to all queries should be completed and submitted within 14 calendar days. 
 
If study forms are not submitted on schedule, the External Sites will periodically receive a Missing 
Form Report from the Coordinating Center noting the missing forms. 

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3.6. 
Protocol Reporting Requirements 
 
3.6.1. Protocol Deviations, Exceptions and Violations 
 
Federal Regulations require an IRB to review proposed changes in a research activity to ensure that 
researchers do not initiate changes in approved research without IRB review and approval, except 
when necessary to eliminate apparent immediate hazards to the participant. DF/HCC requires all 
departures from the defined procedures set forth in the IRB approved protocol to be reported to the 
DF/HCC Sponsor and to the IRB of record. 
 
3.6.2. Reporting Procedures 
 
Requests to deviate from the protocol require approval from the IRB of record and the sponsor. 
 
All protocol violations must be sent to the Coordinating Center in a timely manner. The Coordinating 
Center will provide training for the requirements for the reporting of violations. 
 
3.6.3. Guidelines for Processing IND Safety Reports 
 
The DF/HCC Sponsor will review all IND Safety Reports per DF/HCC requirements, and ensure that 
all IND Safety Reports are distributed to the External Sites as required by DF/HCC Policy. External 
Sites will review/submit to the IRB according to their institutional policies and procedures. 
 
4. MONITORING: QUALITY CONTROL 
 
 
The Coordinating Center, with the aid of the DF/HCC Office of Data Quality, provides quality control 
oversight for the protocol. 
 
4.4. Ongoing Monitoring of Protocol Compliance 
 
The External Sites may be required to submit participant source documents to the Coordinating Center 
for monitoring. External Sites may also be subject to on-site monitoring conducted by the Coordinating 
Center. 
 
The Coordinating Center will implement ongoing monitoring activities to ensure that External Sites are 
complying with regulatory and protocol requirements, data quality, and participant safety. Monitoring 
practices may include but are not limited to source data verification, and review and analysis of 
eligibility requirements, informed consent procedures, adverse events and all associated 
documentation, review of study drug administration/treatment, regulatory files, protocol departures 
reporting, pharmacy records, response assessments, and data management. 
 
Additionally, a plan will be formulated to provide regular and ongoing communication to 
Participating Institutions about study related information which will include participation 
in regular Coordinating Center initiated teleconferences. Teleconferences will occur monthly and will 
continue regularly until completion of accrual. Frequency of teleconferences may be adjusted based 

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on rate of accrual. Upon completion of accrual, teleconferences will occur monthly until all patients 
complete protocol therapy. Upon completion of protocol therapy, teleconferences will occur on an as 
needed basis until study completion. Additional communication may be distributed via “Newsletter” 
or email as deemed appropriate by DF/HCC Sponsor. 
 
On-Site Monitoring: On-site monitoring will occur on an as-needed basis. Participating Institutions 
will be required to provide access to participants’ complete medical record and source documents for 
source documentation verification during the visit. In addition, Participating Institutions should provide 
access to regulatory documents, pharmacy records, local policies related to the conduct of research, and 
any other trial-related documentation maintained by the Participating Site. On-site monitoring visits can 
be substituted with remote (virtual) monitoring visits at the discretion of the Principal Investigator. 
 
Remote Monitoring: Remote monitoring will be performed on an as-needed basis by the Clinical Trial 
Monitor. Sites will be asked to provide source documentation via fax, email, or mail as specified by the 
Clinical Trial Monitor for virtual monitoring. 
 
4.5. Monitoring Reports 
 
The DF/HCC Sponsor will review all monitoring reports to ensure protocol compliance. The DF/HCC 
Sponsor may increase the monitoring activities at External Sites that are unable to comply with the 
protocol, DF/HCC Sponsor requirements or federal and local regulations. 
 
4.6. Accrual Monitoring 
 
Prior to extending a protocol to an external site, the DF/HCC Sponsor will establish accrual 
requirements for each External Site. Accrual will be monitored for each External Site by the DF/HCC 
Sponsor or designee. Sites that are not meeting their accrual expectations may be subject to 
termination. 
 
A minimum of 3 participants per site annually is recommended for Phase II trials. However, given the 
additional regulatory burden and cost of overseeing each site, a consideration of 5 participants per site 
should be a minimum target. 
 
 
5. AUDITING: QUALITY ASSURANCE 
 
5.4. DF/HCC Internal Audits 
 
All External Sites are subject to audit by the DF/HCC Office of Data Quality (ODQ). Typically, 
approximately 3-4 participants would be audited at the site over a 2-day period. If violations which 
impact participant safety or the integrity of the study are found, more participant records may be 
audited. 
 
5.5. Audit Notifications 

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It is the External Site’s responsibility to notify the Coordinating Center of all external audits or 
inspections (e.g., FDA, EMA, NCI) that involve this protocol. All institutions will forward a copy of 
final audit and/or re-audit reports and corrective action plans (if applicable) to the Coordinating Center, 
within 12 weeks after the audit date. 
 
5.6. Audit Reports 
 
The DF/HCC Sponsor will review all final audit reports and corrective action plans, if applicable. The 
Coordinating Center must forward any reports to the DF/HCC ODQ per DF/HCC policy for review by 
the DF/HCC Audit Committee. For unacceptable audits, the DF/HCC Audit Committee would forward 
the final audit report and corrective action plan to the IRB as applicable. 
 
5.7. External Site Performance 
 
The DF/HCC Sponsor and the IRB of record are charged with considering the totality of an institution’s 
performance in considering institutional participation in the protocol. 
 
External Sites that fail to meet the performance goals of accrual, submission of timely and accurate 
data, adherence to protocol requirements, and compliance with state and federal regulations, may be 
put on hold or closed. 

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APPENDIX C 
DIET AND PHYSICAL ACTIVITY ASSESSMENTS 
Please note: the below is a copy of the Block Fat/Sugar/Fruit/Vegetable Screener for reference. Please 
use the official Scantron version of the Screener rather than the appendix. 
 

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APPENDIX D 
DIET AND PHYSICAL ACTIVITY ASSESSMENTS 
Below is a copy of the Gordin Leisure-Time Exercise Questionnaire (LSI) with three additional 
questions about fiber intake from the Block Vegetable/Fruit/Fiber Screener. 
 

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APPENDIX E 
STOOL QUESTIONNAIRE 
 
Breast Cancer Stool Collection Questionnaire 
 
Subject ID: 
Date collected  
/ 
/ 
 
Month 
Day 
Year 
o am 
Hour collected  
 o pm 
 
1. 
Based on the small chart included in the postcard, what did the stool you put into the tube look like? 
(Choose one or two answers). 
 

 
 
 
2. 
Prior to this collection, when was your last bowel movement? 
 
Earlier today, in 
the last 6 hours 
Earlier today, more 
than 6 hours ago 
Yesterday 
Two days 
ago 
More than two 
days ago 
 
 
 
 
 
 
 
 
 
 
3. 
In the past 2 months, how often have you had a bowel movement and what was the 
frequency of stool with the following textures? 
More than 
twice per day 
Twice 
per day 
Once 
per day 
Every 
other day 
Every 3-6 
days 
Once a 
week or 
less 
Never 
Any bowel movement 
 
 
 
 
 
 
Stool texture (The answers can be different from the above) 
Hard / lumpy 
Soft / smooth 
Watery liquid 
 
 
 
 
4. 
In the past 2 months, have you used any of the following medications? 
No 
Yes, 
occasionally 
Yes, regularly 
Oral antibiotics 
 
 
 
If yes, what is the name (list of used)? 
Injected antibiotics 
 
 
 
If yes, what is the name (list of used)? 
Prilosec, Nexium, Prevacid (Iansoprazole), Protonix, 
Aciphex 
 
 
 
H2 blocker: Pepcid, Tagamet, Zantac, Axid 
 
 
 
 
5. 
In the past 2 months, have you used any medications modifying bile production, 
including (but not limited to): Cholesytramine (e.g. Questran, Prevalite, Locholest), 
colestipol (e.g, colestid), colesevelam (e.g. Welchol), chenodeoxycholic acids (e.g. 
CDCA), or 
ursodeoxycholic acid (e.g. UDCA, Ursodiol, Actigall)? 
 
No 
Yes, occasionally 
Yes, regularly 
 
 
 
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In the past 2 months, have you undergone a colonoscopy or other procedure requiring 
bowel preparation? 
No 
Yes 
 
7. 
In the past week, have you taken (or eaten) any of the following? If so, please specify the 
frequency. 
Not 
used 
Once 
or 
twice 
Three 
to six 
times 
Daily 
More than 
once per 
day 
Fiber substitute, such as Metamucil, Konsyl or Citracel 
Laxatives, such as Ex-lax, Dulcolax, MiraLax, Senna, or 
enema 
Stool softener, such as Colace 
Probiotic supplements 
Yogurt or kefir 
Other fermented foods, such as sauerkraut or kombucha 
 
8. 
In the past 6 months, did you gain or lose weight? 
No 
Gained ≤5 lbs. 
Gained >5 lbs. 
Lost ≤5 lbs. 
Lost >5 lbs. 
 
 
 
 
 
 
9. 
Did you have any problems or concerns with the stool sample collection, for example the 
solution spilled out of the tube or you had problems with catching stool in the toilet 
accessory? (Please describe) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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