Open-Label, Multicenter, Phase 1 Study to Assess the Safety of P BCMA-101 in Subjects With Relapsed / Refractory Multiple Myeloma (MM) Followed by a Phase 2 Assessment of Response and Safety (PRIME)
Phase: PHASE1
Conditions: Multiple Myeloma
Sponsor: Poseida Therapeutics, Inc.

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 1 of 117 
 
 
Poseida Therapeutics, Inc. 
 
 
Open-Label, Multicenter, Phase 1 Study to Assess the Safety of 
P-BCMA-101 in Subjects with Relapsed / Refractory Multiple 
Myeloma (MM) Followed by a Phase 2 Assessment of Response and 
Safety (PRIME) 
 
PROTOCOL NUMBER P-BCMA-101-001 A5 
AMENDMENT 5 
 
 
 
PROTOCOL DATE  
ORIGINAL: 14 MARCH 2017 
AMENDMENT 1: 26 JULY 2017 
AMENDMENT 2: 03 APRIL 2018 
AMENDMENT 3: 24 JANUARY 2019 
AMENDMENT 4: 06 MARCH 2019 
AMENDMENT 5: 20 SEPTEMBER 2019 
 
 
CONFIDENTIALITY STATEMENT 
The information contained in this document is confidential and is the property of Poseida 
Therapeutics, Inc. No part of it may be transmitted, reproduced, published, or used by anyone 
without the written permission of Poseida Therapeutics, Inc. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 2 of 117 
INVESTIGATOR PROTOCOL AGREEMENT PAGE 
 
Protocol Title: Open-Label, Multicenter, Phase 1 Study to Assess the Safety of P-BCMA-101 in 
Subjects with Relapsed / Refractory Multiple Myeloma (MM) Followed by a Phase 2 
Assessment of Response and Safety (PRIME) 
 
I, the undersigned, have reviewed the protocol, including the appendices, and I will conduct the 
clinical study as described and will adhere to the current International Conference on 
Harmonisation (ICH) “Guideline for Clinical Practice” (GCP) and all the ethical and regulatory 
considerations stated or any applicable local laws.  
 
Investigator Name 
 
Investigator Title 
 
Investigator Site and Address 
 
Investigator Signature 
 
Date 
 
 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 3 of 117 
CLINICAL STUDY PROTOCOL 
 
Title: Open-Label, Multicenter, Phase 1 Study to Assess the Safety of P-BCMA-101 in Subjects 
with Relapsed / Refractory Multiple Myeloma (MM) Followed by a Phase 2 Assessment of 
Response and Safety (PRIME) 
Product Name: P-BCMA-101 
Protocol Number: P-BCMA-101-001 A5 
Regulatory Agency Identifying Number:  
 
DATE OF ORIGINAL PROTOCOL: 14-MAR-2017 
 
Amendment Number 
Date 
1 
26 July 2017 
2 
03 April 2018 
3 
24 January 2019 
4 
06 March 2019 
5 
20 September 2019 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 4 of 117 
SYNOPSIS… 
Title: 
Open-Label, Multicenter, Phase 1 Study to Assess the Safety of P-BCMA-101 in 
Subjects with Relapsed / Refractory Multiple Myeloma (MM) Followed by a Phase 
2 Assessment of Response and Safety (PRIME) 
Study Number: 
P-BCMA-101-001 
Phase: 
Phase 1 / 2 
Name of 
Investigational 
Product: 
P-BCMA-101 and Rimiducid 
Autologous CAR-T Cells Engineered to Contain an Anti-B-Cell Maturation 
Antigen (BCMA) Centyrin Coupled to TCR ζ and 4-1BB Signaling Domains 
(CARTyrin) 
Brief 
Description of 
Investigational 
Product:  
P-BCMA-101 is comprised of T cells genetically modified using an 
electroporation-based, non-viral (DNA transposon) gene delivery system called the 
piggyBac™ (PB) DNA modification system, which efficiently moves DNA from a 
plasmid to a chromosome via a "cut and paste" mechanism. Compared to lentivirus 
or –retrovirus transduction, PB offers advantages, including a safer insertion 
profile, higher levels of transgene expression, stable and longer duration transgene 
expression, and a highly enriched, favorable T stem cell memory (Tscm) 
phenotype.  
P-BCMA-101 cells are autologous T cells harvested from the subject 
 
 
 
Test Product, 
Dose, Route of 
Administration: 
Phase 1: Single Administration- dose levels of P-BCMA-101 administered 
intravenously as a single dose. Dose levels will be tested by cohort in the 3+3 
escalation design described in the Study Design.  
Phase 1: Cycle Administration- multiple doses of P-BCMA-101 administered 
intravenously in 2 cycles (Cohort A and Cohort C) or 3 cycles (Cohort B) of 2 
weeks each. The total dose administered will follow the 3+3 design starting at ≤ the 
maximum tolerated dose (MTD) as determined during single dose escalation. In the 
first cycle for both Cohorts A and B, 1/3 the total dose will be administered. In 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 5 of 117 
Cohort A up to 2/3 the total dose will be administered in the 2nd cycle. In Cohort B 
up to 1/3 the total dose will be administered in each of the 2nd and 3rd cycles. In 
Cohort C up to 2/3 the total dose will be administered in the 1st cycle and up to 1/3 
the total dose will be administered in the 2nd cycle. 
Phase 1: Combination Administration- P-BCMA-101 will be administered in 
combination with approved therapies: lenalidomide (Cohort R: 
before P-BCMA-101 infusion; and 
Cohort RP: 
before apheresis 
before P-BCMA-101 infusion) and rituximab (Cohort 
RIT: 
The dose of P-BCMA-101 administered will follow the 3+3 design starting at ≤ the 
MTD as determined during dose escalation. 
Phase 2: P-BCMA-101 administered intravenously as a total dose of 6-15 × 106 
cells/kg. 
Rimiducid may be administered intravenously at 0.4 mg/kg if clinically indicated. 
Subjects who meet the criteria in Section 15.4 may be eligible to receive another 
infusion of P-BCMA-101. 
Reference 
Therapy: 
None 
Objectives 
Endpoints 
Primary: 
The primary objective of this study is: 
Phase 1: 
To determine the safety and maximum 
tolerated dose (MTD) of P-BCMA-101 
based on dose limiting toxicities (DLT)  
Phase 2: 
To assess the safety and efficacy of P-
BCMA-101 
Primary: 
Phase 1: 
Number of subjects with DLT at each dose level to 
define an MTD 
Phase 2: 
• 
Safety and tolerability based on adverse events 
(AEs), examinations, and standard laboratory studies 
• 
Overall response rate (ORR) and duration of 
response (DOR) by International Myeloma Working 
Group Criteria (Kumar, 2016) as assessed by an 
independent review committee (IRC) 
Secondary: 
Secondary objectives of this study are to 
evaluate: 
Phase 1: 
• 
The safety and feasibility of P-BCMA-
101  
• 
The anti-myeloma effect of P-BCMA-
101  
• 
The effect of cell dose to guide 
selection of doses for further 
assessment in Phase 2/3 studies 
Phase 2: 
• 
Incidence and severity of cytokine 
release syndrome (CRS) 
Secondary: 
The following secondary endpoints will be evaluated: 
Phase 1: 
• 
Ability to generate protocol-proscribed doses of P-
BCMA-101 
• 
Safety and tolerability based on AEs, examinations, 
and standard laboratory studies 
• 
CRS graded using Lee criteria (Lee, 2014) 
• 
Efficacy based on International Myeloma Working 
Group (IMWG) Uniform Response Criteria 
(Rajkumar, 2011; Kumar 2016; Cavo, 2017) 
o Overall response rate (ORR) 
o Time to response (TTR) 
o Duration of response (DOR) 
o Progression free survival (PFS) 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 6 of 117 
• 
Additional efficacy endpoints 
o Overall survival (OS) 
Phase 2: 
• 
CRS graded using Lee criteria (Lee, 2014) 
• 
Rate of IL-6 antagonist, corticosteroid, and 
rimiducid use 
• 
OS, PFS, TTR, minimal residual disease (MRD) 
negative rate 
 
Subject 
Population and 
Number 
Adults with confirmed relapsed / refractory MM.  
Up to approximately 120 subjects are planned for Phase 1. 
Approximately 100 evaluable subjects will be treated in Phase 2.  
Study Centers 
Up to 20 sites are planned for the study. 
Study Design 
The study will be conducted in multiple parts, a Phase 1, open-label, single 
ascending dose (SAD) phase; a Phase 1, multiple dose, cycle administration phase; 
a Phase 1, combination administration with lenalidomide or rituximab phase; and a 
Phase 2, open-label, efficacy and safety phase, in adult subjects with relapsed / 
refractory MM. 
Only sites that are experienced in managing oncology subjects and stem-cell/bone 
marrow transplant with the resources to manage the types of acute emergent events 
expected with chimeric antigen receptor (CAR)-T cell administration will be 
selected to participate in this study. A Safety Committee will meet regularly to 
review data throughout the study. 
Subjects meeting the protocol entry criteria will be eligible to enroll in the study. 
After a subject enrolls, leukapheresis will be performed to obtain peripheral blood 
mononuclear cells (PBMCs) which will be sent to a manufacturing site to produce 
P-BCMA-101 CARTyrin-T cells. The cells will then be returned to the 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 7 of 117 
investigational site and, after a standard chemotherapy-based conditioning regimen, 
will be administered to the subject as described below. 
Phase 1: 
Phase 1 of the study is comprised of an open-label, multi-center, single ascending 
dose (SAD), multiple cohort study; a multiple dose cycle administration cohort 
study; and a combination administration study, in up to approximately 120 adult 
subjects. Phase 1 of the study will follow a 3 + 3 design of dose-escalating cohorts, 
wherein 3 subjects are initially planned to be dosed with P-BCMA-101 T cells for 
each cohort (Table 1). The Safety Committee may recommend enrollment of 
additional subjects in a cohort to further evaluate the outcomes observed at that 
dose level. For each of the first 2 cohorts, dosing of the first 3 subjects will be 
staggered. If Grade 3-related toxicity, CRS, or DLT is reported, the Safety 
Committee will review the data and determine whether to proceed to the next 
subject. The Safety Committee will review the data at the end of each cohort to 
determine progression to the next cohort. At the discretion of the Safety 
Committee, beginning with the 3rd cohort, dosing of the first and second subject in 
each cohort will be staggered.  
DLT is defined as any National Cancer Institute – Common Terminology Criteria 
for Adverse Events (NCI CTCAE) Grade ≥3 event at least possibly related to P-
BCMA-101, including uncontrollable expansion of P-BCMA-101 cells, and not 
attributable to the underlying disease or lymphodepleting chemotherapy regimen 
with onset within the first 28 days following the last P-BCMA-101 infusion with 
the following exceptions: 
• 
Grade 3 or 4 neutropenia with or without neutropenic fever resolving within 28 
days following the last P-BCMA-101 cell infusion 
• 
Grade 3 fever 
• 
Grade 3 or 4 thrombocytopenia, with or without bleeding due to 
thrombocytopenia, resolving within 28 days following the last P-BCMA-101 
cell infusion  
• 
Grade 3 or 4 anemia and lymphopenia 
• 
Grade 3 or 4 hypogammaglobulinemia 
• 
Alopecia 
• 
Grade 3 or 4 nausea, vomiting or diarrhea which responds to medical treatment 
within 24 hours 
• 
Immediate hypersensitivity reactions (fever, rash, bronchospasm) occurring 
within 2 hours of cell infusion (related to cell infusion) that are reversible to a 
Grade 2 or less within 6 hours of cell administration with standard 
antihistamine-based therapy 
• 
Grade 3 encephalopathy that recovers to less than Grade 2 within 28 days 
• 
Grade 3 CRS per Lee criteria (Lee, 2014) that resolves within 14 days 
• 
Grade 3 non-hematological laboratory abnormalities that recover to ≤Grade 2 
in 14 days 
• 
Grade 4 non-hematological laboratory abnormalities that recover to ≤Grade 2 
in 7 days 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 8 of 117 
Table 1: 
Dose Escalation Guidelines 
Outcome:  
(# subjects with DLT) 
Action:  
0 out of 3 subjects 
Escalate dose for next cohort of 3 subjects 
1 out of 3 subjects 
Treat next 3 subjects at the same dose 
≥2 out of 3 subjects 
Halt dose escalation; treat at least 6 subjects at a 
lower dose to determine the MTD1 
1 out of 6 subjects 
Escalate dose for next cohort of 3 subjects 
≥2 out of 6 subjects  
Halt dose escalation; treat at least 6 subjects at a 
lower dose to determine the MTD1 
1. MTD – the highest dose for which no more than 1 of 6 treated subjects exhibits 
DLT 
 
The 3 + 3 dose escalation will be conducted as follows, with the Safety Committee 
reviewing the data at the end of each cohort to determine the outcome. Beginning 
with Cohort 1, at least 3 subjects will be dosed in the cohort. If no DLT through 
Day 28 after last dose is observed in the first 3 subjects, then escalation may 
proceed to the next cohort. If DLT is observed in 1 of the first 3 subjects, then at 
least 3 additional subjects will be treated at this dose level. If no further DLT is 
observed, escalation may proceed. If DLTs are observed in 2 or more of 3 or 6 
subjects, the MTD will be considered to be at the next lower dose level and further 
enrollment may take place at a lower dose level, or an intermediate dose level may 
be tested at the discretion of the Safety Committee. In the event that 2 or more 
subjects experience DLTs in Cohort 1, the Safety Committee, after reviewing 
available data, may elect to dose 3 subjects in Cohort -1 with the same 3 + 3 
expansion rules. In the event that 2 or more subjects experience DLTs in Cohort -1, 
the Safety Committee, based on consideration of safety and efficacy data to assess 
risk vs. benefit, may elect to dose 3 subjects at a lower dose with the same 3 + 3 
expansion rules or discontinue the study. 
Proposed Doses (P-BCMA-101 cells/kg/dose) include: 
 Cohort minus 1:  
0.25 × 106 
 
Cohort 1:  
0.75 × 106  
 
Cohort 2:  
2 × 106 
 
Cohort 3: 
6 × 106  
 
Cohort 4:  
10 × 106 
 
Cohort 5:  
15 × 106 
Additional subjects may be dosed in a cohort at the direction of the Safety 
Committee based on the safety and efficacy data from that cohort to further 
evaluate the effects of P-BCMA-101, provided the dose does not exceed the MTD. 
If Cohort 5 is completed without concluding an overall MTD, the Safety 
Committee may elect to assess further escalation cohorts in 5-10 × 106 P-BCMA-
101 cells/kg increments. 
Phase 1 – Single Dose Administration: 
In the Phase 1 single dose administration portion of the study, a single dose P-
BCMA-101 will be administered once intravenously. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 9 of 117 
Phase 1 – Cycle Administration: 
In the Phase 1 cycle dose administration portion of the study, multiple doses of P-
BCMA-101 will be administered intravenously in 2 cycles (Cohort A and Cohort 
C) or 3 cycles (Cohort B) of 2 weeks each. The total dose administered will follow 
the 3+3 design starting at ≤ the MTD as determined during single dose escalation. 
In the first cycle for both Cohorts A and B, 1/3 the total dose will be administered. 
In Cohort A up to 2/3 the total dose will be administered in the 2nd cycle. In Cohort 
B up to 1/3 the total dose will be administered in each of the 2nd and 3rd cycles. In 
Cohort C up to 2/3 the total dose will be administered in the 1st cycle and up to 1/3 
the total dose will be administered in the 2nd cycle. The same 3+3 dose escalation 
and/or de-escalation rules described for single administration will be utilized 
These procedures are detailed in Section 15.5. 
Phase 1 – Combination Administration: 
P-BCMA-101 will be administered in combination with approved therapies: 
lenalidomide (Cohort R and Cohort RP) and rituximab (Cohort RIT). The dose of 
P-BCMA-101 administered will follow the 3+3 design starting at ≤ the MTD as 
determined during dose escalation. The same 3+3 dose escalation and/or de-
escalation rules described for single administration will be utilized. These 
procedures are detailed in Section 15.6. 
Phase 2: 
Phase 2 of the study is an open-label, multi-center study in approximately 100 adult 
subjects with relapsed and/or refractory MM. Subjects will receive a total dose of 
6-15 × 106 cells/kg (per the schedule determined in Phase 1). 
Study visits  
Treated subjects in Phase 1 and Phase 2 will undergo serial measurements of safety, 
tolerability and response (myeloma staging). These measures will be obtained at 
Screening, Enrollment or Baseline Visit and the Conditioning Chemotherapy 
Period. The P-BCMA-101 Administration Period and follow-up visits in both Phase 
1 and Phase 2 will be at Day 10, Week 2, 3, 4, 6, 8, Month 3, 4, 5, 6, 7, 8, 9, and 
then every 3 months thereafter for up to 24 months after P-BCMA-101 
administration. After completing or withdrawing from this protocol, consenting 
subjects who have received P-BCMA-101 should enroll in a separate protocol that 
allows for continued follow-up for a total of 15 years after last dosing to evaluate 
long-term safety. 
Screening Visit  
Consented subjects will undergo a Screening Visit to determine eligibility. Subjects 
who meet all the inclusion criteria and none of the exclusion criteria will return for 
the Enrollment and Leukapheresis Visits.  
Enrollment Visit 
Eligible subjects will return for an Enrollment visit to provide samples and 
measurements that must be collected in advance of Leukapheresis. Enrollment 
assessments are to be conducted 14 days (± 3 days) prior to Leukapheresis or have 
medical monitor approval. 
Leukapheresis Visit  
Eligible subjects who enroll will return and undergo leukapheresis to obtain 
PBMCs for P-BCMA-101 manufacturing. This visit should occur within ~28 days 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 10 of 117 
of the Screening Visit. Once the product is manufactured, subjects will return for 
the combination therapy (if applicable), Conditioning Chemotherapy and P-BCMA-
101 cell Administration Periods approximately 4 weeks after the Leukapheresis 
Visit. If P-BCMA-101 cells that meet release criteria cannot be manufactured from 
the leukapheresis sample, a second leukapheresis and manufacturing may be 
attempted. If the second attempt also fails, the subject will be withdrawn from the 
study and considered not to have undergone study treatment.  
Subjects who experience rapid disease progression following the Leukapheresis 
Visit and prior to the Conditioning Chemotherapy and P-BCMA-101 cell 
Administration Period may be administered salvage therapy at the discretion of the 
Investigator. Salvage therapy should not be used unless necessary and will be 
determined by the subject’s clinical history (previously used agents are preferred, 
and medical monitor approval needed) at the discretion of the Investigator. If a 
subject receives salvage therapy, the Conditioning Chemotherapy and P-BCMA-
101 cell Administration Period should be scheduled at least 2 weeks or 5 half-lives 
after the date of the last treatment of salvage therapy and the subject should meet 
the criteria described in Sections 4 and 6 regarding entry criteria (including those 
for measurable MM) and concomitant medications. The subject’s response to the 
salvage therapy will be evaluated by the Investigator and medical monitor to 
determine whether the subject will remain eligible to receive the Investigational 
Product.  
Subjects will be permitted to receive radiation therapy or plasmapheresis and 
exchange for palliative purposes throughout the study period. 
Baseline Visit (Day -12 to Day -6) 
Once the product is manufactured, during the week prior to starting Conditioning 
Chemotherapy, subjects will return for Baseline assessments and to confirm 
continued eligibility. The following assessments should be repeated within 72 hours 
prior to Day -5: Mini Mental Status Exam (MMSE), physical exam, vital signs, 
chemistry panel including electrolytes and magnesium, hematology including B 
and T cell counts, coagulation, assessment of circulating myeloma/plasma cells, 
and pregnancy test (if applicable). A baseline myeloma response assessment must 
be conducted within 7 days of initiating conditioning chemotherapy and 
combination therapy. The baseline Fresh Sample of Bone Marrow and Tumor is not 
used to confirm eligibility and the 7-day window is intended to provide flexibility 
for subjects and investigators; if a new bone marrow biopsy/aspirate was performed 
and provided during Screening, this does not need to be repeated during the 
Baseline visit. 
Conditioning Chemotherapy and P-BCMA-101 Cell Administration Period  
Before dosing with the P-BCMA-101 cell infusion, subjects will receive a 
conditioning lymphodepletion chemotherapy regimen of 300 mg/m2 of 
cyclophosphamide and 30 mg/m2 of fludarabine, with each chemotherapy agent 
given intravenously daily for 3 consecutive days (Day -5 through Day -3). Subjects 
should continue to meet entry criteria at the time of initiation of conditioning 
chemotherapy or have medical monitor approval. For subjects in Cohort R, Cohort 
RP and Cohort RIT, the combination therapy should be administered prior to 
conditioning chemotherapy on applicable days. 
After 2 rest days following the lymphodepletion chemotherapy regimen, subjects 
will be dosed with P-BCMA-101 administered intravenously over approximately 5 
to 20 mins (Day 0) (subjects should be pre-medicated with acetaminophen and 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 11 of 117 
diphenhydramine). Prior studies conducted with CAR-T therapies have observed 
peak toxicity to occur within 3-7 days of investigational product administration. 
Study subjects will be closely monitored during and after the infusion and for 
approximately 7 days afterwards. This observation period will include serial 
assessments of AEs, including the emergence of P-BCMA-101 cell-related 
toxicities, such as CRS, for all subjects. CRS will be graded using the Lee criteria 
(Lee, 2014). Guidance regarding grading and management of AEs can be found in 
Section 8 of this protocol and in the Study Reference Manual. Guidance for the use 
of rimiducid for significant P-BCMA-101-related toxicity can be found in Section 
15.3 and the Study Reference Manual. 
Subjects may be admitted to the hospital for the P-BCMA-101 administration if the 
Investigator deems appropriate based on an individual patient’s risks. Admission is 
not required, but subjects should remain within 50 miles of the hospital through 
approximately 14 days after last dose of P-BCMA-101 and assessed for admission 
in case of symptoms of CRS or neurotoxicity such as fever. If admitted, subjects 
will not be discharged until they are assessed as stable by the Investigator. Subjects 
may be maintained as an inpatient before P-BCMA-101 administration during 
lymphodepleting chemotherapy or after the above criteria are met as the 
Investigator deems appropriate. 
Follow up visits: 
Day 10, Week 2, 3, 4, 6, 8, Month 3, 4, 5, 6, 7, 8, 9, 12, 15, 18, 21 and 24. 
Subjects will return for regular follow up after last dose of P-BCMA-101 and will 
undergo serial assessment of safety, tolerability and anti-myeloma response as 
specified in the Schedule of Events. 
Repeat Administration: 
If sufficient P-BCMA-101 cells remain from manufacturing when a subject’s 
disease progresses, with Safety Committee approval additional cells may be 
administered up to the highest dose level that has successfully completed dose-
limiting toxicity assessment. In order to receive an additional P-BCMA-101 T-cell 
infusion, subjects will be assigned a new subject identification number, they will 
have to meet all eligibility criteria as described for the initial dosing, and will 
undergo the same screening, enrollment, conditioning chemotherapy, and follow-up 
procedures except for leukapheresis. Retreatment procedures are outlined in 
Section 15.4. 
Safety 
Monitoring 
A Safety Committee comprised of the Investigators and a clinical representative of 
the sponsor will be established and will review data regularly for all subjects and 
for each cohort to determine dose escalation and enrollment.  
Inclusion 
Criteria 
1. Must have signed written, informed consent. 
2. Males or females, ≥18 years of age. 
3. Must have a confirmed diagnosis of active MM as defined by the IMWG 
criteria at initial diagnosis (Rajkumar, 2014). 
4. Must have measurable MM as defined by at least 1 of the following criteria: 
Phase 1: 
• 
Serum M-protein greater or equal to 0.5 g/dL (5 g/L) 
• 
Urine M-protein greater or equal to 200 mg/24 h 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 12 of 117 
• 
Serum free light chain (FLC) assay: involved FLC level greater or equal 
to 10 mg/dL (100 mg/L) provided serum FLC ratio is abnormal 
• 
Bone marrow plasma cells >30% of total bone marrow cells, or other 
measurable bone disease (e.g., plasmacytomas measurable by PET or CT) 
(with medical monitor approval) 
Phase 2: 
• 
Serum M-protein greater or equal to 1.0 g/dL (10 g/L) 
• 
Urine M-protein greater or equal to 200 mg/24 h 
• 
Serum FLC assay: involved FLC level greater or equal to 10 mg/dL (100 
mg/L) provided serum FLC ratio is abnormal 
5. Must have relapsed / refractory MM as defined by the following: 
Phase 1: 
• 
Received at least 3 prior lines of therapy, which must have contained a 
proteasome inhibitor and immunomodulatory agent (IMiD) 
 OR 
• 
Received at least 2 prior lines of therapy if "double-refractory" to a 
proteasome inhibitor and IMiD, defined as progression on or within 60 
days of treatment with these agents. 
Phase 2: 
• 
Received at least 3 prior lines of therapy which must have contained a 
proteasome inhibitor, an IMiD, and CD38 targeted therapy with at least 2 
of the prior lines in the form of triplet combinations, and undergone ≥2 
cycles of each line unless PD was the best response. 
AND 
• 
Refractory to the most recent line of therapy. 
AND 
• 
Undergone ASCT or not be a candidate for ASCT. 
Note: induction therapy, autologous stem cell transplant (ASCT), and 
maintenance therapy, if given sequentially without intervening 
progression, should be considered as single line. 
6. Must be willing to practice birth control from the time of Screening and 
throughout the study (both males and females of childbearing potential).  
• 
Females on cohorts R, RP or RIT must commit either to abstain 
continuously from sexual intercourse or to use two methods of reliable 
birth control, beginning 4 weeks prior to initiating treatment, during 
therapy, during dose interruptions and continuing for 4 weeks following 
discontinuation of lenalidomide and 12 months after last dose of 
rituximab. 
• 
Males in cohort R or RP must always use a latex or synthetic condom 
during any sexual contact with females of reproductive potential while 
taking lenalidomide and for up to 4 weeks after discontinuing 
lenalidomide, even if they have undergone a successful vasectomy. Male 
patients taking lenalidomide must not donate sperm. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 13 of 117 
7. Must have a negative serum pregnancy test at Screening and a negative urine 
test within 3 days prior to initiating the lymphodepletion chemotherapy 
regimen (females of childbearing potential).  
• 
Female subjects in cohort R and RP must have two negative pregnancy 
tests prior to initiating lenalidomide. The first test should be performed 
within 10-14 days and the second test within 24 hours prior to subject 
starting lenalidomide therapy and then weekly during the first month, 
then monthly thereafter in females with regular menstrual cycles or every 
2 weeks in females with irregular menstrual cycles. 
8. Must be at least 90 days since autologous stem cell transplant, if performed. 
9. Must have adequate vital organ function, defined as follows (or medical 
monitor approval): 
• 
Serum creatinine ≤2.0 mg/dL and estimated creatinine clearance ≥30 
mL/min as calculated using the Cockcroft-Gault formula and not dialysis-
dependent. 
• 
Absolute neutrophil count ≥1000/μL and platelet count ≥50,000/μL 
(≥30,000/μL if bone marrow plasma cells are ≥50% of cellularity). 
• 
• 
Hemoglobin >8 g/dL (transfusion and/or growth factor support is 
allowable). 
• 
Serum glutamic oxaloacetic transaminase (SGOT) ≤3 × the upper limit of 
normal and total bilirubin ≤2.0 mg/dL (unless there is a molecularly 
documented history of Gilbert’s syndrome). 
• 
Left ventricular ejection fraction (LVEF) ≥45%. LVEF assessment must 
have been performed within 4 weeks of enrollment. 
10. Must have recovered from toxicities due to prior therapies, with the exception 
of peripheral neuropathy, to Grade ≤2 according to the NCI CTCAE Version 
4.03 criteria or to the subject's prior baseline. 
11. Must have an Eastern Cooperative Oncology Group (ECOG) performance 
status of 0 to 1. 
Exclusion 
Criteria 
1. Is pregnant or lactating  
2. Has inadequate venous access and/or contraindications to leukapheresis. 
3. Has active hemolytic anemia, plasma cell leukemia, Waldenstrom's 
macroglobulinemia, POEMS syndrome (polyneuropathy, organomegaly, 
endocrinopathy, monoclonal protein, and skin changes), disseminated 
intravascular coagulation, leukostasis, or amyloidosis. 
4. Has an active second malignancy (not disease-free for at least 5 years) in 
addition to MM, excluding low-risk neoplasms such as non-metastatic basal 
cell or squamous cell skin carcinoma.  
5. Has active autoimmune disease, such as psoriasis, multiple sclerosis, lupus, 
rheumatoid arthritis, etc. (the medical monitor will determine if a disease is 
active and autoimmune). 
6. Has a history of significant central nervous system (CNS) disease, such as 
stroke, epilepsy, etc. (the medical monitor will determine if significant). 
7. Has an active systemic infection (e.g. causing fevers or requiring antimicrobial 
treatment). 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 14 of 117 
8. Has hepatitis B or C virus, human immunodeficiency virus (HIV), or human T-
lymphotropic virus (HTLV) infection, or any immunodeficiency syndrome. 
9. Has New York Heart Association (NYHA) Class III or IV heart failure, 
unstable angina, or a history of myocardial infarction or significant arrhythmia 
(e.g. atrial fibrillation, sustained [>30 seconds] ventricular tachyarrhythmias, 
etc.). 
10. Has any psychiatric or medical disorder (e.g. cardiovascular, endocrine, renal, 
gastrointestinal, genitourinary, immunodeficiency or pulmonary disorder not 
otherwise specified) that would, in the opinion of the Investigator or medical 
monitor, preclude safe participation in and/or adherence to the protocol 
(including medical conditions or laboratory findings that indicate a significant 
probability of not qualifying for or being unable to undergo adequate 
leukapheresis, conditioning chemotherapy and/or CAR-T cell administration). 
11. Has received prior gene therapy or gene-modified cellular immunotherapy (or 
have approval of the medical monitor). Subject may have received non-gene-
modified autologous T-cells or stem cells in association with an anti-myeloma 
treatment. 
12. Has received anti-cancer medications within 2 weeks or 5 half-lives (whichever 
is longer or have medical monitor approval) of the time of initiating 
conditioning chemotherapy. 
13. Has received immunosuppressive medications within 2 weeks of the time of 
initiating leukapheresis, and/or expected to require them while on study (the 
medical monitor will determine if a medication is considered 
immunosuppressive). Generally, all non-essential medications (including 
supplements, herbal medications, etc.) should be discontinued from 2 weeks 
before leukapheresis until 2 months after P-BCMA-101 administration due to 
the potential for unappreciated immunosuppressive effects. 
14. Has received systemic corticosteroid therapy ≥5 mg/day of prednisone or 
equivalent dose of another corticosteroid within 2 weeks of either the required 
leukapheresis or 1 week or 5 half-lives (whichever is shorter) of the 
administration of P-BCMA-101 or is expected to require it during the course of 
the study. (Topical and inhaled steroids are permitted. Systemic corticosteroids 
are contraindicated after receiving P-BCMA-101 cells outside of study-specific 
guidance). 
15. Has CNS metastases or symptomatic CNS involvement (including 
leptomeningeal carcinomatosis, cranial neuropathies or mass lesions and spinal 
cord compression) of their myeloma. 
16. Has a history of severe immediate hypersensitivity reaction to any of the agents 
used in this study. 
17. Has a history of having undergone allogeneic stem cell transplantation, or any 
other allogeneic or xenogeneic transplant, or has undergone autologous 
transplantation within 90 days. 
18. Unable to take acetylsalicylic acid (ASA) (325 mg) daily as prophylactic 
anticoagulation. Patients intolerant to ASA may use warfarin or low molecular 
weight heparin) (Cohorts R and RP only). 
19. History of thromboembolic disease within the past 6 months, regardless of 
anticoagulation (Cohorts R and RP only). 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 15 of 117 
Duration of 
Study 
Subjects will be followed for up to 2 years after the last dose in this study, 
following which consenting subjects will roll over into a long-term safety follow-up 
protocol for a total of 15 years follow-up post-last dose. 
Schedule of 
Events 
See Table 2, for single administration Schedule of Events – Screening through 
Conditioning Chemotherapy, and Table 3, Schedule of Events – P-BCMA-101 
Administration and Follow-Up. The Schedules of Events for retreatment of subjects 
with P-BCMA-101 is described in Table 9 and Table 10 (see Section 15.4). For 
rimiducid treatment see the Schedule of Events in Table 8. The Schedule of Events 
for subjects in Cycle Administration cohorts is described in Table 11, Table 12, 
Table 13, and Table 14 (see Section 15.5). The Schedule of Events for subjects in 
Combination Administration cohorts is described in Table 15 and Table 16 (see 
Section 15.6).  
Criteria for 
pausing dosing 
or stopping the 
study 
If a study-defined DLT or any treatment related death occurs, dosing of new 
subjects will be paused until the Safety Committee meets, reviews the event(s), and 
determines forward plans, which might include stopping the study, reducing 
subsequent dose levels, instituting additional safety procedures or a study 
amendment, continuing the study as planned or other measures as appropriate to the 
event. As described above, if 2 or more subjects have DLTs in a cohort during 
Phase 1, and a ≥10% incidence of ≥ Grade 4 or ≥30% incidence of ≥Grade 3 CRS 
or neurotoxicity at or below a corresponding dose level in Phase 2 with >10 
patients treated, that dose level will have exceeded the MTD and any further dosing 
would take place at a lower dose level. 
Statistical 
Methodology 
The demographic and baseline characteristics, safety, and efficacy data will be 
summarized using appropriate descriptive statistics. Data analyses will be provided 
by dose cohort, as well as for all subjects combined where appropriate. Descriptive 
statistics including means, medians, standard deviations, and ranges will be 
calculated for continuous variables, and categorical data will be summarized using 
counts and percentages. For response rate endpoints, point estimates and two-sided 
exact binomial 95% confidence intervals will be computed. Time-to-event variables 
will be summarized using the Kaplan-Meier method. 
Treatment-emergent AEs (TEAEs) will be summarized using counts and 
percentages of subjects by cohort, and for all subjects combined. TEAEs will also 
be summarized by severity and relationship. Concomitant medications will be 
summarized using counts and percentages of subjects by dose cohort. 
Vital signs, electrocardiogram (ECG) measurements, and laboratory results will be 
summarized using descriptive statistics for observed values and change from 
baseline values by cohort. Laboratory results will also be summarized relative to 
the normal range (below, within, or above) by cohort. 
The Phase 1 part of the study is a standard 3+3 design of dose cohorts intended to 
determine a dose below which a 33% incidence of DLTs occurs. Thus, up to 120 
subjects may be enrolled to include the possibility of 18 cohorts of 6 subjects 
during dose escalation, cycle administration and combination administration, as 
well as subjects who might be enrolled to replace those who discontinue prior to 
completion of the DLT evaluation period or further assess findings in a cohort. 
For the Phase 2 part of the study response rate endpoints will be tested to exclude a 
response rate of ≤30% as obtained with the recently approved standard of care 
agent daratumumab at p<0.05. Time-to-event variables will be summarized using 
the Kaplan-Meier method. With a 100-subject sample, the Phase 2 part of the trial 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 16 of 117 
will have 90% power to detect a 15-percentage point improvement over a 30% 
response rate. This power calculation is based on an exact test for a binomial 
proportion with a 1-sided 0.05 significance level. A futility analysis will be 
conducted once 35 subjects are enrolled, received P-BCMA-101, and followed up 
for 4 months or progressed prior to 4-month follow-up. This analysis set is called 
Futility Analysis Set (FAS). The futility analysis will use Futility Index (FI) which 
is equal to 1 minus the Conditional Power (CP) based on the observed proportion of 
BOR in FAS. The study may be stopped if FI is above 0.80 (that is, if CP falls 
below 0.20). 
Subjects who receive additional infusions of P-BCMA-101 will also be analyzed as 
separate subgroups for all outcomes afterwards.  
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 17 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 18 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 19 of 117 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 20 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 21 of 117 
 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 22 of 117 
TABLE OF CONTENTS 
SYNOPSIS… ...................................................................................................................................4 
TABLE OF CONTENTS ...............................................................................................................22 
1. 
INTRODUCTION ......................................................................................................31 
1.1. 
Multiple Myeloma ......................................................................................................31 
1.2. 
Rationale for P-BCMA-101 T Cell Therapy in Multiple Myeloma ...........................32 
1.2.1. 
P-BCMA-101 T Cell Therapy ....................................................................................32 
1.2.2. 
BCMA as a Therapeutic Target for CAR-T cells .......................................................33 
1.2.3. 
P-BCMA-101 Design and Rationale ..........................................................................35 
1.2.4. 
Summary of Nonclinical Studies with P-BCMA-101 ................................................36 
1.2.4.1. 
Product Candidate Screening and Selection ...............................................................36 
1.2.4.1.1. 
In vitro Screening .......................................................................................................36 
1.2.4.1.2. 
In vivo Screening in MM Xenograft Models ..............................................................37 
1.2.4.2. 
P-BCMA-101 Preclinical Toxicology ........................................................................38 
1.2.4.2.1. 
In vitro Binding of the P-BCMA-101 Centyrin to a Human Protein Panel................38 
1.2.4.2.2. 
P-BCMA-101 Reactivity Against Normal Human Tissues ........................................38 
1.2.4.2.3. 
Single-Dose GLP Safety and Efficacy Study of P-BCMA-101 CAR-T Cells 
in MM1.S Myeloma Tumor-bearing NSG Mice ........................................................38 
1.3. 
Potential Risks and Benefits .......................................................................................40 
1.3.1. 
Benefit Assessment .....................................................................................................40 
1.3.2. 
Risk Assessment .........................................................................................................40 
1.3.3. 
Overall Benefit: Risk Conclusion ...............................................................................41 
2. 
STUDY OBJECTIVES AND ENDPOINTS ..............................................................42 
3. 
INVESTIGATIONAL PLAN .....................................................................................44 
3.1. 
Overall Study Design ..................................................................................................44 
3.2. 
Study Dosing ..............................................................................................................45 
3.2.1. 
Dose Escalation Guidelines for Phase 1 .....................................................................45 
3.2.2. 
Dosing in Cycle Administration .................................................................................47 
3.2.3. 
Dosing in Combination Administration......................................................................47 
3.2.4. 
Dosing in Phase 2 .......................................................................................................48 
3.2.5. 
Repeat Dosing .............................................................................................................48 
3.3. 
Evaluation of Dose-Limiting Toxicity ........................................................................48 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 23 of 117 
3.4. 
Number of Subjects and Duration of Study ................................................................49 
4. 
SELECTION OF STUDY POPULATION, WITHDRAWAL, 
COMPLETION, AND STOPPING CRITERIA ........................................................50 
4.1. 
Inclusion Criteria ........................................................................................................50 
4.2. 
Exclusion Criteria .......................................................................................................52 
4.3. 
Subject Withdrawal ....................................................................................................53 
4.4. 
Study Termination ......................................................................................................54 
5. 
STUDY TREATMENTS............................................................................................55 
5.1. 
Leukapheresis .............................................................................................................55 
5.2. 
Conditioning Chemotherapy .......................................................................................57 
5.3. 
P-BCMA-101 Administration ....................................................................................57 
5.3.1. 
Description ..................................................................................................................57 
5.3.2. 
Product Labeling .........................................................................................................57 
5.3.3. 
Storage ........................................................................................................................58 
5.3.4. 
Preparation ..................................................................................................................58 
5.3.5. 
Dosing and Administration .........................................................................................58 
6. 
CONCOMITANT MEDICATION AND TREATMENT ..........................................61 
6.1. 
Prohibited Concomitant Medications and Treatments ...............................................61 
6.2. 
Permitted Concomitant Medications and Treatments .................................................61 
6.3. 
Supportive Care Guidance ..........................................................................................62 
7. 
SCHEDULE OF ASSESSMENTS AND PROCEDURES ........................................64 
7.1. 
Schedule of Procedures ...............................................................................................64 
7.2. 
Clinical Assessments ..................................................................................................64 
7.2.1. 
Medical History ..........................................................................................................64 
7.2.2. 
Physical and Neurological Examination .....................................................................64 
7.2.3. 
Vital Signs ..................................................................................................................64 
7.2.4. 
Performance Status .....................................................................................................65 
7.2.5. 
Clinical Safety Assessments .......................................................................................65 
7.2.6. 
Cardiac Assessments ..................................................................................................65 
7.2.7. 
Laboratory Assessments .............................................................................................65 
7.2.7.1. 
Clinical Chemistry and Hematology ..........................................................................65 
7.2.7.2. 
Pregnancy Testing ......................................................................................................65 
7.2.7.3. 
Infectious Disease Screening ......................................................................................66 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 24 of 117 
7.2.8. 
Cytokine Release Syndrome .......................................................................................66 
7.2.9. 
Mini Mental Status Exam ...........................................................................................66 
7.2.10. 
Disease Response Assessments ..................................................................................66 
7.2.10.1. 
PET-CT Assessment ...................................................................................................66 
7.2.10.2. 
Response and Response Rates ....................................................................................66 
7.2.10.3. 
Time to Response .......................................................................................................67 
7.2.10.4. 
Duration of Response .................................................................................................67 
7.2.10.5. 
Progression Free Survival ...........................................................................................67 
7.2.10.6. 
Overall Survival ..........................................................................................................67 
7.2.11. 
Long-Term Follow-up ................................................................................................67 
8. 
RECORDING ADVERSE EVENTS .........................................................................69 
8.1. 
Time Period for Collecting AE and SAE Information ...............................................69 
8.2. 
Definition of Adverse Event .......................................................................................69 
8.2.1. 
Assessment of Intensity ..............................................................................................69 
8.2.2. 
Assessment of Causality .............................................................................................70 
8.3. 
Reporting Serious Adverse Events (SAEs) ................................................................71 
8.4. 
Adverse Events of Special Interest (AESI) ................................................................71 
8.5. 
Regulatory Reporting Requirements for SAEs and AESIs ........................................72 
8.6. 
Pregnancy ...................................................................................................................72 
9. 
SAFETY MONITORING ..........................................................................................74 
9.1. 
Safety Committee .......................................................................................................74 
9.2. 
Criteria for Pausing Dosing or Stopping the Study ....................................................74 
10. 
STATISTICAL AND DATA ANALYSIS ................................................................75 
10.1. 
Study Populations .......................................................................................................75 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 25 of 117 
10.2. 
Sample Size Calculation .............................................................................................75 
10.3. 
Statistical Methods ......................................................................................................75 
11. 
DATA HANDLING AND RECORD KEEPING ......................................................77 
11.1. 
Confidentiality ............................................................................................................77 
11.2. 
Data Management .......................................................................................................77 
11.3. 
Source Documents ......................................................................................................78 
11.4. 
Case Report Forms .....................................................................................................78 
11.5. 
Records Retention .......................................................................................................78 
12. 
STUDY MONITORING, AUDITING, AND INSPECTING ....................................79 
12.1. 
Study Monitoring Plan ................................................................................................79 
12.2. 
Audits and Inspections ................................................................................................79 
13. 
REGULATORY AND ETHICAL CONSIDERATIONS ..........................................79 
13.1. 
Institutional Review Board/Independent Ethics Committees .....................................79 
13.2. 
Ethical Considerations ................................................................................................79 
13.3. 
Informed Consent .......................................................................................................79 
13.4. 
Protocol Adherence ....................................................................................................80 
13.5. 
Public Posting of Study Information ..........................................................................80 
13.6. 
Clinical Study Report .................................................................................................80 
13.7. 
Publication Policy .......................................................................................................80 
14. 
LIST OF REFERENCES ............................................................................................81 
15. 
APPENDICES ............................................................................................................85 
15.1. 
ECOG Performance status ..........................................................................................85 
15.2. 
IMWG Uniform Response Criteria ............................................................................86 
15.3. 
Rimiducid ...................................................................................................................89 
15.3.1. 
Introduction .................................................................................................................89 
15.3.2. 
Investigational Use .....................................................................................................90 
15.3.3. 
Study Treatments ........................................................................................................90 
15.3.3.1. 
Rimiducid Administration ..........................................................................................90 
15.3.3.1.1. Description ..................................................................................................................90 
15.3.3.1.2. Supply and Storage .....................................................................................................91 
15.3.3.1.3. Preparation ..................................................................................................................91 
15.3.3.1.4. Dosing and Administration .........................................................................................91 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 26 of 117 
15.3.4. 
Concomitant Medications and Treatment ...................................................................91 
15.3.5. 
Schedule of Assessments and Procedures ..................................................................91 
15.3.6. 
Recording Adverse Events .........................................................................................92 
15.4. 
Retreatment with P-BCMA-101 .................................................................................94 
15.5. 
Cycle Administration ................................................................................................100 
15.6. 
Phase 1 – Combination Administration ....................................................................111 
 
LIST OF TABLES 
Table 1: 
Dose Escalation Guidelines ..........................................................................................8 
Table 4: 
Dose Escalation Guidelines ........................................................................................46 
Table 5: 
Grading of AEs Not Specified in NCI CTCAE version 4.03 .....................................70 
Table 6: 
Qualitative and Quantitative Composition of Rimiducid Drug Product ....................90 
Table 7: 
Rimiducid Dosing Calculation Examples ...................................................................91 
 
LIST OF FIGURES 
Figure 1: 
Stable Expression and Function of CARTyrin ...........................................................37 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 27 of 117 
Figure 2: 
In Vivo Efficacy in MM.1S-Luc Tumor-Bearing NSG Mice Treated with P-
BCMA-101 in GLP Safety Study ...............................................................................40 
Figure 3: 
Schematic for Study P-BCMA-101-001 – Single Administration .............................45 
Figure 4: 
Clinical Product Manufacturing and Process Diagram ..............................................56 
Figure 5: 
Schematic for Study P-BCMA-101-001 –Cycle Administration– Cohort A 
and Cohort C .............................................................................................................100 
Figure 6: 
Schematic for Study P-BCMA-101-001 –Cycle Administration – Cohort B ..........101 
Figure 7: 
Schematic for Study P-BCMA-101-001 – Phase 1 Combination 
Administration ..........................................................................................................112 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 28 of 117 
LIST OF DEFINITIONS AND ABBREVIATIONS 
AE 
adverse event 
AESI 
adverse event of special interest 
ALL 
acute lymphoblastic leukemia 
ALT 
alanine aminotransferase 
ASA 
acetylsalicylic acid 
AST 
aspartate aminotransferase 
ASCT 
autologous stem cell transplant 
BCMA 
B-cell maturation antigen 
BP 
blood pressure 
CAR 
chimeric antigen receptor (CAR + cells = P-BCMA-101 cells) 
CARTyrin 
anti-BCMA Centyrin CAR 
CNS 
central nervous system 
CP 
conditional power 
CR 
complete response 
CRO 
Contract Research Organization 
CRP 
C-reactive protein 
CRS 
cytokine release syndrome 
CSR 
Clinical Study Report 
CTCAE 
Common Terminology Criteria for Adverse Events 
DHFR 
dihydrofolate reductase 
DLT 
dose limiting toxicity 
DMSO 
dimethyl sulfoxide 
DOR 
duration of response 
ECG 
Electrocardiogram 
ECOG 
Eastern Cooperative Oncology Group 
eCRF 
electronic Case Report Form 
EDC 
electronic data capture 
FAS 
futility analysis set  
FDA 
Food and Drug Administration 
FI 
Futility index 
FKBP12 
FK506-binding protein 12 
FLC 
free light chain 
GCP 
Good Clinical Practice 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 29 of 117 
GVHD 
Graft Versus Host Disease 
HDAC 
histone deacetylase 
HIPAA 
Health Insurance Portability and Accountability Act 
HIV 
human immunodeficiency virus 
HR 
heart rate 
HTLV 
human T-lymphotropic virus 
iCasp9 
inducible caspase 9 
ICH 
International Conference on Harmonisation 
ICMJE 
International Committee of Medical Journal Editors 
IEC 
Independent Ethics Committee 
IFN-γ 
interferon gamma 
IgG 
immunoglobulin G 
IMiD 
immunomodulatory agent 
IMWG 
International Myeloma Working Group 
INR 
international normalized ratio 
IRB 
Institutional Review Board 
IRC 
Independent Review Committee 
ITT 
Intent-to-Treat 
IV 
intravenous(ly) 
Kg 
Kilogram 
LDH 
lactate dehydrogenase 
LTFU 
long-term follow-up 
LVEF 
left ventricular ejection fraction 
mAb 
monoclonal antibody 
MedDRA 
Medical Dictionary for Regulatory Activities 
MM 
multiple myeloma 
MMSE 
Mini Mental Status Exam 
MR 
minimal response 
MRD 
minimal residual disease 
MTD 
maximum tolerated dose 
NCI 
National Cancer Institute 
NIH 
National Institute of Health  
NOAEL 
no observed adverse effect level 
NYHA 
New York Heart Association 
ORR 
overall response rate 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 30 of 117 
OS 
overall survival 
PB 
piggyBac™ 
PBMC 
peripheral blood mononuclear cells 
PET 
positron emission tomography 
PFS 
progression free survival 
PHI 
protected health information 
POEMS 
polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and 
skin changes 
PD 
progressive disease 
PR 
partial response 
PT 
prothrombin time 
PTT 
partial thromboplastin time 
RNA 
ribonucleic acid 
RR 
respiratory rate 
SAD 
single ascending dose 
SAE 
serious adverse event 
SAP 
Statistical Analysis Plan 
sCR 
stringent complete response 
SD 
stable disease 
SGOT 
serum glutamic oxaloacetic transaminase 
SIFE 
serum immunofixation 
SPB 
Super piggyBac™ transposase 
SPEP 
serum protein electrophoresis 
TCR 
T cell receptor 
TEAE 
treatment-emergent adverse event 
TLS 
tumor lysis syndrome 
TNF-α 
tumor necrosis factor alpha 
Tscm 
T stem cell memory 
TTR 
time to response 
UIFE 
urine immunofixation 
UPEP 
urine protein electrophoresis 
VGPR 
very good partial response 
WHO 
World Health Organization 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 31 of 117 
1. 
INTRODUCTION 
Multiple myeloma (MM) is generally an incurable and fatal disease which typically runs a course 
of multiple relapses and recurrences. Currently available therapies are inadequate and there 
remains an unmet need for an effective and durable MM therapy. Chimeric antigen receptor T 
cell (CAR-T) immunotherapy is emerging as an important potential therapeutic approach for 
cancer, including MM. B-cell maturation antigen (BCMA) is an attractive target given that 
BCMA is expressed in MM cells, but among non-malignant cells, BCMA expression is largely 
restricted to plasma cells and a subset of B cells. Clinical data in MM patients has recently been 
published using two similar BCMA-targeted CAR-T cell products (NCI/NIH, University of 
Pennsylvania and BlueBird Bio studies) demonstrating the safety and efficacy of the approach 
(Ali, 2016; Cohen, 2016; Berdeja, 2016). In vitro and in vivo studies have shown that the P-
BCMA-101 T cells bind to BCMA+ tumor lines with high affinity and specificity, resulting in 
robust degranulation and cytotoxicity. The unmet medical need, when taken together with the 
available preclinical and clinical data, and the potential safety and efficacy advantages of this 
construct, provide the rationale for evaluating P-BCMA-101 in patients with recurrent or 
relapsing MM. The information below is also described in detail in the Investigator’s Brochure. 
1.1. 
Multiple Myeloma 
Multiple myeloma (MM) is a treatable but typically incurable plasma cell malignancy that often 
runs an aggressive and lethal clinical course. It is estimated that about 26,850 new cases of MM 
occurred in the U.S. in 2015 with approximately 11,240 deaths. The diagnosis is most common 
in the 6th and 7th decades of life (Howlader, 2015).  
The hallmark feature of MM is monoclonal expansion of plasma cells in the bone marrow with 
accompanying excessive production of monoclonal antibodies (mAbs) that produce an “M 
spike” on serum protein electrophoresis (Raab, 2009). The clinical features of the disease result 
from bone marrow infiltration by the malignant clone, high levels of circulating monoclonal 
antibody (mAb) and/or free light chains, depressed immunity and end-organ damage. The classic 
signs and symptoms of MM include anemia, bleeding due to thrombocytopenia, frequent 
infections due to leukopenia and low antibody production, bone pain due to bone lesions and 
fractures and renal impairment due to high levels of M protein accumulation and hypercalcemia.  
Recent advances in the understanding of MM’s pathophysiology and the introduction of novel 
therapeutic agents have contributed toward the management of this disease with dramatic 
improvements in survival observed in the last 2 decades. Median survival increased from about 2 
years in the 1980s up to 5-6 years or more today (Engelhardt, 2010). Treatment regimens tend to 
be comprised of two to three agents; most all patients receive a proteasome inhibitor (bortezomib 
or carfilzomib) and an immunomodulatory agent (IMiD) (lenalidomide, pomalidomide, 
thalidomide) both early and late in the course of treatment of their disease. In addition, eligible 
patients may undergo autologous hematopoietic stem cell transplantation and/or, less frequently, 
allogeneic hematopoietic stem cell transplantation. In 2015, several new therapies were approved 
in the United States including 2 mAbs (daratumumab and elotuzumab), a pan histone deacetylase 
(HDAC) inhibitor (panabinostat), and an oral proteasome inhibitor (ixazomib). The long-term 
impact of these recent approvals remains to be determined, but they do not appear to produce 
cures in the relapsed and/or refractory setting, and most patients will ultimately relapse and die 
(Kumar, 2008). Tumors that relapse tend to recur more aggressively with each relapse. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 32 of 117 
Responses to treatment are less durable with subsequent disease progression resulting in 
treatment-refractory disease associated with shortened survival times (Kumar, 2012).  
1.2. 
Rationale for P-BCMA-101 T Cell Therapy in Multiple Myeloma 
1.2.1. 
P-BCMA-101 T Cell Therapy 
P-BCMA-101 is an autologous Centyrin-based CAR-T cell therapy, referred to as CARTyrin T 
cells. It is a biologic product designed to target MM cells expressing the cell surface antigen 
BCMA and to direct cytotoxic effects to the targeted cell (Tai, 2015). The mechanism of action 
of P-BCMA-101 is the same as that of other CAR-T approaches (e.g. Ali, 2016; Berdeja, 2016). 
Each patient’s peripheral blood mononuclear cells (PBMCs) will be harvested by leukapheresis, 
then will be used to generate the PBCMA-101 investigational product for that individual patient 
via electroporation of transposase ribonucleic acid (RNA) along with a DNA plasmid encoding a 
PB transposon carrying the CARTyrin (i.e. the piggyBac™ (PB) DNA modification system), 
followed by culture/expansion. 
As of 14 July 2019, 36 subjects had been treated with P-BCMA-101 cells (34 in Phase 1 and 2 in 
Phase 2), 3 of whom have received a second administration of P-BCMA-101. All Phase 1 dose 
escalation cohorts (1-5: 0.75-15 × 106 P-BCMA-101 cells/kg/dose) had successfully been 
completed with good safety and efficacy reported through the highest dose level. No DLTs had 
been reported and enrollment of new subjects is continuing in expansions of cohorts, suggesting 
additional cohorts should be assessed. Patients were heavily pre-treated (3-18 prior therapies), 
most had failed IMiDs, proteasome inhibitors, daratumumab and ASCT. Patients were treated 
with 48-1545 × 106 total P-BCMA-101 cells/kg. Circulating P-BCMA-101 cells have been 
detected in the blood of patients by PCR, with expansion peaking at 2-3 weeks. Above a 
threshold level reached in Cohorts 2-3, greater response appears to occur in patients with broader 
peaks, suggesting there may be additional benefit in repeat or fractionated dosing. Although of 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 33 of 117 
unknown significance, indications of anti-CAR-T antibodies have been seen in some patients. 
The most common TEAEs (>30%) were neutropenia, WBC decreased, thrombocytopenia, 
anemia, nausea, constipation and febrile neutropenia. Only 4 subjects had cases of CRS (1 
subject had Grade 2 at 2 × 106 cells/kg and 3 subjects had Grade 2 at 15 × 106 cells/kg) and 1 
case of CRES (Grade 2 at 6 × 106 cells/kg, transient confusion) had been reported. Repeat 
administrations of P-BCMA-101 were also well tolerated. Twenty-nine of the Phase 1 subjects 
were evaluable for response by IMWG criteria and had completed at least one myeloma response 
assessment, with 17 thus far demonstrating a response (1/2 at ~0.75 × 106 cells/kg, 5/7 at ~2 × 
106 cells/kg, 4/9 (+ 2 MR) at ~6 × 106 cells/kg, 3/4 (+ 1 MR) at ~10 × 106 cells/kg, and 4/7 at 
~15 × 106 cells/kg). Based on these results the study was further expanded with a Phase 2 portion 
to further characterize the safety and efficacy at dose levels 3-5.  
1.2.2. 
BCMA as a Therapeutic Target for CAR-T cells 
Myeloma has several characteristics that make it suitable to treat with adoptive T cell therapy. 
First, myeloma is primarily a disease of the bone marrow and adoptive T cell therapy targeting 
CD19 has been particularly successful in bone marrow-predominant diseases, such as acute 
lymphoblastic leukemia (ALL) (Brentjens, 2013). Second, autologous stem cell transplantation is 
the standard of care in myeloma, and lymphodepletion may enhance the efficacy of adoptive T 
cell therapy (Brentjens, 2011; Pegram, 2012). Third, unlike all other treatments for myeloma, an 
allo-SCT is potentially curative, however, its application is limited by transplant-associated 
toxicity, mortality, patient eligibility and availability of suitable donors. CAR-T cell therapy has 
the potential to be a safer way to achieve such anti-tumor efficacy (Milone, 2015). 
The utility of CD19 as a target is limited by the fact that it is infrequently expressed on the 
malignant plasma cells of MM; therefore, other antigens have been explored, with particular 
attention to antigens expressed by tumor cells but not normal tissues. One attractive target is 
BCMA. The rationale for selecting this target is that BCMA is detected in MM cells, but among 
non-malignant cells, BCMA expression is largely restricted to plasma cells and a subset of B 
cells, and therefore may have less potential for on-target, off-tumor effects. 
MM tumor cell recognition occurs when the BCMA-specific CAR expressed on the surface of a 
P-BCMA-101 T cell binds to BCMA antigen expressed on the surface of a MM tumor cell. 
Signaling and activation is mediated by the intracytoplasmic signaling domains 4-1BB and 
CD3 encoded within the CAR. Activation can lead to direct cytotoxicity of MM tumor targeted 
by CAR-T cell-mediated release of granzyme and perforin. Tumor killing can also be mediated 
by activation of other components of the immune system through release of cytokines by CD4+ 
T cells. Long-term eradication and prevention against tumor relapse may be provided either by 
immediate tumor ablation or by long-term memory CAR-T cells that remain after the initial 
tumor response. Thus, there may be particular advantage to having CAR-T cells that are of the T 
stem cell memory phenotype (Tscm) and T central memory phenotype (Tcm). In addition, 
release of non-BMCA tumor-associated antigens during CAR-T-mediated tumor cell lysis may 
lead to the priming and/or reactivation of non-engineered tumor-specific cells of the adaptive 
immune system, a phenomenon termed ‘epitope-spreading’, that may also assist in the long-term 
eradication and prevention against tumor relapse. 
In a nonclinical study conducted by Carpenter, et al. (Carpenter, 2013) anti-BCMA-CAR T cells 
exhibited specific anti-BCMA functions, including cytokine production, proliferation, 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 34 of 117 
cytotoxicity, and in vivo tumor eradication. Importantly, anti-BCMA-CAR T cells recognized 
and killed primary MM cells. The authors concluded that BCMA is a suitable target for CAR-
expressing T cells, and adoptive transfer of anti-BCMA-CAR T cells is a promising new strategy 
for treating MM (Carpenter, 2013). 
Data was published that demonstrated the first clinical proof of concept for T cells expressing 
anti-BCMA CAR in subjects with relapsed/refractory MM from a study performed at the 
National Cancer Institute (NCI). Patients (N=16) were enrolled at 4 dose levels, including: 0.3 × 
106; 1 × 106; 3 × 106 and 9 × 106 cells/kg-body wt. Responses were dose-dependent and included 
partial response (N=3), very good partial response (N=4) and stringent complete response (N=1). 
At the highest dose level, the response rate was 100%. Data on duration of response is not yet 
available. Tolerability was consistent with expectations from other CAR-T studies. Toxicities 
attributable to anti-BCMA CAR-T cells were minimal in patients treated at the low dose level. 
Subsequently, patients exhibited signs of CRS correlating with dose level. No unexpected 
damage to non-hematopoietic organs was observed (Ali, 2016; Kochenderfer, 2016). Initial 
results of another study utilizing anti-BCMA CAR-T cells by Cohen et al. (Cohen, 2016) have 
recently been presented. In this study, 6 patients were treated with 1-5 × 108 CAR-T cells. Four 
patients responded: minimal response (N=2), very good partial response (N=1) and minimal 
residual disease negative (MRD negative) stringent complete response (N=1). Five patients 
developed CRS, of which 1 was Grade 3 with neurotoxicity that responded to treatment without 
sequelae. CAR-T cell expansion appeared to correlate with efficacy. In an ongoing study of a 
third anti-BCMA CAR-T construct presented by Berdeja et al., 11 patients were enrolled at 3 
fixed dose levels; 5 × 107; 15 × 107 and 45 × 107 CAR-T+ cells per patient (80 × 107 and 120 × 
107 CAR-T+ cells per patient are planned for upcoming cohorts). The response rate was 
impressive and dose-dependent, including partial response (N=4), very good partial response 
(N=1) and stringent complete response (N=2), with 2 patients becoming MRD negative. 
Tolerability was better than what has been reported in other CAR-T studies. CRS was seen in 70-
80% of the patients, but it was limited to Grade 1-2. No neurotoxicity or other significant or 
unexpected toxicities were reported (Berdeja, 2016). The relative paucity of toxicity in these 
studies has been variously attributed to use of the 4-1BB costimulatory domain, lessened disease 
burden and/or more gradual exposure of the T-cells to myeloma cells, compared to the anti-
CD19 products used in leukemias which have generated the most publications. 
Lenalidomide (Lenalidomide, 2019) is a member of the class of immunomodulatory imide drugs 
(IMiDs) known for significant activity against myeloma as well as pleiotropic effects on the 
immune system, and is approved for the treatment of myeloma, myelodysplastic syndrome and 
lymphomas in the United States (Moreau, 2019; Fink, 2015). In addition to its direct anti-
myeloma properties, it is hypothesized lenalidomide could enhance the efficacy of CAR-T cells 
such as P-BCMA-101. Lenalidomide treatment increases the frequency of naïve and stem cell 
memory T cells, and not only are these two T subsets the preferred starting material for the P-
BCMA-101 manufacturing process, but they have also been associated with improved clinical 
outcome in CAR-T cell products (Fostier, 2018; Barnett, 2016a; Cohen, 2019). Inclusion of 
lenalidomide directly in the manufacturing process is not being proposed as this approach may 
increase the number and effector function of CAR-T cells produced (Wang, 2018). Thus, 
including lenalidomide treatment prior to apheresis is hypothesized to improve the quality of the 
T cells in the input material and, subsequently, the manufactured CAR-T cell product. Co-
administration of lenalidomide with CAR-T cells is being proposed as it has been shown to 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 35 of 117 
augment CAR-T cell effector functions and overall anti-myeloma activity both in vitro and in 
mouse models (Otáhal, 2016; Wang, 2018; Works, 2019). Moreover, a similar combination with 
lenalidomide and an anti-BCMA CAR-T cell product is currently being explored in at least one 
other clinical trial (NCT03070327). 
1.2.3. 
P-BCMA-101 Design and Rationale 
As described above, P-BCMA-101 cells are designed to express 3 major components: an anti-
BCMA Centyrin chimeric antigen receptor (CARTyrin) gene, a dihydrofolate reductase (DHFR) 
resistance gene, and an inducible caspase 9 (iCasp9)-based safety switch gene (Hermanson, 
2016). Binding of BCMA antigen expressed on the surface of a MM tumor cell by the BCMA-
specific CARTyrin triggers signaling and activation within the P-BCMA-101 cells that is 
mediated by the CARTyrin-encoded intracytoplasmic signaling domains. 
 
Whereas genetic modification of autologous T cells for expression of CAR molecules is 
generally accomplished via lentivirus or γ–retrovirus transduction, P-BCMA-101 is 
manufactured using an electroporation-based non-viral (DNA transposon) gene delivery system 
called the piggyBac (PB) DNA modification system (Nakazawa, 2013) which efficiently moves 
DNA from a plasmid to a chromosome via a "cut and paste" mechanism and have been used 
extensively as a human gene transfer method, including CAR-T production (Woodard, 2015; 
Fraser, 1996; Singh, 2013; Huls, 2013). Compared to viral-based delivery, PB offers advantages, 
including a safer insertion profile (Cunningham, 2015), larger transgene capacity (enabling the 
delivery of genetic components to enhance safety and efficacy), higher level and more stable 
transgene expression (Cunningham, 2015), longer duration transgene expression (Mossine, 2013) 
as well as a preponderance of the highly favorable TSCM phenotype. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 36 of 117 
1.2.4. 
Summary of Nonclinical Studies with P-BCMA-101 
1.2.4.1. 
Product Candidate Screening and Selection 
1.2.4.1.1. In vitro Screening 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
CONFIDENTIAL 
 
Page 37 of 117 
 
1.2.4.1.2. In vivo Screening in MM Xenograft Models 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 38 of 117 
1.2.4.2. 
P-BCMA-101 Preclinical Toxicology 
1.2.4.2.1. In vitro Binding of the P-BCMA-101 Centyrin to a Human Protein Panel  
1.2.4.2.2. P-BCMA-101 Reactivity Against Normal Human Tissues 
1.2.4.2.3. Single-Dose GLP Safety and Efficacy Study of P-BCMA-101 CAR-T Cells in 
MM1.S Myeloma Tumor-bearing NSG Mice 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 39 of 117 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
 
Page 40 of 117 
 
1.3. 
Potential Risks and Benefits 
1.3.1. 
Benefit Assessment 
Based on data with P-BCMA-101 and other CAR-T cells (including anti-BCMA CAR-T cells) it 
is reasonable to expect that P-BCMA-101 may exert an anti-tumor effect. 
 
1.3.2. 
Risk Assessment 
Participation in this study will expose the subject to genetically engineered autologous T cells. 
The risk is acceptable based on clinical experience with similar products. The potential safety 
concerns for P-BCMA-101 are effectively the same as for other CAR-T cell products. The 
primary adverse effect seen in CAR-T cell studies is CRS and associated symptoms related to the 
activation of the CAR-T cells through their intended mechanism of action (significant increases 
in cytokines have also been reported to correlate with efficacy). Descriptions and guidelines for 
management of these toxicities are provided in Section 6.3. Although not yet reported with 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 41 of 117 
BCMA-targeted CAR-T cells, other theoretical concerns with CAR-T cells include: 1) “on-
target/on-tumor” toxicity, manifest as tumor lysis syndrome (TLS) through rapid destruction of 
myeloma tumor cells; 2) “on-target/off-tumor” toxicity related to destruction of BCMA+ non-
tumor cells in healthy tissues (other than hypogammaglobulinemia); 3) “off-target” toxicity due 
to potential cross-reactivity of the BCMA-binding domain with BCMA-negative targets; and; 4) 
immune-related reactions secondary to the development of anti-CAR-T antibodies. Many of 
these questions are addressed in the data in Section 1.2. The potential for tumorigenicity is 
another hypothetical risk that is considered negligible (Tey, 2014; Hackett, 2013), based upon 
the terminal differentiation of these cells, insertion profile and character of the gene addition 
materials and process, as well as the extensive clinical experience to date with long-term follow 
up of patients receiving other CAR-T cell products (Jena, 2010). At least one previous CAR-T 
study used a similar DNA transposon approach, and was found to be well-tolerated in a Phase 1 
clinical trial at doses up 1.2 × 109 total CAR-T cells (Singh, 2013; Huls, 2013). Potential risks of 
the moderate conditioning chemotherapy regimen utilized in this protocol are expected to be 
typical for these agents, in particular cytopenias, gastrointestinal effects, and infertility. 
Hemorrhagic cystitis, pulmonary, cardiac and neurologic effects have also been reported. 
The proposed starting dose (0.75 × 106 CAR-T cells/kg) in this Phase 1 study is ~3-fold lower 
than that reported in one clinical trial of CAR-T cells targeting BCMA (Cohen 2016) and 
approximately the same as others (Ali, 2016; Berdeja, 2016) who described toxicity as mild 
through doses up to 10-fold higher. 
further supporting a large margin 
of safety for the proposed FIH trial. 
 
As described above, P-BCMA-101 was designed with a number of features to increase safety, 
This study incorporates several further measures to address potential risks, including the 
following: step-wise escalation of the T cell dose, staggered enrollment of subjects, treatment in 
specialized academic centers experienced with management of toxicities associated with 
autologous T cell therapies, guidelines for management of toxicities, and a Safety Review 
Committee to evaluate safety throughout the study. As of 14 July 2019, the most common 
TEAEs (>30%) in Phase 1 were neutropenia, WBC decreased, thrombocytopenia, anemia, 
nausea, constipation, and febrile neutropenia. Only 4 subjects had cases of CRS (1 subject had 
Grade 2 at 2 × 106 cells/kg and 3 subjects had Grade 2 at 15 × 106 cells/kg) and 1 case of CRES 
(Grade 2 at 6 × 106 cells/kg) had been reported.  
1.3.3. 
Overall Benefit: Risk Conclusion 
The known and potential risks anticipated with P-BCMA-101 T cell therapy appear justified by 
the potential benefits that may be afforded to subjects with relapsed/refractory MM, a fatal 
malignancy. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 42 of 117 
2. 
STUDY OBJECTIVES AND ENDPOINTS 
Objectives 
Endpoints 
Primary 
The primary objective of this study is: 
Phase 1: 
To determine the safety and maximum 
tolerated dose (MTD) of P-BCMA-101 based 
on dose limiting toxicities (DLT) 
Phase 2: 
To assess the safety and efficacy of P-
BCMA-101 
Phase 1: 
Number of subjects with DLT at each dose level to 
define an MTD 
Phase 2: 
• Safety and tolerability based on adverse events 
(AEs), examinations, and standard laboratory 
studies 
• Overall response rate (ORR) and duration of 
response (DOR) by International Myeloma 
Working Group Criteria (Kumar, 2016) as assessed 
by an independent review committee (IRC) 
Secondary 
Secondary objectives of this study are to 
evaluate: 
Phase 1: 
• 
The safety and feasibility of P-BCMA-
101  
• 
The anti-myeloma effect of P-BCMA-101  
• 
The effect of cell dose to guide selection 
of doses for further assessment in Phase 
2/ 3 studies 
Phase 2: 
• 
Incidence and severity of CRS 
• 
Additional efficacy endpoints 
The following secondary endpoints will be 
evaluated: 
Phase 1: 
• Ability to generate the protocol-proscribed doses of 
P-BCMA-101 
• Safety and tolerability based on AEs, examinations, 
and standard laboratory studies 
• CRS graded using Lee criteria (Lee, 2014) 
• Efficacy based on International Myeloma Working 
Group (IMWG) Uniform Response Criteria 
(Rajkumar, 2011; Kumar, 2016; Cavo, 2017) 
o Overall response rate (ORR) 
o Time to response (TTR) 
o Duration of response (DOR) 
o Progression free survival (PFS) 
o Overall survival (OS) 
Phase 2: 
• CRS graded using Lee criteria (Lee, 2014) 
• Rate of IL-6 antagonist, corticosteroid, and 
rimiducid use 
• OS, PFS, TTR, MRD negative rate 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
 
Page 43 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 44 of 117 
3. 
INVESTIGATIONAL PLAN 
3.1. 
Overall Study Design 
The study will be conducted in multiple parts: a Phase 1, open-label, SAD phase; a Phase 1, 
multiple dose cycle administration phase; a Phase 1, combination administration phase; and a 
Phase 2 open-label efficacy and safety phase, in adult subjects with relapsed / refractory MM. A 
schematic of the study design for single dose administration is shown in Figure 3. Schematics for 
the Phase 1 cycle administration cohorts are shown in Figure 5 and Figure 6 in Section 15.5. A 
schematic of the study design for combination administration is shown in Figure 7 in Section 
15.6. 
Only sites that are experienced in managing oncology subjects and stem-cell/bone marrow 
transplant with the resources to manage the types of acute emergent events expected with CAR-T 
cell administration will be selected to participate in this study. A Safety Committee will meet 
regularly to review data throughout the study. 
Subjects meeting the protocol entry criteria will be eligible to enroll in the study and will follow 
the procedures outlined in Table 2 for single administration cohorts. Procedures for cycle 
administration cohorts are detailed in Section 15.5. Procedures for the Phase 1 combination 
administration are detailed in Section 15.6. After a subject enrolls, leukapheresis will be 
performed to obtain PBMCs which will be sent to a manufacturing site to produce P-BCMA-101 
CARTyrin-T cells. Allowing approximately 4 weeks for P-BCMA-101 manufacturing, subjects 
are intended to return for conditioning chemotherapy and P-BCMA-101 administration 
approximately 4 weeks from the Leukapheresis Visit (this period may be extended as deemed 
necessary by the Investigator).  
Before dosing with the P-BCMA-101 cell infusion, subjects will receive a lymphodepletion 
chemotherapy regimen of 300 mg/m2 of cyclophosphamide and 30 mg/m2 of fludarabine, with 
each agent given daily for 3 consecutive days starting at Day -5. Subjects may be maintained as 
an inpatient during lymphodepleting chemotherapy as the Investigator deems appropriate. 
After 2 rest days following the lymphodepletion chemotherapy regimen, subjects will be dosed 
with P-BCMA-101 cells administered IV over approximately 5 to 20 mins on Day 0. Prior 
studies conducted with other CAR-T therapies have observed peak toxicity to occur within 3-7 
days of investigational product administration. Study subjects will be closely monitored during 
and after the infusion and for approximately 7 days afterwards. This observation period will 
include serial assessments of adverse events (AEs), including the emergence of P-BCMA-101 
cell-related toxicities, including CRS for all subjects. CRS will be graded using the Lee criteria 
(Lee, 2014).  
Subjects may be admitted to the hospital for the P-BCMA-101 administration based on the 
Investigator’s assessment of the individual patient’s risks. Admission is not required, but subjects 
should remain within 50 miles of the hospital through approximately 14 days after last dose of P-
BCMA-101 and assessed for admission in case of symptoms of CRS or neurotoxicity such as 
fever. If admitted, subjects will not be discharged until they are assessed as stable by the 
Investigator. Subjects may be maintained as an inpatient during lymphodepleting chemotherapy 
or after the above criteria are met as the Investigator deems appropriate. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 45 of 117 
Subjects will return for regular follow up and will undergo serial assessment of safety, 
tolerability and anti-myeloma response, as specified in the Schedule of Events (Table 3). Post-
treatment follow-up visits in both Phase 1 and Phase 2 will occur at Day 10, Weeks 2, 3, 4, 6, 8, 
Months 3, 4, 5, 6, 7, 8, 9, and then every 3 months thereafter for up to 24 months after P-BCMA-
101 administration. Follow-up procedures for cycle administration cohorts are detailed in Section 
15.5. Follow-up procedures for combination administration cohorts are detailed in Section 15.6. 
All consenting subjects who receive P-BCMA-101 and who complete or withdraw from the 
study will be encouraged to enter a long-term follow-up (LTFU) protocol (P-BCMA-101-002). 
Between this study and the LTFU study, a subject will be followed for 15 years from the time of 
the last P-BCMA-101 infusion. This LTFU is for observation of delayed AEs in accordance with 
FDA (FDA, 2006) requirements for gene therapy clinical trials. Subjects will continue to be 
followed for overall survival during the LTFU phase. 
 
Figure 3: 
Schematic for Study P-BCMA-101-001 – Single Administration 
 
 
3.2. 
Study Dosing  
3.2.1. 
Dose Escalation Guidelines for Phase 1 
Phase 1 of the study is an open-label, multi-center, SAD multiple cohort study, a multiple dose 
cycle administration cohort study, and a combination administration study in approximately 120 
adult subjects. Initially, up to 6 dose levels of P-BCMA-101 will be administered intravenously 
as a single dose.  

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 46 of 117 
Proposed Doses (P-BCMA-101 cells/kg/dose) include: 
 Cohort minus 1:  0.25 × 106 
 
Cohort 1:  0.75 × 106  
 
Cohort 2:  
2 × 106 
 
Cohort 3: 
6 × 106  
 
Cohort 4:  
10 × 106 
 
Cohort 5:  
15 × 106 
Phase 1 of the study will follow a 3 + 3 design of dose-escalating cohorts, wherein 3 subjects are 
initially planned to be dosed with P-BCMA-101 T cells for each cohort. Additional subjects may 
be dosed in a cohort depending on the outcomes observed in those subjects. 
For each of the first 2 cohorts, dosing of the first 3 subjects will be staggered rather than 
concurrently, with at least a 14-day interval between subjects to assess safety, as the peak of 
toxicity in CAR-T studies occurs in 3-7 days of administration, with the vast majority within 2 
weeks and resolving by 2-3 weeks (Frey, 2016). 
At the discretion of the Safety Committee, beginning with the 3rd cohort, dosing of the first and 
second subject in each cohort will be staggered.  
Dose escalation guidelines are outlined in Table 4. 
Table 4: 
Dose Escalation Guidelines 
Outcome:  
(# subjects with DLT) 
Action:  
0 out of 3 subjects 
Escalate dose for next cohort of 3 subjects 
1 out of 3 subjects 
Treat next 3 subjects at the same dose 
≥2 out of 3 subjects 
Halt dose escalation; treat at least 6 subjects at a lower dose to determine 
the MTD1 
1 out of 6 subjects 
Escalate dose for next cohort of 3 subjects 
≥2 out of 6 subjects  
Halt dose escalation; treat at least 6 subjects at a lower dose to determine 
the MTD1 
1. MTD – the highest dose for which no more than 1 of 6 treated subjects exhibits DLT 
 
Administration of P-BCMA-101 cells will be conducted in escalating dose cohorts in a 3+3 
design. Beginning with Cohort 1, at least 3 subjects will be dosed in the cohort. If no P-BCMA-
101 cell-related DLT through Day 28 is observed in the first 3 subjects, then escalation may 
proceed to the next cohort. If a P-BCMA-101 cell-related DLT is observed in 1 of the first 3 
subjects, then at least 3 additional subjects will be treated at this dose level. If DLTs are observed 
in 2 or more subjects, the MTD will be considered to be at or below the next lower dose level 
and further enrollment may take place at a lower dose level, or an intermediate dose level may be 
tested at the discretion of the Safety Committee, otherwise escalation may proceed (i.e. the MTD 
is the highest dose cohort assessed in which this has not occurred). In the event that 2 or more 
subjects experience DLTs in Cohort 1, the Safety Committee, after review of all available data, 
may elect to dose 3 subjects in Cohort -1 with the same 3+3 expansion rules. In the event that 2 
or more subjects experience DLTs in Cohort -1, the Safety Committee, based on consideration of 
safety and efficacy data to assess risk vs. benefit, may elect to dose 3 subjects at a lower dose 
with the same 3+3 expansion rules or discontinue the study.  

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 47 of 117 
Additional subjects may be added to a cohort by the Safety Committee based on the safety and 
efficacy data from that cohort to further evaluate the safety and anti-myeloma effects of P-
BCMA-101, provided the dose does not exceed the MTD. If Cohort 5 is completed without 
concluding an overall MTD, the Safety Committee may elect to assess further escalation cohorts 
in 5-10 × 106 P-BCMA-101 cells/kg increments.  
3.2.2. 
Dosing in Cycle Administration 
In Phase 1 – Cycle Administration, multiple doses of P-BCMA-101 will be administered 
intravenously in 2 cycles (Cohort A and Cohort C) or 3 cycles (Cohort B) of 2 weeks each. The 
total dose administered will follow the 3+3 design starting at ≤ the MTD as determined during 
single administration escalation. In the first cycle 1/3 the total dose will be administered. In 
Cohort A up to 2/3 the total dose will be administered in the 2nd cycle. In Cohort B up to 1/3 the 
total dose will be administered in each of the 2nd and 3rd cycles. In Cohort C up to 2/3 the total 
dose will be administered in the 1st cycle and up to 1/3 the total dose will be administered in the 
2nd cycle. Details of the procedures are provided in Section 15.5. Prior to each infusion Serum 
creatinine should be ≤2.0 mg/dL, serum glutamic oxaloacetic transaminase (SGOT) ≤3 × the 
upper limit of normal and total bilirubin ≤2.0 mg/dL or have medical monitor approval to 
proceed with P-BCMA-101 infusion. 
3.2.3. 
Dosing in Combination Administration 
In Phase 1 – Combination Administration, P-BCMA-101 will be administered in combination 
with approved therapies:  
Lenalidomide 
Cohort R: lenalidomide 
before P-
BCMA-101 infusion; and  
Cohort RP: lenalidomide 
before apheresis 
before P-BCMA-101 infusion. 
Dosing with lenalidomide will continue for Cohort R and Cohort RP unless disease progresses. 
Refer to the lenalidomide package insert for prescribing information (Lenalidomide, 2019) (note 
particularly that lenalidomide is a presumed teratogen, pregnancy avoidance and monitoring is 
necessary). The following are additional recommendations specific to this protocol. If no DLTs 
are reported and platelets are ≥50,000/μL and neutrophils ≥1000/μL 28 days after P-BCMA-101 
administration 
If <2 
DLTs are reported in the first 6 patients treated at this dose, the starting dose in all patients may 
at the determination of the Safety 
Committee. During treatment if neutrophils decrease to <1000/μL hold lenalidomide until they 
are ≥1000/μL, 
During treatment if platelets decrease to 
<30,000/μL hold lenalidomide until they are ≥30,000/μL, 
If 
creatinine clearance is 30-60 mL/min the maximum lenalidomide dose 
 If 
creatinine clearance is <30 mL/min hold lenalidomide. Lenalidomide should be discontinued in 
case of DLT. The lowest dose allowed on this study 
 The investigator and Safety 
Committee may decide to discontinue lenalidomide at time based on other safety findings. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 48 of 117 
Patients should receive concomitant anticoagulation as indicated (eg. aspirin 325 mg orally 
daily). Do not administer glucocorticoids with lenalidomide.  
Rituximab  
Cohort RIT: 
. Refer to the rituximab package insert for 
prescribing information (Rituximab, 2019). The following are additional recommendations 
specific to this protocol. Rituximab should only be administered by a healthcare professional 
with appropriate medical support to manage severe infusion-related reactions that can be fatal if 
they occur. 
Administer only as an intravenous infusion. Do not administer as an 
intravenous push or bolus. Premedicate before each infusion with acetaminophen, an 
antihistamine, and 100 mg intravenous methylprednisolone to be completed 30 minutes prior to 
each infusion. Rituximab should be discontinued in case of infusion reaction or DLT. The 
investigator and Safety Committee may decide to discontinue rituximab at any time based on 
other safety findings. Prophylaxis and observation for infectious diseases such as 
Pneumocystis pneumonia (PCP) should be considered for patients during and following 
treatment per rituximab prescribing information. 
The dose of P-BCMA-101 administered will escalate or de-escalate following the 3+3 design 
starting at ≤ the MTD as determined during dose escalation. Details of the procedures are 
provided in Section 15.6. 
3.2.4. 
Dosing in Phase 2 
Phase 2 of the study is an open-label, multi-center study in approximately 100 adult subjects with 
relapsed/refractory MM. Subjects in Phase 2 will receive a total dose of 6-15 × 106 cells/kg (per 
the schedule determined in Phase 1). 
3.2.5. 
Repeat Dosing 
If sufficient P-BCMA-101 cells remain from manufacturing when a subject’s disease progresses, 
with Safety Committee approval additional cells may be administered up to the highest dose 
level that has successfully completed dose-limiting toxicity assessment. In order to receive an 
additional P-BCMA-101 T-cell infusion, subjects will be assigned a new subject identification 
number, they will have to meet all eligibility criteria as described for the initial dosing, and will 
undergo the same screening, enrollment, conditioning chemotherapy, and follow-up procedures 
except for leukapheresis. Details regarding retreatment procedures are provided in Section 15.4. 
3.3. 
Evaluation of Dose-Limiting Toxicity  
DLT is defined as any National Cancer Institute Common Terminology Criteria for Adverse 
Events (NCI CTCAE) Grade ≥3 event at least possibly related to P-BCMA-101 cell therapy, 
including uncontrollable expansion of P-BCMA-101 cells, and not attributable to the underlying 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 49 of 117 
disease or lymphodepleting chemotherapy regimen with onset within the first 28 days following 
the last P-BCMA-101 cell infusion with the following exceptions: 
• Grade 3 or 4 neutropenia with or without neutropenic fever resolving within 28 days 
following the last P-BCMA-101 cell infusion 
• Grade 3 fever 
• Grade 3 or 4 thrombocytopenia, with or without bleeding due to thrombocytopenia, 
resolving within 28 days following the last P-BCMA-101 cell infusion  
• Grade 3 or 4 anemia and lymphopenia 
• Grade 3 or 4 hypogammaglobulinemia 
• Alopecia 
• Grade 3 or 4 nausea, vomiting, or diarrhea which responds to medical treatment 
within 24 hours 
• Immediate hypersensitivity reactions (fever, rash, bronchospasm) occurring within 2 
hours of cell infusion (related to cell infusion) that are reversible to a Grade 2 or less 
within 6 hours of cell administration with standard antihistamine based therapy 
• Grade 3 encephalopathy that recovers to less than Grade 2 within 28 days 
• Grade 3 CRS per Lee criteria (Lee, 2014) that resolves within 14 days 
• Grade 3 non-hematological laboratory abnormalities that recover to ≤Grade 2 in 14 
days 
• Grade 4 non-hematological laboratory abnormalities that recover to ≤Grade 2 in 7 
days 
3.4. 
Number of Subjects and Duration of Study 
In Phase 1, up to 120 subjects at up to 20 sites are planned to be enrolled. In Phase 2, 
approximately 100 subjects at up to 20 sites are planned to be enrolled. Enrolled subjects will 
undergo serial measurements of safety, tolerability and response (myeloma staging). These 
measures will be obtained during a period between Screening and up to 24 months after P-
BCMA-101 administration according to the schedule of events described in Table 2 and Table 3 
for single administration, and in Section 15.5 for cycle administration cohorts and Section 15.6 
for combination administration cohorts. Subjects who experience disease progression may 
receive an additional infusion of P-BCMA-101 according to the schedule of events described in 
Table 9 and Table 10. 
After completing or withdrawing from this protocol, consenting subjects who have received P-
BCMA-101 will be encouraged to enroll in a separate protocol (P-BCMA-101-002) that allows 
for continued follow-up for a total of 15 years after the last dosing to evaluate long-term safety. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 50 of 117 
4. 
SELECTION OF STUDY POPULATION, WITHDRAWAL, 
COMPLETION, AND STOPPING CRITERIA 
4.1. 
Inclusion Criteria 
A subject must meet the following inclusion criteria to be eligible for participation in this study: 
1. Must have signed written, informed consent. 
2. Males or females, ≥18 years of age. 
3. Must have a confirmed diagnosis of active MM as defined by the IMWG criteria at initial 
diagnosis (Rajkumar, 2014). 
4. Must have measurable MM as defined by at least 1 of the following criteria: 
Phase 1: 
• Serum M-protein greater or equal to 0.5 g/dL (5 g/L) 
• Urine M-protein greater or equal to 200 mg/24 h 
• Serum free light chain (FLC) assay: involved FLC level greater or equal to 10 mg/dL 
(100 mg/L) provided serum FLC ratio is abnormal 
• Bone marrow plasma cells >30% of total bone marrow cells, or other measurable 
bone disease (e.g., plasmacytomas measurable by PET or CT) (with medical monitor 
approval) 
Phase 2: 
• Serum M-protein greater or equal to 1.0 g/dL (10 g/L) 
• Urine M-protein greater or equal to 200 mg/24 h 
• Serum FLC assay: involved FLC level greater or equal to 10 mg/dL (100 mg/L) 
provided serum FLC ratio is abnormal 
5. Must have relapsed / refractory MM as defined by the following: 
Phase 1: 
• Received at least 3 prior lines of therapy, which must have contained a proteasome 
inhibitor and immunomodulatory agent (IMiD) 
 OR 
• Received at least 2 prior lines of therapy if "double-refractory" to a proteasome 
inhibitor and IMiD, defined as progression on or within 60 days of treatment with 
these agents. 
Phase 2: 
• Received at least 3 prior lines of therapy which must have contained a proteasome 
inhibitor, an IMiD, and CD38 targeted therapy with at least 2 of the lines in the form 
of triplet combinations, and undergone ≥2 cycles of each line unless PD was the best 
response. 
AND 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 51 of 117 
• Refractory to the most recent line of therapy. 
AND 
• Undergone ASCT or not be a candidate for ASCT. 
Note: induction therapy, autologous stem cell transplant, and maintenance therapy, if 
given sequentially without intervening progression, should be considered as single 
line. 
6. Must be willing to practice birth control from the time of Screening and for the duration 
of the study (both males and females of childbearing potential).  
• Females on cohorts R, RP or RIT must commit either to abstain continuously from 
sexual intercourse or to use two methods of reliable birth control, beginning 4 weeks 
prior to initiating treatment, during therapy, during dose interruptions and continuing 
for 4 weeks following discontinuation of lenalidomide and 12 months after last dose 
of rituximab. 
• Males in cohort R or RP must always use a latex or synthetic condom during any 
sexual contact with females of reproductive potential while taking lenalidomide and 
for up to 4 weeks after discontinuing lenalidomide, even if they have undergone a 
successful vasectomy. Male patients taking lenalidomide must not donate sperm. 
7. Must have a negative serum pregnancy test at Screening and a negative urine pregnancy 
test within 3 days prior to initiating the lymphodepletion chemotherapy regimen (females 
of childbearing potential). 
• Female subjects in cohort R and RP must have two negative pregnancy tests prior to 
initiating lenalidomide. The first test should be performed within 10-14 days and the 
second test within 24 hours prior to subject starting lenalidomide therapy and then 
weekly during the first month, then monthly thereafter in females with regular 
menstrual cycles or every 2 weeks in females with irregular menstrual cycles 
8. Must be at least 90 days since autologous stem cell transplant, if performed. 
9. Must have adequate vital organ function, defined as follows (or medical monitor 
approval): 
• Serum creatinine ≤2.0 mg/dL and estimated creatinine clearance ≥30 mL/min as 
calculated using the Cockcroft-Gault formula and not dialysis-dependent. 
• Absolute neutrophil count ≥1000/μL and platelet count ≥50,000/μL (≥30,000/μL if 
bone marrow plasma cells are ≥50% of cellularity). 
• Hemoglobin >8 g/dL (transfusion and/or growth factor support is allowable). 
• Serum glutamic oxaloacetic transaminase (SGOT) ≤3 × the upper limit of normal and 
total bilirubin ≤2.0 mg/dL (unless there is a molecularly documented history of 
Gilbert’s syndrome). 
• Left ventricular ejection fraction (LVEF) ≥45%. LVEF assessment must have been 
performed within 4 weeks of enrollment. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 52 of 117 
10. Must have recovered from toxicities due to prior therapies, with the exception of 
peripheral neuropathy, to Grade ≤2 according to the NCI CTCAE version 4.03 criteria or 
to the subject's prior baseline. 
11. Subjects must have an Eastern Cooperative Oncology Group (ECOG) performance status 
of 0-1. 
4.2. 
Exclusion Criteria 
1. Is pregnant or lactating  
2. Has inadequate venous access and/or contraindications to leukapheresis. 
3. Has active hemolytic anemia, plasma cell leukemia, Waldenstrom's macroglobulinemia, 
POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, 
and skin changes), disseminated intravascular coagulation, leukostasis, or amyloidosis. 
4. Has an active second malignancy (not disease-free for at least 5 years) in addition to MM, 
excluding low-risk neoplasms such as non-metastatic basal cell or squamous cell skin 
carcinoma.  
5. Has active autoimmune disease, such as psoriasis, multiple sclerosis, lupus, rheumatoid 
arthritis, etc. (the medical monitor will determine if a disease is active and autoimmune). 
6. Has a history of significant central nervous system (CNS) disease, such as stroke, 
epilepsy, etc. (the medical monitor will determine if significant). 
7. Has an active systemic infection (e.g. causing fevers or requiring antimicrobial 
treatment). 
8. Has hepatitis B or C virus, human immunodeficiency virus (HIV) or human T-
lymphotropic virus (HTLV) infection, or any immunodeficiency syndrome. 
9. Has New York Heart Association (NYHA) Class III or IV heart failure, unstable angina, 
or a history of myocardial infarction or significant arrhythmia (e.g. atrial fibrillation, 
sustained [>30 seconds] ventricular tachyarrhythmias, etc.) 
10. Has any psychiatric or medical disorder (e.g. cardiovascular, endocrine, renal, 
gastrointestinal, genitourinary, immunodeficiency or pulmonary disorder not otherwise 
specified) that would, in the opinion of the Investigator or medical monitor, preclude safe 
participation in and/or adherence to the protocol (including medical conditions or 
laboratory findings that indicate a significant probability of not qualifying for or being 
unable to undergo adequate leukapheresis, conditioning chemotherapy and/or CAR-T cell 
administration). 
11. Has received prior gene therapy or gene-modified cellular immunotherapy (or have 
approval of the medical monitor). Subject may have received non-gene-modified 
autologous T-cells or stem cells in association with an anti-myeloma treatment. 
12. Has received anti-cancer medications within 2 weeks or 5 half-lives (whichever is longer 
or have medical monitor approval) of the time of initiating conditioning chemotherapy. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 53 of 117 
13. Has received immunosuppressive medications within 2 weeks of the time of initiating 
leukapheresis, and/or expected to require them while on study (the medical monitor will 
determine if a medication is considered immunosuppressive). Generally, all non-essential 
medications (including supplements, herbal medications, etc.) should be discontinued 
from 2 weeks before leukapheresis until 2 months after P-BCMA-101 administration due 
to the potential for unappreciated immunosuppressive effects. 
14. Has received systemic corticosteroid therapy ≥5 mg/day of prednisone or equivalent dose 
of another corticosteroid within 2 weeks of either the required leukapheresis or 1 week or 
5 half-lives (whichever is shorter) of the administration of P-BCMA-101 or is expected to 
require it during the course of the study. (Topical and inhaled steroids are permitted. 
Systemic corticosteroids are contraindicated after receiving P-BCMA-101 cells outside of 
study specific guidance). 
15. Has CNS metastases or symptomatic CNS involvement (including leptomeningeal 
carcinomatosis, cranial neuropathies or mass lesions and spinal cord compression) of 
their myeloma. 
16. Has a history of severe immediate hypersensitivity reaction to any of the agents used in 
this study. 
17. Has a history of having undergone allogeneic stem cell transplantation, or any other 
allogenic or xenogeneic transplant, or has undergone autologous transplantation within 
90 days. 
18.  Unable to take acetylsalicylic acid (ASA) (325 mg) daily as prophylactic 
anticoagulation. Patients intolerant to ASA may use warfarin or low molecular weight 
heparin) (Cohorts R and RP only). 
19. History of thromboembolic disease within the past 6 months, regardless of 
anticoagulation (Cohorts R and RP only).  
4.3. 
Subject Withdrawal 
Subjects who are enrolled and do not complete the study protocol will be considered to have 
prematurely discontinued the study. The reasons for premature discontinuation (for example, 
voluntary withdrawal, toxicity, death) must be recorded on the case report form. Final study 
evaluations will be completed at the time of discontinuation. If a subject discontinues from this 
study, the events for the next visit scheduled should be performed (including all safety and 
efficacy evaluations) prior to initiating alternative medical, radiation or surgical intervention and 
recorded as an end-of-study visit for this study. Subjects who withdraw from the protocol after 
having received P-BCMA-101 will be encouraged to enroll in the companion long-term follow-
up protocol P-BCMA-101-002. Potential reasons for premature discontinuation include: 
1. The subject is lost to follow-up. 
2. The judgment of the Investigator is that the subject is too ill to continue. 
3. Subject noncompliance with study therapy and/or clinic appointments. 
4. Pregnancy 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 54 of 117 
5. Voluntary withdrawal; a subject may remove himself/herself from the study at any time 
without prejudice. A subject may withdraw from the study at any time they wish to 
withdraw consent. 
6. Significant progression of malignancy, requiring alternative medical, radiation or surgical 
intervention. If disease markers decrease from P-BCMA-101 cell activity after reaching 
progressive disease instead of confirming a prior increase, they should subsequently 
increase from that level for consideration of progressive disease to discontinue the subject 
from the protocol unless another systemic myeloma therapy is indicated.  
7. Technical difficulties are encountered in the T cell genetic modification and expansion 
procedure that precludes the generation of clinical cell doses that meet all Quality Control 
criteria. 
8. Termination of the study by the Principal Investigator, the sponsor, the study funder, the 
Institutional Review Board (IRB)/Independent Ethics Committee (IEC), or the Food and 
Drug Administration (FDA). 
4.4. 
Study Termination 
The Sponsor may suspend or terminate the study at any time for any reason. If the study is 
suspended or terminated, the Sponsor will ensure applicable sites, regulatory agencies and 
IRBs/IECs are notified as appropriate. 
If the Investigator stops/terminates the study at their site the Sponsor must be notified. The 
Sponsor will ensure Regulatory Agencies and IRBs/IECs are notified as appropriate. 
The Sponsor will ensure appropriate end of study declarations are made to the relevant 
Regulatory Agencies/IECs in accordance with local regulations. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 55 of 117 
5. 
STUDY TREATMENTS 
5.1. 
Leukapheresis 
Subjects who complete all screening procedures and meet all eligibility criteria will 
undergo leukapheresis to harvest peripheral blood mononuclear cells (PBMCs) for the 
manufacture of P-BCMA-101. This visit should occur within ~28 days of the Screening 
Visit. Subjects enrolled in the study will undergo standard leukapheresis procedure using 
Spectra Optia system (Terumo BCT), or equivalent leukapheresis machine, at the 
enrolling hospital. Immediately following the procedure, leukapheresed cells will be 
shipped in validated, temperature-controlled conditions to the manufacturing and analytic 
sites. The intent is to perform a 10-15 liter (minimum and maximum defined by site 
policies) apheresis and harvest a target 
white blood cells (WBC) (count is also acceptable as total nucleated cells 
[TNC]). For additional detail, please refer to the Study Reference Manual (Apheresis 
Center Manual). As it is recognized that volume, cell number and other output parameters 
reached at the end of apheresis will vary between patients, machines, methods and 
operators, this is provided as guidance as opposed to absolute requirements. 
The manufacturing of P-BCMA-101 is diagramed in Figure 4 below. The collected apheresis 
products will be transported by courier to the manufacturer for immediate manufacturing. 
Manufacturing of P-BCMA-101, which includes T cell isolation, electroporation with piggyBac 
DNA plasmid (P-BCMA-101 plasmid encoding anti-BCMA CARTyrin) and Super piggyBac 
transposase mRNA (SPB mRNA), CARTyrin+ T cell selection, and cell expansion, will be 
completed 
  
Following product release for infusion, frozen P-BCMA-101 product will be shipped by courier 
to the pharmacy or applicable cell therapy facility of the enrolling study center. P-BCMA-101 
will be stored there at ≤-130°C until time of administration. 
If P-BCMA-101 cells that meet release criteria cannot be manufactured from the leukapheresis 
sample, a second leukapheresis and manufacturing may be attempted. If the second attempt also 
fails, the subject will be withdrawn from the study and considered not to have undergone study 
treatment. If sufficient P-BCMA-101 cells remain from manufacturing when a subject’s disease 
progresses, with Safety Committee approval additional cells may be administered up to the 
highest dose level that has successfully completed dose-limiting toxicity assessment. 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 56 of 117 
Figure 4: 
Clinical Product Manufacturing and Process Diagram 
Once the product is manufactured, subjects will return to the clinic for the Conditioning 
Chemotherapy and P-BCMA-101 Administration Periods approximately 4 weeks (this period 
may be extended at the discretion of the Investigator and medical monitor) after the 
Leukapheresis Visit.  
Subjects who experience rapid disease progression following the Leukapheresis Visit and prior 
to admission for the Conditioning Chemotherapy and P-BCMA-101 Administration Period may 
be administered salvage therapy at the discretion of the Investigator. Salvage therapy should not 
be used unless necessary and will be determined by the subject’s clinical history (previously used 
agents are preferred, and medical monitor approval needed) at the discretion of the Investigator. 
If a subject receives salvage therapy, the Conditioning Chemotherapy and P-BCMA-101 
Administration Period should be scheduled at least 2 weeks or 5 half-lives after the date of the 
last treatment of salvage therapy and the subject should meet the criteria described in Section 4 
and Section 6 regarding entry criteria and concomitant medications. The subject’s response to the 
salvage therapy will be evaluated by the Investigator and medical monitor in order to determine 
whether the subject will remain eligible to receive the Investigational Product.  
Subjects will be permitted to receive radiation therapy or plasmapheresis and exchange for 
palliative purposes throughout the study period. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 57 of 117 
5.2. 
Conditioning Chemotherapy 
Before dosing with the P-BCMA-101 cell infusion, subjects will receive a conditioning 
lymphodepletion chemotherapy regimen of 300 mg/m2 of cyclophosphamide and 30 mg/m2 of 
fludarabine, with each chemotherapy agent given sequentially IV over 30 minutes daily for 3 
consecutive days (Day -5 through Day -3). Subjects should continue to meet entry criteria at the 
time of initiation of conditioning chemotherapy or have medical monitor approval. For subjects 
in Cohort R, Cohort RP and Cohort RIT, the combination therapy should be administered prior 
to conditioning chemotherapy on applicable days. The following assessments should be repeated 
within 72 hours prior to Day -5: Mini Mental Status Exam (MMSE), physical exam, vital signs, 
chemistry panel including electrolytes and magnesium, hematology including B and T cell 
counts, coagulation, assessment of circulating myeloma/plasma cells, and pregnancy test (if 
applicable). A baseline myeloma response assessment must be conducted within 7 days prior to 
initiating conditioning chemotherapy. Subjects may be admitted and treated as inpatients at this 
point at the discretion of the Investigator. 
5.3. 
P-BCMA-101 Administration 
5.3.1. 
Description 
P-BCMA-101 is comprised of activated T cells genetically modified through an electroporation-
based, non-viral (DNA transposon) gene delivery system called the piggyBac (PB) DNA 
modification system. The PB DNA modification system efficiently moves DNA from a plasmid 
to a chromosome via a "cut and paste" mechanism. 
 
 
 
 
 
5.3.2. 
Product Labeling 
Each product bag will be labeled with product name (P-BCMA-101), date of product 
manufacturing, product lot number, storage conditions, part number, and at least two non-

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 58 of 117 
personal subject identifiers (such as the subject’s initials, birth date, and/or study subject 
identification number). In addition, the product bags will be labeled with the following for 
caution: “FOR AUTOLOGOUS USE ONLY”, “NOT EVALUATED FOR INFECTIOUS 
SUBSTANCES”, and “Caution: New Drug—Limited by Federal law to Investigational Use”. 
5.3.3. 
Storage  
Upon receipt of the investigational product and any related study treatment supplies, an 
inventory must be performed, and a drug receipt log filled out and signed by the person 
accepting the shipment. It is important that the designated study staff inventories, counts and 
verifies that the shipment contains all the items noted in the shipment inventory. Any damaged or 
unusable investigational product study drug in a given shipment will be documented in the study 
files. The Investigator must notify study sponsor or designee of any damaged or unusable study 
treatments that were supplied to the Investigator’s site. P-BCMA-101 cells may require return to 
the sponsor or designee for various reasons, including but not limited to: 1) mislabeled product; 
2) condition of subject prohibits infusion/injection, and 3) subject refuses infusion/injection. 
Overall, any unused product will be returned to the sponsor or designee. 
Bags containing P-BCMA-101 cells will be stored at the site in blood bank conditions in a 
monitored ≤-130oC freezer until the subject is ready for infusion. 
5.3.4. 
Preparation 
Recommended pre-medications prior to T cell infusion include 650 mg acetaminophen and 25-
50 mg diphenhydramine hydrochloride. These medications may be given every 6 hours, as 
needed. Non-steroidal anti-inflammatory agents may be given for fever not controlled by 
acetaminophen, however, use should be carefully considered with regards to factors potentially 
impacting the subject’s tolerance, such as bleeding risk and renal function. Evaluation for sepsis 
should be considered for fever of unexpected severity or duration, or other suggestive 
symptomology. Systemic corticosteroids should not be administered unless necessitated as 
described in supportive care guidance (Section 6.3 ), due to the potential for adverse impact on 
the efficacy of the T cell-based investigational product. 
Subjects should continue to meet liver and renal laboratory entry requirements prior to dosing 
(i.e. prior to initiating conditioning chemotherapy). Additionally, there should continue to be no 
evidence of active infection, or significant cardiac (e.g. hypotension requiring pressor or 
uncontrollable arrhythmia) or pulmonary compromise (e.g. supplemental oxygen requirement or 
significant progressive infiltrates on chest x-ray). 
5.3.5. 
Dosing and Administration 
In Phase 1, dose levels of P-BCMA-101 will be administered intravenously as a single dose or 
multiple doses. Dose levels will be tested by cohort in the 3+3 escalation design described in the 
Dose Escalation Guidelines (Section 3.2). In Phase 2, subjects will receive a total dose of 6 to 15 
× 106 cells/kg (per the schedule determined in Phase 1). 
Cryopreserved P-BCMA-101 is transported to the enrolling study center and stored at ≤-130oC 
until infusion. If the label on a cryobag received for a subject indicates the contents are more 
than the assigned dose of P-BCMA-101 cells for the cohort 
only a volume of the 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 59 of 117 
 
Immediately 
prior to infusion, P-BCMA-101 is thawed and infused as detailed below. No further processing 
of P-BCMA-101 will be needed prior to infusion. Cells should be logged in the investigational 
pharmacy or applicable cell therapy facility.  
After 2 rest days following the lymphodepletion chemotherapy regimen, subjects will be dosed 
with P-BCMA-101 administered IV. Subjects may be admitted to the hospital for the P-BCMA-
101 administration based on the investigator’s assessment. Admission is not required, but 
subjects should remain within 50 miles of the hospital through approximately 14 days after last 
dose of P-BCMA-101 and assessed for admission in case of symptoms of CRS or neurotoxicity 
such as fever. Immediately prior to infusion, P-BCMA-101 cells are transferred at ≤-130oC (in 
vapor phase liquid nitrogen) to the subject bedside. The cells will be thawed at the bedside just 
prior to infusing using a water bath maintained at 36°C to 38°C (thawing at a different location 
and transporting to bedside at 2-8°C must be pre-approved by the sponsor). The bag will be 
gently massaged until the cells have just thawed. There should be no frozen clumps left in the 
container. If the bag appears to be damaged or leaking, or otherwise compromised, it should not 
be infused, and should be returned to the sponsor or sponsor’s designee. The infusion bag label 
will have at least 2 unique identifiers including the subject’s study identification number and 
initials or birth date. Prior to the infusion, 2 individuals will independently verify all this 
information in the presence of the subject and so confirm that the information is correctly 
matched to the participant. Emergency medical equipment (i.e., emergency trolley) will be 
available during the infusion in case the subject has an allergic response, or severe hypotensive 
crisis, or any other reaction to the infusion. An intensive care unit should be within a reasonable 
distance of the study administration site. 
The P-BCMA-101 cells will generally be provided in 250 mL infusion bags at a concentration 
ranging approximately from 
, dependent on the dose. They should be 
administered by intravenous infusion at a flow rate of approximately 1 mL to 20 mL per minute 
through an 18-gauge latex-free, Y-type blood set with a 3-way stopcock or butterfly needle as 
appropriate for the dose and volume. The duration of the infusion should be approximately 5-20 
minutes, as appropriate for the volume. It is intended P-BCMA-101 cells be infused within 2 
hours of thawing, and the maximum stability assessed is 4 hours. For additional detail, see also 
Study Reference Manual (Pharmacy and Administration Manual).  
Vital signs (temperature, respiration rate, pulse, and blood pressure) will be taken before and 
after infusion, then every 15 minutes for at least one hour and until these signs are satisfactory 
and stable. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 60 of 117 
Empty bags and remaining cells should be disposed of per institutional biosafety guidelines. In 
case of unused or damage product/packaging, the sponsor should be contacted to determine 
disposition. 
Prior studies conducted with other CAR-T therapies have observed peak toxicity to occur within 
3-7 days of investigational product administration. Study subjects will be closely monitored 
during and after the infusion and for approximately 7 days afterwards. This observation period 
will include serial assessments of AEs, including the emergence of P-BCMA-101-related 
toxicities, such as CRS for all subjects.  
If admitted, subjects will not be discharged until they are assessed as stable by the Investigator. 
Subjects may be maintained as an inpatient during lymphodepleting chemotherapy or after the 
above criteria are met as the Investigator deems appropriate. Subjects will return for regular 
follow up and will undergo serial assessment of safety, tolerability and anti-myeloma response as 
specified in the Schedule of Events tables. 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 61 of 117 
6. 
CONCOMITANT MEDICATION AND TREATMENT 
6.1. 
Prohibited Concomitant Medications and Treatments 
• May not receive on study or have received anticancer/anti-myeloma medications 
after P-BCMA-101 administration or within 2 weeks or 5 half-lives (whichever is 
longer or have medical monitor approval) of the time of initiating leukapheresis or 
conditioning chemotherapy. Salvage treatment should not be used unless 
necessary but may be administered between leukapheresis and conditioning 
chemotherapy if deemed necessary by the Investigator and approved by the 
medical monitor. The intervals described in the exclusion criteria need to be met 
for the relevant agents.  
• May not have received immunosuppressive medications within 2 weeks or 5 half-
lives (whichever is longer) at the time of initiating leukapheresis, and/or is 
expected to require them while enrolled in the study, or receive them after P-
BCMA-101 administration (the medical monitor will determine when and if a 
potentially immunosuppressive medication is allowed). 
• May not have received systemic corticosteroid therapy ≥5 mg/day of prednisone 
or equivalent dose of another corticosteroid within 2 weeks of either the required 
leukapheresis or 1 week or 5 half-lives (whichever is shorter) of the 
administration of P-BCMA-101 or is expected to require it during the course of 
the study (topical, and inhaled steroids are permitted). Systemic corticosteroids 
are generally contraindicated after receiving P-BCMA-101 outside of study 
specific guidance regarding the management of AEs, directed use with 
combination therapies, or with medical monitor approval. 
• May not receive G-CSF or GM-CSF within 2 weeks of the time of initiating 
leukapheresis, within 5 half-lives before planned administration of P-BCMA-101, 
or within 2 months after administration of P-BCMA-101 without medical monitor 
approval. 
• Generally, all non-essential medications (including supplements, herbal 
medications, etc.) should be discontinued from 2 weeks before leukapheresis until 
2 months after P-BCMA-101 administration due to the potential for unappreciated 
immunosuppressive effects. 
6.2. 
Permitted Concomitant Medications and Treatments 
Subjects will be permitted to receive radiation therapy or plasmapheresis and exchange for 
palliative purposes throughout the study period. Other diagnostics or treatments that the 
Investigator considers necessary for a subject’s welfare may be conducted at the discretion of the 
Investigator in keeping with standards of medical care and in adherence to the protocol.  
All prescription and nonprescription medication, vitamins, herbal and nutritional supplements, 
taken by the subject during the 30 days prior to Screening will be recorded at the Screening Visit. 
At every visit, concomitant medications will be recorded in the medical record and on the 
appropriate electronic Case Report Form (eCRF). Any additions, deletions, or changes of these 
medications will be documented. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 62 of 117 
6.3. 
Supportive Care Guidance 
Recommended pre-medications prior to P-BCMA-101 infusion include 650 mg acetaminophen 
and 25 to 50 mg diphenhydramine hydrochloride. These medications may be given every 6 hours 
as needed. Non-steroidal anti-inflammatory agents may be given for fever not controlled by 
acetaminophen, however, use should be carefully considered with regards to factors potentially 
impacting the subjects’ tolerance, such as bleeding risk and renal function. Work-up for sepsis 
should be considered for fever of unexpected severity or duration, or other suggestive 
symptomology. Systemic corticosteroids should not be administered unless necessitated by a 
severe or life-threatening AE as described below, due to the known adverse impact on the 
survival of the T cells and consequent efficacy of the T cell-based investigational product. 
The Investigator must use appropriate medical judgment in the management of AEs, including 
expected events such as those of conditioning chemotherapy, as well as those of CAR-T cell 
therapies including CRS. CRS is perhaps the most common AE associated with CAR-T cell 
administration and is characterized by cytokines being released into circulation by active T-cells 
and the downstream effects on multiple organ systems. CRS has also been seen following the 
infusion of therapeutic monoclonal antibodies (mAbs), systemic interleukin-2 (IL-2), and the 
bispecific CD19-CD3 T-cell engaging antibody, blinatumomab. The incidence and severity of 
CRS has been reported to correlate with disease burden in patients with acute lymphoblastic 
leukemia. Clinical and laboratory measures range from mild CRS (e.g. constitutional symptoms, 
high fever) to severe CRS and/or potentially life threatening (e.g. high fever, malaise, fatigue, 
myalgia, nausea, anorexia, tachycardia/hypotension, hypoxia, capillary leak, cytopenias, cardiac 
dysfunction, renal impairment, hepatic failure, disseminated intravascular coagulation. 
Neurologic changes and/or cerebral edema have been associated with the potential for severe or 
fatal outcomes). The goal of CRS management in CAR-T cell therapy is to prevent life-
threatening conditions while preserving the benefits of antitumor effects, thus therapy is 
generally carefully tailored to symptoms and/or markers of CRS. For example, corticosteroids 
and other aggressive immunosuppressive agents are effective treatments for CRS, but also 
frequently toxic the CAR-T cells. Suggested management of CRS is generally per Lee et al. 
(Lee, 2014) and Brudno et al. (Brudno, 2016). For detailed toxicity management 
recommendations see the Study Reference Manual (Toxicity Reference Manual). In summary: 
Symptomatic treatment of grade 1 CRS is suggested. CRS is defined as Grade 2 when the subject 
develops hypotension responsive to fluids or 1 low-dose vasopressor or mild respiratory 
symptoms responsive to low flow oxygen (40% FiO2) or Grade 2 organ toxicity. Because 
hypotension is a major driver of severity grading, it is imperative that a clear baseline blood 
pressure be established prior to initiation of therapy. The decision to intervene with 
immunosuppressive agents (tocilizumab +/- corticosteroids) for subjects with Grade 2 CRS is 
influenced by the degree to which the subject is judged to be able to tolerate the altered 
hemodynamics and organ stresses associated with the syndrome. In older subjects and subjects 
with significant comorbidities, depending on clinical judgment, it may be appropriate to 
intervene with immunosuppression in subjects with Grade 2 CRS. Subjects in whom fluid 
therapy and 1 low-dose vasopressor are not sufficient to reverse hypotension are classified as 
severe or Grade 3 CRS. Similarly, subjects who require more than low flow oxygen or show 
evidence for Grade 3 organ toxicity, including but not limited to coagulopathy, renal, or cardiac 
dysfunction, should be considered Grade 3. Subjects with Grade 3 CRS need to be monitored 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 63 of 117 
very closely, likely in an intensive care unit with 1:1 nursing care. Importantly, in subjects with 
Grade 2 or higher CRS, careful attention should be paid to cardiac function, as cardiac 
decompensation may occur and may not be readily evident without careful monitoring. Frequent 
echocardiographic monitoring may be indicated in subjects in whom there is a concern of cardiac 
dysfunction. Subjects with Grade 3 CRS should be treated with immunosuppressive agents such 
as tocilizumab and corticosteroids (e.g. 10 mg dexamethasone IV every 6 hours) because of the 
risk for progression and the potential for irreversible organ dysfunction, with the goal of 
preventing progression to Grade 4. Grade 4 CRS occurs when subjects experience toxicity that is 
immediately life threatening, including a need for mechanical ventilation or Grade 4 organ 
toxicity. It is recommended that all subjects with Grade 4 CRS be treated with 
immunosuppressive and/or cytotoxic agents such as tocilizumab (typically 8 mg/kg daily for 1 to 
2 days), corticosteroids (e.g. methylprednisolone 1g daily for 3 days), rimiducid (typically 0.4 
mg/kg) and/or an aggressive immunosuppressive/cytotoxic agent such as cyclophosphamide (e.g. 
1.5 g/m2) (generally use of rimiducid would be prioritized over use of a systemically toxic 
cytotoxic agent) in an attempt to suppress the inflammatory cascade and to prevent irreversible 
organ dysfunction. These options may also be considered for Grade 3 toxicity unresponsive to 
other measures. 
When indicated, tocilizumab is typically administered intravenously over 1 hour at a dose of 
8 mg/kg, with an option to repeat the dose if clinical improvement does not occur within 24 to 48 
hours. In subjects with CRS who respond to tocilizumab, fever and hypotension often resolve 
within a few hours, and pressors and other supportive care measures can potentially be weaned 
quickly thereafter. In some cases, however, symptoms may not completely resolve, and 
continued aggressive support may be necessary for several days. 
If a subject develops uncontrollable P-BCMA-101 T cell expansion or other clinically significant 
Grade 3-4 toxicities possibly related to P-BCMA-101, it is recommended the Investigator review 
the clinical scenario and potential confounding factors, and consider treating with 
immunosuppressive and/or cytotoxic agents, such as corticosteroids (e.g. methylprednisolone 1g 
daily for 3 days), rimiducid (typically 0.4 mg/kg) and/or an aggressive 
immunosuppressive/cytotoxic agent such as cyclophosphamide (e.g. 1.5 g/m2). 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 64 of 117 
7. 
SCHEDULE OF ASSESSMENTS AND PROCEDURES 
7.1. 
Schedule of Procedures 
The Schedule of Procedures for this study will be the same for subjects in single administration, 
and is provided in Table 2 for procedures from Screening through conditioning chemotherapy 
and Table 3 for procedures from P-BCMA-101 administration through follow-up. The Schedule 
of Procedures tables for cycle administration cohorts are provided in Section 15.5. The Schedule 
of Procedures tables for combination administration are provided in Section 15.6. Following 
obtaining consent, screening and confirmation of eligibility, all subjects will undergo 
leukapheresis, conditioning chemotherapy, and P-BCMA-101 administration as described in 
Section 5.3. Subjects will return for regular follow up and will undergo serial assessment of 
safety, tolerability and anti-myeloma response as specified in each respective Schedule of Events 
table. Post-treatment follow-up visits will occur at Day 10, Weeks 2, 3, 4, 6, 8, Months 3, 4, 5, 6, 
7, 8, 9, 12, 15, 18, 21, and 24. 
7.2. 
Clinical Assessments  
Clinical assessments and procedures to be performed throughout the study are outlined in the 
Schedule of Events tables. Assessment timing windows not described in these tables may be 
found in the Study Reference Manual. 
7.2.1. 
Medical History 
General medical history and demographics will be recorded at Screening, as well as any baseline 
symptoms or medical conditions that would be considered AEs on study. MM disease history, 
including results of MM assessments obtained in the 6 months prior to Screening, as described in 
Inclusion Criterion #4, will also be obtained. Myeloma response will be collected as described in 
Section 7.2.10. 
7.2.2. 
Physical and Neurological Examination 
A complete physical examination, including a neurological examination, will be performed at 
Screening; within 72 hours prior to start of conditioning chemotherapy; on Day -5, on Day 0 
before and approximately 1 hour after P-BCMA-101 administration; on Days 1, 4, 7, 10; Weeks 
2, 3, 4, 6, and 8, and starting at Month 3 every 3 months for 24 months. After administration of 
P-BCMA-101, physical examination, including a neurological examination (or any other 
assessments deemed appropriate by the Investigator) should be repeated as often as clinically 
indicated by the AEs observed or by the institution’s standards, but at minimum once per study 
visit.  
7.2.3. 
Vital Signs 
Vital signs, including blood pressure, heart rate, respiration rate, O2 saturation and temperature 
will be obtained at visits as outlined in the Schedule of Events tables. On Day 0, vital signs 
(temperature, respiration rate, heart rate, O2 saturation and blood pressure) will be taken before 
and approximately one hour after P-BCMA-101 administration, then every 15 minutes (+/- 5 
minutes) for at least one hour and until these signs are satisfactory and stable. Weight will be 
obtained at Screening, Enrollment and Leukapheresis. Height will be recorded only at Screening. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 65 of 117 
7.2.4. 
Performance Status 
ECOG performance status will be assessed at Screening and Day -5 using the ECOG 
performance scale described in Appendix 15.1. 
7.2.5. 
Clinical Safety Assessments 
Subjects will be assessed for AEs throughout the study. AEs will be graded by the NCI CTCAE 
Version 4.03 criteria. Details on assessment and reporting of AEs and SAEs are provided in 
Section 8.  
7.2.6. 
Cardiac Assessments 
A 12-lead electrocardiogram (ECG) will be obtained at Screening, Days 0 (before and 
approximately 1 hour after P-BCMA-101 administration), 1, 4, 7, Week 4, and starting at Month 
3 every 3 months for 24 months. Echocardiogram will be obtained at Screening only. 
7.2.7. 
Laboratory Assessments 
7.2.7.1. 
Clinical Chemistry and Hematology 
Clinical chemistry and hematology laboratory evaluations will be performed as outlined in the 
Schedule of Events tables (Chemistry Panel, Hematology including B and T cells, Coagulation).  
The chemistry panel will include sodium, potassium, chloride, magnesium, bicarbonate, blood 
urea nitrogen, creatinine, calcium, albumin, glucose, lactate dehydrogenase (LDH), total protein, 
alanine aminotransferase (ALT), aspartate aminotransferase (AST)/ Serum glutamic oxaloacetic 
transaminase (SGOT), bilirubin (total and direct), and alkaline phosphatase. Coagulation 
evaluations will include PTT (partial thromboplastin time) and PT (prothrombin time) or 
international normalized ratio (INR). Assessments for tumor lysis (uric acid and phosphate) will 
be performed at baseline and Days 1, 4, 7, then as clinically indicated. 
On Day 0, chemistry panel, hematology including B and T cells, and coagulation evaluations 
should be obtained before and approximately 1 hour after P-BCMA-101 administration. After 
administration of P-BCMA-101, these (or any other assessments deemed appropriate by the 
Investigator) should be repeated as often as clinically indicated by the AEs observed or by the 
institution’s standards, but at minimum once daily on Days 1, 4, 7 and 10 and as outlined in the 
Schedule of Events tables.  
Hematology laboratory evaluation will include complete blood count, platelets, B (CD19) and T 
(CD3) cell counts and CD4 and CD8 (at all timepoints except Days -3 and -4), and assessment of 
circulating myeloma/plasma cells (e.g., by flow cytometry or CBC with manual differential) is 
required at timepoints prior to P-BCMA-101 administration. Contact the sponsor and refer to 
exclusion criteria #3 and #10 if circulating myeloma/plasma cells are identified in the Enrollment 
& Baseline sample. 
7.2.7.2. 
Pregnancy Testing 
Female subjects of childbearing potential must have a negative serum pregnancy test at 
Screening and a negative urine pregnancy test within 72 hours prior to initiating the conditioning 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 66 of 117 
chemotherapy. Urine pregnancy tests will be performed prior to each dose of P-BCMA-101 and 
at subsequent post-treatment visits starting at Week 2. 
Female subjects in cohort R and RP must have two negative pregnancy tests prior to initiating 
lenalidomide. The first test should be performed within 10-14 days and the second test within 24 
hours prior to subject starting lenalidomide therapy and then weekly during the first month, then 
monthly thereafter in females with regular menstrual cycles or every 2 weeks in females with 
irregular menstrual cycles. 
7.2.7.3. 
Infectious Disease Screening 
Laboratory test will be performed at Screening for the presence of HIV 1 and 2 antibody, 
hepatitis B surface antigen, hepatitis C antibody, and HTLV. 
7.2.8. 
Cytokine Release Syndrome  
Blood samples for detection of CRS markers: 
 
will be obtained as indicated in the Schedule of Events tables.  
7.2.9. 
Mini Mental Status Exam 
Mini Mental Status Exam (MMSE) will be performed as indicated in the Schedule of Events 
tables. The MMSE should include a sample of the subject’s handwriting at all timepoints. 
7.2.10. 
Disease Response Assessments 
7.2.10.1. PET-CT Assessment 
Assessment of disease by PET-CT scan will be performed at the Baseline visit within 7 days 
prior to initiating conditioning chemotherapy, then as clinically indicated (e.g. every 8 weeks if 
soft tissue plasmacytomas are found at baseline that require imaging as part of response 
assessments or to confirm response). 
7.2.10.2. Response and Response Rates 
Laboratory samples for evaluation of myeloma response will be drawn at Screening, Baseline 
visit within 7 days of initiating conditioning chemotherapy, Day 0 (before P-BCMA-101 
administration), Weeks 2, 3, 4, 6, 8, Months 3, 4, 5, 6, 7, 8, 9, 12, 15, 18, 21, and 24. 
Myeloma response will be assessed per the International Myeloma Working Group criteria and 
based on the standard assessments, as clinically indicated (e.g., ≤1 week after an assessment 
demonstrating a response for confirmation), for each subject, such as serum protein 
electrophoresis (SPEP), urine protein electrophoresis (UPEP), serum immunofixation (SIFE), 
urine immunofixation (UIFE), serum free light chains (FLC), PET/CT (Positron Emission 
Tomography / Computed Tomography, liver background) and/or bone marrow biopsy/aspirate. 
A baseline myeloma response assessment must be done within 7 days prior to initiating 
conditioning chemotherapy. Fresh bone marrow biopsy and aspirate must be collected at either 
screening or baseline (typically within 7 days of initiating conditioning chemotherapy) and at 
Week 4, Months 3, 6 and 12, then as clinically indicated, or have a medical monitor exemption.  

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 67 of 117 
Response rate will be determined as the number of subjects in each best overall response 
category divided by the number of subjects in the study population. 
7.2.10.3. Time to Response 
For subjects with a response, the time to response will be assessed from time of P-BCMA-101 
administration to time of first documented response (partial response [PR] or better). 
7.2.10.4. Duration of Response 
For subjects with a response, the duration of response will be assessed from time of first 
documented response (PR or better) to time of confirmed disease progression (deaths from other 
causes will be censored). 
7.2.10.5. Progression Free Survival 
Progression Free Survival (PFS) from time of P-BCMA-101 administration to time of confirmed 
disease progression or death will be assessed for all subjects.  
7.2.10.6. Overall Survival 
Overall survival (OS) from time of P-BCMA-101 administration to time of death will be 
assessed for all subjects.  
7.2.11. 
Long-Term Follow-up 
All subjects treated with P-BCMA-101 in this study will be followed for up to 2 years in this 
study. After they discontinue this protocol, consenting subjects will roll over into a separate 
long-term safety follow-up protocol (P-BCMA-101-002) and be followed for a total of 15 years 
post-last dosing with P-BCMA-101. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 68 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 69 of 117 
8. 
RECORDING ADVERSE EVENTS 
The Principal Investigators are responsible for detecting, documenting, and reporting events that 
meet the definition of an AE or a serious adverse event (SAE). Individual AEs should be 
evaluated by the Investigator and reported to the Sponsor via the eCRF. This includes the 
evaluation of the intensity, the causality between the investigational product and/or concomitant 
therapy and the AE, seriousness, etc. 
8.1. 
Time Period for Collecting AE and SAE Information 
All AEs and SAEs will be collected from enrollment until the Month 24 visit, or withdrawal 
from the protocol, whichever is shorter. 
8.2. 
Definition of Adverse Event 
In accordance with the International Conference of Harmonization (ICH), an AE is any untoward 
medical occurrence in a subject or clinical investigation subject who receives a pharmaceutical 
product. The event does not necessarily have a causal relationship with study treatment to be an 
AE. An AE can therefore be any unfavorable and unintended sign (including an abnormal 
laboratory finding), symptom, or disease temporally associated with the use of an investigational 
product, whether or not considered related to the investigational product. Preexisting conditions 
should only be reported as AEs if they worsen during the study. Progression of the cancer under 
study and symptoms thereof are not considered an AE unless it is considered to be drug related 
by the Investigator. New abnormal laboratory findings should only be considered AEs if they 
necessitate treatment or are considered clinically significant by the Investigator. 
AEs should be recorded in the eCRF using a diagnosis or possible diagnosis, and rated for 
intensity, causality, and seriousness. In the absence of a diagnosis, individual symptoms or 
findings may be recorded and the eCRF updated to reflect a final diagnosis once additional 
information becomes available.  
All AEs should be followed until:  
• Resolved or improved to baseline. 
• Investigator confirms no further improvement can be expected. 
On completion or discontinuation from the study, AEs will be followed for 30 days or until one 
of the above criteria is met. Ongoing AEs will continue to be recorded and monitored into the 
long-term follow up study. 
8.2.1. 
Assessment of Intensity 
Adverse events will be graded according to the NCI CTCAE version 4.03. The Investigator will 
assess intensity of all AEs using this five-point scale (Grade 1-5) and record on the eCRF. 
AEs not specifically listed on the NCI CTCAE should be graded according to Table 5: 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 70 of 117 
Table 5: 
Grading of AEs Not Specified in NCI CTCAE version 4.03 
NCI CTCAE 
Grade 
Equivalent to 
Definition 
Grade 1 
Mild 
Discomfort noticed but no disruption of normal daily 
activity. 
Grade 2 
Moderate 
Discomfort sufficient to reduce or affect daily activity; 
minimal medical intervention is indicated. 
Grade 3 
Severe 
Incapacitating with inability to work or perform normal 
daily activity; treatment or medical intervention is indicated 
in order to improve the overall well-being or symptoms; 
delaying the onset of treatment is not putting the survival of 
the subject at direct risk. 
Grade 4 
Life-threatening/ 
disabling 
An immediate threat to life that requires urgent medical 
intervention. 
Grade 5 
Death 
AE resulting in death. 
 
8.2.2. 
Assessment of Causality 
The Investigator will assess the causal relationship between the AE and investigational product 
(P-BCMA-101 and/or rimiducid, if administered) according to his/her best clinical judgement. 
An assessment of possibly/probably/definitely related is meant to convey there is evidence of a 
causal relationship, not that a relationship cannot be ruled out. The Investigator should consider 
alternative causes such as natural history of the underlying disease, lymphodepleting 
chemotherapy, concomitant medications, and other risk factors when making an assessment. The 
following scale will be used as guidance: 
• Not related – The subject did not receive the investigational product; the temporal 
sequence of the AE onset relative to administration of the investigational product is 
not reasonable; or there is another highly likely cause of the AE. 
• Unlikely related – The AE is not reasonably, temporally correlated with T-cell 
infusion; the AE is more likely explained by another cause or causes, but a theoretical 
impact of T cell infusion on the onset or severity of the event is remotely possible in a 
multi-factorial context 
• Possibly related – There is evidence of exposure to the investigational product; the 
temporal sequence of the AE onset relative to T cell infusion is plausible; there is a 
reasonable explanation for the investigational product to have elicited the AE; and the 
investigational product is equally likely to have caused the AE as other explanations. 
• Probably related – There is evidence of exposure to the investigational product; the 
temporal sequence of the AE onset relative to T cell infusion is plausible; the AE 
shows a pattern consistent with previous knowledge of the investigational product; or 
the AE is more likely explained by the investigational product than any other cause. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 71 of 117 
• Definitely related – There is evidence of exposure to the investigational product; the 
temporal sequence of the AE onset relative to T cell infusion is plausible; the AE 
shows a pattern consistent with previous knowledge of the investigational product, or 
the AE is most likely explained by the investigational product and any other cause is 
improbable. 
The Investigator may change his/her opinion of causality if additional information is received 
and amend the AE eCRF accordingly. The Investigator causality assessment is one of the criteria 
the sponsor will use to determine regulatory reporting requirements for an SAE. 
8.3. 
Reporting Serious Adverse Events (SAEs) 
An SAE is any AE that: 
• Results in death (NOTE: death should be recorded as the outcome, and initiating 
event leading to death as the event). 
• Is life-threatening (NOTE: the term “life-threatening” refers to an event in which the 
subject was at immediate risk of death at the time of the event; it does not refer to an 
event which could hypothetically have caused a death had it been more severe). 
• Requires hospitalization or prolongation of existing hospitalization, except for 
elective or diagnostic procedures associated with pre-existing conditions that have not 
worsened, including the disease under study (e.g. study specified procedures and 
hospitalization). 
• Results in a persistent or significant incapacity. 
• Is a congenital anomaly/birth defect. 
• Is medically significant or requires intervention to prevent one or the outcomes listed 
above. 
Medical and scientific judgment should be exercised in deciding if an AE is of significant 
enough medical importance to be classified as serious outside the above definitions. Important 
medical events that may not result in death, be life-threatening, or require hospitalization may be 
considered serious when, based upon appropriate medical judgment, they may jeopardize the 
subject and may require medical or surgical intervention to prevent one of the outcomes listed 
above. For example, drug overdose or abuse, a seizure that did not result in inpatient 
hospitalization, or intensive treatment of bronchospasm in an emergency department would 
typically be considered serious. 
The study will comply with all local regulatory requirements and adhere to the full requirements 
of the ICH Guideline for Clinical Safety Data Management, Definitions and Standards for 
Expedited Reporting, Topic E2 and FDA Safety Reporting Requirements for INDs, 21 CFR 
312.32.  
8.4. 
Adverse Events of Special Interest (AESI) 
AESIs are events that are of special interest with regards to CAR-T cell products and therefore 
have unique reporting requirements as described in Section 8.5. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 72 of 117 
AESI for P-BCMA-101 currently include: 
1. Any death, regardless of attribution, that occurs within 30 days of the infusion of P-
BCMA-101. 
2. Grade 4 or greater product infusion reactions. 
3. Grade 4 or greater cytokine release syndrome. 
4. Grade 4 or greater neurologic toxicity. 
5. New malignancies.  
6. New incidence or exacerbation of a pre-existing neurological disorder.  
7. New incidence or exacerbation of a prior rheumatologic or other autoimmune disorder.  
8. New incidence of hematologic disorder. 
8.5. 
Regulatory Reporting Requirements for SAEs and AESIs 
An SAE/ AESI must be reported to the Sponsor or designee by emailing or faxing a completed 
SAE/ AESI Report form within 24 hours of the study personnel’s discovery of the event. The 
SAE/ AESI Report form will be the primary source of data for safety reporting. Reporting 
procedures are described in the Study Reference Manual. Shortly following the submission of the 
SAE/ AESI Report form, an eCRF entry within Medidata will be required for each event term. 
Data fields must match those reported on the SAE/AESI Report form.  
8.6. 
Pregnancy 
As described in the entry criteria, subjects must practice birth control from the time of Screening 
and throughout the study (both males and females of childbearing potential).  
Females on cohorts R, RP or RIT must commit either to abstain continuously from sexual 
intercourse or to use two methods of reliable birth control, beginning 4 weeks prior to initiating 
treatment, during therapy, during dose interruptions and continuing for 4 weeks following 
discontinuation of lenalidomide and 12 months after last dose of rituximab.  
Lenalidomide can cause embryo-fetal harm when administered to a pregnant female and is 
contraindicated during pregnancy based on the mechanism of action and findings. Lenalidomide 
is present in the semen of patients receiving the drug. Therefore, males in cohort R or RP must 
always use a latex or synthetic condom during any sexual contact with females of reproductive 
potential while taking lenalidomide and for up to 4 weeks after discontinuing lenalidomide, even 
if they have undergone a successful vasectomy. Male patients taking lenalidomide must not 
donate sperm. 
There is no preclinical or clinical trial data of P-BCMA-101 or rimiducid in pregnant women; 
however, this overall treatment regimen could theoretically be embryotoxic. The effects on 
breast milk are unknown, therefore, breastfeeding should be discontinued for the duration of the 
study starting at Screening and for at least 12 months after receiving the last dose of 
investigational product (P-BCMA-101 or rimiducid, lenalidomide or rituximab), or four months 
after there is no evidence of persistence/gene modified cells in the subject’s blood, whichever is 
longer. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 73 of 117 
Pregnancy (or pregnancy of a male subject’s partner) is not considered an AE/SAE unless there 
is reason to believe the pregnancy may be the result of failure of a contraceptive due to 
interaction with the investigational product, or there is an adverse fetal outcome in the 
pregnancy. However, the Investigator shall report all pregnancies immediately to the Sponsor. A 
woman who becomes and remains pregnant during the study will be discontinued from the study 
and would enter into the LTFU study. The outcome of the pregnancy must also be reported to the 
Sponsor. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 74 of 117 
9. 
SAFETY MONITORING 
9.1. 
Safety Committee 
A Safety Committee comprised of the Investigators and a clinical representative of the sponsor 
will be established and will review data regularly for all subjects and following each cohort to 
determine dose escalation. The Safety Committee may recommend expansion of a cohort to 
further evaluate safety and, if DLT is observed in the first cohort, exploration of a lower dose 
during Phase 1 and continue to manage safety, stopping and pausing criteria during Phase 2. 
9.2. 
Criteria for Pausing Dosing or Stopping the Study 
If a study-defined DLT or any treatment-related death occurs, dosing of new subjects will be 
paused until the Safety Committee meets, reviews the event(s) and determines forward plans, 
which might include stopping the study, reducing subsequent dose levels, instituting additional 
safety procedures or a study amendment, continuing the study as planned or other measures as 
appropriate to the event. As previously described, if 2 or more of 6 subjects have DLTs in a 
cohort during Phase 1, and a ≥10% incidence of ≥Grade 4 or ≥30% incidence of ≥Grade 3 CRS 
or neurotoxicity at or below a corresponding dose level in Phase 2 with >10 patients treated, that 
dose level will have exceeded the MTD and any further dosing would take place at a lower dose 
level. 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 75 of 117 
10. 
STATISTICAL AND DATA ANALYSIS 
Phase 1 of this study is a standard 3 + 3 design of dose cohorts intended to determine a dose 
below which a 33% incidence of DLTs occurs.  
Phase 2 of this study is an open-label, single dose, efficacy and safety evaluation. Details of the 
analyses for all endpoints will be provided in the Statistical Analysis Plan (SAP).  
10.1. 
Study Populations 
The Intent-to-Treat (ITT) population will include all subjects enrolled into the study. 
The Safety population will include all subjects who receive P-BCMA-101 administration. 
The Per Protocol population will include all subjects who receive the protocol directed dose of P-
BCMA-101 (e.g., patients who receive less than the protocol directed dose would be analyzed as 
a separate subgroup). 
10.2. 
Sample Size Calculation 
The Phase 1 part of the study is a standard 3+3 design of dose cohorts intended to determine a 
dose below which a 33% incidence of DLTs occurs. Thus, up to 120 subjects may be enrolled to 
include the possibility of 18 cohorts of 6 subjects during dose escalation, cycle administration 
and combination administration as well as subjects who might be enrolled to replace those who 
discontinue prior to completion of the DLT evaluation period or further assess findings in a 
cohort. 
For the Phase 2 part of the study, response rate endpoints will be tested to exclude a response 
rate of ≤30% as obtained with the recently approved standard of care agent daratumumab at 
p<0.05. With a 100-subject sample, the Phase 2 part of the study will have 90% power to detect a 
15-percentage point improvement over a 30% response rate. This power calculation is based on 
an exact test for a binomial proportion with a 1-sided 0.05 significance level.  
10.3. 
Statistical Methods  
The demographic and baseline characteristics, safety, and efficacy data will be summarized using 
appropriate descriptive statistics. Data analyses will be provided by dose cohort, as well as for all 
subjects combined where appropriate. Descriptive statistics, including means, medians, standard 
deviations and ranges will be calculated for continuous variables, and categorical data will be 
summarized using counts and percentages. For response rate endpoints, point estimates and two-
sided exact binomial 95% confidence intervals will be computed. Time-to-event variables will be 
summarized using the Kaplan-Meier method. 
Treatment-emergent AEs (TEAEs) will be summarized using counts and percentages of subjects 
by cohort and for all subjects combined. TEAEs will also be summarized by severity and 
relationship. Concomitant medications will be summarized using counts and percentages of 
subjects by dose cohort. 
Vital signs, ECG measurements and laboratory results will be summarized using descriptive 
statistics for observed values and change from baseline values by cohort. Laboratory results will 
also be summarized relative to the normal range (below, within, or above) by cohort. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 76 of 117 
Response rates will be determined by comparing each subject’s best response after P-BCMA-101 
administration to the corresponding baseline values per the International Myeloma Working 
Group Uniform Response Criteria (Appendix 15.2) (Rajkumar, 2011; Kumar, 2016; Cavo, 
2017). The overall response rate (ORR) will be determined from subjects having received P-
BCMA-101 and attaining a PR, very good partial response (VGPR), complete response (CR), or 
stringent complete response (sCR), over all subjects having received P-BCMA-101. The 
response rate for each individual response category will also be determined. Likewise, rates of 
stable disease (SD) at 8 weeks, and minimal response (MR) will also be determined. Time to 
response and duration of response will be determined for subjects who have response. OS, and 
PFS will also be determined for all subjects per the International Myeloma Working Group 
criteria.  
A futility analysis will be conducted once 35 subjects are enrolled, received P-BCMA-101, and 
followed up for 4 months or progressed prior to 4-month follow-up. This analysis set is called 
Futility Analysis Set (FAS). The futility analysis will use Futility Index (FI) which is equal to 1 
minus the Conditional Power (CP) based on the observed proportion of BOR in FAS. The study 
may be stopped if FI is above 0.80 (that is, if CP falls below 0.20). 
Subjects who receive additional infusions of P-BCMA-101 T cells will be analyzed as separate 
subgroups for all outcomes. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 77 of 117 
11. 
DATA HANDLING AND RECORD KEEPING 
11.1. 
Confidentiality 
Information about study subjects will be kept confidential and managed according to the 
requirements of the Health Insurance Portability and Accountability Act of 1996 (HIPAA) and 
any other applicable laws, regulation, and guidelines. Those regulations require a signed subject 
authorization informing the subject of the following: 
• What protected health information (PHI) will be collected from subjects in this study 
• Who will have access to that information and why 
• Who will use or disclose that information 
• The rights of a research subject to revoke their authorization for use of their PHI 
In the event that a subject revokes authorization to collect or use PHI, the Investigator, by 
regulation, retains the ability to use all information collected prior to the revocation of subject 
authorization. For subjects that have revoked authorization to collect or use PHI, attempts should 
be made to obtain permission to collect at least vital status (i.e. that the subject is alive) at the 
end of their scheduled study period. 
11.2. 
Data Management 
An EDC system will be used to collect data pertaining to this trial. Trial data will be captured 
through an eCRF. Within the EDC system the eCRF data will be entered by the site staff and all 
source document verification and data cleaning will be performed by the Sponsor or designee 
(e.g. Contract Research Organization [CRO]). 
The specifications for the EDC system will be documented and approved before the EDC system 
is released for live use. The validation of the eCRF data will be defined in a Data Management 
Plan. As data are entered into the eCRF, the validation checks will be performed, and where 
necessary, queries will be raised. All queries raised will be held in the EDC database. 
The EDC system is a validated software program that has been designed to comply with CFR21 
Part 11 requirements. All users will access the system via unique username and password. A full 
audit history of all actions performed within the system is maintained. User accounts ensure that 
each user can only perform the tasks applicable to their role and only have access to the data 
applicable to their role. 
Standard coding dictionaries, World Health Organization (WHO) Drug and Medical Dictionary 
for Regulatory Activities (MedDRA) will be used to code medications, AEs and medical history. 
When all data have been entered and all data cleaning is complete the data will be locked and 
made available for analysis and reporting. 
On completion of the study, all eCRF data, including all associated queries and audit history, will 
be made available on a CD or USB drive to both the study Sponsor and the sites. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 78 of 117 
11.3. 
Source Documents 
Source data is all information, original records of clinical findings, observations or other 
activities in a clinical trial necessary for the reconstruction and evaluation of the trial. Source 
data are contained in source documents. Examples of these original documents and data records 
include: hospital records, clinical and office charts, laboratory notes, memoranda, subjects’ 
diaries or evaluation checklists, pharmacy dispensing records, recorded data from automated 
instruments, copies or transcriptions certified after verification as being accurate and complete, 
microfiches, photographic negatives, microfilm or magnetic media, x-rays, subject files, records 
kept at the pharmacy, at the laboratories and at medico-technical departments involved in the 
clinical trial, etc. 
The Investigator must ensure the availability of source documents from which the information on 
the eCRF was derived. 
The Investigator must permit authorized representatives of the Sponsor, the respective national, 
local or foreign regulatory authorities, the IRB/IEC and auditors to inspect facilities and to have 
direct access to the Investigator Site File and all source documents relevant to this study 
regardless of the type of media. 
11.4. 
Case Report Forms 
For each subject enrolled, the completed eCRF must be reviewed and signed by the Principal 
Investigator or authorized delegate. If a subject withdraws from the study, the reason must be 
noted on the eCRF. 
The Investigator should ensure the accuracy, completeness, legibility and timeliness of the data 
reported to the Sponsor in the eCRFs and in all required reports. 
11.5. 
Records Retention 
It is the Investigator’s responsibility to retain study essential documents for at least 2 years after 
the last approval of a marketing application in their country and until there are no pending or 
contemplated marketing applications in their country or at least 2 years have elapsed since the 
formal discontinuation of clinical development of the investigational product. These documents 
should be retained for a longer period if required by an agreement with the sponsor. In such an 
instance, it is the responsibility of the sponsor to inform the Investigator/institution as to when 
these documents no longer need to be retained. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 79 of 117 
12. 
STUDY MONITORING, AUDITING, AND INSPECTING 
12.1. 
Study Monitoring Plan 
This study will be monitored according to a written monitoring plan. The Investigator will 
allocate adequate time for such monitoring activities. The Investigator will also ensure that the 
monitor or other compliance or quality assurance reviewer is given access to all the above noted 
study-related documents and study related facilities (e.g. pharmacy, diagnostic laboratory, etc.) 
and has adequate space to conduct the monitoring visit. 
12.2. 
Audits and Inspections 
The Investigator will permit study-related monitoring, audits, and inspections by the IRB/IEC, 
the sponsor, government regulatory bodies, and university compliance and quality assurance 
groups of all study related documents (e.g. source documents, regulatory documents, data 
collection instruments, study data etc.). The Investigator will ensure the capability for 
inspections of applicable study-related facilities (e.g. pharmacy, diagnostic laboratory, etc.). 
Participation as an Investigator in this study implies acceptance of potential inspection by 
government regulatory authorities and applicable university compliance and quality assurance 
offices. 
13. 
REGULATORY AND ETHICAL CONSIDERATIONS 
13.1. 
Institutional Review Board/Independent Ethics Committees 
The final study protocol and subject informed consent documentation will be approved by the 
IRB/IEC and any other site-level committee deemed appropriate by the Institution. Approval 
from each applicable committee will be received in writing before initiation of the study. 
Protocol amendments must also be approved by the IRB/IEC (and other committees, as 
applicable) before implementation, except in the case of changes made to protect subjects from 
immediate hazard, which may be implemented immediately. 
13.2. 
Ethical Considerations 
The Investigator will ensure this study is conducted in full compliance with the principles of the 
“Declaration of Helsinki” or with the laws and regulations of the country in which the research is 
conducted, whichever affords the greater protection to the subject. The study must fully adhere to 
the principles outlined in the current ICH “Guideline for Good Clinical Practice” or with local 
law if it affords greater protection to the subject. 
13.3. 
Informed Consent 
It is the responsibility of the Investigator to obtain written informed consent from all study 
subjects prior to any study-related procedures being performed. All consent documentation must 
be in accordance with applicable regulations and ICH GCP. Documentation must include the 
dated signature of both the subject (or the subject’s legally authorized representative as 
applicable) and the person conducting the consent discussion. If the subject is illiterate, an 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 80 of 117 
impartial witness should be present during the consent discussion, and the consent signed and 
dated by the witness, the subject, and the person conducting the consent discussion. The consent 
form should be translated and communicated to the subject in a language that is understandable 
to the subject. Certified translations of the informed consent documentation will be provided as 
applicable. 
A copy of the signed and dated informed consent should be provided to the subject before 
participation in the study. 
Tests performed as standard-of-care prior to documentation of consent may be used for screening 
results as appropriate. 
13.4. 
Protocol Adherence 
The Investigator must sign the protocol to confirm acceptance and willingness to comply with 
the study protocol. 
The Investigator or designee will not deviate from the protocol unless necessary to eliminate an 
apparent immediate hazard to the safety, rights or welfare of any study subject. In the event of a 
protocol deviation for any reason, the Investigator will promptly report the deviation to the 
Sponsor or designee via the eCRF. 
13.5. 
Public Posting of Study Information 
The Sponsor is responsible for posting appropriate study information on applicable clinical study 
registry websites. Information included in clinical study registries may include participating 
Investigator’s names and contact information. 
13.6. 
Clinical Study Report 
The results of the study will be presented in an integrated Clinical Study Report (CSR) according 
to ICH guideline E3: Structure and Content of Clinical Study Reports. 
13.7. 
Publication Policy 
The Investigator may not submit the results of the study for publication or present the results of 
the study without the prior written agreement of the Sponsor in accordance with the Clinical 
Trial Agreement. Interim publications of data from the study may be made if mutually agreed 
between the Sponsor and the Investigators. Agreement will not be provided by the Sponsor 
where in the Sponsor’s view interim publications would introduce bias or lead to any 
misrepresentation or inaccuracies in data. 
Authorship will be determined in conformance with the International Committee of Medical 
Journal Editors (ICMJE) guidelines and/or publication guidelines if applicable. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 81 of 117 
14. 
LIST OF REFERENCES 
Ali SA, Shi V, Maric I, et al. T cells expressing an anti-B-cell maturation antigen chimeric 
antigen receptor cause remissions of multiple myeloma. Blood. 2016;128(13):1688-700 
Barnett BE, Hermanson DL, Smith JB, et al. piggyBac-produced CAR-T cells exhibit stem-cell 
memory phenotype. Blood. 2016a;128:2167. 
Barnett BE, Wang X, Hermanson D, et al. Development of novel non-immunoglobulin Centyrin-
based CARs (CARTyrins) targeting human BCMA. 2016b; ASH Annual Meeting 2016, Abstract 
4557 
Berdeja JG, Lin Y, et al. Clinical remissions and limited toxicity in a first-in human multicenter 
study of bb2121, a novel anti-BCMA CAR T cell therapy for relapsed/refractory multiple 
myeloma. Abstract. AACR Symposium on Mol Targets and Cancer Therapeutics. Munich-
December 2016 
Bødker JS, Brøndum RF, Schmitz A, et al. A multiple myeloma classification system that 
associates normal B-cell subset phenotypes with prognosis. Blood Adv. 2018;2(18):2400-11 
Brentjens RJ, Davila ML, Riviere I, et al. CD19-targeted T cells rapidly induce molecular 
remissions in adults with chemotherapy-refractory acute lymphoblastic leukemia. Sci Transl 
Med. 2013;5:177ra138 
Brentjens RJ, Riviere I, et al. Safety and persistence of adoptively transferred autologous CD19-
targeted T cells in patients with relapsed or chemotherapy refractory B-cell leukemias. Blood. 
2011;118:4817–28 
Brudno JN, Kochenderfer JN. Toxicities of chimeric antigen receptor T cells: recognition and 
management. Blood. 2016;127:3321-30 
Carpenter RO, Evbuomwan MO, Pittaluga S, et al. B-cell maturation antigen is a promising 
target for adoptive T-cell therapy of multiple myeloma. Clin Cancer Res. 2013;19:2048-60 
Cavo M, Terpos E, et al. Role of 18F-FDG PET/CT in the diagnosis and management of 
multiple myeloma and other plasma cell disorders: a consensus statement by the International 
Myeloma Working Group. Lancet Oncol. 2017;17:206-217 
Cohen A, Garfall A, et al. B-Cell Maturation Antigen (BCMA)-Specific Chimeric Antigen 
Receptor T Cells (CART-BCMA) for Multiple Myeloma (MM): Initial Safety and Efficacy from 
a Phase I Study. Abstract. Am Soc Hem. San Diego-2016 
Cohen AD, Garfall AL, Stadtmauer EA, et al. B cell maturation antigen-specific CAR T cells are 
clinically active in multiple myeloma. J Clin Invest. 2019;129(6):2210-2221 
Cunningham S, Siew S, et al. Modeling correction of severe urea cycle defect in the growing 
murine liver using a hybrid recombinant Adeno-associated virus/ PiggyBac transposase gene 
delivery system. Hepatology. 2015;62:2 
Di Stasi A, Tey SK, Dotti G, Fujita Y, Kennedy-Nasser A, Martinez C, et al. Inducible apoptosis 
as a safety switch for adoptive cell therapy. N Engl J Med 2011;365(18):1673-83 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 82 of 117 
Engelhardt, M., Kleber, M., Udi J, et al. Consensus statement from European experts on the 
diagnosis, management, and treatment of multiple myeloma: from standard therapy to novel 
approaches. Leuk Lymphoma. 2010;51:1424–1443. 
Fink EC, Ebert BL. The novel mechanism of lenalidomide activity. Blood 2015;126:2366-2369 
Flores-Montero J, de Ture R, Paiva B, et al. Immunophenotype of normal vs. myeloma plasma 
cells: Toward antibody panel specifications for MRD detection in multiple myeloma. Cytometry 
B Clin Cytom. 2016;90(1):61-72 
Food and Drug Administration (FDA). Guidance for Industry, Gene Therapy Clinical Trials-
Observing Subjects for Delayed Adverse Events. 2006 
Fostier K, Caers J, Meuleman N, et al. Impact of lenalidomide maintenance on the immune 
environment of multiple myeloma patients with low tumor burden after autologous stem cell 
transplantation. Oncotarget. 2018;9(29):20476-20489 
Fraser, MJ, et al. Precise excision of TTAA-specific lepidopteran transposons piggyBac™ 
(IFP2) and tagalong (TFP3) from the baculovirus genome in cell lines from two species of 
Lepidoptera. Insect Mol. Biol. 1996;5:141–151 
Frey NV, Porter DL. CAR T-cells merge into the fast lane of cancer care. Am J Hematol. 
2016;91(1):146-150 
Hackett PB, Largaespada DA, Switzer KC, Cooper LJ. Evaluating risks of insertional 
mutagenesis by DNA transposons in gene therapy. Transl Res. 2013;161:265-83 
Hermanson D, Barnett BE, Rengarajan S, et al. A novel BCMA-specific, Centyrin-based CAR-T 
product for the treatment of multiple myeloma. 2016; ASH Annual Meeting 2016, Abstract 
Howlader N, Noone AM, et al. SEER Cancer Statistics Review, 1975-2012, National Cancer 
Institute. Bethesda, MD, http://seer.cancer.gov/csr/1975_2012/, based on November 2014 SEER 
data submission, posted to the SEER web site, April 2015 
Huls MH, Figliola MJ, et al. Clinical application of Sleeping Beauty and artificial antigen 
presenting cells to genetically modify T cells from peripheral and umbilical cord blood. J Vis 
Exp. 2013;Feb 1(72) 
Iuliucci JD, Oliver SD, Morley S, Ward C, Ward J, Dalgamo D. Intravenous safety and 
pharmacokinetics of a novel dimerizer drug, AP1903, in healthy volunteers. J Clin Pharm 
2001;41:870-879. 
Jena B, Dotti G, Cooper LJ. Redirecting T-cell specificity by introducing a tumor-specific 
chimeric antigen receptor. Blood. 2010;116:1035-44 
Johnsen HE, Bogsted M, Schmitz A, et al. The myeloma stem cell concept, revisited: from 
phenomenology to operational terms. Haematologica. 2016;101(12):1451-59 
Kapoor N, Bertaina A, Merli P, Naik S, Qasim W, Slatter M, et al. Outcome of children with 
primary immune-deficiencies (PIDs) enrolled in a phase I-II trial based on the infusion of BPX-
501 donor T Cells genetically modified with a novel suicide gene (inducible Caspase 9, iC9) 
after T-cell depleted HLA-haploidentical allogeneic stem cell transplantation (haplo-HSCT). 
Blood 2016 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 83 of 117 
Kapoor P, Greipp PT, Morice WG. Anti-CD20 monoclonal antibody therapy in multiple 
myeloma. Br J Hematol. 2008;141(2):135-48 
Kochenderfer JN. New and emerging immune-based approaches. Abstract. Am Soc Hem. San 
Diego; 2016. 
Kumar S, Lee JH, Lahuerta JJ, et al. Risk of progression and survival in multiple myeloma 
relapsing after therapy with IMiDs and bortezomib: a multicenter International Myeloma 
Working Group study. Leukemia. 2012;26(1):149-157 
Kumar, SK, Rajkumar SV, Dispenzieri A, et al. Improved survival in multiple myeloma and the 
impact of novel therapies. Blood. 2008;111:2516–2520 
Kumar S, Paiva B, Anderson K, et al. International Myeloma Working Group consensus criteria 
for response and minimal residual disease assessment in multiple myeloma. Lancet Oncol. 
2016;17(8):e328-e346 
Lee DW, Gardner R, et al. Current concepts in the diagnosis and management of cytokine release 
syndrome. Blood. 2014;124(2):188-195. doi: 10.1182/blood-2014-05-552729 
Lenalidomide (REVLIMID®) US Prescribing Information, May 2019. 
https://media.celgene.com/content/uploads/revlimid-pi.pdf 
Matsui W, Wang Q, Barber JP, et al. Clonogenic multiple myeloma progenitors, stem cell 
properties, and drug resistance. Cancer Res. 2008;68(1):190-7 
Milone G, Camudia MG, et al. Acute Graft versus Host Disease after allogeneic hematopoietic 
transplantation affects early marrow reconstitution and speed of engraftment. Exp Hematol. 
2015;43(6) 
Moreau P, Zamagni E, Mateos M-V. Treatment of patients with multiple myeloma progressing 
on frontline-therapy with lenalidomide. Blood Cancer J. 2019;9(4):38 
Mossine VV, Waters JK, et al. piggyBac transposon plus insulators overcome epigenetic 
silencing to provide for stable signaling pathway reporter cell lines. PLoS One. 
2013;8(12):e85494 
Nakazawa Y, Saha S. Evaluation of long-term transgene expression in piggyBac-modified 
human T lymphocytes. J Immunother. 2013;36(1):3-10. doi: 10.1097/CJI.0b013e3182791234.  
Otáhal P, Průková D, Král V, et al. Lenalidomide enhances antitumor functions of chimeric 
antigen receptor modified T cells. Oncoimmunology. 2016;5(4):e1115940 
Pegram HJ, Lee JC, Hayman EG, et al. Tumor-targeted T cells modified to secrete IL-12 
eradicate systemic tumors without need for prior conditioning. Blood. 2012;119:4133–41 
Raab MS, Podar K, Breitkreutz I, et al. Multiple myeloma. Lancet. 2009;374:324-39. doi: 
10.1016/S0140-6736(09)60221-X. Epub 2009 Jun 21) 
Rajkumar SV, Dimopoulos MA, Palumbo A, et al. International Myeloma Working Group 
updated criteria for the diagnosis of multiple myeloma. Lancet Oncol. 2014;15(12):e538-48 
Rajkumar SV, Harousseau J, Durie B, et al. Consensus recommendations for the uniform 
reporting of clinical trials: report of the International Myeloma Workshop Consensus Panel 1. 
Blood. 2011;117(18):4691-4695 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 84 of 117 
Rituximab (RITUXAN®) US Prescribing Information, April 2019. 
https://www.gene.com/download/pdf/rituxan_prescribing.pdf 
Rushworth D, Alpert A, et al. Antithymidylate resistance enables transgene selection and cell 
survival for T cells in the presence of 5-fluorouracil and antifolates. Gene Ther. 2016;23(2):119-
28. doi: 10.1038/gt.2015.88 
Salles G, Barnett M, Foa R, et al. Rituximab in B-cell hematologic malignancies: A review of 20 
years of clinical experience. Adv Ther. 2017;34(10):2232-2273 
Singh H, Figliola MJ, et al. Manufacture of clinical-grade CD19-specific T cells stably 
expressing chimeric antigen receptor using Sleeping Beauty system and artificial antigen 
presenting cells. PLoS One. 2013;8(5):e64138. 
Straathof KC, Pule MA, et al. An inducible caspase 9 safety switch for T-cell therapy. Blood. 
2005;105(11):4247-54 
Tai YT, Anderson KC, et al. Targeting B-cell maturation antigen in multiple myeloma. 
Immunotherapy. 2015;7(11):1187-99. doi: 10.2217/imt.15.77. Epub Sep 15 2015 
Tey S-K. Adoptive T-cell therapy: adverse events and safety switches. Clinical Translational 
Immunol. 2014;3:e17 
Thomis DC, Marktel S, Magnani Z, Traversari C, Gilman M, Bordignon C, et al. A humanized 
Fas receptor-based suicide switch expressed in human T lymphocytes for the induction of 
controlled graft-versus-leukemia. Blood 2001;97:1249-1257. 
Wang X, Walter M, Urak R, et al. Lenalidomide enhance the function of CS1 chimeric antigen 
receptor-redirected T cells against multiple myeloma. Clin Cancer Res. 2018;24(1):106-119 
Woodard LE, Wilson MH. piggyBac-ing models and new therapeutic strategies. Trends 
Biotechnol. 2015;33 (9): 525-33. 
Works M, Soni N, Hauskins C, et al. Anti-B-cell maturation antigen chimeric antigen receptor T 
cell function against multiple myeloma is enhanced in the presence of lenalidomide. Mol Cancer 
Ther. 2019; Aug 8. pii: molcanther.1146.2018. doi: 10.1158/1535-7163.MCT-18-1146 
Xu J, Chen LJ, Yang SS, et al. Exploratory trial of a biepitopic CAR T-targeting B cell 
maturation antigen in replased/refractory multiple myeloma. Proc Natl Acad Sci USA. 
2019;116(19):9543-51 
Yutaka T, Ito S, Ohigashi H, et al. Sustained CD4 and CD8 lymphopenia after rituximab 
maintenance therapy following bendamustine and rituximab combination therapy for lymphoma. 
Leuk Lymphoma. 2015;56(11):3216-8 
Zhou X, Brenner MK. Improving the safety of T-Cell therapies using an inducible caspase-9 
gene. Exp Hematol 2016; 44(11):1013-1019. 
Zhou X, DiStasi A, Brenner MK. iCaspase9 suicide gene system. Methods Mol Biol 
2015a;1317:87-105. 
Zhou X, Dotti G, Krance RA, Martinez CA, Naik S, Kamble RT, et al. Inducible caspase-9 
suicide gene controls adverse effects from alloreplete T cells after haploidentical stem cell 
transplantation. Blood 2015b;125(26):4103-13. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 85 of 117 
15. 
APPENDICES 
 
15.1. 
ECOG Performance status 
Grade ECOG 
0 
Fully active, able to carry on all pre-disease performance without restriction 
1 
Restricted in physically strenuous activity but ambulatory and able to carry out work of a light 
or sedentary nature, e.g. light house work, office work 
2 
Ambulatory and capable of all self-care but unable to carry out any work activities. Up and 
about more than 50% of waking hours 
3 
Capable of only limited self-care, confined to bed or chair more than 50% of waking hours 
4 
Completely disabled. Cannot carry on any self-care. Totally confined to bed or chair 
5 
Dead 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 86 of 117 
15.2. 
IMWG Uniform Response Criteria 
IMWG uniform response criteria by response subcategory for multiple myeloma (Kumar, 
2016)*|| 
CR 
Stringent 
complete 
response 
(sCR)  
VGPR 
PR 
Minimal  
Response  
(MR) 
SD 
PD¶¶,|||| 
Negative 
immunofixatio
n of serum and 
urine, and 
CR as 
defined, plus 
Serum and 
urine M-
component 
detectable by 
immunofixatio
n but not on 
electrophoresis
, or 
≥ 50% 
reduction of 
serum M-
protein and 
reduction in 
24-hour 
urinary M-
protein by ≥ 
90% or to < 
200 mg/24 
hours 
≥ 25% but ≤ 49% 
reduction of 
serum M protein 
or urine M-
protein by 50%-
89% 
Not meeting 
criteria for CR, 
VGPR, PR, 
MR or PD 
Increase of 
25% from 
lowest 
confirmed 
response value 
in any of the 
following: 
Disappearance 
of any soft 
tissue 
plasmacytoma
s, and 
Normal FLC 
ratio** and 
≥ 90% 
reduction in 
serum M-
component 
plus urine M-
component < 
100 mg/24 h 
If the serum 
and urine M-
protein are 
unmeasurable, 
a decrease ≥ 
50% in the 
difference 
between 
involved and 
uninvolved 
FLC levels is 
required in 
place of the 
M-protein 
criteria 
In addition to the 
above criteria, if 
present at 
baseline, ≥ 50% 
reduction in the 
size (SPD)§§ of 
soft tissue 
plasmacytomas 
is also required 
Serum M-
protein 
(absolute 
increase must 
be ≥ 0.5 
g/dL), and/or 
Serum M-
protein 
increase ≥ 1 
g/dL, if the 
lowest M 
component 
was ≥ 5 g/dL  
< 5% PCs in 
bone marrow 
aspirates 
Absence of 
clonal PCs in 
bone marrow 
biopsy by 
immunohistoc
hemistry (κ/λ 
ratio ≤4:1 or 
≥1:2 for 
κ and λ 
patients, 
respectively, 
after counting 
≥100 plasma 
cells) †† 
If serum and 
urine M-
protein are 
unmeasurable, 
and serum free 
light assay is 
also 
unmeasurable, 
≥ 50% 
reduction in 
bone marrow 
PCs is 
required in 
place of M-
protein, 
provided 
baseline 
percentage 
was ≥ 30% 
 
Urine M-
protein 
(absolute 
increase must 
be ≥ 200 
mg/24 
h), and/or 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 87 of 117 
CR 
Stringent 
complete 
response 
(sCR)  
VGPR 
PR 
Minimal  
Response  
(MR) 
SD 
PD¶¶,|||| 
In addition to 
the above 
criteria, if 
present at 
baseline, ≥ 
50% reduction 
in the size 
(SPD)§§ of 
soft tissue 
plasmacytoma
s is also 
required 
 
Only in 
patients 
without 
measurable 
serum and 
urine M-
protein levels: 
the difference 
between 
involved and 
uninvolved 
FLC levels 
(absolute 
increase must 
be > 10 
mg/dL) 
 
Only in 
patients 
without 
measurable 
serum and 
urine M 
protein levels 
and without 
measurable 
disease by 
FLC levels, 
bone marrow 
PC percentage 
(absolute 
percentage 
must be ≥ 
10%) 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 88 of 117 
CR 
Stringent 
complete 
response 
(sCR)  
VGPR 
PR 
Minimal  
Response  
(MR) 
SD 
PD¶¶,|||| 
 
Appearance of 
a new 
lesion(s), 
≥50% increase 
from nadir in 
SPD§§ of >1 
lesion, or 
≥50% increase 
in the longest 
diameter of a 
previous 
lesion >1 cm 
in short axis; 
≥50% increase 
in circulating 
plasma cells 
(minimum of 
200 cells per 
μL) if this is 
the only 
measure of 
disease  
IMWG=International Myeloma Working Group. MRD=minimal residual disease. FLC=free light chain. M-protein=myeloma 
protein. SPD=sum of the products of the maximal perpendicular diameters of measured lesions. SUVmax=maximum standardised 
uptake value. ¹⁸F-FDG PET=¹⁸F-fluorodeoxyglucose PET. *All response categories require two consecutive assessments made 
any time before starting any new therapy. ||Derived from international uniform response criteria for multiple myeloma (see Durie 
et al., Leukemia 2006; 20: 1467-73). When the only method to measure disease is by serum FLC levels: complete response can 
be defined as a normal FLC ratio of 0.26 to 1.65 in addition to the complete response criteria listed previously. Very good partial 
response in such patients requires a ≥90% decrease in the difference between involved and uninvolved FLC levels. All response 
categories require two consecutive assessments made at any time before the institution of any new therapy; all categories also 
require no known evidence of progressive or new bone lesions or extramedullary plasmacytomas if radiographic studies were 
performed. Radiographic studies are not required to satisfy these response requirements. Bone marrow assessments do not need 
to be confirmed. Each category, except for stable disease, will be considered unconfirmed until the confirmatory test is 
performed. The date of the initial test is considered as the date of response for evaluation of time dependent outcomes such as 
duration of response. **All recommendations regarding clinical uses relating to serum FLC levels or FLC ratio are based on 
results obtained with the validated Freelite test (Binding Site, Birmingham, UK). ††Presence/absence of clonal cells on 
immunohistochemistry is based upon the κ/λ/L ratio. An abnormal κ/λ ratio by immunohistochemistry requires a minimum of 
100 plasma cells for analysis. An abnormal ratio reflecting presence of an abnormal clone is κ/λ of >4:1 or <1:2. 
§§Plasmacytoma measurements should be taken from the CT portion of the PET/CT, or MRI scans, or dedicated CT scans where 
applicable. For patients with only skin involvement, skin lesions should be measured with a ruler. Measurement of tumour size 
will be determined by the SPD. ¶¶Positive immunofixation alone in a patient previously classified as achieving a complete 
response will not be considered progression. For purposes of calculating time to progression and progression-free survival, 
patients who have achieved a complete response and are MRD-negative should be evaluated using criteria listed for progressive 
disease. Criteria for relapse from a complete response or relapse from MRD should be used only when calculating disease-free 
survival. ||||In the case where a value is felt to be a spurious result per physician discretion (eg, a possible laboratory error), that 
value will not be considered when determining the lowest value. 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 89 of 117 
15.3. 
Rimiducid 
15.3.1. 
Introduction 
Rimiducid (a.k.a. AP1903) (See also Rimiducid Investigator’s Brochure) is an investigational 
small molecule drug that has been previously evaluated in Phase 1 human studies as the 
activation agent for cell therapies transduced with an inducible caspase 9 (iCasp9) safety switch 
gene. Rimiducid is a member of a class of compounds termed dimerizer drugs that act by 
inducing clustering of engineered proteins inside cells. Rimiducid-inducible cell death is 
achieved by expressing a chimeric protein comprising a human FK506-binding protein 12 
(FKBP12) domain linked via a flexible linker to human delta caspase-9. Rimiducid is a cell-
permeable synthetic ligand that binds to an engineered high-affinity version of FKBP12 that 
interacts minimally with endogenous FKBP. This chimeric protein is quiescent inside cells until 
administration of rimiducid, which cross-links the FKBP12 domains, initiating dimerization of 
the modified caspase-9 molecule, and results in cell apoptosis (Zhou, 2015a). A single 
intravenous infusion of rimiducid triggers apoptosis and eventual cell death in cells expressing 
the iCasp9 gene but does not affect non-transduced cells and has no therapeutic benefit on its 
own. 
 P-BCMA-101 is a proprietary CAR-T product that consists of 
autologous T-cells that have been genetically altered to target and eliminate myeloma cancer 
cells expressing BCMA, and these T cells also carry an iCasp9-based safety switch gene. 
Rimiducid is administered as a single intravenous dose of 0.4 mg/kg. Rimiducid drug product is 
supplied as a sterile solution for injection that contains 40 mg of rimiducid in 8 mL of solution (5 
mg/mL) and is then further diluted in 0.9% normal sterile saline for injection prior to infusion 
administration. 
Nonclinical studies with rimiducid demonstrated that primary human T lymphocytes transduced 
with the rimiducid-based safety switch; (1) retain their function, and (2) can be eliminated by 
exposure to rimiducid with high efficiency, potency, and specificity (Thomis, 2001). 
 
Rimiducid has previously been evaluated in phase 1 clinical studies, including healthy 
volunteers, and for Graft versus Host Disease (GVHD) in transplant patients treated with other 
genetically modified T cell products carrying an iCasp9-based safety switch gene, which support 
the potential for clinical use of rimiducid in conjunction with P-BCMA-101. In clinical studies 
published to date with rimiducid, there were no significant adverse events and no clinically 
significant changes in vital signs, ECGs, serum biochemistry, hematology, coagulation 
parameters, or urinalysis results. In subjects who developed GVHD and received 0.4 mg/kg of 
rimiducid as a 2-hour infusion, 90% of the modified T cells were eliminated within 30 minutes 
following rimiducid infusion, with a further log depletion during the next 24 hours. GVHD 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 90 of 117 
completely resolved in these patients without recurrence (Zhou, 2015b; Iuliucci, 2001; Di Stasi, 
2011; Kapoor, 2016; Zhou, 2016). 
15.3.2. 
Investigational Use 
Rimiducid may be used for subjects that experience significant adverse reactions to P-BCMA-
101 as described in Section 6.3 and the Study Reference Manual (Toxicity Reference Manual). 
Generally, subjects with Grade 4 CRS may be treated with rimiducid in addition to other 
standard measures (e.g. tocilizumab, steroids and/or cytotoxic/immunosuppressive agents) 
(generally, use of rimiducid would be prioritized over use of a systemically toxic cytotoxic 
agent). This option may also be considered for Grade 3 toxicity unresponsive to other measures. 
Rimiducid use would also be considered in addition to other standard measures if subject 
develops uncontrollable P-BCMA-101 T cell expansion or other clinically significant Grade 3-4 
toxicities possibly related to P-BCMA-101. It is recommended the Investigator review the 
clinical scenario and potential confounding factors before administration. The study medical 
monitor should be consulted if time permits and a rimiducid use form completed. There are no 
absolute predefined inclusion or exclusion criteria. 
15.3.3. 
Study Treatments 
15.3.3.1. Rimiducid Administration 
15.3.3.1.1. Description 
The dosage form for the rimiducid drug product is a sterile solution for injection. The drug 
product contains 40 mg of rimiducid and is intended to be further diluted in 0.9% normal sterile 
saline for injection prior to administration by intravenous infusion.  
The sterile rimiducid solution, 5 mg/mL, is provided as an 8 ml fill in a Type 1 glass 10 mL vial, 
with a gray butyl stopper and aluminum overseal. The quantitative composition of rimiducid 
injection, 5 mg/mL is provided in Table 6. 
Table 6: 
Qualitative and Quantitative Composition of Rimiducid Drug Product 
Component 
Quality Reference  
Function 
Quantity/Unit Dose  
(mg/vial) 
Rimiducid 
In-house  
Active Ingredient  
40.0a 
Polyoxyl 15 hydroxystearateb 
USP 
Surfactant 
2000 
Water for Injection  
USP 
Diluent  
QS to 8 mL 
a. 
The actual quantity will be adjusted based on the purity of the drug substance. 
b. Also referred to as KollilphorR HS 15 or solutol HS 15. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 91 of 117 
15.3.3.1.2. Supply and Storage 
The drug product should be stored refrigerated at 2-8°C. Prior to dilution and administration, the 
drug product should be brought to room temperature and mixed several times by inversion to 
ensure a clear and homogenous solution, in accordance with protocol directions below. 
 
15.3.3.1.4. Dosing and Administration 
If indicated, rimiducid should be administered at a dose of 0.4 mg/kg as a ~2-hour intravenous 
infusion. 
15.3.4. 
Concomitant Medications and Treatment 
There are no limitations or requirements for concomitant medications and treatments with 
rimiducid. 
15.3.5. 
Schedule of Assessments and Procedures 
The schedule of events and procedures to be followed in case of the use of rimiducid is shown in 
Table 8.  
In the event of the occurrence of a specific AE as described in Section 6.3, the use of rimiducid 
should be considered. The rimiducid use form is to be completed and, if time permits, reviewed 
and approved by the Medical Monitor. The consent for rimiducid will be included in the main 
study ICF.  

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
 
Page 92 of 117 
 
 
15.3.6. 
Recording Adverse Events 
See Section 8 for procedures for recording adverse events. Adverse events are to be recorded on 
study CRFs and marked with attribution assigned to rimiducid if appropriate. 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 93 of 117 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 94 of 117 
15.4. 
Retreatment with P-BCMA-101 
If sufficient P-BCMA-101 cells remain from manufacturing when a subject’s disease progresses, 
with Safety Committee approval additional cells may be administered up to the highest dose 
level that has successfully completed dose-limiting toxicity assessment. 
In order to receive an additional P-BCMA-101 cell infusion, subjects will be assigned a new 
subject identification number, they will have to meet all eligibility criteria as outlined in Section 
4, and will undergo the same screening, enrollment, conditioning chemotherapy, and follow-up 
procedures except for leukapheresis, as outlined in Table 9 and Table 10.  
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 95 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 96 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 97 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 98 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 99 of 117 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 100 of 117 
15.5. 
 Cycle Administration 
During Phase 1 – Cycle Administration, multiple doses of P-BCMA-101 will be administered 
intravenously in 2 cycles (Cohort A and Cohort C) or 3 cycles (Cohort B) of 2 weeks. The total 
dose administered may start at ≤ the MTD as determined during Phase 1 single dose escalation.  
In the first cycle for both cohorts A and B, 1/3 the total dose will be administered. In Cohort A 
up to 2/3 the total dose will be administered in the 2nd cycle. In Cohort B up to 1/3 the total dose 
will be administered in each of the 2nd and 3rd cycles. In Cohort C up to 2/3 the total dose will be 
administered in the 1st cycle and up to 1/3 the total dose will be administered in the 2nd cycle. 
Schematics of the study design are shown in Figure 5 for Cohort A and Cohort C, and Figure 6 
for Cohort B.  
The same 3+3 dose escalation and/or de-escalation rules described for single administration will 
be utilized. 
 
Figure 5: 
Schematic for Study P-BCMA-101-001 –Cycle Administration– Cohort A 
and Cohort C 
 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 101 of 117 
Figure 6: 
Schematic for Study P-BCMA-101-001 –Cycle Administration – Cohort B 
 
The Schedule of Events for Screening through conditioning chemotherapy for Cohorts A, B, and 
C is shown in Table 11.  
The Schedule of Events for P-BCMA-101 administration for cycle dosing is shown in Table 12 
for Cohort A and Cohort C, and Table 13 for Cohort B.  
The Schedule of Events for post-treatment follow-up for Cohorts A, B, and C is shown in 
Table 14.  
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 102 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 103 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 104 of 117 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 105 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 106 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 107 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 108 of 117 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 109 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 110 of 117 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 111 of 117 
15.6. 
Phase 1 – Combination Administration 
In Phase 1 – Combination Administration, P-BCMA-101 will be administered in combination 
with approved therapies:  
Lenalidomide 
Cohort R: lenalidomide 
before P-
BCMA-101 infusion; and  
Cohort RP: lenalidomide 
before apheresis 
before P-BCMA-101 infusion. 
Dosing with lenalidomide will continue for Cohort R and Cohort RP unless disease progresses. 
Refer to the lenalidomide package insert for prescribing information (Lenalidomide, 2019) (note 
particularly that lenalidomide is a presumed teratogen, pregnancy avoidance and monitoring is 
necessary). The following are additional recommendations specific to this protocol. If no DLTs 
are reported and platelets are ≥50,000/μL and neutrophils ≥1000/μL 28 days after P-BCMA-101 
administration the dose may be 
If <2 
DLTs are reported in the first 6 patients treated at this dose, the starting dose in all patients may 
be 
at the determination of the Safety 
Committee. During treatment if neutrophils decrease to <1000/μL hold lenalidomide until they 
are ≥1000/μL, 
 During treatment if platelets decrease to 
<30,000/μL hold lenalidomide until they are ≥30,000/μL, 
 If 
creatinine clearance is 30-60 mL/min the maximum lenalidomide dose 
If 
creatinine clearance is <30 mL/min hold lenalidomide. Lenalidomide should be discontinued in 
case of DLT. The lowest dose allowed on this study 
The investigator and Safety 
Committee may decide to discontinue lenalidomide at time based on other safety findings. 
Patients should receive concomitant anticoagulation as indicated (eg. aspirin 325 mg orally 
daily). Do not administer glucocorticoids with lenalidomide.  
Rituximab  
Cohort RIT: 
Refer to the rituximab package insert for 
prescribing information (Rituximab, 2019). The following are additional recommendations 
specific to this protocol. Rituximab should only be administered by a healthcare professional 
with appropriate medical support to manage severe infusion-related reactions that can be fatal if 
they occur. 
Administer only as an intravenous infusion. Do not administer as an 
intravenous push or bolus. Premedicate before each infusion with acetaminophen, an 
antihistamine, and 100 mg intravenous methylprednisolone to be completed 30 minutes prior to 
each infusion. Rituximab should be discontinued in case of infusion reaction or DLT. The 
investigator and Safety Committee may decide to discontinue rituximab at any time based on 
other safety findings. Pneumocystis pneumonia (PCP) prophylaxis should be considered for 
patients during and following treatment. 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
 
 
 
CONFIDENTIAL 
Page 112 of 117 
The dose of P-BCMA-101 administered will escalate or de-escalate following the 3+3 design 
starting at ≤ the MTD as determined during dose escalation. 
 
Figure 7: 
Schematic for Study P-BCMA-101-001 – Phase 1 Combination 
Administration 
 
The Schedule of Events for Screening through conditioning chemotherapy for combination 
administration is shown in Table 15. The Schedule of Events for P-BCMA-101 administration 
and follow-up for combination administration is shown in Table 16. 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 113 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 114 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 115 of 117 
 
 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 116 of 117 

P-BCMA-101 
 
Protocol Number: P-BCMA-101-001 A5 
Poseida Therapeutics, Inc. 
 
20 SEP 2019 
 
CONFIDENTIAL 
Page 117 of 117