Abstract PS13-39: Efficacy and tolerability of neoadjuvant Pertuzumab, Trastuzumab, and weekly Paclitaxel in Locally advanced Her-2 positive Breast cancer
Authors: Gupta Niraj , Giblin Erica , Spivey Tara , Govert Kristen , Leagre Christopher , Liebross Robert , Tumati Vasu , Dugan Thomas , Yadav Rina , Henman Patrick , Beaudrie Nick , Bair Tessa , Durk Jessica , Hancock Marjaorie , Engle Trisha , Myers Michelle , Schneiders Julie , Tigges Thomas 
Published: February 2021

Background:Administration of neoadjuvant Pertuzumab (P), trastuzumab (T) along with chemotherapy is the standard of care for the management of locally advanced/inflammatory Her-2 positive breast cancer. Neutropenia and diarrhea are often the significant side-effects observed with the commonly used chemotherapy regimens. We evaluated the efficacy and safety of neo-adjuvant regimen consisting of P and T with weekly paclitaxel (Pac) in locally- advanced Her-2 +ve patients.Methods: Patients with newly diagnosed Her-2 positive tumor were treated in a neo-adjuvant fashion. The schedule of the treatment regimen was; P on D-1 at a loading dose of 840 mg, followed by 420 mg every 3 weeks , T on D-1 at a dose of 8 mg/kg loading dose, followed by 6 mg/kg every 3 weeks, and Pac on D-1/8 at a dose of 80 mg/m2. Cycles were repeated every three weeks. A total of six cycles were given prior to the surgery. Herceptin was continued for a total of one year. NCCN guidelines were followed for adjuvant radiation and hormonal treatments. LVEF was measured at baseline and every 6 weeks during neo-adjuvant treatments.Results: A total of 64 women were treated between Mar 2014 - Mar 2019. Median age was 56 years (30-81). Twelve pts had T-1 disease, 43 had T-2, 7 had T-3 and, 2 pts. had inflammatory breast ca. Twenty five pts. (39%) had lymph node involvement at diagnosis. The receptor profile was: ER/PR +ve: 43 pts., ER+/PR-ve: 5 pts., ER/PR -ve: 16 pts. All patients completed the planned six cycles. Twenty seven pts. achieved a pCR (42.8%). Nine out of 16 ER/PR-ve patients (56.2%) had a pCR. Grade-3/4 neutropenia was seen in 7 patients (10.9%) but febrile neutropenia was not observed in any pt. (0%). Grade-3/4 diarrhea was seen only in 2 pt. (3.1%).Grade-3/4 neuropathy was seen in 4 pts. (6.2%). LVEF drop of more than 10% from baseline to less than 50% was seen in two patient (3.1%). No recurrence has been observed with a median follow-up of 31 months.Conclusions: A combination of Pertuzumab, Trastuzumab and weekly Paclitaxel (PTPac) delivers impressive pCR rates with an acceptable side-effects as compared to other commonly used chemotherapy regimens given along with anti-Her-2 therapy. This combination should be explored in larger studies.

Citation Format: Niraj Gupta, Erica Giblin, Tara Spivey, Kristen Govert, Christopher Leagre, Robert Liebross, Vasu Tumati, Thomas Dugan, Rina Yadav, Patrick Henman, Nick Beaudrie, Tessa Bair, Jessica Durk, Marjaorie Hancock, Trisha Engle, Michelle Myers, Julie Schneiders, Thomas Tigges. Efficacy and tolerability of neoadjuvant Pertuzumab, Trastuzumab, and weekly Paclitaxel in Locally advanced Her-2 positive Breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-39.