Preliminary analysis of an expanded access study of the fixed-dose combination of pertuzumab (P) and trastuzumab (H) for subcutaneous injection (PH FDC SC) for at-home administration (admin) in patients (pts) with HER2-positive (HER2+) breast cancer (BC) during the COVID-19 pandemic.

person Chau T. Dang Memorial Sloan Kettering Cancer Center, New York, NY info_outline Chau T. Dang, Sara M. Tolaney, Fauzia Riaz, Antoinette R. Tan, Katherine H. R. Tkaczuk, Anthony Francis Yu, Jennifer Liu, Anita M. Fung, Anna Yang, Bann-mo Day, Hope S. Rugo

Authors person Chau T. Dang Memorial Sloan Kettering Cancer Center, New York, NY info_outline Chau T. Dang, Sara M. Tolaney, Fauzia Riaz, Antoinette R. Tan, Katherine H. R. Tkaczuk, Anthony Francis Yu, Jennifer Liu, Anita M. Fung, Anna Yang, Bann-mo Day, Hope S. Rugo Organizations Memorial Sloan Kettering Cancer Center, New York, NY, Dana-Farber Cancer Institute, Boston, MA, Stanford University, Division of Oncology, Stanford, CA, Levine Cancer Institute, Atrium Health, Charlotte, NC, University of Maryland School of Medicine, Baltimore, MD, Genentech, Inc., San Francisco, CA, Genentech, Inc., South San Francisco, CA, University of California-San Francisco, San Francisco, CA Abstract Disclosures Research Funding Pharmaceutical/Biotech Company Background: Standard of care for HER2+ early/first-line metastatic BC (EBC/MBC) is P + H and concurrent chemotherapy (CT); PH FDC SC offers faster, more convenient admin vs intravenous (IV) P + H. COVID-19 has caused unprecedented strain on healthcare systems and disruption to cancer care; treatment (Tx) at home may: enable pts to continue cancer Tx; reduce exposure to COVID-19; free up hospital resources. This study’s main objectives: to enable continuity of care during COVID-19; to assess safety of PH FDC SC given at home. Methods: This is an ongoing single-arm, hybrid, decentralized clinical trial (NCT04395508). Pts with HER2+ EBC/MBC who completed concurrent CT with P + H IV and are receiving/about to receive maintenance P + H IV, PH FDC SC, or H SC are switched to PH FDC SC given at home by a home health nursing provider (HHNP) until disease progression, unacceptable toxicity, pt withdrawal, or physician recommendation (pts with EBC will complete ≤18 cycles). The study endpoint is safety. A subset of pts took part in HARRIET, a substudy of at-home cardiac surveillance with artificial intelligence-guided cardiac ultrasound and optional 6L ECG acquired by an HHNP. Results: Data for 114 pts (1 male) were available at cutoff (Jan 19, 2022): 18 (16%) completed Tx; 20 (18%) discontinued; 76 (67%) remain on study; 79 (69%) had a COVID-19 vaccine while on study. Median age was 49 years; pts were balanced between EBC (n = 55, 48%) and MBC (n = 59, 52%); received a median of 6 (EBC) and 8 (MBC) cycles; and were from metropolitan (n = 109), urban (n = 4), and rural (n = 1) areas. 11 pts tested COVID-19-positive during the Tx phase: 8 continued Tx after appropriate COVID-19 Tx and/or quarantine. Safety is summarized in the table. No new adverse events (AEs) emerged due to home admin. AEs of special interest were grade (gr) 1–2: admin-related reactions (n = 76, 67%), hypersensitivity (n = 5, 4%), cardiac dysfunction (n = 4, 4%), except 1 case of gr ≥3 diarrhea. AEs leading to study Tx discontinuation or interruption/dose reduction occurred in 3 (3%) and 15 (13%) pts. A subset of 7 pts completed at-home cardiac surveillance testing; quantitative assessment of left ventricular ejection fraction was feasible in 3 (43%); 5 (71%) preferred at-home surveillance to clinic. Conclusions: In this preliminary analysis, safety of PH FDC SC at home was consistent with the established P + H safety profile, indicating that PH FDC SC at home is a viable option for continuing BC care during and beyond COVID-19. Clinical trial information: NCT04395508. AEs Pts, n / % Most common, any grade Injection site reaction 67 / 59 Diarrhea 17 / 15 Fatigue 10 / 9 Nausea 8 / 7 Injection site pain 6 / 5 Gr ≥3 4 / 4 Serious* 5 / 4 Fatal 0 *Not Tx-related: COVID-19 pneumonia, cystitis, acute kidney injury, diarrhea, seizure, sepsis, transient ischemic attack (gr 2).