Pertuzumab plus trastuzumab (P+T) in patients (Pts) with colorectal cancer (CRC) with <i>ERBB2</i> amplification or overexpression: Results from the TAPUR Study.
R. Gupta, Elizabeth Garrett‐Mayer, Susan Halabi, Pam K. Mangat, Stacy D. D’Andre, Eyal Meiri, Sagun Shrestha, Sasha L. Warren, Shamika Ranasinghe, Richard L. Schilsky
Abstract
132 Background: TAPUR is a phase II basket trial evaluating anti-tumor activity of commercially available targeted agents in pts with advanced cancers with genomic alterations. Results in a cohort of CRC pts with ERBB2 overexpression or amplification treated with P+T are reported. Methods: Eligible pts had advanced CRC, no standard treatment (tx) options, measurable disease, ECOG PS 0-2, and adequate organ function. Genomic testing was performed in CLIA-certified, CAP-accredited site selected labs. Pts had ERBB2 overexpression or amplification, or certain ERBB2 mutations. Recommended dosing after initial dosing was P, 420 mg IV over 30-60 mins every 3 weeks (wks) and T, 6 mg/kg over 30-60 mins every 3 wks. Simon two-stage design was used to test a null rate of 15% vs. 35% (power = 0.85; α = 0.10). If ≥2 of 10 pts in stage 1 have disease control (DC) (objective response (OR) or stable disease at 16+ wks per RECIST (SD16+)), 18 more pts enrolled. If ≥7 of 28 pts have DC, the tx is worthy of further study. Secondary endpoints are progression-free survival (PFS), overall survival (OS) and safety. Results: Twenty-eight pts enrolled from November 2016 to September 2018 were evaluable for efficacy and safety. Demographics and outcomes are summarized in Table. All pts had ERBB2 amplification; 1 also had an ERBB2 mutation. 79% of pts had at least 3 prior txs. Four PR and 10 SD16+ were observed for DC and OR rates of 50% (90% CI, 36% to 60%) and 14% (95% CI, 4% to 33%), respectively. Two pts had at least one grade 3 AE or SAE at least possibly related to P+T including anemia, infusion reaction, and left ventricular dysfunction. Conclusions: The combination of P+T showed anti-tumor activity in heavily pre-treated CRC pts with ERBB2 amplification . Additional analyses by RAS mutation status are pending. Further study is warranted to confirm efficacy of P+T in this population. Clinical trial information: NCT02693535. [Table: see text]