Abstract CT135: Cetuximab (C) in patients (Pts) with breast cancer (BC) and non-small cell lung cancer (NSCLC) without reported KRAS, NRAS, BRAF mutations: Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) Study
Authors: Fisher Julie , Garrett-Mayer Elizabeth , Halabi Susan , Mangat Pam K. , Alvarez Ricardo H. , Cannon Timothy L. , Crilley Pamela , Pollock Theodore , Baghdadi Tareq Al , Cotta Jared A. , Rygiel Andrew L. , Antonelli Kaitlyn R. , Islam Samiha , Bruinooge Suanna S. , Schilsky Richard L. 
Published: August 2019

Background: The TAPUR Study is a phase II multi-basket study that evaluates the anti-tumor activity of commercially available targeted agents in pts with advanced cancers with genomic alterations known to be drug targets. Results in two cohorts of BC and NSCLC pts each without reported KRAS, NRAS, BRAF mutationstreated with C are reported.

Methods: Simon’s optimal two stage design was used to test the null hypothesis of 15% response rate versus the alternative of 35%. Power and alpha were set at 85% and 10%, respectively. Response was assessed per RECIST v1.1. This design requires 10 pts in stage 1 and if &lt;2 pts have objective response (OR) or stable disease (SD) at 16 weeks (wks), the cohort is closed. Secondary endpoints are progression-free survival (PFS), overall survival (OS) and safety. Genomic testing was performed using commercially available tests selected by clinical sites. Treatment was determined according to protocol matching rules based on genomic inclusion criteria.

Results: Ten pts were enrolled in the BC cohort from June 2016 to May 2018. Ten pts were enrolled in the NSCLC cohort from January 2017 to May 2018. Pts received C at an initial intravenous infusion of 400 mg/m2 over 120 minutes and subsequent weekly infusions of 250 mg/m2 over 60 minutes. All pts are included in the data analysis for demographics, safety, PFS and OS (Table 1). No ORs or SD at 16 wks were observed in either cohort and both were therefore closed. Grades 3-4 adverse events (AEs) at least possibly related to drug are required to be reported. A single grade 3 AE of hypomagnesemia was reported in the NSCLC cohort as possibly related to C.

Conclusions: Results from these cohorts suggest monotherapy with C does not have clinical activity in BC or NSCLC pts without reported KRAS, NRAS, BRAF mutations. Other treatments should be considered for these pts, including treatments offered in clinical trials.

Table 1:Baseline demographics, clinical characteristics and outcomes by cohortCetuximab targeting tumors without reported KRAS, NRAS, BRAF mutationsTumor TypeBC (N=10)NSCLC (N=10)Median age, yrs (range)59 (45, 65)60 (55, 82)Male, %060ECOG Performance Status, %01260301010900Median PFS, wks (90% CI)6.7 (4.0, 7.9)8.0 (7.6, 8.4)Median OS, wks (90% CI)11.0 (4.9, 30.1)19.6 (8.6, 25.6)Drug-related AEs, grades 3-4 (% of pts)010

Citation Format: Julie Fisher, Elizabeth Garrett-Mayer, Susan Halabi, Pam K. Mangat, Ricardo H. Alvarez, Timothy L. Cannon, Pamela Crilley, Theodore Pollock, Tareq Al Baghdadi, Jared A. Cotta, Andrew L. Rygiel, Kaitlyn R. Antonelli, Samiha Islam, Suanna S. Bruinooge, Richard L. Schilsky. Cetuximab (C) in patients (Pts) with breast cancer (BC) and non-small cell lung cancer (NSCLC) without reported KRAS, NRAS, BRAF mutations: Results from the Targeted Agent and Profiling Utilization Registry (TAPUR) Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT135.