Prausová, Jana

TPS149 Background: METamp is a secondary, or co-driving, genetic change in pts with mCRC and acquired resistance to anti-EGFR therapy, which can contribute to disease progression. In EGFR-resistant pts with mCRC and METamp, MET inhibition + an anti-EGFR agent could achieve disease control by targeting emerging MET pathway activation and maintaining EGFR pathway inhibition. Tepotinib is an oral, once-daily, highly selective, potent MET tyrosine kinase inhibitor (TKI). Tepotinib + the EGFR TKI gefitinib demonstrated improved outcomes in pts with EGFR-mutant METamp non-small cell lung cancer and acquired EGFR TKI resistance vs chemotherapy (INSIGHT: NCT01982955). In these pts, progression-free survival (PFS) was 16.6 vs 4.2 months (HR = 0.13; 90% CI: 0.04, 0.43) and overall survival (OS) was 37.3 vs 13.1 months (HR = 0.08; 90% CI: 0.01, 0.51). In pts with mCRC and acquired resistance to anti-EGFR antibody therapy due to METamp, tepotinib + anti-EGFR antibody cetuximab may be active and therefore provide an effective therapeutic option. Methods: This Phase II, multicenter, single-arm, open-label study will assess preliminary antitumor activity, safety and tolerability, and explore pharmacokinetic (PK) profiles of tepotinib + cetuximab in pts with RAS/BRAF wild-type left-sided mCRC and acquired resistance to anti-EGFR antibody-targeted therapy due to METamp. A safety run-in (6-12 pts) will evaluate the recommended Phase II dose of tepotinib to be used in combination with cetuximab (endpoint:dose-limiting toxicities). Enrollment is based on a confirmed advanced left-sided CRC diagnosis, with RAS/BRAF wild-type, documented previous anti-EGFR therapy and acquired resistance on the most recent anti-EGFR antibody and METamp confirmed by liquid and/or tissue biopsy. Pts must be ≥18 years old and have an Eastern Cooperative Oncology Group performance status of 0/1 and normal organ function. The study will screen sufficient pts to account for setting-specific METamp heterogenicity. Approximately 42 pts are planned to receive study treatment: ~22 in Cohort A (tepotinib second-line, outside US) and 20 in Cohort B (tepotinib ≥third-line, US only). Primary endpoint:investigator-assessed objective response (RECIST 1.1). Secondary endpoints are investigator-assessed duration of response (DoR) and PFS (RECIST 1.1), OS, tolerability and safety (NCI-CTCAE v5.0) and cetuximab immunogenicity (measured by antidrug antibody assays at the start and end of treatment). Additional endpoints include assessment of tepotinib and cetuximab PK profiles and expression of biomarkers of resistance (from blood and/or tissue samples). Retrospective assessment of best overall response, DoR and PFS by an independent review committee may be conducted. No formal statistical hypothesis will be tested in this exploratory study. Clinical trial information: NCT04515394.

668 Background: Ramucirumab is a human IgG1 monoclonal antibody antagonist of VEGFR-2. Overall survival (OS) and progression-free survival (PFS) in 2nd line FOLFIRI based treatment for metastatic colorectal cancer (mCRC) were improved with RAM therapy versus PBO in the RAISE trial. Recent work suggests mCRC primary tumor location is both prognostic and predictive; with improved OS and therapy-specific sensitivity observed in left (L)- vs right (R)-sided tumors. Given these findings, the RAISE trial data was subjected to post-hoc analysis to determine if sidedness influenced RAM efficacy. Methods: Primary tumor site was obtained. L-CRC was defined as the splenic flexure, descending and sigmoid colon, and rectum, while R-CRC included transverse, ascending colon and cecum. OS/PFS in L and R subgroups were analyzed via Kaplan-Meier method and unstratified log-rank test (treatments within subgroup), unstratified Cox proportional hazards model (estimate hazard ratio [HR] and 95% CI), and Wald test (treatment-by-subgroup interaction). Results: Tumor location was available for 1012/1072 (94%) patients, 699 L- and 313 R-CRC. Baseline characteristics were balanced between arms. RAM treatment enhanced L-CRC median OS by 2.5 mo (median 14.5 vs 12.0 mo) with a HR (95% CI) = 0.807 (0.675, 0.965), P = 0.019; compared to a 1.1 mo increase in median OS in R-CRC vs PBO (12.7 vs 11.6) with a HR (95% CI) = 0.971 (0.750, 1.258), P = 0.823; and, RAM enhanced L-CRC median PFS by 1.6 mo (6.0 vs 4.4 mo) and HR (95% CI) = 0.776 (0.664, 0.906), P = 0.001 compared to a 1.1 mo increase in median PFS R-CRC vs PBO (5.6 vs 4.5) with a HR (95% CI) = 0.855 (0.674, 1.084), P = 0.197. The treatment-by-subgroup interaction for both OS and PFS was not significant ( P = 0.276, 0.578, respectively). Conclusions: Despite L-CRC patients having longer OS/PFS and a seemingly stronger RAM treatment effect than R-CRC, the non-significant interaction test cannot verify sidedness as being predictive of RAM efficacy. The current study confirms ramucirumab benefits mCRC patients regardless primary tumor location. Clinical trial information: NCT01183780.

512 Background: Angiogenesis is an important therapeutic target in CRC; VEGF plays a key role in angiogenesis. RAM is a human IgG1 monoclonal antibody that targets the extracellular domain of VEGFR-2. The RAISE study evaluated the efficacy and safety of adding RAM to standard second-line treatment FOLFIRI. Methods: Eligible pts with mCRC who progressed on or after first-line combination therapy with bev, ox, and fp, had an ECOG PS of 0 or 1, and adequate organ function were randomized 1:1 (stratified by region, KRAS mutation status, and time to progressive disease [PD] after beginning first-line treatment) to receive RAM (8 mg/kg IV) plus FOLFIRI or PBO plus FOLFIRI every 2 weeks until PD, unacceptable toxicity, or death. The primary endpoint was overall survival (OS). Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and safety. Planned sample size of 1,050 pts ensured 85% power to demonstrate statistical significance at an overall two-sided alpha of 0.05, assuming a hazard ratio (HR) of 0.8. Results: Between Dec 2010 and Aug 2013, 1,072 eligible pts were randomized (RAM 536; PBO 536). Baseline pt characteristics were similar between treatment arms. The OS HR was 0.84 (95% CI: 0.73, 0.98; log-rank p=0.0219). Median OS was 13.3months (m) for RAM vs 11.7m for PBO. The PFS HR was 0.79 (95% CI: 0.70, 0.90; log-rank p = 0.0005). Median PFS with RAM was 5.7m and 4.5m for PBO. ORR was 13.4% RAM; 12.5% PBO (p = 0.6336). Subgroup results were consistent with the OS and PFS results. Grade ≥3 adverse events (AEs) occurring in >5% of pts in RAM+FOLFIRI were: neutropenia (RAM 38.4% vs PBO 23.3% ), hypertension (11.2% vs 2.8%), diarrhea (10.8% vs 9.7%), and fatigue (11.5% vs 7.8%). Conclusions: RAISE met its primary end-point, demonstrating a statistically significant improvement in OS for RAM and FOLFIRI vs PBO and FOLFIRI in second-line mCRC pts. Benefits were similar across important clinical subgroups and no unexpected AEs were identified. Clinical trial information: NCT01183780.