Nivolumab In Patients With Dna Mismatch Repairdeficient/Microsatellite Instability-High (Dmmr/Msi-H) Metastatic Colorectal Cancer (Mcrc): Long-Term Survival According To Prior Line Of Treatment From Checkmate-142.

554Background: Nivolumab (NIVO) provided durable responses (ORR, 32% per central assessment) and disease control (DCR, 64%) in pre-treated pts with dMMR/MSI-H mCRC (NCT02060188; Overman MJ et al Lancet Oncol 2017). NIVO was approved in the US for pts with dMMR/MSI-H mCRC who progress after standard chemotherapy (SC) with a fluoropyrimidine (F), oxaliplatin (Ox), and irinotecan (Iri). Here we present long-term survival and outcomes by prior chemotherapy with NIVO in CheckMate-142. Methods: Pts with dMMR/MSI-H mCRC received NIVO 3 mg/kg Q2W. The primary endpoint was ORR per RECIST 1.1. Other endpoints were DCR, DOR, PFS, OS, and safety/tolerability. Results: Of 74 pts evaluated, 53 had received F, Ox and Iri (group A); 21 pts had ≤ 2 SC regimens (group B). Median follow-up was 21 mo. Efficacy by central assessment is shown in the Table. In the 74 pts, ORR was 34%; CRs increased from 3% in prior database lock (DBL) to 9%. Numerically higher responses were noted in group B vs group A (Table). Grade 3–4 TRAEs ...