GICS 2017. Abstract 519: Nivolumab alone or in combination with ipilimumab in patients with DNA mismatch repair deficient/ microsatellite instability high metastatic colorectal cancer: Updated results from CheckMate 142.

Michael J. Overman et al.

Results: Among pts treated with nivo 3 Q2W (N = 74), 84% had received ≥ 2 prior lines of therapy. ORRs were 31% (INV) and 27% (IRRC); disease control rates were 69% (INV) and 62% (IRRC). The median time to response was ≈2.7 mo (INV/IRRC). PFS rates at 12 mo were 48.4% (INV) and 45.6% (IRRC). The duration of response and OS medians were not yet reached; OS rates were 83.4% (6 mo) and 73.8% (12 mo). Responses were observed in pts regardless of tumour programmed death-1 ligand 1 (PD-L1) expression level or BRAF or KRAS mutation status and were observed in pts with or without a history of Lynch syndrome (Table). Grade 3–4 treatment-related adverse events (TRAEs) occurred in 20% of pts. TRAEs leading to discontinuation included acute kidney injury, increased ALT, colitis, and stomatitis (1 each). No treatment-related deaths occurred in this arm.

Conclusions: Nivo showed durable responses and disease control in heavily pretreated pts with dMMR/MSI-H mCRC. Treatment was well tolerated, with no new safety signals. Clinical trial information: NCT02060188