News | January 24, 2017 | ASCO 2017 Gastrointestinal Cancers Symposium. Nivolumab [immunotherapy] New Standard for Previously Treated MSI-H Metastatic CRC.
"The immune checkpoint inhibitor nivolumab showed durable responses and disease control in a group of heavily pretreated patients with DNA mismatch repair deficient/microsatellite instability high (MSI-H) metastatic colorectal cancer, according to updated results from the CheckMate 142 study (abstract 519) [...]
"“Nivolumab monotherapy provided durable responses, disease control, and long-term survival in patients with MSI-H metastatic CRC
,” said Michael J. Overman, MD, of the University of Texas MD Anderson Cancer Center. “Responses were observed regardless of tumor or immune cell PD-L1 expression, regardless of BRAF or KRAS mutation status, and regardless of clinical history of Lynch syndrome
"[...] about 4% of patients with metastatic colorectal cancer have a high degree of microsatellite instability due to a deficiency in the DNA mismatch repair system. These patients may be less responsive to conventional chemotherapy than patients who are mismatch repair proficient
, and their disease is associated with elevated levels of tumor neoantigens, and tumor-infiltrating lymphocytes, and have upregulated expression of checkpoint regulators in immune cells.
"“These results suggest that nivolumab should be considered a new standard of care for patients with previously treated MSI-H advanced CRC
,” Overman said. “This is in line with the recent amendment to NCCN guidelines which recommend all metastatic colorectal cancer patients have testing for MSI-H and also patients with MSI-H colorectal cancer after initial therapy be considered for either pembrolizumab or nivolumab monotherapy.”"
More: http://www.cancernetwork.com/asco-2017- ... static-crc
MSS = MicroSatellite S
table (or also "repair PROeficient)
MSI = MicroSatellite I
nstable (or also "repair DEeficient) MSI-H = microsatellite instable High,