ICI (anti-PD-1) shows promising results in MSI rectal CA “Immunotherapy has proven successful in treating a subset of patients with colon and rectal cancer that has metastasized, meaning spread to other tissues.”
The patients in this subset, Dr. Luis Diaz explains, have tumors with a specific genetic makeup known as mismatch repair-deficient (MMRd) or microsatellite instability (MSI).
This study was run in early stage rectal cancer patients.
In every case, the rectal cancer disappeared after immunotherapy — without the need for the standard treatments of radiation, surgery, or chemotherapy — and the cancer has not returned in any of the patients, who have been cancer-free for up to two years.
Between 5% and 10% of all rectal cancer patients are thought to have MMRd tumors, including all the patients in the MSK clinical trial that Sascha participated in. There are 45,000 Americans diagnosed a year with rectal cancer.
https://www.mskcc.org/news/rectal-cancer-disappears-after-experimental-use-immunotherapy
https://www.gsk.com/en-gb/media/press-releases/gsk-receives-fda-accelerated-approval-for-jemperli-dostarlimab-gxly-for-adult-patients-with-mismatch-repair-deficient-dmmr-recurrent-or-advanced-solid-tumours/
ONCY is running a Phase 2 trial trial (IRENE) in rectal cancer with Incyte Pharma's immune checkpoint inhibitor retifanlimab (anti-PD-1) in combination with ONCY' pelareorep. https://www.oncolyticsbiotech.com/press-releases/detail/515/oncolytics-biotech-doses-first-patient-in-phase-2-irene