Loading
The trial that tried to make immunotherapy work in ordinary bowel cancer by adding a MEK inhibitor. It failed outright.
IMblaze370 randomised 363 patients 2:1:1 to atezolizumab with cobimetinib, atezolizumab alone, or regorafenib, after progression on at least two previous chemotherapy regimens. Median overall survival was 8.87 months with the combination, 7.10 months with atezolizumab alone and 8.51 months with regorafenib; the hazard ratio was 1.00 (95% CI 0.73 to 1.38, p=0.99) for the combination against regorafenib. Grade 3 to 4 adverse events affected 61 percent of the combination group. The preclinical rationale, that MEK inhibition raises MHC class I expression and drives T cells into tumours, did not translate. IMblaze370 is the reference failure for checkpoint inhibition in microsatellite-stable colorectal cancer and the reason later attempts focus on Fc-enhanced CTLA-4 blockade, on excluding patients with liver metastases, or on combining with targeted therapy.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
The full inclusion and exclusion criteria are on the registry record. Read 2026-10-07. Recruiting overall does not mean a particular site is open; ask the study team.
ClinicalTrials.gov data courtesy of the US National Library of Medicine.
Shares Regorafenib, Hot vs cold tumours, Atezolizumab, PD-1.
Shares Regorafenib, Atezolizumab, Small-molecule kinase inhibitors, Colorectal cancer.
Shares Atezolizumab, Small-molecule kinase inhibitors, Colorectal cancer, Immune checkpoint inhibitors.
Shares Hot vs cold tumours, Microsatellite instability (MSI-H) / mismatch repair deficiency (dMMR), Colorectal cancer, Immune checkpoint inhibitors.
Shares Cobimetinib, Atezolizumab, Small-molecule kinase inhibitors, Immune checkpoint inhibitors.
Shares MEK1/2, Regorafenib, Colorectal cancer.
Shares Cobimetinib, Atezolizumab, Roche / Genentech.
Shares Atezolizumab, Roche / Genentech, Colorectal cancer, Immune checkpoint inhibitors.
Every source this page cites, grouped by who published it. Grouping is read from the web address, not assigned by hand.
A source that has moved or gone is reported by the weekly link check. /audit/