Pembrolizumab in Microsatellite-Instability–High Advanced Colorectal Cancer
At 2nd interim analysis of RCT (n=307), after median follow-up of 32.4 months, pembrolizumab as 1st-line therapy was superior to chemotherapy for progression-free survival (median 16.5 vs. 8.2 months;HR 0.60;95% CI, 0.45-0.80;p=0.0002), with fewer treatment-related adverse events
Source:
New England Journal of Medicine
SPS commentary:
In the trial, patients were assigned to receive pembrolizumab at a dose of 200 mg every 3 weeks or chemotherapy (5-fluorouracil–based therapy with or without bevacizumab or cetuximab) every 2 weeks
According to an editorial, these results support ongoing trials investigating immune checkpoint inhibitors in earlier treatment lines, such as the ongoing ATOMIC trial. It notes neoadjuvant approaches are also being investigated in rectal cancer, and the preliminary data are intriguing. It adds that the ultimate goal of immunotherapy in colorectal cancer, however, is to find active treatment approaches for microsatellite-stable, mismatch repair–proficient metastatic cancers, which constitute the vast majority of advanced colorectal cancers. It suggests that for high degree of microsatellite instability–deficient mismatch repair colorectal cancer, the durability of response, better safety profile, and improved quality of life associated with immunotherapy as compared with chemotherapy make pembrolizumab the preferred choice.