36.7 months for chemotherapy, but the pre-specified alpha of 0.025 required for statistical significance was not reached, so superiority of pembrolizumab over chemotherapy in OS was not statistically demonstrated, although a favorable trend was observed (HR = 0.74, 95% CI: 0.53–1.03, p = 0.036) [ 59 ].
The LEAP-017 study, which investigated the efficacy of pembrolizumab + lenvatinib as third-line treatment for MSS colon cancer, also showed a trend toward an improvement in OS, its primary endpoint, but no statistically significant difference was reported [ 65 ]. 4.2 Future Perspectives of ICI for Colon Cancer As mentioned above, the efficacy of ICI for MSS colon cancer is presumed to be quite limited, and the development of new treatments, including further combination therapy, seems to be losing momentum.