Combination of radiotherapy (radiation) with PD1 immunotherapy in MSS-CRC.
I just saw a copy of the full ASCO-2016 poster which disclosed the first MSS-CRC clinical data using this combo strategy. Previously I only had seen the abstract...
22 MSS-CRC patients evaluated as of ASCO in the preliminary Phase 2 study
Results were judged by CT-scan of tumors that were **not** irradiated, i.e. looking for a systemic immunotherapy effect
1/22 patients (5%) showed tumor shrinkage of >30%
2/22 patients (10%) showed stable disease of >6 months
2/22 patients (10%) showed a "mixed response" i.e. some tumors shrank whereas some tumors grew
Seeing preliminary signs of successful immune activation in 25% of the first 22 patients tested is pretty intriguing... Another sign that additional immunotherapy steps forward will happen... yes, the immune system can see MSS-CRC tumors in some patients when proper combination therapies are found. It is interesting that it uses a common technology (radiotherapy) rather than a brand new drug or technology (other than PD1 of course!).
Three current related clinical trials open to MSS-CRC patients: