MSI-H/dMMR + TMB-H

Pts received intravenous atezo 1200 mg every 21 days and physician’s choice chemo (docetaxel; paclitaxel; capecitabine) until progressive disease (PD), toxicity or death. In this small cohort, treatment with atezo + chemo demonstrated clinical activity in pts with advanced solid tumors with TMB-H and/or MSI-H/dMMR. Responses were observed in different tumor types and were numerically higher in pts whose tumors had both biomarkers vs those with TMB-H alone. Further analyses with a larger cohort and longer follow-up will be required to confirm these results.

However, several questions remain to be addressed, including the identification of patients who may benefit from the addition of ICIs as well as those who do not need immunotherapy. In the current paper, we provide an overview of the clinical development of immunotherapy in advanced or recurrent EC, discussing the role of MMR and the "elective affinities" between ICIs and this predictive biomarker in this setting.

"MSI-H/dMMR and TMB-H prostate cancers are rare but up to two thirds of such patients respond to IO with many durable responses. MSIsensor score and TMB were not predictive of response to IO in these molecularly defined populations. Other clinical and genomic factors are being investigated to identify biomarkers to guide treatment selection."