ESGO 2026 – regulators don’t buy Merck’s all-comers claim

Merck & Co has trumpeted Keytruda’s apparent overall survival benefit in the Keynote-B96 trial in relapsed ovarian cancer, but regulators – both in the EU and US – are having none of it. The all-comers data from this study, which combined Keytruda plus chemo with or without Avastin, were presented on Friday at the European Society of Gynaecological Oncology; earlier the first OS data were revealed at last year’s ESMO, backing a benefit versus chemo/Avastin in PD-L1 ≥1% expressers. Merck’s all-comers claim would have seemed impressive were it not for the fact that the FDA last month limited Keytruda’s approval in this setting to PD-L1 expressers (the agency will surely have seen the all-comers data as part of its review), and last week the CHMP followed suit, recommending EU approval similarly only in PD-L1-positives. For the record the all-comers population in Keynote-B96 showed an 18% reduction in risk of death, while the number for PD-L1 expressers was 24%. The giveaway lies in the fact that the vast majority of Keynote-B96 patients – 73% – were in fact PD-L1 expressers, and these will have driven the all-comers benefit. Merck didn’t provide an OS analysis for PD-L1-negatives.

Overall survival in Keynote-B96 (platinum-resistant ovarian cancer)

Note: *Avastin or biosimilar bevacizumab. Source: ESGO.