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Keynote-B21 checks Keytruda’s endometrial advance

It looks like for now the endometrial cancer battle between Merck & Co’s Keytruda and GSK’s Jemperli will be limited to first and second-line settings, after the Merck drug today failed in the adjuvant Keynote-B21 phase 3 study. The trial combined Keytruda with chemotherapy, with or without radiation, and Merck said it failed its key primary endpoint of disease-free survival versus chemo/radiation alone. According to the statistical analysis plan, with DFS having failed Keynote-B21’s co-primary endpoint of OS wasn’t tested. Both Keytruda and Jemperli are US approved second line, albeit in different settings, and Jemperli has a first-line label in MSI-high/mismatch repair-deficient disease as part of a chemo combination. The next showdown between the two will be decisions on US approvals for first-line chemo combo use irrespective of microsatellite/MMR status: a PDUFA date for Keytruda here falls in late June, while that for Jemperli will come two months later. Today’s setback isn’t Keytruda's first in endometrial cancer: last December Leap-001, a first-line trial looking at a combination with Eisai’s Lenvima, failed to hit co-primary survival endpoints.


Merck vs GSK in endometrial cancer

                            Keytruda                          Jemperli
AdjuvantKeynote-B21 (chemo +/- RT combo)(None)
Failed for DFS, OS not tested

1st-lineKeynote-868 (chemo combo)Ruby (chemo combo)
PDUFA 21 June 2024PDUFA 23 August 2024
Keynote-C93 (dMMR)Ruby (MSI-H/dMMR, chemo combo)
Reads out 2026FDA approved
Leap-001 (Lenvima combo) 
Failed for OS & PFS

2nd-lineKeynote-158 (MSI-H/dMMR)Garnet (dMMR)
FDA approvedFDA approved
Keynote-775 (MSS/pMMR, Lenvima combo) 
FDA approved

Source: OncologyPipeline.


Molecular Drug Targets