GSK on Thursday was cleared to broaden use of its cancer immunotherapy Jemperli, winning approval from the Food and Drug Administration to market the medicine for certain patients with newly diagnosed endometrial tumors.
The FDA approved a regimen of Jemperli and chemotherapy for first-line use in endometrial cancers with a specific type of genetic error that disrupts cells’ ability to repair DNA. It expands on the drug’s initial approval in 2021 and allows for earlier treatment.
Eligible patients must have genetic abnormalities known as microsatellite instability-high, known as MSI-H for short, or mismatch repair deficiency (dMMR). Before Thursday’s decision, Jemperli was approved as a monotherapy for patients whose disease progressed after chemotherapy and weren’t candidates for surgery or radiation. It was also cleared for dMMR or MSI-H positive patients who have no other treatment options, regardless of where in the body their tumors originated.
GSK’s latest FDA OK is based on a study showing that, after two years of treatment, Jemperli and chemotherapy reduced the risk of disease progression or death by 71% when compared to chemotherapy alone.
GSK still has significant ground to make up on its rivals, however.
Jemperli came to market well after similar, rival cancer immunotherapies from Merck & Co., Bristol Myers Squibb and Roche. Each of those drugs are billion-dollar sellers, and Keytruda ranks as one of the world’s most lucrative medicines. GSK, by comparison, reported 36 million pounds, or $45 million, in Jemperli sales through the first six months of 2023.
Keytruda may soon compete with Jemperli in endometrial cancer, too. A regimen involving the drug and another medicine, Lenvima, is currently approved for advanced endometrial tumors without dMMR or MSI-H mutations. But in March, Merck reported positive results from a Keytruda-chemotherapy combination trial in first-line disease.
In that study, Keytruda and chemo reduced the risk of cancer progression or death by 70% after a year in patients positive for dMMR or MSI-H, and by 46% in study participants without those mutations.