- The Food and Drug Administration has granted full approval to GSK’s cancer immunotherapy Jemperli in a type of endometrial cancer, the company said Friday, converting an accelerated approval that made the drug the seventh of its type to be cleared for U.S. use.
- The announcement came one day after FDA advisers recommended, in a mixed vote, GSK’s plan to study Jemperli in rectal cancer. GSK proposed a trial that used remission rates after 12 months of treatment as its primary measurement, and will use data from that along with independent research to seek approval.
- Jemperli is used after chemotherapy to treat tumors with a specific genetic error that disrupts cells’ ability to repair DNA in endometrial tissue and, under accelerated approval, all other locations where patients have no other treatment options. Under accelerated approval, Merck & Co.’s Keytruda can be used in all tumors with this genetic signature and, along with Bristol Myers Squibb’s Opdivo, in colorectal cancer with this same genetic error.
In gaining full approval for Jemperli, GSK avoided a mishap that has affected other makers of cancer immunotherapies. Merck, Bristol Myers and Roche have each had to withdraw their respective immunotherapies for certain uses over so-called “dangling” accelerated approvals, when the drug in question has failed in mandated confirmatory trials or the sponsor hasn’t followed through in completing the trial.
The full approval for endometrial cancer with mismatch repair deficient tumors gives GSK a market to itself, albeit a small one.
Still, its efforts to become an oncology player have sputtered. Jemperli had sales of 21 million pounds, or $26 million, in 2022. And late last year, GSK pulled another of its cancer drugs, Blenrep, because it failed a confirmatory trial. GSK’s oncology business is led by Zejula, which had sales of 463 million pounds in 2022 but is widely outsold by AstraZeneca’s Lynparza.
The FDA decided to give full approval to Jemperli in endometrial cancer with mismatch repair deficient tumors based on additional results from a trial called GARNET, which GSK used to gain accelerated approval. The company found that 45% of patients saw their tumors shrink or disappear, and 16% of all patients in the trial had complete elimination of their tumors. Accelerated approval was granted based on earlier data.
For rectal cancer with mismatch repair deficient tumors, GSK should have some confidence going into the trial. A small researcher-led trial of Jemperli conducted at Memorial Sloan Kettering Cancer Center found the drug eliminated tumors in all 12 patients enrolled without need for further drug therapy or surgery — a result that got significant attention at the time.