First approved in 2021, Jemperli has now become a cornerstone of GSK’s cancer business, earning more than $160 million in the third quarter.
GSK on Friday unveiled headline findings from the Phase III FIRST-ENGOT-OV44 study, posting mixed survival results for add-on Jemperli to standard-of-care chemotherapy and Zejula in patients with advanced ovarian cancer.
The pharma did not reveal specific data in its press release, announcing only that the FIRST trial hit its primary endpoint: Adding Jemperli, an anti-PD-1 antibody, led to significant improvements in progression-free survival (PFS) when used in the first-line setting. GSK additionally noted that the PFS benefits of Jemperli remained significant regardless of concurrent bevacizumab treatment.
However, adding Jemperli to Zejula and platinum-based chemotherapy did not significantly boost overall survival—a key secondary endpoint of the trial. Safety was consistent with the known adverse event profiles of the individual medicines.
GSK is trading around 1% lower Friday morning.
The pharma will “continue to evaluate the potential of this combination,” Hesham Abdullah, global head of Oncology R&D at GSK, said in a statement. GSK plans to share full findings from the FIRST study in the future.
FIRST-ENGOT-OV44 is a double-blinded and randomized trial that has enrolled more than 1,400 patients newly diagnosed with Stage III or IV ovarian cancer. Participants randomized to the experimental arm received Jemperli, Zejula and standard-of-care chemotherapy. Active controls were treated with Zejula plus chemotherapy, while passive controls were given chemotherapy and placebo. The study is set to complete by June 2026.
Designed to be administered intravenously, Jemperli is an IgG humanized monoclonal antibody that binds and block the PD-1 receptor, preventing its interaction with its corresponding ligands. This mechanism allows Jemperli to disrupt the cancer cells’ ability to evade the immune system.
Since winning the FDA’s accelerated approval in April 2021—for the treatment of advanced endometrial cancer patients with a specific biomarker and who had progressed after prior platinum chemotherapy—Jemperli has become a cornerstone of GSK’s cancer franchise, alongside the PARP inhibitor Zejula. In its most recent financial report, the pharma reported that Jemperli sales surged more than 100% in the third quarter of 2024, bringing in more than $160 million.
The FDA converted Jemperli’s accelerated approval to a traditional one in February 2023. In August of that year, GSK won the FDA’s nod the drug’s use for the frontline treatment of patients with primary advanced or recurrent endometrial cancer, becoming the first immuno-oncology and PD-1 blocker to be approved for first-line use in this indication—and beating out Merck’s PD-1 powerhouse Keytruda.
More recently, GSK secured a broad label expansion for Jemperli, allowing its frontline use in all adult patients with primary advanced or recurrent endometrial cancer.
