GSK’s Jemperli Wins Accelerated Approval for Rectal Cancer

FDA has granted GSK accelerated approval for a new use of the immunotherapy Jemperli (dostarlimab-gxly) —treating adults with previously untreated stage II or stage III locally advanced rectal cancer. “At these stages, the cancer has grown into nearby tissue or reached nearby lymph nodes but has not spread to distant organs,” an FDA release says. “To be eligible, patients’ tumors must be mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H), as determined by an FDA-authorized test. Published estimates suggest that approximately 3% of locally advanced rectal cancers are dMMR or MSI-H.”

FDA says the therapy may allow some patients with locally advanced rectal cancer to avoid certain care that can have a lasting impact on their daily life. “Patients with locally advanced rectal cancer often receive chemotherapy and radiation prior to surgery, which can affect bowel, urinary, and sexual function, as well as fertility,” it says. “Surgery also carries risks of serious, sometimes life-threatening complications, including poor healing and leaks where the bowel is reconnected, and in some patients, permanent colostomy.”

Jemperli is said to work by blocking a signal that cancer cells use to shield themselves from the immune system by targeting the PD-1 protein.

Approval is based on data from AZUR-1 (NCT05723562), a Phase 2 study evaluating Jemperli alone in 154 patients with previously untreated dMMR or MSI-H locally advanced rectal cancer. “After a median follow-up of more than two years — meaning at least half of patients had been monitored for that long — almost three-fourths of patients had not needed surgery, radiotherapy or chemotherapy,” FDA says. “Longer follow-up is needed to understand the duration of response and how often the cancer returns.”

The agency says an earlier study at Memorial Sloan Kettering Cancer Center assessed Jemperli alone in 50 patients with previously untreated dMMR or MSI-H locally advanced rectal cancer, and none of the patients had detectable signs of cancer after Jemperli treatment. It also found that 93% of patients treated maintained that cancer-free status for at least 12 months. “Of the 27 patients followed for at least 3 years, only one had their cancer return, and it recurred in the same area,” it says.

The approval was granted under the Commissioner’s National Priority Voucher pilot program.