The U.S. Food and Drug Administration has granted accelerated approval for a new use of the immunotherapy Jemperli (dostarlimab-gxly). This approval is intended for adults with previously untreated stage II or stage III locally advanced rectal cancer who have mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H) tumors. According to the FDA, approximately 3% of locally advanced rectal cancers are dMMR or MSI-H.
The approval is based on interim results from the AZUR-1 study (NCT05723562), a phase 2 trial evaluating Jemperli alone in 154 patients with the specified cancer type. Patients received up to nine doses of the medication every three weeks over six months. After a median follow-up of more than two years, nearly three-fourths of patients had not required surgery, radiotherapy, or chemotherapy.
Separate data from a study at Memorial Sloan Kettering Cancer Center (NCT04165772) involving 50 patients showed that none had detectable signs of cancer after treatment, with 93% remaining cancer-free for at least 12 months. Of the 27 patients followed for at least three years, only one experienced a recurrence in the same area.
The FDA granted Priority Review and Breakthrough Therapy designation to Jemperli for this indication. The approval was granted to GSK. Because this is an accelerated approval based on interim results, the sponsor is required to continue following patients to confirm that the treatment provides lasting clinical benefit. Common side effects reported in at least 15% of patients include fatigue, rash, diarrhea, and itching.
