Patients with locally advanced rectal cancer and tumors with deficient mismatch repair (dMMR) have shown a remarkable response to treatment with the programmed cell death-1 (PD-1) inhibitor dostarlimab (Jemperli).
So far, the study has involved only 12 patients, but all of them have had a clinical complete response to treatment. They continue to show no signs of cancer (during follow-up ranging from 6 to 25 months) and have not undergone surgery or had radiation and chemotherapy, which are the standard treatment approaches.
Dostarlimab is already approved by the US Food and Drug Administration for use in the treatment of recurrent or advanced endometrial cancer with dMMR. Rectal cancer is an off-label use.
All patients had mismatch repair-deficient stage 2 or 3 rectal adenocarcinoma. The authors note that these tumors respond poorly to standard chemotherapy regimens, including neoadjuvant chemotherapy. The median age of enrolled patients was 54 years and 62% were women.
Source: NEJM