Andrea Cercek, MD, Memorial Sloan Kettering Cancer Center, New York, New York, discussed results from a phase 2 study which demonstrated that neoadjuvant dostarlimab yielded durable recurrence-free response among patients with locally advanced mismatch repair deficient rectal cancer. 

Transcript: 

Hi, I am Andrea Cercek, I am a medical oncologist at Memorial Sloan Kettering Cancer Center, and it's my pleasure to discuss our abstract that I'm presenting this year at ASCO 2024. Our trial is a phase 2 study of neoadjuvant dostarlimab in mismatch repair deficient locally advanced rectal cancer. 

Normally, the standard treatment is effective but the treatment, in particular the radiation and the surgery, have a lot of toxicity [and] a lot of morbidities for patients. This trial was really asking the question: could we potentially use just PD-1 blockade, just dostarlimab alone, in this subset of patients with mismatch repair deficiency to replace all standard treatments and really maintain the patient's quality of life, preserve their overall quality of life. Because the issues that come about from radiation and surgery are infertility, bowel, bladder, and sexual dysfunction, and then about 30% of patients need a permanent colostomy due to the location of the tumor. 

The data that we're showing is that all 42 [patients] that have received just dostarlimab alone have had a clinical complete response. None of them have needed any of these interventions so they have really maintained their quality of life. The durability in the 24 patients that have had a clinical response of over a year really suggests that these responses are long-term responses and effectively equivalent to as if they have had surgery, but no patients have needed surgery because the tumor responded to just dostarlimab. 

Source: 

Cercek A. Durable complete responses to PD-1 blockade alone in mismatch repair deficient locally advanced rectal cancer. Presented at the ASCO Annual Meeting. May 31 – June 4, 2024; Chicago, IL. Abstract #LBA3512