Dostarlimab achieves durable complete clinical responses in dMMR/MSI-H locally advanced rectal cancer

Dr Meredith Pelster speaks to ecancer about the first results from the global registrational AZUR-1 trial, which evaluated dostarlimab monotherapy in patients with mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) locally advanced rectal cancer.

This patient population can be particularly responsive to PD-1 blockade, potentially avoiding the need for standard treatment with chemotherapy, radiotherapy and surgery.

Among 144 patients with at least 12 months of follow-up, 68% achieved a sustained clinical complete response for at least 12 months after treatment, as assessed by investigators.

The combined rate of sustained clinical complete response or pathological complete response was 76%.

No recurrences have been reported to date among patients achieving a clinical or pathological complete response, and 71% of all enrolled patients remained under surveillance with no evidence of disease progression after dostarlimab alone.

Dr Pelster says the treatment was generally well tolerated, with grade 3 or higher immune-mediated adverse events reported in four patients.

These findings highlight the potential of dostarlimab to offer a chemotherapy, radiotherapy and surgery-free treatment approach for selected patients with dMMR/MSI-H rectal cancer.