AZUR-1 Neoadjuvant Dostarlimab for Organ Preservation in Rectal Cancer

The AZUR-1 trial builds on earlier single-institution data showing that single-agent anti-PD-1 therapy could spare select patients with mismatch repair-deficient rectal cancer from surgery and radiation. This single-arm study evaluated neoadjuvant dostarlimab alone in patients with locally advanced disease, asking whether giving immunotherapy first could remove the need for further treatment. The panel reviews the primary end point of clinical complete response, judged by endoscopy combined with imaging, including MRI. They note that some patients who had surgery for suspected remaining disease turned out to have pathologic complete responses. They describe the results as encouraging and potentially practice-changing, offering patients a way to avoid the harms of surgery and radiation. Challenges remain, including agreeing on a standard definition of clinical complete response, setting structured surveillance schedules for patients managed without surgery, and bringing an approach developed at a well-resourced academic center with a strong tumor board to community and rural practices.