32 bowel cancer patients remain cancer-free after experimental immunotherapy trial
Updated
Updated · Fox News · May 4
32 bowel cancer patients remain cancer-free after experimental immunotherapy trial
11 articles · Updated · Fox News · May 4
University College London and UCL Hospitals said 32 stage 2 or 3 patients with MMR-deficient or MSI-high tumours stayed recurrence-free after 33 months.
Patients received up to nine weeks of pembrolizumab before surgery, and 59% had no detectable cancer by the operation date, suggesting better outcomes than standard surgery followed by chemotherapy.
Researchers said about 25% of comparable patients would usually relapse within three years, but cautioned the trial was small, limited to a genetic subset, and needs longer follow-up.
This cancer therapy has a 100% success rate, so what is the hidden long-term risk for patients?
Could a nine-week drug course soon replace surgery and chemotherapy for a type of bowel cancer?
If a genetic flaw is the key, how many other cancers could this immunotherapy approach unlock?
The 2026 NEOPRISM-CRC trial treated 32 patients with stage 2/3 MMRd/MSI-H bowel cancer using neoadjuvant pembrolizumab, achieving a remarkable 59% pathological complete response rate. Importantly, none of these patients experienced cancer recurrence after a median 33-month follow-up, while only 6.2% had severe side effects, leading to faster recovery compared to chemotherapy. The trial also used advanced biomarkers—post-surgery ctDNA negativity and high baseline tumor T-cell receptor clonality—to predict outcomes and personalize treatment. These findings suggest pembrolizumab could become a new standard of care, potentially allowing some patients to avoid surgery and chemotherapy, though phase 3 trials and accessibility challenges remain.