Retrospective study of immune checkpoint inhibition and cytotoxic chemotherapy for dMMR/MSI-H pancreatic cancer

Pancreatic cancer (PaC) has a very poor prognosis, with limited systemic treatment options. dMMR/MSI-H PaC may represent a subset of patients in whom immunotherapy may have benefit, but the PaC subset of KEYNOTE-158 (pembrolizumab for MSI-H solid tumors) was disappointing. A retrospective study among dMMR/MSI-H PaC patients of Mayo Clinic centers found impressive and durable responses to immunotherapy, with menial responses to chemotherapy. There were uncharacteristically favorable outcomes to surgery and chemoradiotherapy. The authors conclude that these findings support the use of immunotherapy in dMMR/MSI-H PaC whenever systemic therapy is needed, including first-line in the palliative, adjuvant, of neoadjuvant settings.