Checkpoint inhibitor delays disease progression in anal cancer trial

BARCELONA, Spain — A widely used immunotherapy approach helped stave off disease progression in patients with a type of anal tumor, researchers reported Saturday, potentially setting up the drug for approval in a cancer that’s largely caused by human papillomavirus. 

The Phase 3 trial tested the PD-1 targeting antibody retifanlimab in combination with chemotherapy versus chemotherapy alone in patients with recurrent or metastatic squamous cell carcinoma of the anal canal. Retifanlimab was developed by Incyte and is approved as Zynyz in Merkel cell carcinoma.

In the study, adding retifanlimab to chemotherapy cut the risk of disease progression or death by more than a third. Patients on the immunotherapy went 9.3 months at the median without their disease progressing, versus 7.4 months for people who received chemotherapy alone. Those on the combination also appeared to have higher rates of overall survival, although researchers did not have enough long-term data yet to confirm that advantage.