Surrogate endpoints based on ctDNA will require standards, specificity

There’s a compelling case for validating reduction in circulating tumor DNA (ctDNA) as a surrogate endpoint in solid tumor studies. Done right, ctDNA could shrink trials and accelerate development by providing an earlier — and potentially more sensitive — signal of clinical benefit than radiographic imaging. But in the settings where ctDNA would matter most, the work needed to validate it has barely begun.

At a Friends of Cancer Research meeting on Modernizing Oncology Endpoints this month, former government officials and industry R&D leaders outlined both the promise of ctDNA-based endpoints and the obstacles to making them reliable...