Turning ctDNA into an intermediate endpoint will require harmonization

Evidence for circulating tumor DNA reduction as a new intermediate endpoint to support accelerated approvals of solid tumor therapies is nearing a tipping point. The endpoint stands to transform clinical development across many settings, but it must first be more fully validated. 

For that to happen, companies need to commit to standardizing both the assays used to measure circulating tumor DNA (ctDNA) and the protocols for collecting samples and analyzing the data. ...