Daiichi jettisons ADC after flunking early solid tumor test

Daiichi Sankyo’s antibody-drug conjugate (ADC) team has hit a rare bump in the road, dumping a gastrointestinal stromal tumor (GIST) candidate after seeing “no clear responses” in a phase 1 trial.

Daiichi took DS-6157 into the clinic in light of the unmet need in GIST and evidence that GPR20 is selectively and abundantly expressed in the indication. Tyrosine kinase inhibitors such as Gleevec are already used to treat GIST, but many patients progress after developing resistance mutations. Equally, the therapies have limited efficacy in some subsets of GIST patients.