Phase 1/2 ZINNIA tests REC-7735, a PIK3CA H1047R-selective inhibitor, across advanced solid tumors

Recursion Pharmaceuticals’ first-in-human, open-label ZINNIA study evaluates oral REC-7735 in unresectable, locally advanced, or metastatic solid tumors with the PIK3CA H1047R mutation. The drug is designed to inhibit mutant PI3K alpha while sparing the wild-type protein. Dose finding and expansion assess safety, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity, with twice-daily oral administration.

This mutation-selected basket study can include breast, endometrial, colorectal, and other cancers meeting the protocol. Mutant selectivity is intended to improve the treatment window of PI3K inhibition, where effects on normal glucose regulation can limit dosing. Whether this selectivity translates into improved tolerability and tumor control remains to be established in patients. Existing treatment remains tumor-type specific, with PI3K-pathway therapies established only in selected settings; the trial examines whether a mutation-focused inhibitor can extend that opportunity.