The phase 3 VIKTORIA-1 trial showed that treatment regimens including gedatolisib significantly improved outcomes for patients with hormone receptor–positive, HER2-negative, and PIK3CA wild-type metastatic breast cancer that had progressed after CDK4/6 inhibitor therapy.
Patients who received the triplet regimen (gedatolisib, palbociclib, and fulvestrant) had a median progression-free survival (PFS) of 9.3 months compared to 2.0 months with fulvestrant alone. The doublet regimen (gedatolisib plus fulvestrant) achieved a PFS of 7.4 months versus 2.0 months with fulvestrant alone. The benefit was observed even in patients without PIK3CA mutations.
Gedatolisib is an intravenous PI3K and mTOR inhibitor that blocks multiple isoforms of PI3K and both mTORC1 and mTORC2, pathways commonly altered in this cancer type. Side effects such as hyperglycemia and diarrhea occurred less frequently than with other PI3K inhibitors, though stomatitis remained a concern.
If approved, gedatolisib-based regimens could become valuable new options for patients who have developed resistance to CDK4/6 inhibitors, offering better outcomes than current single-agent endocrine therapies.