A phase 3 trial of Celcuity’s pan-PI3K/mTOR inhibitor has hit its primary endpoint, clearing the biotech to file a second submission for a molecule already under review by the FDA.
Celcuity previously filed for FDA approval of the drug candidate, gedatolisib, in PIK3CA-wild-type breast cancer. The agency is set to rule on the application by July 17. In parallel, Celcuity continued to study the candidate in the PIK3CA-mutant cohort of the phase 3 study, dubbed Viktoria-1, pitting a gedatolisib-based regimen against a doublet featuring Novartis’ PI3K inhibitor Piqray.
Progression-free survival (PFS) was significantly longer in people who received gedatolisib, AstraZeneca’s Faslodex and Pfizer’s Ibrance than in patients who took Piqray and Faslodex, achieving the trial’s primary endpoint. The study also hit a secondary endpoint that compared gedatolisib and Faslodex as a doublet to the combination of Piqray and the AstraZeneca drug.
Celcuity shares rose about 15% to $144 a piece in premarket trading as of publication time.
Celcuity plans to submit the data to the FDA as a supplemental new drug application. If everything goes to plan, the FDA will approve gedatolisib in PIK3CA-wild-type breast cancer and then quickly expand the label to cover PIK3CA-mutant patients.
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Celcuity plans to seek approval in Europe in the fourth quarter, CEO Brian Sullivan said on an earnings call in March. After filing for approval in Europe, Celcuity will step up efforts to find a partner for the drug in the region and in other parts of the world, Sullivan said.
Evaluate included gedatolisib in its top 10 drug launches for 2026, reflecting the forecast that sales will reach $2.1 billion by 2032. Sales in the same ballpark of that forecast would represent a dramatic turnaround for gedatolisib, which Pfizer let go for $10 million upfront in 2021. Pfizer terminated another PI3K/mTOR drug over tolerability, and Eli Lilly dropped a program after seeing clinical data.
How high gedatolisib sales peak will depend on as-yet-undisclosed aspects of the phase 3 data. Celcuity plans to share detailed data in a late-breaking session at the 2026 ASCO Annual Meeting, which will take place in late May and early June. The magnitude of the PFS win and details of the safety and tolerability profile of gedatolisib will be areas of focus.
The gedatolisib presentation was posted by ASCO Friday, after the organization released initial late-breaking titles on April, Leerink Partners analysts noted Monday. The late inclusion, possibly after ASCO’s original abstract submission deadline, bodes well for the magnitude of gedatolisib’s benefit, the Leerink team said.
The PIK3CA-wild-type data suggested gedatolisib causes lower rates of hyperglycemia than Piqray, which Novartis linked (PDF) to grade 3 cases in one-third of patients during development. However, “high rates” of stomatitis are a safety concern for gedatolisib, TD Cowen analysts said in a note to investors in December. Relay Therapeutics’ mutant‑selective PI3K-alpha inhibitor could compete with gedatolisib.
