Celcuity reports phase 3 win for gedatolisib in PIK3CA-mutant breast cancer: full analysis
Celcuity has posted another positive phase 3 result for gedatolisib, this time in the PIK3CA-mutant arm of the VIKTORIA-1 trial in HR-positive, HER2-negative advanced breast cancer. In a May 1 announcement, the company said the gedatolisib triplet of gedatolisib, fulvestrant, and palbociclib significantly improved progression-free survival versus alpelisib plus fulvestrant after prior CDK4/6 inhibitor and aromatase inhibitor treatment. Celcuity also said the gedatolisib doublet with fulvestrant beat alpelisib plus fulvestrant on the same endpoint, with no new safety signals reported in the topline release. (globenewswire.com)
The result builds on momentum from the same study’s PIK3CA wild-type cohort, which previously showed strong progression-free survival gains for gedatolisib-based regimens versus fulvestrant alone and was later published in the Journal of Clinical Oncology. In that cohort, median progression-free survival reached 9.3 months for the triplet and 7.4 months for the doublet, versus 2.0 months for fulvestrant monotherapy, according to the published report summarized by The ASCO Post. Those wild-type data helped support Celcuity’s NDA, which the FDA accepted under Priority Review with a July 17, 2026, action date. (ascopost.com)
VIKTORIA-1 is an open-label, randomized phase 3 trial in adults with HR-positive, HER2-negative advanced breast cancer whose disease progressed on or after prior CDK4/6 therapy plus an aromatase inhibitor. The study enrolled patients regardless of PIK3CA status, while evaluating mutant and wild-type populations separately. In the mutant cohort, Celcuity used alpelisib plus fulvestrant as the comparator, a notable design choice because it pits gedatolisib directly against an established PI3K-pathway therapy rather than endocrine therapy alone. (globenewswire.com)
That matters because the treatment landscape for PIK3CA-mutant disease has changed quickly. The FDA approved inavolisib with palbociclib and fulvestrant on October 10, 2024, for adults with endocrine-resistant, PIK3CA-mutated, HR-positive, HER2-negative locally advanced or metastatic breast cancer, and also cleared the FoundationOne Liquid CDx assay as a companion diagnostic. That approval gave clinicians a newer biomarker-directed option in a space previously defined in part by alpelisib-based regimens, so any new entrant will need to show not just efficacy, but also a clear place in sequencing and tolerability. (fda.gov)
Expert reaction so far has been limited because Celcuity has only released topline results for the mutant cohort. Still, co-principal investigator Sara Hurvitz said in the company release that patients whose disease progresses on or after CDK4/6 therapy often derive only modest benefit from therapies that target a single node in the PI3K/AKT/mTOR pathway. Celcuity’s broader pitch is that gedatolisib’s pan-PI3K and mTORC1/2 inhibition may provide more comprehensive pathway blockade than single-target agents. That mechanistic argument has also appeared in discussion of the wild-type cohort, where investigators and company materials framed gedatolisib as distinct from more selective pathway inhibitors. (globenewswire.com)
Why it matters: For oncology practices, this is less about one positive press release and more about whether gedatolisib can carve out a role across multiple biomarker-defined segments of HR-positive, HER2-negative advanced breast cancer. If the full mutant-cohort data show a meaningful efficacy advantage with manageable toxicity against alpelisib, that could strengthen the case for gedatolisib as a serious post-CDK4/6 option. It could also complicate treatment algorithms, especially as clinicians weigh prior exposure, mutation status, companion diagnostics, adverse-event profiles, and payer considerations across alpelisib, inavolisib, capivasertib-based strategies, and potentially gedatolisib. The implication is a more crowded, but potentially more personalized, second-line setting. (globenewswire.com)
What to watch: The next inflection point is the ASCO late-breaking presentation in Chicago, where the field should get the actual progression-free survival numbers, hazard ratios, subgroup analyses, and fuller safety data for the mutant cohort. After that, attention will likely turn to whether Celcuity pursues another regulatory filing in the PIK3CA-mutant setting, how the company positions gedatolisib against approved competitors, and whether the FDA’s July 17, 2026 decision in the wild-type population gives the drug a commercial foothold before any expansion effort. (globenewswire.com)