Celcuity Inc. (CELC), a clinical-stage biotechnology company focused on targeted cancer therapies, announced positive topline results from the PIK3CA wild-type cohort of its Phase 3 VIKTORIA-1 trial, sending shares soaring over 200% in pre-market trading.

The trial evaluated gedatolisib combined with fulvestrant, with or without palbociclib, in patients with hormone receptor-positive (HR+), HER2-negative, PIK3CA wild-type advanced breast cancer who had progressed after treatment with CDK4/6 inhibitors and aromatase inhibitors.

In the trial, the gedatolisib triplet regimen (gedatolisib + fulvestrant + palbociclib) demonstrated a 76% reduction in the risk of disease progression or death compared to fulvestrant alone, with a hazard ratio (HR) of 0.24 (95% CI: 0.17–0.35; p<0.0001). The median progression-free survival (mPFS) was 9.3 months, representing a 7.3-month improvement over the control arm. The gedatolisib doublet (gedatolisib + fulvestrant) also showed strong results, reducing the risk of progression or death by 67% (HR: 0.33; 95% CI: 0.24–0.48; p<0.0001), with an mPFS of 7.4 months, or 5.4 months longer than fulvestrant alone.

These results mark the most favorable hazard ratios and median PFS gains ever reported in a Phase 3 trial for patients with HR+/HER2- advanced breast cancer (ABC) in a second-line setting.

According to Celcuity, gedatolisib is the first PI3K/AKT/mTOR pathway inhibitor to show positive Phase 3 results in PIK3CA wild-type HR+/HER2- breast cancer patients who progressed following CDK4/6 inhibitor therapy.

Dr. Sara Hurvitz, Senior Vice President at Fred Hutchinson Cancer Center and co-principal investigator, commented:“These are potentially practice-changing results. To my knowledge, we’ve never seen Phase 3 data showing a quadrupling in the likelihood of survival without disease progression compared to control.”

Dr. Igor Gorbatchevsky, Chief Medical Officer of Celcuity, also emphasized the clinical significance of the data, stating:“The 7.3- and 5.4-month improvements in PFS are potentially paradigm-shifting. Gedatolisib was also well tolerated, with few patients discontinuing due to side effects.”

In addition to strong efficacy, treatment discontinuation rates due to adverse events were lower than those observed in prior Phase 1b studies, and also below the levels seen in currently approved combinations for HR+/HER2- breast cancer. The regimens showed improved tolerability, with fewer instances of hyperglycemia and stomatitis than in earlier-stage trials.

Celcuity plans to present full results from the PIK3CA wild-type cohort at a medical conference later this year, and intends to submit a New Drug Application (NDA) for gedatolisib to the FDA in Q4 2025. Topline data from the PIK3CA mutation cohort of the VIKTORIA-1 trial is expected by year-end 2025.

Meanwhile, the company will host a webcast and conference call on Monday, July 28, 2025, at 8:00 a.m. ET to discuss the topline findings