Celcuity’s Gedatolisib Regimens Double Progression-Free Survival in Pivotal Phase 3 VIKTORIA-1 Trial for Advanced Breast Cancer
Major Milestone Achieved: Potential New Standard of Care for HR+/HER2- PIK3CA-Mutant Advanced Breast Cancer
Key Points for Investors
- Gedatolisib-based therapies delivered a statistically significant and clinically meaningful improvement in progression-free survival (PFS) for patients with HR+/HER2- advanced breast cancer (ABC) harboring PIK3CA mutations compared to the current standard therapy, alpelisib plus fulvestrant.
- The VIKTORIA-1 Phase 3 trial results represent the first demonstration of superiority of a multi-target PAM inhibitor (gedatolisib) over a single-target PAM inhibitor (alpelisib) in this patient population.
- Gedatolisib regimens also exhibited more favorable safety profiles and lower discontinuation rates due to adverse events compared to alpelisib plus fulvestrant.
- Celcuity plans to submit these results as a supplemental New Drug Application (sNDA) to the FDA and other regulators, and is preparing for a potential commercial launch in Q3 2026.
- The FDA has already granted Priority Review for gedatolisib in PIK3CA wild-type patients, with a PDUFA date of July 17, 2026.
Detailed Results and Implications
1. Efficacy Highlights
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The Phase 3 VIKTORIA-1 trial evaluated gedatolisib in two regimens:
- Gedatolisib-triplet: Gedatolisib + fulvestrant + palbociclib
- Gedatolisib-doublet: Gedatolisib + fulvestrant
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In the PIK3CA-mutant cohort:
- Gedatolisib-triplet reduced risk of progression or death by 50% vs. alpelisib plus fulvestrant (HR=0.50, 95% CI: 0.37–0.68, p<0.0001). Median PFS was 11.1 vs. 5.6 months.
- Gedatolisib-doublet reduced risk of progression or death by 49% vs. alpelisib plus fulvestrant (HR=0.51, 95% CI: 0.33–0.79, p=0.0013). Median PFS was 11.3 vs. 5.6 months.
- Objective response rate (ORR): 48.9% for the triplet (vs. 26.0% for control) and 35.7% for the doublet.
- Median duration of response (DoR): 15.7 months (triplet), 24.2 months (doublet), both longer than the 7.5 months for alpelisib plus fulvestrant.
- These efficacy outcomes are the best ever reported in any Phase 3 trial for a regimen including endocrine therapy in the second-line setting for HR+/HER2- advanced breast cancer.
- The VIKTORIA-1 trial is the first to demonstrate a statistically significant advantage of one PAM pathway inhibitor over another, establishing gedatolisib as a potential new standard of care.
2. Safety Profile
- Low discontinuation rates due to adverse events: 2.6% (triplet), 3.8% (doublet), compared to 7.1% for alpelisib plus fulvestrant.
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Most common Grade 3+ treatment-related adverse events (TRAEs):
- Neutropenia: 58.8% (triplet), 0% (doublet), 0.7% (control)
- Stomatitis: 16.3% (triplet), 5.8% (doublet), 5.3% (control)
- Rash: 6.5% (triplet), 5.8% (doublet), 15.1% (control)
- Hyperglycemia: 2.6% (triplet), 0% (doublet), 14.5% (control)
- Grade 5 TRAEs: One in the triplet group (related to palbociclib), two in the control group, none in the doublet group.
- Overall, the multi-target mechanism and intravenous administration of gedatolisib are believed to contribute to the improved safety profile.
3. Regulatory and Commercial Outlook
- Celcuity intends to submit these results for sNDA to the FDA and other regulatory agencies.
- Anticipated commercial launch: Target Q3 2026, pending FDA approval.
- FDA Priority Review already granted for gedatolisib in PIK3CA wild-type advanced breast cancer, with a PDUFA date of July 17, 2026.
- Ongoing pipeline: Phase 3 VIKTORIA-2 trial (first-line setting in HR+/HER2- ABC) and Phase 1b/2 CELC-G-201 trial (prostate cancer) are underway, further expanding potential market opportunities.
4. Scientific and Market Significance
- Gedatolisib’s comprehensive inhibition of the PI3K/AKT/mTOR (PAM) pathway overcomes resistance mechanisms associated with single-target inhibitors (such as alpelisib, AKT inhibitors, or mTORC1 inhibitors).
- This could position gedatolisib as a first-in-class, best-in-class therapy for a large segment of advanced breast cancer patients, especially those with resistance to current standards.
- Market opportunity: HR+/HER2- breast cancer is the most common subtype, accounting for approximately 70% of all breast cancers. The addressable population is substantial, and superior efficacy and safety could drive swift uptake if approved.
Statements from Management and Investigators
“By comprehensively blocking the PI3K/AKT/mTOR, or PAM, pathway, gedatolisib combined with fulvestrant, with or without palbociclib, showed it can offer these patients two times the likelihood of survival without disease progression or death relative to a single-target inhibitor of the PAM pathway. With these results, the gedatolisib regimens, if approved, represent a new potential standard of care for patients with HR+, HER2-negative, PIK3CA mutant advanced breast cancer whose disease progressed on or after treatment with a CDK4/6 inhibitor.”
– Dr. Sara Hurvitz, Co-Principal Investigator“Both gedatolisib regimens were well-tolerated with few VIKTORIA-1 patients discontinuing treatment due to an adverse event. These safety results compare very favorably to those from the patient group treated with alpelisib and fulvestrant, which we believe reflects the benefit of gedatolisib’s multi-target mechanism of action, pharmacokinetic profile, and intravenous administration.”
– Dr. Igor Gorbatchevsky, Chief Medical Officer of Celcuity“It is rare in oncology for a targeted therapy to offer both improved efficacy and better safety results relative to another drug in its class. This second positive Phase 3 data readout further underscores the broad potential of multi-target PAM inhibition.”
– Brian Sullivan, CEO of Celcuity
What This Means for Shareholders
- Potential for significant share price movement: These results could materially increase Celcuity’s valuation, given the strong efficacy, favorable safety, and clear regulatory and commercial pathway.
- Competitive advantage: Gedatolisib is positioned to potentially displace existing standards in a large market, with additional pipeline catalysts ahead (ongoing trials in first-line and other indications).
- Regulatory milestones: Priority review and upcoming PDUFA date set the stage for potential U.S. market entry in mid-to-late 2026; further approvals could follow globally.
- Risks: As with all clinical-stage biotech companies, regulatory approval is not guaranteed, and unforeseen safety or efficacy issues could still arise.
Conclusion
Celcuity’s VIKTORIA-1 Phase 3 data for gedatolisib represent a major potential inflection point for the company and its shareholders. With best-in-class efficacy, improved safety, and a clear regulatory path, gedatolisib could soon become a new standard of care for a large, underserved population in advanced breast cancer. Investors should closely monitor regulatory updates, commercial launch plans, and ongoing additional studies for further catalysts.
Disclaimer: This article is for informational purposes only and does not constitute investment advice. Investors should perform their own due diligence and consult with a qualified financial advisor before making investment decisions. All statements herein are based on company disclosures as of the date indicated and are subject to change without notice.
