Celcuity Presents Updated Results from the PIK3CA MT Cohort of the Phase 3 VIKTORIA-1 Study in Patients with HR+/HER2- Advanced Breast Cancer at the ESMO Congress 2026

Updated results include longer response durations and lower adverse-event discontinuation rates than the alpelisib comparator.

Rhea-AI Summary

Celcuity (Nasdaq: CELC) presented updated Phase 3 VIKTORIA-1 results for gedatolisib in patients with PIK3CA-mutant advanced breast cancer at ESMO 2026.

The triplet combines gedatolisib, fulvestrant and palbociclib; the doublet omits palbociclib. Without liver metastases, median progression-free survival, or time without cancer worsening or death, was 21.5 months with the triplet and 11.5 months with the doublet, versus 9.1 months with alpelisib plus fulvestrant. With liver metastases, results were 9.1, 11.1 and 4.6 months, respectively.

In evaluable mutant-cohort patients, response rates were 59%, 43% and 33%; median response durations were 19.4, 27.8 and 7.5 months, respectively. Adverse-event discontinuation rates were 5% and 4% for gedatolisib versus 19% for alpelisib. The doublet's no-liver-metastases comparison had a p-value of 0.1627, qualifying the broader efficacy findings.

Positive

• Minor pointNo-liver-metastases median progression-free survival: 21.5 months triplet, 11.5 months doublet versus 9.1 months with alpelisib plus fulvestrant.
• Minor pointLiver-metastases median progression-free survival: 9.1 months triplet, 11.1 months doublet versus 4.6 months with alpelisib plus fulvestrant.
• Minor pointNo-visceral-metastases median progression-free survival: 21.5 months triplet, not reached doublet versus 9.2 months with alpelisib plus fulvestrant.
• Minor pointVisceral-metastases median progression-free survival: 9.8 months triplet, 11.3 months doublet versus 5.6 months with alpelisib plus fulvestrant.
• Minor pointEvaluable mutant-cohort response rates, confirmed and unconfirmed: 59% triplet, 43% doublet versus 33% with alpelisib plus fulvestrant.

7 minor points

• Minor pointMutant-cohort median response duration: 19.4 months triplet, 27.8 months doublet versus 7.5 months with alpelisib plus fulvestrant.
• Minor pointEvaluable wild-type-cohort response rates, confirmed and unconfirmed: 39% triplet, 34% doublet versus 1% with fulvestrant.
• Minor pointWild-type-cohort median response duration: 19.2 months triplet, 13.8 months doublet; fulvestrant's result was not evaluable.
• Minor pointMutant-cohort adverse-event discontinuations: gedatolisib 5% triplet, 4% doublet versus 19% for alpelisib.
• Minor pointGrade 3 mouth inflammation improved within 1–2 weeks; fewer than 3% had it by treatment cycle two.
• Minor pointEight-study indirect analysis found statistically significant or numerically superior progression-free survival outcomes for gedatolisib regimens versus evaluated alternatives.
• Minor pointIndirect analysis found statistically significant 2x triplet, 1.5x doublet likelihood of survival without progression versus imlunestrant plus abemaciclib.

Negative

• Minor pointDoublet subgroup comparisons had p=0.1627 without liver metastases and p=0.0703 without visceral metastases; neither establishes statistical significance.
• Minor pointMouth inflammation caused treatment discontinuation in 1% of triplet patients, versus 0% with the doublet.

News Explained

The new data extend efficacy reporting into additional disease subgroups, with the no-visceral doublet comparison reported at p=0.0703.

At the ESMO Congress, Celcuity presented additional PIK3CA-mutant subgroup results from Phase 3 VIKTORIA-1; among patients with liver metastases, median PFS was 9.1 months with the triplet and 11.1 months with the doublet, versus 4.6 months with alpelisib plus fulvestrant.

The release describes significant PFS improvement across liver and visceral subgroups, but the no-visceral doublet row reports p=0.0703 (hazard ratio 0.40; 90% CI 0.15–1.1), qualifying that broad claim for this arm and subgroup.

Key Figures

Median PFS, no liver metastases: 21.5 vs 9.1 months (triplet); 11.5 vs 9.1 months (doublet) Median PFS, liver metastases: 9.1 vs 4.6 months (triplet); 11.1 vs 4.6 months (doublet) Median PFS, no visceral metastases: 21.5 vs 9.2 months (triplet); NR vs 9.2 months (doublet) +4 more

Median PFS, no liver metastases

21.5 vs 9.1 months (triplet); 11.5 vs 9.1 months (doublet)

PIK3CA-mutant cohort; alpelisib plus fulvestrant comparator; doublet p=0.1627

Median PFS, liver metastases

9.1 vs 4.6 months (triplet); 11.1 vs 4.6 months (doublet)

PIK3CA-mutant cohort; alpelisib plus fulvestrant comparator

Median PFS, no visceral metastases

21.5 vs 9.2 months (triplet); NR vs 9.2 months (doublet)

PIK3CA-mutant cohort; fulvestrant plus alpelisib comparator

Median PFS, visceral metastases

9.8 vs 5.6 months (triplet); 11.3 vs 5.6 months (doublet)

PIK3CA-mutant cohort; alpelisib plus fulvestrant comparator

Objective response rate

59% (triplet); 43% (doublet); 33% (control)

PIK3CA-mutant cohort; control was alpelisib plus fulvestrant

Median duration of response

19.4 months (triplet); 27.8 months (doublet); 7.5 months (control)

PIK3CA-mutant cohort; control was alpelisib plus fulvestrant

TEAE discontinuation rate

5% (triplet); 4% (doublet); 19% (alpelisib)

PIK3CA-mutant cohort

Previous Clinical trial Reports

2 past events · Latest: Jun 02

Same Type 2 events

1. Jun 02

   Phase 3 trial results

   24h Move

   -25.6%

   Reported PIK3CA-mutant VIKTORIA-1 PFS results comparing gedatolisib regimens with alpelisib plus fulvestrant.

2. May 01

   Trial endpoint result

   24h Move

   +15.4%

   Reported that the VIKTORIA-1 PIK3CA-mutant cohort met its primary progression-free-survival endpoint.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

pfs, orr, treatment-emergent adverse events, mTORC1/2 inhibitor, +1 more

5 terms

pfs medical

"median progression-free survival (“PFS”)"

Progression-free survival (PFS) is a clinical-trial measure that records how long, on average, patients live without their disease getting worse after starting a treatment. For investors, PFS acts like a stopwatch of a drug’s effectiveness: longer PFS can signal meaningful patient benefit, improve chances of regulatory approval or label strength, and raise a drug’s commercial value, while shorter or unchanged PFS can weigh on a company’s prospects.

orr medical

"objective response rates (“ORR”)"

Objective Response Rate (ORR) is the percentage of patients in a clinical trial whose tumors shrink or disappear by a predefined amount after treatment. For investors, ORR is a quick, measurable signal of a therapy’s effectiveness—like early sales numbers for a new product—and strong ORR data can boost a drug’s commercial prospects and company valuation, while weak ORR can temper expectations.

treatment-emergent adverse events medical

"discontinuation rate of gedatolisib due to treatment-emergent adverse events"

Events or symptoms that either appear for the first time or get worse after a patient starts a treatment; think of new or intensified side effects that show up once medicine or a medical device is used. Investors watch these closely because they affect whether a therapy can gain regulatory approval, be prescribed widely, or face legal and commercial setbacks—similar to how early customer complaints can sink a new product’s prospects.

mTORC1/2 inhibitor medical

"pan-PI3K and mTORC1/2 inhibitor"

An mTORC1/2 inhibitor is a drug that blocks the activity of both protein complexes formed by the mechanistic target of rapamycin (mTOR) — mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). mTORC1 and mTORC2 are cellular signaling hubs that regulate growth, protein synthesis, metabolism and survival; inhibitors that target both complexes typically act at the mTOR kinase and therefore prevent signals from either complex rather than selectively blocking only mTORC1. Compared with agents that inhibit only mTORC1, dual mTORC1/2 inhibitors produce broader pathway suppression (including effects on AKT activation) and so can have different therapeutic effects and side‑effect profiles.

pharmacokinetic medical

"mechanism of action and pharmacokinetic properties"

Pharmacokinetic describes how a drug moves through and leaves the body — how it is absorbed, spread to tissues, broken down and excreted — like tracking a package from pickup to delivery and disposal. For investors, these properties determine effective dose, safety risks, how often a medicine must be taken, and how reliably it works, which in turn influence clinical trial success, regulatory approval chances, production complexity and a drug’s commercial value.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Median PFS was 21.5 months with the gedatolisib triplet and 11.5 months with the gedatolisib doublet versus 9.1 months with alpelisib + fulvestrant in patients who had no liver metastases 

ORR and median duration of response was 59% and 19.4 months for the gedatolisib triplet and 43% and 27.8 months for the gedatolisib doublet, respectively, compared to 33% and 7.5 months for alpelisib + fulvestrant

The discontinuation rate for gedatolisib due to treatment-emergent adverse events was 5% and 4% with the gedatolisib triplet and doublet, respectively, compared to 19% for alpelisib

MINNEAPOLIS, Oct. 24, 2026 (GLOBE NEWSWIRE) -- Celcuity Inc. (Nasdaq: CELC), a biotechnology company focused on developing and commercializing targeted therapies for the treatment of multiple solid tumor indications, today announced new subgroup analyses from the PIK3CA mutant (“MT”) cohort of the Phase 3 VIKTORIA-1 study evaluating gedatolisib in patients with HR+/HER2- locally advanced or metastatic breast cancer (“ABC”). These data were presented by Dr. Barbara Pistilli, Head of the Breast Cancer Unit, Gustave Roussy, at the European Society of Medical Oncology (ESMO) Congress 2026 today, Saturday, October 24, 2026, at 4:15 a.m. EST/10:15 a.m. CEST during a late breaking rapid oral presentation:

Presentation LBA 16: VIKTORIA-1: Updated results of a randomized, open-label, phase 3 study of gedatolisib (geda) + fulvestrant (fulv) ± palbociclib (palbo) vs standard of care in patients with HR+/HER2- advanced breast cancer (ABC) (Study 2)

Gedatolisib plus fulvestrant with palbociclib (“gedatolisib triplet”) or without palbociclib (“gedatolisib doublet”) significantly improved median progression-free survival (“PFS”) compared with alpelisib plus fulvestrant in HR+/HER2-, PIK3CA mutant ABC patients with and without liver metastases and those with or without visceral metastases:

Subgroup	Gedatolisib Triplet	Gedatolisib Doublet	Alpelisib + Fulvestrant
No Liver metastases, n	77	28	76
mPFS, mos. (95% CI)	21.5 (11.4-NR)	11.5 (9.2-NR)	9.1 (5.6-16.9)
HR (90% CI) vs. control	0.46 (0.30-0.72)	0.71 (0.41-1.25)
p-value	0.0016	0.1627
Liver Metastases, n	78	24	79
mPFS, mos. (95% CI)	9.1 (5.7-11.1)	11.1 (3.7-NR)	4.6 (3.7-5.6)
HR (90% CI) vs. control	0.47 (0.34-0.65)	0.38 (0.23-0.62)
p-value	<0.0001	0.0006
Subgroup	Gedatolisib Triplet	Gedatolisib Doublet	Alpelisib + Fulvestrant
No Visceral Metastases, n	38	13	37
mPFS, mos. (95% CI)	21.5 (9.6 – NR)	NR (1.6-NR)	9.2 (3.9-16.9)
HR (90% CI) vs. control	0.38 (0.21-0.73)	0.40 (0.15-1.1)
p-value	0.0059	0.0703
Visceral Metastases, n	117	39	118
mPFS, mos (95% CI)	9.8 (7.5-12.9)	11.3 (7.4-22.1)	5.6 (4.6-7.2)
HR (90% CI) vs. control	0.52 (0.39-0.70)	0.53 (0.35-0.79)
p-value	<0.0001	0.0042

* NR, not reached

In patients with evaluable disease, the gedatolisib-based regimens induced higher objective response rates (“ORR”) (confirmed and unconfirmed) and longer median durations of response in both the PIK3CA mutant and wild-type cohorts compared to the control:

Study 2 (PIK3CA Mutant Cohort)
Endpoint	Gedatolisib Triplet (n=133)	Gedatolisib Doublet (n=42)	Alpelisib + Fulvestrant (n=127)
Objective Response Rate, n (%)	78 (59%)	18 (43%)	42 (33%)
Median Duration of Response, mos. (95% CI)	19.4 (11.1-25.1)	27.8 (9.2-NR)	7.5 (5.6 – 16.6)
Study 1 (PIK3CA Wild-type Cohort)
	Gedatolisib Triplet (n=124)	Gedatolisib Doublet (n=113)	Fulvestrant (n=105)
Objective Response Rate, n (%)	48 (39%)	38 (34%)	1 (1%)
Median Duration of Response, mos. (95% CI)	19.2 (10.7-NR)	13.8 (9.4-NR)	Not evaluable

In the PIK3CA mutant cohort, the discontinuation rate of gedatolisib due to treatment-emergent adverse events (“TEAEs”) was 5% and 4% for the gedatolisib triplet and doublet, respectively, compared to a 19% discontinuation rate due to TEAEs for alpelisib. Grade 3 stomatitis with gedatolisib was transient. By the second cycle of treatment, less than 3% of patients had Grade 3 stomatitis, and all grade 3 events improved within 1-2 weeks. Discontinuations due to stomatitis for the gedatolisib triplet and gedatolisib doublet were minimal, 1% and 0%, respectively.

“The additional data from Study 2 of VIKTORIA-1 show consistent and significant clinical benefit for important sub-groups of breast cancer patients treated with gedatolisib regimens,” said Igor Gorbachevsky, Chief Medical Officer of Celcuity. “For patients who do not have liver metastases and received the gedatolisib triplet, the median progression-free survival was approximately 21 months, versus approximately 9 months for the alpelisib regimen. This is a particularly important result since patients with no liver metastases represent approximately 60%-70% of all patients treated in this setting.”

“Additionally, the median duration of response was over 19 months for the gedatolisib triplet in both the PIK3CA wild-type cohort, or Study 1, and the PIK3CA mutant cohort, or Study 2, compared to not evaluable for fulvestrant in the PIK3CA wild-type cohort and 7.5 months for alpelisib plus fulvestrant in the PIK3CA mutant cohort. To our knowledge, the gedatolisib triplet in each study demonstrated the longest median duration of response results ever reported for a therapeutic regimen used in the primary analysis for a Phase 3 trial in the second-line HR+/HER2- advanced breast cancer setting.”

VIKTORIA-1 PIK3CA Wild-Type Cohort Comparative Analysis

Dr. Sara Tolaney, Chief of the Division of Breast Oncology at Dana-Farber Cancer Institute, presented a comparative analysis of data for the gedatolisib regimens from the PIK3CA wild-type cohort of VIKTORIA-1 and other regimens evaluated in patients with HR+/HER2- advanced breast cancer.

Poster 1873P: Gedatolisib (Ged) vs Other Regimens Post-CDK4/6i and Endocrine Therapy (ET) in PIK3CA Wild-Type (WT) HR+/ HER2- Advanced Breast Cancer (aBC): A Network Meta-Analysis (NMA)

Eight studies were included in this network meta-analysis comparing progression-free survival outcomes in randomized controlled trials of systemic treatments evaluated among patients with HR+/HER2- advanced breast cancer with CDK4/6 inhibitor experience and PIK3CA wild-type tumors. This analysis found that the gedatolisib triplet and doublet each demonstrated statistically significant or numerically superior improvement in PFS and in progression-free survival rate at 6 months relative to the non-gedatolisib regimens evaluated. Of note, the analysis found that patients treated with the gedatolisib triplet and doublet were a statistically significant 2x and 1.5x more likely to survive without disease progression or death compared to imlunestrant plus abemaciclib, respectively.

About HR+/HER2- Breast Cancer

Breast cancer is the second most common cancer and one of the leading causes of cancer-related deaths worldwide.¹ More than two million breast cancer cases were diagnosed globally in 2022.¹ While survival rates are high for those diagnosed with early breast cancer, only approximately 30% of patients who are diagnosed with or who progress to metastatic disease are expected to live five years after their diagnosis.² HR+/HER2- breast cancer is the most common subtype of breast cancer, accounting for approximately 70% of all breast cancers.²

About Celcuity

Celcuity is a biotechnology company focused on developing and commercializing targeted therapies for the treatment of multiple solid tumor indications. The company's first FDA-approved product is REVTORPYK™ (gedatolisib), pan-PI3K and mTORC1/2 inhibitor that comprehensively blockades the PAM (PI3K/AKT/mTOR) pathway. Its mechanism of action and pharmacokinetic properties are differentiated from other currently approved and investigational therapies that target PI3Kα, AKT or mTORC1 alone or together. A Phase 3 clinical trial, VIKTORIA-1, evaluating gedatolisib in combination with fulvestrant with or without palbociclib in patients with HR+/HER2- locally advanced or metastatic breast cancer, supported FDA approval of REVTORPYK for use in patients without a PIK3CA mutation detected following progression on or after treatment with at least one line of endocrine therapy in the metastatic setting. Results for the PIK3CA mutant cohort of VIKTORIA-1 have been released. VIKTORIA-2 is an ongoing Phase 3 clinical trial incorporating two independent studies, Study 1 and Study 2, in two separate cohorts of patients with ABC who are treatment-naive in the advanced setting. Study 1 is evaluating gedatolisib plus palbociclib plus fulvestrant as first-line treatment for patients with endocrine-resistant HR+/HER2- ABC. Study 2 is evaluating gedatolisib plus palbociclib plus letrozole as first-line treatment for patients with endocrine-sensitive HR+/HER2- ABC. A Phase 1/2 clinical trial, CELC-G-201, evaluating gedatolisib in combination with darolutamide in patients with metastatic castration-resistant prostate cancer, is ongoing. More detailed information about Celcuity’s active clinical trials can be found at ClinicalTrials.gov. Celcuity is headquartered in Minneapolis. Further information about Celcuity can be found at www.celcuity.com. Follow us on LinkedIn and X.

Forward Looking Statements

This press release contains statements that constitute "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 including statements relating to the potential therapeutic benefits of gedatolisib; the size, design and timing of the Company’s clinical trials; the Company’s interpretation of clinical trial data; and the Company’s strategy, marketing and commercialization plans, including the benefits of strategic decisions regarding studies and trials. Words such as, but not limited to, “look forward to,” “believe,” “expect,” “anticipate,” “estimate,” “intend,” "confidence," "encouraged," “potential,” “plan,” “targets,” “likely,” “may,” “will,” “would,” “should” and “could,” and similar expressions or words identify forward-looking statements. The forward-looking statements included in this press release are based on management's current expectations and beliefs which are subject to a number of risks, uncertainties and factors, including that the Company’s topline clinical results are based on an ongoing analysis of efficacy and safety data and such data may change following a more comprehensive review of the data related to the clinical trial; and the development of therapies and tools competitive with gedatolisib. In addition, all forward-looking statements are subject to other risks detailed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, as such risks may be updated in its subsequent filings with the Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. All forward-looking statements are qualified in their entirety by these cautionary statements, and the Company undertakes no obligation to revise or update this press release to reflect events or circumstances after the date hereof.

References

1. Sung H, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin. 2021;10.3322/caac.21660.
2. National Cancer Institute. Surveillance, Epidemiology and End Results Program (accessed July 2025). https://seer.cancer.gov/statfacts/html/breast-subtypes.html

Contacts

For Investors: 
Brian Sullivan, bsullivan@celcuity.com
Vicky Hahne, vhahne@celcuity.com   
(763) 392-0123
Jodi Sievers, jsievers@celcuity.com
(415) 494-9924

For Media:
Sam Brown LLC
Laura Morgan, lauramorgan@sambrown.com
(951) 333-9110

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did Celcuity's VIKTORIA-1 update show for patients without liver metastases?

Median progression-free survival was 21.5 months with the gedatolisib triplet and 11.5 months with the doublet, versus 9.1 months with alpelisib plus fulvestrant. These PIK3CA-mutant subgroups included 77, 28 and 76 patients, respectively. The comparison p-values were 0.0016 for the triplet and 0.1627 for the doublet.

How did treatment discontinuations compare in Celcuity's PIK3CA-mutant VIKTORIA-1 cohort?

Discontinuation of gedatolisib because of treatment-emergent adverse events occurred in 5% of triplet patients and 4% of doublet patients, compared with 19% for alpelisib. Mouth inflammation caused discontinuation in 1% and 0% of triplet and doublet patients, respectively.

Was Celcuity's comparison with imlunestrant plus abemaciclib a head-to-head trial?

The comparison used an eight-study network meta-analysis, rather than a direct head-to-head comparison. It evaluated randomized trials involving patients with HR+/HER2- advanced breast cancer, prior CDK4/6 inhibitor experience and PIK3CA-wild-type tumors. Outcomes included progression-free survival and the progression-free survival rate at six months.