FDA Approves Gedatolisib Combination for Metastatic Breast Cancer
The U.S. Food and Drug Administration (FDA) has approved the combination of gedatolisib, a novel PI3K/mTOR inhibitor, with fulvestrant (with or without palbociclib) for patients with HR+ and HER2- metastatic breast cancer following endocrine therapy resistance. Data from the VIKTORIA-1 clinical trial demonstrated that this new combination significantly prolongs progression-free survival.
July 14, 2026 — A significant development has occurred in the world of oncology. As of July 14, 2026, the FDA approved Revtorpyk (gedatolisib) in combination with fulvestrant (with or without palbociclib) for the treatment of adult patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, PIK3CA-wildtype (non-mutated) locally advanced or metastatic breast cancer who progressed on or after at least one line of endocrine therapy in the metastatic setting.
Under this new treatment protocol, gedatolisib can be administered either as a doublet combination with fulvestrant or as a triplet combination with the addition of the CDK4/6 inhibitor palbociclib, depending on the patient's clinical status.
The VIKTORIA-1 Study: Significantly Prolonging Progression-Free Survival
This clinical approval is based on results from the open-label, randomized, multicenter Phase 3 VIKTORIA-1 clinical trial involving 392 patients. The trial evaluated the efficacy of gedatolisib combinations compared to fulvestrant monotherapy, showing the following progression-free survival (PFS) times:
- Triple Combination (Gedatolisib + Fulvestrant + Palbociclib - Arm A): Patients achieved a median progression-free survival of 9.3 months.
- Double Combination (Gedatolisib + Fulvestrant - Arm B): Patients achieved a median progression-free survival of 7.4 months.
- Control Group (Fulvestrant alone - Arm C): The median progression-free survival in the control group was recorded at only 2.0 months.
- Objective Response Rate (ORR): In patients with measurable disease, the ORR was 32% in the triple combination arm, 28% in the double combination arm, and 1% in the fulvestrant monotherapy arm.
Overall survival (OS) data were not mature at the time of the analysis.
💬 Clinical Significance
In patients with HR+/HER2- advanced breast cancer, treatment options are limited once resistance to endocrine therapy develops. While previously approved PI3K inhibitors are only effective in patients harboring PIK3CA mutations, gedatolisib simultaneously targets all four class I PI3K isoforms as well as mTOR, overcoming resistance in the broader PIK3CA wild-type patient population. The extension of progression-free survival from 2.0 months to 9.3 months with the triple combination and 7.4 months with the double combination in the VIKTORIA-1 trial highlights the clinical importance of this dual-inhibition strategy.
Recommended Treatment Schedule and Dosage
The general treatment protocol applied in the VIKTORIA-1 study and detailed in the FDA prescribing information is as follows:
| Drug / Combination | Recommended Dosage | Route and Duration |
|---|---|---|
| Gedatolisib (Revtorpyk) | 180 mg | 30-minute intravenous (IV) infusion Once weekly on Days 1, 8, and 15 of every 28-day cycle. |
| Fulvestrant | 500 mg | Intramuscular (IM) injection On Days 1, 15, and 29, and every 28 days thereafter. |
| Palbociclib (In triple combination) | 125 mg | Oral Once daily for 3 weeks, followed by 1 week off (28-day cycles). |
Safety and Notable Side Effects
The most important warnings and precautions to closely monitor during gedatolisib therapy include:
- Stomatitis: Mouth sores and oral inflammation.
- Dermatological Adverse Reactions: Skin rashes and allergic reactions.
- Hyperglycemia: Elevated blood glucose levels (glucose levels must be closely monitored).
- Embryo-Fetal Toxicity: Risk of harm to the developing fetus during pregnancy.
Conclusion
With this approval, gedatolisib combinations are now available in clinical practice as a powerful and effective new treatment option to delay disease progression and maintain quality of life in patients with endocrine-resistant, PIK3CA-wildtype HR+/HER2- advanced breast cancer.