Palvella Therapeutics, Inc. has announced a key milestone in the development of therapies for rare genetic skin diseases: the completion of enrollment in its Phase 2 TOIVA trial of QTORIN™ 3.9% rapamycin anhydrous gel for cutaneous venous malformations (VMs). As reported by Globe Newswire, sixteen subjects were successfully enrolled at leading vascular anomaly centers, meeting the original target and setting the stage for top-line results anticipated in mid-December 2025.
Venous malformations are the most common form of vascular malformation, often presenting with significant skin involvement that can affect 50–80% of patients. These lesions can lead to complications such as bleeding, thrombosis, ulceration, disfigurement, and uncontrolled proliferation, severely impacting quality of life. In the United States alone, more than 75,000 patients are estimated to be affected by cutaneous VMs, yet there is currently no FDA-approved therapy.
QTORIN™ rapamycin, a novel topical formulation, aims to address this significant unmet need. The drug is built on a patented platform and harnesses the power of rapamycin—an mTOR inhibitor—engineered to be applied directly to the skin. This approach is designed to maximize therapeutic benefit while minimizing systemic exposure and associated side effects common with oral or systemic treatments.
The Phase 2 TOIVA study is a single-arm, open-label, baseline-controlled clinical trial. Participants receive QTORIN™ rapamycin gel topically once daily. The trial primarily assesses safety and tolerability by monitoring the incidence and severity of adverse events. Efficacy is evaluated through multiple measures, including changes from baseline to week 12 in both clinician and patient global impression assessments, as well as detailed analysis of specific clinical manifestations that determine disease burden.
Dr. Megha Tollefson, Principal Investigator of TOIVA and a pediatric dermatologist at the Mayo Clinic, emphasized the significance of this research: “Cutaneous venous malformations can have a severe impact on quality of life, leading to substantial morbidity and functional impairment of the skin, and yet there are currently no FDA-approved therapies to address this high unmet need. We are excited to see the results from TOIVA, and to better understand the potential benefit of QTORIN™ rapamycin for patients with cutaneous VMs.”
Wes Kaupinen, Founder and CEO of Palvella, highlighted the urgency for targeted, localized therapies, calling the insights from the TOIVA trial “critical in guiding the design of future clinical trials and advancing Palvella’s mission to bring the first FDA-approved therapy to the estimated more than 75,000 U.S. patients living with cutaneous VMs.”
Palvella, a clinical-stage biopharmaceutical company, is led by rare disease drug development veterans and is focused on delivering novel therapies for serious, lifelong genetic skin conditions. Beyond the TOIVA trial for cutaneous VMs, QTORIN™ rapamycin is also in Phase 3 development for microcystic lymphatic malformations.
QTORIN™ rapamycin remains investigational and has not yet received regulatory approval. The results from the TOIVA trial, expected in December 2025, may represent an important step toward the first FDA-approved treatment for cutaneous venous malformations.
