Palvella Therapeutics presented new Phase 3 and Phase 2 data at ISSVA 2026 showing QTORIN™ rapamycin significantly improved outcomes in microcystic lymphatic and cutaneous venous malformations, reinforcing its potential as the first FDA‑approved therapy for these rare vascular disorders.
Written By: Nikita Jha, BPharm
Reviewed By: Pharmacally Editorial Team
Palvella Therapeutics presented new clinical data from the Phase 3 SELVA study in microcystic lymphatic malformations (LMs) and the Phase 2 TOIVA study in cutaneous venous malformations (VMs) at the ISSVA World Congress 2026 in Philadelphia. The findings strengthen support for QTORIN™ rapamycin as a potential first FDA-approved therapy for both rare vascular disorders, which currently have no approved U.S. treatments.
QTORIN™ rapamycin is a topical formulation targeting dysregulated mTOR signaling, a key pathway implicated in lymphatic and venous malformations. The localized approach aims to control disease activity while minimizing systemic exposure, supporting long-term use in pediatric and adult patients.
Phase 3 SELVA Data in Microcystic LMs
SELVA (NCT06239480) evaluated once-daily topical QTORIN™ rapamycin over 24 weeks using a single-arm, baseline-controlled design selected to address the rarity and heterogeneity of microcystic LMs. Palvella previously reported statistically significant improvements across the primary and all pre-specified secondary endpoints.
New analyses showed strong responses in patients aged 6 to 11 years, with a +2.46 improvement on the microcystic LM Investigator Global Assessment (mLM-IGA) at Week 24 (p<0.001). All treated patients in this cohort were rated “Much Improved” or “Very Much Improved.”
Among patients with moderate or severe baseline leaking or bleeding, QTORIN™ rapamycin produced a +2.48 improvement on the leaking/bleeding assessment scale at Week 24 (p<0.001), with 87% achieving “Much Improved” or “Very Much Improved” ratings. Independent blinded review also confirmed disease stability during the run-in period followed by marked improvement after treatment initiation, reinforcing the robustness of the study design.
Patient Outcomes and TOIVA Phase 2 Data
SELVA incorporated validated patient-reported outcome measures and qualitative interviews under the FDA’s Patient-Focused Drug Development framework. All participants completing the efficacy period reported at least some treatment satisfaction on the TSQM-9 questionnaire, alongside reported improvements in symptoms and daily quality of life.
Additional data from the Phase 2 TOIVA study (NCT06653842 ) showed statistically significant improvements in lesion height and appearance in patients with cutaneous VMs. At Week 24, QTORIN™ rapamycin reduced cVM-MCSS Height scores by 1.50 points and Appearance scores by 1.43 points (p<0.001). Responses continued to deepen through Week 24, supporting the potential role of chronic topical therapy.
Chief Executive Officer Wes Kaupinen said the expanding dataset strengthens confidence in QTORIN™ rapamycin as a chronic therapy for localized vascular malformations and supports earlier intervention in progressive disease.
Regulatory Outlook
Palvella plans to submit a New Drug Application to the FDA for QTORIN™ rapamycin in microcystic LMs in the second half of 2026, with potential approval targeted for the first half of 2027. The therapy has received FDA Breakthrough Therapy, Fast Track, and Orphan Drug designations for microcystic LMs. The company also plans to initiate a Phase 3 trial in cutaneous VMs later this year
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About the Writer
Nikita Jha, BPharm (LinkedIn) a pharmacy graduate specializing in medical writing, with a strong ability to interpret complex medical and regulatory information and translate it into clear, accurate, and evidence-based healthcare content. Known for her attention to detail and precision, she focuses on delivering high-quality scientific communication that supports drug safety and informed decision-making.