Palvella Therapeutics Announces Scientific Publication in Journal of Vascular Anomalies Highlighting the Infiltrative Growth and Therapeutic Challenges of Microcystic Lymphatic Malformations
Review delineates differences in clinical strategies between microcystic and macrocystic lymphatic malformations to guide disease-specific clinical trial design and treatment approaches
Manuscript emphasizes the importance of early therapeutic intervention in children to help reduce the risk of more serious complications over time
Review supports the scientific rationale of QTORIN™ 3.9% rapamycin anhydrous gel as a potential targeted therapy for microcystic lymphatic malformations
WAYNE, Pa., March 30, 2026 (GLOBE NEWSWIRE) — Palvella Therapeutics, Inc. (Palvella or “the Company”) (Nasdaq: PVLA), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapies to treat patients suffering from serious, rare skin diseases and vascular malformations for which there are no U.S. Food and Drug Administration (FDA)-approved therapies, today announced the publication of a comprehensive review article in the Journal of Vascular Anomalies (JoVA) titled “Microcystic and Macrocystic Lymphatic Malformations: Distinct Genetics and Clinical Strategies.“
“Microcystic lymphatic malformations remain one of the most difficult-to-treat vascular anomalies and represent a substantial unmet medical need,” said Maria Buethe, M.D., Ph.D., Chief of the Pediatric Dermatology Division at Rady Children’s Hospital of Orange County (RCHOC)/University of California, Irvine, and senior author of the publication. “Unlike macrocystic lesions, which can often be managed with interventional approaches, microcystic disease is characterized by diffuse tissue involvement, resistance to existing therapies, and frequent post-treatment recurrence. These distinctions underscore that lymphatic malformations cannot be approached as a single disease. To achieve meaningful and lasting patient outcomes, future research and therapy development must target the unique biological drivers of each specific subtype.”
The review article highlights fundamental clinical differences between microcystic and macrocystic lymphatic malformations (LMs), reinforcing the significant unmet need in microcystic disease, where there are no FDA-approved therapies and where subtype-specific clinical trial design and targeted pharmacologic approaches are warranted. The publication highlights the following key distinguishing features of microcystic and macrocystic LMs:
| Feature | Microcystic LMs | Macrocystic LMs |
| Size of Cysts | Small, diffuse cysts (<2 cm in diameter) | Large, fluid-filled cysts (>2 cm in diameter) |
| Structure | Dense network of small cysts infiltrating surrounding tissues | Discrete, few larger, fluid-filled cysts. Well-defined cysts, often singular or clustered |
| Common Locations | Often found on the cutaneous tissue or oral cavity | Commonly located in the neck, axilla, or mediastinum. Usually deep internal location |
| Clinical Presentation | Persistent lymphorrhea, bleeding, red/dark vesicles and plaques on the skin, highly prone to infection (cellulitis) | Visible swelling, compressible masses, may fluctuate in size |
| Risk of Spontaneous Regression | No spontaneous regression | Spontaneous regression possible, particularly in the head and neck (cystic hygroma) |
| Diagnosis | Clinical diagnosis | Easier to detect with US, CT, or MRI |
| Prognosis | Chronic, progressive disease. Worsens with time | Lower risk of recurrence, especially after complete removal |
| Complications | Increased risk of infection and cellulitis | May become secondarily infected or compress surrounding organs |
| Common Management Approaches | No FDA-approved therapies; interventional approaches not as effective | Sclerotherapy, surgical resection, possible observation for regression |
| Response to Treatment | No effective treatments | May resolve with fewer interventions; often better response to sclerotherapy |
The publication further supports the scientific rationale of QTORIN™ rapamycin, which recently achieved the primary endpoint in the Phase 3 SELVA trial with highly statistically significant results across all pre-specified primary, key secondary, and secondary endpoints. Additionally, QTORIN™ rapamycin was well-tolerated, with systemic levels of rapamycin below 2ng/mL for all timepoints measured.
“An urgent need exists for safe and effective FDA-approved therapies for microcystic lymphatic malformations,” said Jeff Martini, Ph.D., Chief Scientific Officer of Palvella. “This publication reinforces that current procedural approaches are often inadequate for microcystic disease. We believe this work further supports Palvella’s strategy of developing QTORIN™ rapamycin as a targeted topical therapy designed specifically for patients with microcystic lymphatic malformations.”
About Microcystic Lymphatic Malformations
Microcystic LMs are a rare, chronically debilitating genetic disease caused by dysregulation of the phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway. The condition is characterized by malformed lymphatic vessels that protrude through the skin and persistently leak lymph fluid (lymphorrhea) and bleed, often leading to recurrent serious infections and cellulitis that can cause hospitalization. The natural history of microcystic LMs is persistent and progressive without spontaneous resolution, with symptoms generally worsening over time, including increases in the number and size of malformed vessels that lead to complications and lifetime morbidity. There are currently no FDA-approved treatments for the estimated more than 30,000 diagnosed patients with microcystic LMs in the United States.
About Palvella Therapeutics
Founded and led by rare disease biotech veterans, Palvella Therapeutics, Inc. (Nasdaq: PVLA) is a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapies to treat patients suffering from serious, rare skin diseases and vascular malformations for which there are no FDA-approved therapies. Palvella is developing a broad pipeline of product candidates based on its patented QTORIN™ platform, with an initial focus on serious, rare skin diseases and vascular malformations, many of which are lifelong in nature. Palvella’s lead product candidate, QTORIN™ 3.9% rapamycin anhydrous gel (QTORIN™ rapamycin), is currently being developed for the treatment of microcystic lymphatic malformations, cutaneous venous malformations, and clinically significant angiokeratomas. Palvella’s second product candidate, QTORIN™ pitavastatin, is currently being developed for the treatment of disseminated superficial actinic porokeratosis. For more information, please visit www.palvellatx.com or follow Palvella on LinkedIn or X (formerly known as Twitter).
QTORIN™ rapamycin and QTORIN™ pitavastatin are for investigational use only and neither has been approved by the FDA or by any other regulatory agency for any indication.
Forward-Looking Statements
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Contact Information
Investors
Wesley H. Kaupinen
Founder and CEO, Palvella Therapeutics
wes.kaupinen@palvellatx.com
Media
Marcy Nanus
Managing Partner, Trilon Advisors LLC
mnanus@trilonadvisors.com
