Palvella Secures New US Patent for Qtorin Rapamycin in Microcystic Lymphatic Malformations

Palvella Therapeutics announced today the issuance of a new US patent for its investigational therapy, Qtorin rapamycin, in the treatment of microcystic lymphatic malformations.¹ The patent, granted by the United States Patent and Trademark Office, marks the fifth patent issued for the company’s flagship product and extends intellectual property coverage into 2038.

Lymphatic malformation | Image Credit: © DermNet

Qtorin 3.9% rapamycin anhydrous gel, a novel topical formulation of the mTOR inhibitor, is being developed as a potential first-in-class therapy for microcystic lymphatic malformations, a rare, serious, and chronically debilitating genetic skin disorder. Currently, there are no US Food and Drug Administration (FDA)-approved therapies specifically indicated for this condition, leaving patients with limited treatment options and inconsistent standards of care.

The newly granted patent, titled “Anhydrous Compositions of mTOR Inhibitors and Methods of Use,” expands Palvella’s proprietary claims over the formulation and its clinical application in a range of dermatologic indications, including microcystic lymphatic malformations.

"This fifth US patent reflects the significant innovation behind the development of Qtorin rapamycin and Palvella’s Qtorin platform,” said Wes Kaupinen, founder and chief executive officer of Palvella, in a news release.¹ “We are pleased to further strengthen our growing intellectual property portfolio as part of our pursuit to develop the first targeted therapy for microcystic lymphatic malformations."

The issuance of the US patent follows a series of clinical advancements that have demonstrated Qtorin rapamycin’s therapeutic promise in rare dermatologic conditions, notably cutaneous venous malformations and microcystic lymphatic malformations, both of which involve overactivation of the PI3K/mTOR signaling pathway.

The gel formulation, which delivers rapamycin directly to affected skin sites with minimal systemic absorption, differentiates Qtorin from oral mTOR inhibitors.

The investigational therapy has garnered multiple FDA designations that highlight its therapeutic potential and the urgency of addressing microcystic lymphatic malformations. These include Breakthrough Therapy, Orphan Drug, and Fast Track designations,² and its performance in phase 2 trials has been pivotal in supporting the ongoing phase 3 SELVA and TOIVA studies.³

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Palvella’s Qtorin platform also holds promise for a range of other rare dermatologic disorders, and the company continues to explore additional indications across its development pipeline.

As Palvella advances Qtorin through late-stage development, the patent provides strategic protection for the proprietary formulation.

References

1. Palvella Therapeutics granted additional US patent for Qtorin rapamycin for the treatment of microcystic lymphatic malformations. News release. Globe Newswire. April 22, 2025. Accessed April 22, 2025. https://www.globenewswire.com/news-release/2025/04/22/3065388/0/en/Palvella-Therapeutics-Granted-Additional-U-S-Patent-for-QTORIN-Rapamycin-for-the-Treatment-of-Microcystic-Lymphatic-Malformations.html
2. Palvella Therapeutics. Palvella Therapeutics announces US FDA Breakthrough therapy designation granted to Qtorin 3.9% rapamycin anhydrous gel (Qtorin rapamycin) for the treatment of microcystic lymphatic malformations. News release. GlobeNewswire. November 16, 2023. Accessed April 22, 2025. https://www.globenewswire.com/news-release/2023/11/16/2781752/0/en/Palvella-Therapeutics-Announces-U-S-FDA-Breakthrough-Therapy-Designation-Granted-to-QTORIN-3-9-Rapamycin-Anhydrous-Gel-QTORIN-rapamycin-for-the-Treatment-of-Microcystic-Lymphatic-M.html
3. Palvella Therapeutics announces Qtorin rapamycin 3.9% anhydrous gel for the treatment of microcystic lymphatic malformations featured in oral presentation by Amy Paller, MS, MD, chair of dermatology at Northwestern University’s Feinberg School of Medicine, at the 15th World Congress of Pediatric Dermatology. News release. GlobeNewswire. April 11, 2025. Accessed April 22, 2025. https://www.globenewswire.com/news-release/2025/04/11/3060025/0/en/Palvella-Therapeutics-Announces-QTORIN-Rapamycin-3-9-Anhydrous-Gel-for-the-Treatment-of-Microcystic-Lymphatic-Malformations-Featured-in-Oral-Presentation-by-Amy-Paller-M-S-M-D-Chai.html