RARE Daily

FDA Grants Breakthrough Therapy Designation to Palvella’s Qtorin for the Treatment of Microcystic LMs

November 17, 2023

Rare Daily Staff

The U.S. Food and Drug Administration granted Breakthrough Therapy designation to Palvella Therapeutics Qtorin rapamycin for the treatment of microcystic lymphatic malformations.

Microcystic lymphatic malformations (microcystic LMs) is a rare, chronically debilitating genetic disease caused by dysregulation of the PI3K/mTOR pathway. The disease is characterized by localized masses of malformed lymphatic vessels that protrude through the skin barrier and persistently leak lymph fluid (lymphorrhea) and bleed, often leading to recurrent serious infections and cellulitis. The natural history of microcystic LMs is progressive, with symptoms generally worsening during life, including increases in the number and size of cysts that lead to complications and lifetime morbidity. There are currently no FDA-approved treatments for the estimated more than 30,000 patients with microcystic LMs in the United States.

Qtorin rapamycin is a novel, 3.9 percent rapamycin anhydrous gel currently under development by Palvella for the treatment of microcystic LMs and other serious, functionally debilitating skin diseases driven by the overactivation of the mammalian target of rapamycin (mTOR) pathway.

“We are very encouraged that the FDA has granted Breakthrough Therapy designation to Qtorin rapamycin, recognizing the strength of the clinical results from our phase 2 study and the potential for Qtorin rapamycin as a novel, targeted therapy for the treatment of microcystic LMs,” said Wes Kaupinen, founder and CEO of Palvella Therapeutics.

The Breakthrough Therapy designation for Qtorin rapamycin is based on positive phase 2 results from a multi-center, open-label trial of once-daily Qtorin rapamycin in microcystic LMs. In the phase 2 study, 100 percent of participants were either “Much Improved” or “Very Much Improved” as rated by the Clinician Global Impression of Change after 12 weeks of Qtorin rapamycin treatment. Based on the positive phase 2 results and a productive end-of-phase 2 meeting with FDA, Palvella previously announced plans to conduct a pivotal phase 3 study in approximately 50 adult and pediatric patients.

Breakthrough Therapy designation is intended to expedite the development and review of therapies for serious or life-threatening conditions and whose preliminary clinical evidence indicates that the drug may demonstrate substantial improvement on one or more clinically significant endpoints over existing therapies. Under the designation, the FDA provides intensive guidance, organizational commitment involving senior managers, and eligibility for rolling and priority reviews.

In addition to Breakthrough Therapy Designation, the FDA previously granted Fast Track and Orphan Drug designations to Qtorin rapamycin for the treatment of microcystic LMs. The European Medicines Agency has also granted Orphan Drug designation to Qtorin rapamycin for the treatment of microcystic LMs.

Photo: Wes Kaupinen, founder and CEO of Palvella Therapeutics

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