Benzinga | Jul 19, 2021 10:53AM EDT

Athenex Reports European Commission Approval Of Klisyri For Topical Treatment Of Actinic Keratosis

Athenex, Inc., (NASDAQ:ATNX), a global biopharmaceutical company dedicated to the discovery, development, and commercialization of novel therapies for the treatment of cancer and related conditions, announced today that its partner, Almirall (Almirall, S.A., BME: ALM), has received approval from the European Commission to market Klisyri(r) (tirbanibulin), indicated for the topical treatment of actinic keratosis (AK) of the face or scalp in adults. Almirall launched Klisyri in the U.S. in February 2021 and will be launching the product in Europe.

Tirbanibulin is a novel, topical first-in-class microtubule inhibitor with a selective antiproliferative mechanism of action that represents a significant step forward in the treatment of AK due to its short treatment protocol (one application daily for 5 days), proven efficacy, and safety profile.

"This approval by the European Commission marks another significant milestone for Klisyri(r), shortly following the marketing approval and launch of Klisyri in the U.S.," said Dr. Johnson Lau, Chief Executive Officer of Athenex. "We are delighted that physicians and patients across Europe can now have access to a new important treatment option for the AK indication, that has a short treatment duration and good tolerability."

This approval is based on the positive results from two pivotal Phase III studies (KX01-AK-003 and KX01-AK-004), which were also published in the New England Journal of Medicine[1]. These two double-blind, vehicle-controlled, randomised, parallel-group, multi-center Phase III clinical trials, included 702 patients from 62 clinical sites across the U.S., and demonstrated that once-daily application of tirbanibulin ointment 1% (10 mg/g) during 5 consecutive days in adults with AK on the face or scalp is effective and well tolerated. Both Phase III studies achieved their primary endpoint, which was defined as 100% clearance of the AK lesions on Day 57 on the face or scalp treatment areas, with each study achieving a statistically significant benefit (p<0.0001) versus vehicle. In KX01-AK-003, complete clearance was observed in 44% of the patients treated with tirbanibulin versus 5% for vehicle-treated groups. In KX01-AK-004, complete clearance was observed in 54% of the patients treated with tirbanibulin versus 13% for vehicle-treated groups. Local reactions were mostly mild-to-moderate erythema, flaking or scaling, application-site pruritus, and application-site pain that resolved spontaneously.

AK is one of the most common diagnoses in dermatology practices and the reported prevalence in the European population is around 18%[2,3]. Treatment is a critical aspect in the management of the disease as it may progress to invasive skin squamous cell carcinoma.

In December 2020, Athenex received approval from the U.S. Food and Drug Administration (FDA) for the commercialization of Klisyri(r) (tirbanibulin) in the U.S. for the topical treatment of AK of the face or scalp. Our partner Almirall led the U.S. launch of Klisyri in February and is leading the launch of Klisyri in Europe. Under the terms of the license agreement with Almirall, Athenex is eligible to receive up to $45 million in milestone payments associated with launch and expansion into additional indications. The Company is also eligible to receive additional sales-related milestone payments. The terms of the agreement included tiered royalties payable to Athenex starting at 15%, based on annual net sales.

In addition, Almirall has submitted Klisyri(r) for a marketing authorisation in Switzerland in Q4 2020 and the dossier is currently under review by Swissmedic. Almirall has also made a submission in Great Britain via the European Commission Decision Reliance Procedure.