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July 19, 2021
Athenex Announces European Commission Approval of Klisyri® (tirbanibulin) for the Topical Treatment of Actinic Keratosis

BUFFALO, N.Y., July 19, 2021 (GLOBE NEWSWIRE) -- 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® (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®, 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® (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® 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.

About Klisyri® (tirbanibulin)

Klisyri® (tirbanibulin) is a microtubule inhibitor indicated for the topical treatment of actinic keratosis (AK) of the face or scalp. Two phase III studies (KX01-AK-003 and KX01-AK-004) evaluated the efficacy and safety of tirbanibulin ointment 1% (10 mg/g) in adults with AK on the face or scalp. The studies achieved their primary endpoint, which was defined as 100% clearance of the AK lesions at Day 57 within the face or scalp treatment areas, each study achieving statistical significance (p<0.0001) on this endpoint[1].

About Actinic Keratosis

Actinic keratosis (AK) or solar keratosis is a chronic and precancerous skin disease that occurs primarily in areas that have been exposed to ultraviolet radiation for a long period of time. It is usually found on the face, ears, lips, bald scalp, forearms, the posterior part of the hands, and lower legs. It is not possible to predict which AK lesions will develop into squamous cell carcinoma. AK is the most common pre-cancerous dermatological condition[4].

About Athenex, Inc.

Founded in 2003, Athenex, Inc. is a global clinical stage biopharmaceutical company dedicated to becoming a leader in the discovery, development, and commercialization of next generation drugs for the treatment of cancer. Athenex is organized around three platforms, including an Oncology Innovation Platform, a Commercial Platform, and a Global Supply Chain Platform. The Company’s current clinical pipeline is derived from four different technologies: (1) Orascovery, based on P-glycoprotein inhibitor, (2) Src kinase inhibition, (3) Cell therapy, and (4) Arginine deprivation therapy. Athenex’s employees worldwide are dedicated to improving the lives of cancer patients by creating more active and tolerable treatments. For more information, please visit www.athenex.com.

Forward-Looking Statements

Except for historical information, all of the statements, expectations, and assumptions contained in this press release are forward-looking statements. These forward-looking statements are typically identified by terms such as “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “foresee,” “goal,” “guidance,” “intend,” “likely,” “may,” “plan,” “potential,” “predict,” “preliminary,” “probable,” “project,” “promising,” “seek,” “should,” “will,” “would,” and similar expressions. Actual results might differ materially from those explicit or implicit in the forward-looking statements. Important factors that could cause actual results to differ materially include: the development stage of our primary clinical candidates and related risks involved in drug development, clinical trials, regulation, uncertainties around regulatory reviews and approvals; our ability to agree with the FDA on a new clinical study for oral paclitaxel that is capital efficient; our ability to scale our manufacturing and commercial supply operations for current and future approved products, and ability to commercialize our products, once approved; ability to successfully demonstrate the safety and efficacy of its drug candidates and gain approval of its drug candidates on a timely basis, if at all; the preclinical and clinical results for Athenex’s drug candidates, which may not support further development of such drug candidates; risks related to counterparty performance, including our reliance on third parties for success in certain areas of Athenex’s business; our history of operating losses and our need and ability to raise additional capital; uncertainties around our ability to meet funding conditions under our financing agreements and access to capital thereunder; risks and uncertainties inherent in litigation, including purported stockholder class actions; risks and uncertainties related to the COVID-19 pandemic and its potential impact on our operations, supply chain, cash flow and financial condition; competition; intellectual property risks; uncertainties around our ability to successfully integrate acquired and merged businesses in a timely and cost-effective manner and to achieve synergies; risks relating to doing business internationally and in China; the risk of development, operational delays, production slowdowns or stoppages or other interruptions at our manufacturing facilities; and the other risk factors set forth from time to time in our SEC filings, copies of which are available for free in the Investor Relations section of our website at http://ir.athenex.com/phoenix.zhtml?c=254495&p=irol-sec or upon request from our Investor Relations Department. All information provided in this release is as of the date hereof and we assume no obligation and do not intend to update these forward-looking statements, except as required by law.

Athenex Contacts


Daniel Lang, MD
Athenex, Inc.
Email: danlang@athenex.com

Tim McCarthy
LifeSci Advisors, LLC
Email: tim@lifesciadvisors.com


  1. Blauvelt A, Kempers S, Lain E, et al. Phase 3 Trials of Tirbanibulin Ointment for Actinic Keratosis. New England Journal of Medicine. 2021 Feb 11;384(6):512-520.
  2. Lucas R, McMichael T, Smith W, Armstrong B. Solar ultraviolet radiation: Global burden of disease from solar ultraviolet radiation: World Health Organization, 2006.
  3. Worldometer. Population of Europe. 2020. Available at: https://www.worldometers.info/world-population/europe-population/ Accessed: October 2020.
  4. Skin Cancer Foundation. Actinic Keratosis Overview. Available at: https://www.skincancer.org/skin-cancer-information/actinic-keratosis/#:~:text=Actinic%20keratosis%20(AK)%20is%20the,to%20ultraviolet%20(UV)%20radiation January 2021

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Source: Athenex, Inc.