New Topical Treatment for Actinic Keratosis Granted FDA Approval

Tirbanibulin is expected to be launched in the United States during the first quarter of 2021.

Officials with the FDA have approved tirbanibulin (Klisyri; Almirall) for the topical treatment of actinic keratosis (AK) of the face or scalp. According to Almirall, tirbanibulin will be launched in the United States during the first quarter of 2021.

Tirbanibulin is a novel, topical first-in-class microtubule inhibitor that is applied once daily for 5 days. According to Almirall, the FDA approval represents a significant step forward in the treatment of AK due to its short treatment protocol, and proven efficacy and safety profile.

Actinic keratosis is the second most common diagnosis made by dermatologists in the United States. According to Deborah S. Sarnoff, MD, president of the Skin Cancer Foundation, early diagnosis and treatment of AK is critical because patients with the condition are likely to develop more actinic keratoses in the future.

“Patients with AK are at higher risk for skin cancer, since AKs can progress into squamous cell carcinoma (SCC), a common and sometimes invasive form of skin cancer,” Sarnoff said in a press release.

The approval of tirbanibulin is based on data from 2 pivotal, randomized, double-blind, vehicle-controlled phase 3 studies (KX01-AK-003 and KX01-AK-004) that evaluated the efficacy and safety of tirbanibulin ointment 1% in adults with AK on the face or scalp. The studies included data from 702 patients across 62 sites in the United States.

“Tirbanibulin achieved a significantly higher number of patients with complete (100%) clearance of AK lesions in the treated area compared to vehicle (44% vs. 5% in study 1 and 54% vs. 13% in study 2), as well as reaching the secondary endpoint of partial (≥75%) clearance of lesions” said lead investigator Andrew Blauvelt, MD, MBA, president of Oregon Medical Research Center, in a press release.

According to Ayman Grada, MD, head of research and development and Medical Affairs for Almirall US, the studies demonstrated safety for tirbanibulin, in addition to efficacy. The most common adverse events (AEs) included application site pruritus and pain, seen in 9% and 10%, respectively, of patients treated with the drug. No patients withdrew from the study due to AEs.

Tirbanibulin is supplied in boxes of 5 single-use sachets, and is applied to the treatment area once daily for 5 days.

“The convenient dosing regimen should lead to better patient compliance” Grada said in the press release.

Almirall entered into a strategic partnership with Athenex, Inc in December 2017 to develop and market tirbanibulin for the treatment of actinic keratosis and other skin conditions in the United States and Europe. According to Almirall, Athenex has been responsible for conducting all preclinical and clinical studies in order to gain FDA approval of tirbanibulin.


Almirall announces FDA approval of Klisyri® (tirbanibulin), a new innovative topical treatment for actinic keratosis [news release]. Barcelona, Spain; December 15, 2020: Almirall. Accesssed December 15, 2020.