Nearly two weeks ahead of its PDUFA date, the FDA has approved Klisyri (tirbanibulin) for treating actinic keratosis (AK) on the face or scalp.
The FDA accepted tirbanibulin’s NDA in March and set a Dec. 30 PDUFA date. No advisory committee meeting was planned.
Buffalo, N.Y.-based Athenex will manufacture and launch the topical treatment along with Almirall SA, of Barcelona, in the first quarter of 2021. The two companies will market Klisyri in the U.S., the EU and Russia. Athenex partnered with Pharmaessentia Corp., of Taipei, Taiwan, in Taiwan and Xiangxue Pharmaceuticals Co. Ltd., of Guangzhou, China, in China, Hong Kong and Macau. In the China deal, Athenex received an up-front payment of $30 million and could receive development, sales and other milestone payments up to $170 million, and tiered royalties ranging from the subteens to low 20s based on annual net sales of licensed products in the territory and a percentage of sublicensing revenue. The total deal size is potentially $200 million, excluding royalty payments.
The five-day treatment was approved based on data from two pivotal, randomized, double-blind, vehicle-controlled phase III studies evaluating its efficacy and safety in 702 adults. Both studies hit their primary endpoints. In the KX01-AK-003 study, 44% of 175 patients treated with tirbanibulin achieved 100% clearance of lesions compared to 5% of 176 patients who received vehicle. In the KX01-AK-004 study, 54% of 178 patients treated with tirbanibulin (also known as KX2-391) achieved the goal compared to 13% of 173 patients who received vehicle (p<0.0001 for both studies).
In both trials, when broken down by face or scalp or measurement of at least 75% clearance of lesions, treatment with the drug was statistically better than vehicle.
AK is a precancerous skin lesion and the second most common dermatological diagnosis. Up to 15% of the lesions will grow into skin cancers.
Company stock (NASDAQ:ATNX) dipped 5% after the market opened Dec. 15.
There are high hopes pinned to the treatment’s sales. By 2026, according to DRG, tirbanibulin will have captured 38.8% of the market share and will generate $85 million in sales.