Results from two Phase III studies of KX2-391, also known as KX-01 ointment,  in the treatment of actinic keratosis show positive results. The findings have been presented at the 2019 American Academy of Dermatology Annual Meeting in Washington, DC and were reported by Almirall, SA and Athenex, Inc. 

KX-391 is a first-in-class dual Src kinase and tubulin polymerization inhibitor being developed by Athenex as a topical 1% ointment for the treatment of AK in adult patients.

Both Phase III studies, KX01-AK-003 and KX01-AK-004, achieved their primary endpoint, which was defined as 100 percent clearance of AK lesions at Day 57 within the face or scalp treatment areas. Safety results showed that KX2-391 ointment was well tolerated. Adverse events were few. Treatment related adverse events were mild to moderate application site symptoms, such as pruritus or pain. There were no serious adverse events or early discontinuations due to study drug related adverse events. Local skin reactions (LSR: erythema, flaking/scaling, crusting, swelling, vesiculation/pustulation, erosion/ulceration) were mostly mild to moderate.

The studies enrolled a total of 702 patients across 62 sites in the US. KX2-391 ointment 1% or vehicle (randomized 1:1) was self-administered to 25cm² of the face or scalp encompassing 4-8 typical AK lesions, once daily for 5 consecutive days. Patients in both studies were predominantly white, elderly males with fair skin type and median baseline AK lesions of 6 on the face or scalp.

The one year follow up of patients who had complete responses is ongoing and is expected to be complete in the second quarter 2019. Athenex plans to submit a request to the FDA for a pre-NDA meeting to discuss the data and regulatory submission timelines.

Athenex and Almirall entered into a license agreement in which Athenex granted Almirall an exclusive license to research, develop and commercialize KX2-391 in the US and European countries, including Russia.

In other news, Almirall has entered into a definitive agreement to divest ThermiGen to Celling Biosciences based in Austin, TX for an undisclosed amount. The transaction is expected to close before or on March 29, 2019.