Both Phase 3 studies of KX2-391met the primary endpoint of complete clearance of actinic keratosis (AK) lesions at day 57 within the face or scalp treatment areas, Almirall, SA reports. Each study achieved statistical significance on this endpoint. 

The double-blind, randomized, vehicle-controlled, studies were designed as pivotal phase III efficacy and safety studies to support the registration of KX2-391 (or KX-01) as field therapy for AK of the face and scalp. The studies, each conducted in 31 centers in the USA, enrolled a total of 702 patients. KX2-391 or vehicle ointment was applied once daily for five days. In addition to the clinical activity of KX2-391, the local skin reaction (LSR) profile was in line with the prior Phase 2 study results reported in the annual American Academy of Dermatology (AAD), meeting in February 2018 in San Diego.  

KX2-391, also known as KX-01, is a first-in-class dual Src kinase and tubulin polymerization inhibitor in phase III development as a topical medicinal product for the treatment of actinic keratosis.

Dr. Bhushan Hardas, Executive Vice President, Research & Development, CSO of Almirall, stated, “As one of the leaders in the medical treatment of actinic keratosis, we were excited to see the successful results in both parallel phase III studies. We were impressed by the Athenex team’s capabilities in drug development execution. The rapid completion of recruitment in these two parallel clinical studies and the ahead of schedule analysis underscore the unmet need in actinic keratosis as well as the quality of the Athenex clinical research team. We are fully committed to this collaboration and will be helping to lead the European development and registration strategy. KX2-391 has the potential to change the standard of care for actinic keratosis and we look forward to combining our leadership capabilities in the field with the drug development expertise of Athenex with the shared goal of advancing patient care.”

Almirall and Athenex entered into a strategic partnership in December 2017 to further develop and commercialize KX2-391 for the treatment of actinic keratosis and other skin conditions in the United States and Europe, including Russia. Athenex is responsible for conducting all preclinical and clinical studies up to US FDA approval. Almirall will employ its expertise to support the development in Europe and also to commercialize the product in the licensed territories. Projected peak sales for KX2-391 are expected to be in excess of €250 million.