Athenex announced that both Phase 3 studies, KX-AK-003 and KX-AK-004, had achieved their primary endpoint of 100% clearance of actinic keratosis lesions at Day 57 within the face or scalp treatment areas, with each study achieving statistical significance. Statistical significance was achieved for both face and scalp subgroups as well. These two double-blind, randomized, vehicle-controlled, studies were designed as pivotal Phase 3 efficacy and safety studies to support the registration of KX2-391 as field therapy for AK of the face and scalp. The studies, each conducted at 31 centers in the USA, enrolled a total of 702 subjects. KX2-391, or vehicle ointment, was applied once daily for 5 days. In addition to the clinical activity of KX2-391, the local skin reaction profile was within expectations, in line with the Phase 2 study reported in the annual American Academy of Dermatology meeting in February 2018 in San Diego. Following an End of Phase 2 meeting with the United States Food and Drug Administration, these two parallel Phase 3 pivotal studies were initiated in September 2017. In February 2018, Athenex announced that the recruitment had been completed ahead of schedule. Both studies are still on-going to complete the one-year follow-up of the patients who had complete responses. Athenex will be submitting a request to the US FDA for a pre-NDA submission meeting to discuss the data and regulatory submission timelines. The Company plans to submit the topline and other related data from the Phase 3 studies for presentation at an upcoming scientific meeting. KX2-391, also known as KX-01, is a first-in-class dual Src kinase and tubulin polymerization inhibitor being developed by Athenex as a topical medicinal product for the treatment of actinic keratosis in adult patients. A Phase 2 clinical study was conducted in 16 US clinical sites comparing a 5 days vs. 3 days treatment and was reported in the AAD meeting earlier this year. The 5-day treatment cohort achieved a higher overall 100% clearance of actinic keratosis lesions at Day 57 than the 3-day treatment cohort. In the 5-day treatment cohort, 23 of 44 subjects with Actinic Keratosis on face, and 13 of 40 on scalp, attained 100% clearance at Day 57. LSRs were mild and mostly erythema, flaking/scaling, crusting and swelling, with the majority of the LSRs scores of less than2 and resolved rapidly.
