Athenex reported that two phase 3 trials of its skin ointment for precancerous lesions saw 100% clearance of actinic keratosis growths within 60 days, including in the face and scalp.
The placebo-controlled studies randomized a total of 702 adult participants, with the 1% ointment, KX-01, being applied once daily for five days. KX-01, also known as KX2-391, is a dual Src kinase and tubulin polymerization inhibitor. Each study demonstrated statistical significance, and both are ongoing through one year of follow-up.
According to Buffalo, New York-based Athenex, Src helps regulate aspects of tumor growth and metastases, while inhibiting tubulin polymerization activity can halt progression of the cell cycle at mitosis. The small molecule KX-01 binds for both targets using a novel site.
If left untreated, the common patches of thick or crusty skin can progress to squamous cell carcinoma. Caused by ultraviolet light damage, actinic keratosis is the most common precancerous condition in dermatology and affects more than 55 million Americans, the company said.
“The clinical studies results have been consistent between phase 2 and the two phase 3 studies, highlighting the consistency of this treatment in patients with actinic keratosis,” Chief Medical Officer Rudolf Kwan, M.D., said in a statement. “We believe KX2-391 has the potential to change the paradigm of topical therapy for actinic keratosis.”
In addition, local skin reactions were within expectations and in line with a previous phase 2 study. Athenex plans to request a pre-NDA submission meeting with the FDA and submit topline data to an upcoming scientific meeting.
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“Athenex is currently conducting all the necessary studies and work to complete the follow-up and prepare the regulatory filing,” said Athenex CEO Johnson Lau, M.D. “We are also working closely with our partner, Almirall, to develop the European registration plan.”
Athenex previously granted Almirall an exclusive license to research, develop and commercialize KX2-391 in the U.S. and European countries for $55 million. Athenex retains certain co-promotion rights in the U.S. and the rights for other parts of the world, including Canada, Asia, Africa, Central and South America, Australia and New Zealand.
The KX-01 topical ointment is also being studied in a phase 1 psoriasis trial in Taiwan, in partnership with PharmaEssentia, while an oral formulation is being studied in early-phase trials of solid and liquid tumors. An analog of the molecule, KX-02, can cross the blood-brain barrier and received an FDA orphan designation for gliomas. It is currently enrolling patients in a phase 1 trial.