PharmaTher’s Sairiyo Therapeutics Finds Cepharanthine May Bind to Mpox Proteins

TORONTO, Aug. 21, 2024 - PharmaTher Holdings Ltd. (PharmaTher) and Sairiyo Therapeutics Inc. (Sairiyo) have announced promising findings regarding the use of cepharanthine as a potential treatment for monkeypox (Mpox). Sairiyo, which is partially owned by PharmaTher and PharmaDrug Inc., reported that independent drug screening has highlighted cepharanthine's potential to bind to Mpox proteins, according to a non-peer-reviewed letter published in the Journal of Infection.

Mpox's protein functions are not well understood, making the identification of drugs that interact with these proteins a crucial step in managing the infection. The study, conducted by Yang et al. (2023), selected 10 Mpox target proteins believed to play essential roles and interact with other molecules. Cepharanthine demonstrated significant binding affinities to all ten target proteins, particularly to four predicted Mpox proteins (I1L, VITF3L, A42R, and E8L). These findings may enhance the understanding of viral mechanisms and aid in developing new treatments for Mpox.

On August 19, 2024, Sairiyo received approval from the Australian Human Research Ethics Committee to begin a Phase 1 clinical trial with PD-001, a potential treatment for Medical Countermeasures. PD-001 previously secured a $3.4 million contract from the Defense Threat Reduction Agency (DTRA) for the Ebola virus. However, PharmaTher clarified that no claims are being made about cepharanthine's ability to treat, eliminate, or cure Mpox or other infectious diseases at this time.

Cepharanthine, a natural product, has been used in Japan for over 70 years to treat various acute and chronic diseases. The drug exhibits multiple pharmacological properties, including anti-oxidative, anti-inflammatory, immuno-regulatory, anti-cancer, anti-viral, and anti-parasitic effects. Despite its clinical potential, cepharanthine's low oral bioavailability has been a significant barrier. PD-001, an improved enteric-coated oral formulation of cepharanthine, has shown markedly better bioavailability in rodent and non-rodent models, supporting its development as an orally administered treatment. This eliminates the need for frequent intravenous dosing to maintain therapeutic levels.

Sairiyo aims to develop an effective oral therapeutic to enhance outcomes for infectious diseases and oncology. PD-001 is protected by U.S. Patent US10576077, which expires on March 23, 2036.

Sairiyo Therapeutics Inc. is a collaborative venture between PharmaTher and PharmaDrug Inc., focusing on the clinical development of PD-001. PharmaTher Holdings Ltd. is dedicated to developing and commercializing KETARX™ (Ketamine) to meet global medical needs in anesthesia, sedation, pain, mental health, and neurological conditions. PharmaTher owns a 49% stake in Sairiyo Therapeutics, which is advancing PD-001 for medical countermeasures and cancer.

Cepharanthine represents a potential breakthrough in the treatment of Mpox and other diseases, although its efficacy and safety must be validated through further research and clinical trials. The collaborative efforts between PharmaTher and Sairiyo signify a step forward in addressing unmet medical needs through innovative pharmaceutical solutions.