TEPOXX (tecovirimat) Approved in Japan for the Treatment of Orthopoxviruses
January 2, 2025
The approval of TEPOXX (tecovirimat) in Japan for treating smallpox, mpox, cowpox, and smallpox vaccination complications marks a pivotal advancement in public health preparedness. SIGA Technologies, in collaboration with Japan Biotechno Pharma, achieved this milestone through rigorous clinical trials involving over 800 healthy volunteers and animal studies demonstrating efficacy.
With a long shelf life and targeted antiviral action against orthopoxviruses, TEPOXX strengthens Japan's national stockpile and readiness for outbreaks. This accomplishment reflects the significance of stockpiling effective antiviral therapies to combat infectious diseases and underscores global efforts to safeguard public health against orthopoxvirus-related threats.
Japan’s recent regulatory approval of TEPOXX (tecovirimat) marks a significant stride in the global effort to combat orthopoxvirus-related threats. Developed by SIGA Technologies and distributed in partnership with Japan Biotechno Pharma, TEPOXX is now approved for treating smallpox, mpox, cowpox, and complications arising from smallpox vaccination in both adults and pediatric patients weighing at least 13 kg.
This groundbreaking approval by the Pharmaceuticals and Medical Devices Agency (PMDA) and the Ministry of Health, Labour, and Welfare is supported by robust clinical data. TEPOXX demonstrated efficacy and safety in over 800 healthy volunteers during 15 clinical trials, including a pivotal repeat-dose pharmacokinetics (PK) trial in Japan. Animal studies further validated its potential by significantly reducing mortality and viral load in non-human primates and rabbits infected with orthopoxviruses, with results published in the New England Journal of Medicine.
TEPOXX works by inhibiting the VP37 protein on the surface of orthopoxviruses, effectively halting viral spread and allowing the immune system to combat the infection. Its long shelf life and capsule form make it particularly suited for rapid deployment during public health emergencies, a feature highlighted by its inclusion in Japan’s strategic national stockpile.
Diem Nguyen, CEO of SIGA Technologies, emphasized the importance of this approval in enhancing global health security. Dennis Hruby, Ph.D., SIGA’s Chief Scientific Officer, credited years of dedication and scientific innovation for this achievement, underscoring the critical role of antiviral therapies in combating devastating diseases.
With approvals in the U.S., Canada, the EU, and now Japan, TEPOXX continues to establish itself as a cornerstone of orthopoxvirus outbreak preparedness. This milestone reflects a global commitment to safeguarding public health through scientific innovation and strategic collaboration.