Helicase-primase inhibitors from Medshine Discovery Inc. (WO2018/127207 and WO2020/007355) for the treatment of herpes simplex virus infections – structure proposal for Phaeno Therapeutics drug candidate HN0037

Helicase-primase is an interesting target for small-molecule therapy of herpes simplex virus (HSV) infections. With amenamevir already approved for varicella-zoster virus and with pritelivir's granted breakthrough therapy designation for the treatment of acyclovir-resistant HSV infections in immunocompromised patients, the target has sparked interest for me-too approaches. We describe the opportunities and limitations of the helicase-primase inhibitor patent portfolio from Phaeno Therapeutics and propose the structure of their drug candidate HN0037, which has been in-licensed from Medshine Discovery.