Firefly glows for Day One

Day One Biopharmaceuticals’ stock received a much-needed boost today on data suggesting that tovorafenib might be a viable therapy for paediatric low-grade glioma. The company calls tovorafenib a type II pan-Raf inhibitor, and says most paediatric low-grade gliomas are driven by Braf alterations. The first 22 evaluable patients in the mid-stage Firefly-1 trial generated an overall response rate of 64%, comprising one unconfirmed and 13 confirmed partial responses. The trial has no control arm, but there are no approved therapies for this cancer type; Firefly-1 patients had a median of three prior lines of therapy. A larger dataset is due early in 2023, and the company hopes to file by mid-year, while a front-line pivotal study of tovorafenib, Firefly-2/Loggic, will soon get under way. Despite doubling in value today Day One is still worth 20% less than when it floated just over a year ago, though some have had skin in this game for considerably longer than IPO investors. The asset has an almost two-decade history, having been through the hands of Biogen and Takeda. Viracta, which sold off Sunesis's rights last year, might be kicking itself today.