GSK and Scynexis Resume Brexafemme Trial Amid Payment Dispute

Scynexis has announced the resumption of its phase 3 MARIO study for Brexafemme (ibrexafungerp), a month after the FDA lifted its clinical hold on the antifungal drug. This development has sparked a disagreement between Scynexis and pharmaceutical giant GSK over milestone payments, highlighting the complexities of their partnership in commercializing the treatment.

Trial Resumption and Payment Dispute

The MARIO trial, investigating Brexafemme as a step-down treatment for invasive candidiasis, has dosed its first new patient since the study was put on hold 19 months ago. According to Scynexis, this event triggers a $10 million milestone payment from GSK, with an additional $20 million due in six months. However, GSK is contesting these charges, leading to ongoing discussions between the two companies.

David Angulo, M.D., CEO of Scynexis, expressed enthusiasm about the rapid resumption of patient enrollment, stating, "The rapid resumption of patient enrollment, just a few days after the investigational sites were re-activated in the study, reflects the eagerness of the scientific community to have new treatment options for this life-threatening infection."

Background and Commercial Challenges

Brexafemme, originally approved by the FDA in 2021 for vulvovaginal candidiasis (VVC), has faced several hurdles in its path to commercial success. Despite initial analyst predictions of blockbuster potential, Scynexis reported only $5 million in sales for 2022, leading to a licensing deal with GSK in March 2023.

The partnership hit a snag when GSK discovered that equipment used to produce Brexafemme was also used to manufacture beta-lactam substances, raising concerns about potential allergic reactions. This led to a voluntary recall of Brexafemme tablets and the subsequent clinical hold on the MARIO trial in September 2023.

Future Outlook and Unmet Medical Needs

Despite the ongoing dispute, both companies acknowledge the importance of Brexafemme in addressing rising antifungal resistance. A GSK spokesperson stated, "With rates of resistance to other antifungal treatments rising, Brexafemme addresses a clear unmet need for new oral treatments and is an important asset of our growing anti-infectives portfolio."

Luis Ostrosky-Zeichner, M.D., a professor at UTHealth Houston, emphasized the critical need for new treatments, particularly for resistant Candida strains. As the MARIO trial progresses, the pharmaceutical industry will be watching closely to see if Brexafemme can fulfill its promise in combating life-threatening fungal infections.