BOSTON – May 8, 2026
Day One Biopharmaceuticals, now part of Servier Group, announced the completion of patient enrollment in the pivotal Phase 3 FIREFLY-2 clinical trial evaluating tovorafenib (OJEMDA™) as a front-line treatment for pediatric low-grade glioma (pLGG). The study is considered the largest front-line pLGG clinical trial ever conducted, representing a major milestone in efforts to expand treatment options for children and young adults with one of the most common pediatric brain tumors.
The global FIREFLY-2 trial is evaluating the efficacy, safety and tolerability of oral tovorafenib, a Type II RAF inhibitor, compared with standard-of-care chemotherapy in patients aged six months to 25 years with RAF-altered pediatric low-grade glioma. The completion of enrollment positions Servier and Day One closer to potentially expanding OJEMDA’s use beyond the current relapsed or refractory setting into earlier lines of therapy, where unmet medical need remains substantial.
FIREFLY-2 Becomes Largest Front-Line pLGG Study
According to the companies, the Phase 3 FIREFLY-2 study enrolled approximately 400 participants across nearly 140 clinical sites worldwide, including locations in the United States, Canada, Europe, Australia, Asia, South America and the Middle East. Participants are receiving either once-weekly tovorafenib monotherapy or one of four standard chemotherapy regimens commonly used in pediatric glioma treatment.
The primary endpoint of the trial is overall response rate (ORR), including duration of response based on Response Assessment in Pediatric Neuro-Oncology Low-Grade Glioma (RAPNO-LGG) criteria. Secondary endpoints include progression-free survival, event-free survival, overall survival, time to next treatment and patient-reported quality-of-life outcomes. Preliminary topline insights from the study are expected in mid-2027.
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Elly Barry, M.D., Chief Medical Officer at Day One, stated that achieving full enrollment represents a critical advancement toward establishing OJEMDA as a standard treatment option across multiple therapy lines for patients with BRAF-altered pLGG. She emphasized that moving treatment earlier in the disease course could significantly improve outcomes while reducing the long-term burden associated with pediatric brain cancer progression and repeated treatment exposure.
OJEMDA Targets BRAF-Driven Pediatric Brain Tumors
Tovorafenib, marketed in the United States as OJEMDA™, is currently approved for pediatric patients aged six months and older with relapsed or refractory low-grade glioma harboring BRAF fusion, rearrangement or BRAF V600 mutations. The therapy previously received Breakthrough Therapy Designation, Rare Pediatric Disease Designation and Priority Review from the U.S. Food and Drug Administration (FDA).
Pediatric low-grade gliomas account for the most common brain tumors affecting children, with BRAF gene alterations present in more than half of all global pLGG cases. Prior to the approval of OJEMDA, there were no approved therapies specifically targeting pLGG driven by BRAF fusions, making RAF-targeted therapies a rapidly growing focus in pediatric oncology research.
Although survival rates for pLGG patients are generally high, many children experience chronic disease recurrence and require repeated chemotherapy or radiation treatments throughout childhood. These repeated interventions can cause long-term complications including vision impairment, motor dysfunction, developmental delays, hormonal deficiencies and neurological damage, significantly affecting quality of life.
Servier Expands Precision Pediatric Oncology Strategy
Servier executives stated that FIREFLY-2 reflects the company’s strategy to accelerate development of targeted oncology therapies through global clinical execution and precision medicine approaches. Following Servier’s acquisition of Day One Biopharmaceuticals, the completion of enrollment is being viewed as an early indicator of operational momentum within the combined oncology organization.
David K. Lee, CEO of Servier Pharmaceuticals, noted that the milestone reinforces the company’s commitment to advancing targeted treatments for pediatric cancer patients through global collaboration, scientific innovation and patient-centered development programs.
Industry analysts continue to monitor RAF-targeted therapies as a transformative area within pediatric neuro-oncology. If successful, FIREFLY-2 could help establish OJEMDA as a new first-line standard of care for children diagnosed with BRAF-altered pediatric low-grade glioma, potentially reshaping treatment approaches for one of the most common childhood brain cancers.
Source: Servier press release
