Day One Reports Three-Year OJEMDA Data Shows Sustained Treatment-Free Periods in Pediatric Brain Cancer
核心洞察
Day One Biopharmaceuticals presented three-year follow-up data from the FIREFLY-1 trial showing 77% of pediatric low-grade glioma (搜索) patients remained treatment-free for at least 12 months after completing OJEMDA therapy.
The median time to next treatment following OJEMDA initiation exceeded 3.5 years, with an overall response rate of 53% and median duration of response of 19.4 months in the pivotal trial.
Eight patients successfully received retreatment with OJEMDA after disease progression, achieving a median maximum tumor reduction of 38.3% during retreatment cycles.
Day One Biopharmaceuticals announced compelling three-year follow-up data from its pivotal FIREFLY-1 trial at the 2025 Society for Neuro-Oncology Annual Meeting, demonstrating that pediatric patients with low-grade glioma (搜索) can maintain extended treatment-free periods after completing OJEMDA (tovorafenib) therapy. The updated analysis, with a median study duration of 40.6 months and data cutoff of June 6, 2025, provides new insights into the drug's long-term clinical impact.
Extended Treatment-Free Survival
Among 39 patients who entered a treatment-free observation period following OJEMDA treatment, 77% (30/39) remained off therapy for a minimum of 12 months. The median treatment-free interval, measured from the end of tovorafenib primary treatment to the start of subsequent anticancer treatment or death, was not reached, indicating sustained disease control.
"We are excited by these updated three-year data showing that patients taking tovorafenib were able to spend meaningful time off therapy, with the option to retreat as needed," said Dr. Elly Barry, Chief Medical Officer of Day One. "These findings highlight the potential for a treatment approach to help support patients through the long-term course of their disease and further support our view that tovorafenib has the potential to become the second line standard of care in pLGG (搜索)."
The median time-to-next-treatment, defined as the time from first dose of tovorafenib to the start of first subsequent anticancer treatment or death, was 42.6 months (95% CI [36.7-NE]).
Efficacy and Response Durability
In 76 evaluable patients from Arm 1 of the FIREFLY-1 trial, 44 patients (58%) completed 26 or more cycles of treatment, approximately 24 months. The overall response rate reached 53% (40/76), with a median duration of response of 19.4 months (95% CI [13.8-27.2]) and median time to response of 5.4 months (range [1.6-17.5]).
The pre-specified secondary endpoint of Progression Free Survival, evaluated by Response Assessment in Pediatric Neuro-Oncology Low-Grade Glioma (搜索) criteria, showed a median of 16.6 months (10.9–22.0).
Retreatment Success and Minimal Tumor Rebound
Eight patients received retreatment with tovorafenib, achieving a median retreatment duration of 9 months, with all patients remaining on therapy at the time of data cutoff. The median maximum percentage change in tumor reduction during retreatment was −38.3%.
Importantly, tumor rebound was minimal in the first six months off therapy, with only 31% of patients experiencing a ≥25% increase in tumor size from the last scan prior to the last dose.
"These three-year data showed that patients were able to maintain disease control during extended periods off therapy, with the option to reinitiate tovorafenib treatment if clinically indicated," said Dr. Cassie Kline, Director of Clinical Research in the Division of Neuro-Oncology at the Children's Hospital of Philadelphia. "This approach has the potential to offer patients and their families meaningful time away from treatment."
Safety Profile Remains Consistent
The updated three-year analysis identified no new safety signals. Grade 3 or higher adverse events most commonly reported (≥5% of patients) were decreased growth velocity, anemia, blood creatine phosphokinase increased, maculopapular rash, and alanine aminotransferase increased.
Clinical Context and Regulatory Status
OJEMDA is approved by the U.S. Food and Drug Administration (搜索) for treating pediatric patients 6 months of age and older with relapsed or refractory pediatric low-grade glioma (搜索) harboring a BRAF (搜索) fusion or rearrangement. The drug received Breakthrough Therapy and Rare Pediatric Disease designations and was evaluated under priority review.
Pediatric low-grade glioma (搜索) represents the most common brain tumor (搜索) in children, with an estimated U.S. incidence of 1,100 children per year eligible for front-line systemic therapy. BRAF (搜索) alterations account for more than 50% of pLGG (搜索) cases worldwide, and until OJEMDA's approval, no treatments were specifically approved for BRAF fusion-driven pLGG.
The FIREFLY-1 trial evaluated tovorafenib as once-weekly monotherapy in patients aged 6 months to 25 years with relapsed or progressive pLGG (搜索) harboring activating BRAF (搜索) alterations. The study was conducted in collaboration with the Pediatric Neuro-Oncology Consortium (搜索) and included 137 patients across two arms, with Arm 1 (n=77) used for efficacy analyses.