LOGGIC/FIREFLY-2: A phase 3, randomized trial of tovorafenib vs. chemotherapy in pediatric and young adult patients with newly diagnosed low-grade glioma harboring an activating RAF alteration.

Abstract

TPS10067 Background: Pediatric low-grade gliomas (pLGGs) are the most common CNS tumors of childhood. Genomic alterations of BRAF are oncogenic drivers in almost all pLGGs. Approximately 50%‒60% of pLGGs harbor a KIAA1549-BRAF fusion and 5%‒15% a BRAF V600E mutation. Tovorafenib is an investigational, oral, selective, CNS-penetrant, small molecule, type II pan-RAF inhibitor. The registrational, phase 2 FIREFLY-1 (NCT04775485) study of tovorafenib in pediatric patients with recurrent/progressive LGG is ongoing and interim analysis has shown encouraging anticancer activity. Methods: LOGGIC/FIREFLY-2 (NCT05566795) is a registrational, 2-arm, randomized, multicenter, global (~100 sites across Australia, Canada, Europe, New Zealand, Singapore, South Korea, and USA), phase 3 trial being conducted in collaboration with the SIOPe Brain Tumor Group LOGGIC Consortium. The study is evaluating the efficacy, safety, and tolerability of tovorafenib vs. standard of care (SoC) chemotherapy in patients < 25 years old with pLGG harboring an activating RAF-alteration and requiring first-line systemic therapy. Approximately 400 patients will be randomized 1:1 to receive oral tovorafenib, 420 mg/m2 (≤600 mg) once weekly (tablet or liquid suspension), or an investigator’s choice of SoC chemotherapy: COG-V/C regimen (60 weeks), SIOPe-LGG-V/C regimen (81 weeks), or single-agent vinblastine (70 weeks). Tovorafenib will be continued until the occurrence of radiographic progression (based on Response Assessment in Neuro-Oncology [RANO] criteria as determined by the investigator and confirmed by independent review) or unacceptable toxicity; patients with radiographic progression may be allowed to continue tovorafenib if, in the opinion of the treating investigator, they are deriving clinical benefit from study treatment. Patients who progress in the SoC arm during or after completion of chemotherapy are eligible to cross-over to receive tovorafenib. The primary endpoint is the objective response rate based on RANO criteria, as determined by independent review. Key secondary endpoints are progression-free survival and duration of response per RANO criteria by independent review and overall survival. Other secondary endpoints include efficacy assessments per Response Assessment in Pediatric Neuro-Oncology (RAPNO) criteria, changes in neurological and visual function, and safety and tolerability. Exploratory endpoints include efficacy assessments per investigator, tumor volume, adaptive behavior and quality of life. Prognostic and predictive molecular biomarkers, including senescence profiles for treatment outcome, response prediction, and treatment resistance, will be explored in parallel studies. Clinical trial information: NCT05566795 .