Summary: anticipated first-line position of tovorafenib

Current first-line systemic therapy for unresectable, progressive, or symptomatic pLGG is chemotherapy (carboplatin plus vincristine, or weekly vinblastine), except for BRAF V600E tumors, for which dabrafenib plus trametinib received FDA approval in March 2023 and is recommended upfront by Canadian consensus. European standard clinical practice recommendations (version dated December 2022) state that first-line targeted therapy is acceptable only within clinical trials. Tovorafenib is approved in the US (April 2024, accelerated approval) and the EU for relapsed or refractory pLGG with a BRAF fusion or rearrangement or BRAF V600 mutation; it is not approved for first-line use.

If LOGGIC/FIREFLY-2 is positive, tovorafenib would be positioned as first-line systemic therapy for participants aged 6 months to 25 years with RAF-altered pLGG that is unresectable and meets clinical or radiologic indications for treatment. The population with the largest unmet need is BRAF fusion-driven pLGG (KIAA1549::BRAF fusion in approximately 35% of pLGG), for which type I BRAF inhibitors are contraindicated and no targeted first-line therapy is approved; in BRAF V600E pLGG, tovorafenib would enter a setting with an approved targeted alternative. FIREFLY-2 excluded participants with NF1 and tumors with additional activating alterations (IDH1/2, histone H3, MYBL, FGFR), and FDA labeling carries a warning about potential growth of NF1-associated tumors, so NF1-associated pLGG is not an anticipated use. A Brazilian consensus published in 2026 already lists tovorafenib as a therapeutic option for KIAA1549-BRAF fusion LGG, with 85% agreement and without restriction to line of therapy.

Care is delivered in pediatric neuro-oncology centers with multidisciplinary tumor boards; FIREFLY-2 is conducted at academic centers (approximately 140 sites). Tovorafenib is an oral, once-weekly outpatient therapy that does not require central venous access, whereas chemotherapy comparators are given intravenously on a weekly schedule for 60 to 81 weeks. The primary FIREFLY-2 analysis is expected approximately 12 months after the last participant enrolled (May 2026), with preliminary results expected in 2027.

Current first-line landscape by molecular subgroup

“While chemotherapy remains front-line therapy for unresectable pLGG in most scenarios (with the notable exception of BRAF V600E-altered tumors), many patients recur following cytotoxic agents and require further treatment. Inhibitors of the MAPK pathway, primarily MEK and RAF kinase inhibitors, have emerged as effective and tolerable second-line or later therapy for pLGG.” (opens the source at this quote in a new tab)

“Dabrafenib in combination with trametinib (D + T) was approved by FDA in 2023 for the first-line treatment of pediatric patients 1 year of age and older with LGG with a BRAF V600E mutation who require systemic therapy.” (opens the source at this quote in a new tab)
“Prior to the approval of tovorafenib, there were no approved targeted therapies for patients with pLGG harboring BRAF fusions.” (opens the source at this quote in a new tab)

Molecularly based treatment strategies: first-line options by alteration

Molecular alteration	First-line treatment
BRAF V600E mutation	“Standard chemotherapy: Carboplatin/vincristine (CV)†Targeted therapy: DaBRAFenib (BRAF inhibitor)/trametinib (MEK inhibitor)‡Clinical trials: Tovorafenib vs. CV or vinblastine (NCT05566795)”
BRAF fusions	“Standard chemotherapy: Carboplatin/vincristine (CV)Clinical trials:• Selumetinib (MEK inhibitor) vs. CV (NCT04166409, COG ACNS1833)• Tovorafenib (RAF inhibitor) vs. CV/vinblastine (NCT05566795)• Mirdametinib (MEK inhibitor) (NCT04923126, SJ901)”

LOGGIC/FIREFLY-2: anticipated first-line population

“LOGGIC/FIREFLY-2 is a two-arm, randomized, open-label, multicenter, global, phase 3 trial to evaluate the efficacy, safety, and tolerability of tovorafenib monotherapy vs. current standard of care (SoC) chemotherapy in patients < 25 years of age with pLGG harboring an activating RAF alteration who require first-line systemic therapy.” (opens the source at this quote in a new tab)
“Additionally, an indication for first-line systemic therapy is required, meaning that the tumor is non-resectable (either completely unresectable or partially resected with residual tumor that can no longer be resected) at the time of enrollment” (opens the source at this quote in a new tab)
“Patients with NF1-driven tumors are excluded. Furthermore, patients with a tumor exhibiting activating molecular alterations in addition to activating RAF alterations are also ineligible for participation even if the tumors are histologically of a low-grade.” (opens the source at this quote in a new tab)
“Patients who experience progressive disease in Arm 2 can crossover to Arm 1 and receive tovorafenib.” (opens the source at this quote in a new tab)

Regulatory pathway: FIREFLY-2 as the confirmatory trial

“As a condition of accelerated approval, a confirmatory study to verify the clinical benefit of tovorafenib is required. FIREFLY-2 is an ongoing, international RCT that is being conducted in the front-line setting to compare tovorafenib to physician’s choice of chemotherapy in patients with pLGG with an activating RAF alteration who require systemic therapy.” (opens the source at this quote in a new tab)

“Reaching full enrollment in this trial is a critical step toward our goal of establishing OJEMDA as standard of care across all lines of therapy for individuals with BRAF-altered pLGG.” (opens the source at this quote in a new tab)

Off-label first-line use of MAPK inhibitors before phase 3 results

“Off-label use of MAPK pathway inhibitors, namely their use as first-line therapy in newly diagnosed patients with pLGG, is controversial.” (opens the source at this quote in a new tab)
“Prior to the results of these trials and maturation of the longer-term data on late effects, the use of MAPK inhibitors as front-line therapy raises important ethical considerations.” (opens the source at this quote in a new tab)

Care setting: specialist multidisciplinary oversight

“Decisions on treatment and/ or follow up in pLGG need multidisciplinary information, approach and interpretation. The multidisciplinary tumour board should consist of neurooncology, neurosurgical, neurology, neuroradiology, radiotherapy and neuropathology expertise and should meet at regular scheduled intervals in order to optimize diagnosis, follow up and treatment.” (opens the source at this quote in a new tab)

Consensus statement	Topic
“MAPKi therapies should only be prescribed, and their management overseen, by an appropriate oncology team in a multidisciplinary setting”	General management

“The trial is being conducted at academic centers with patients being recruited from ~ 100 sites, including the SIOPe LOGGIC (Low Grade Glioma in Children) consortium in Europe, the Asia–Pacific region (Singapore, South Korea, Australia and New Zealand), and North America (Canada and the US).” (opens the source at this quote in a new tab)

Care setting: oral outpatient therapy compared with intravenous chemotherapy

“Beyond convenience, oral MAPK inhibitors may also reduce financial toxicity for patients living in low resource or geographically limited areas, since on therapy monitoring necessitates fewer ambulatory office visits compared to a chemotherapy regimen administered weekly. Additionally, unlike chemotherapy, MAPK inhibitors are not associated with serious infectious complications since they do not cause significant myelosuppression or require central venous access, so unexpected hospital admissions are rare.” (opens the source at this quote in a new tab)

“Specific socio-economic situations, such as patients living far away from hospitals, can impact the decision since it is generally easier to administer oral drugs at home with BRAFis with or without MEKis than weekly intravenous (IV) chemotherapy infusions.” (opens the source at this quote in a new tab)

Proportion of children with a targetable alteration who actually received a targeted agent

“Interestingly, only 23% (18 of 78) of those received a targeted agent at some point during therapy. Of the remaining 60 patients with a targetable alteration, 30 underwent a curative total resection and were subsequently monitored.” (opens the source at this quote in a new tab)
“However, only 23% received a targeted agent. This may be partly explained by the fact that most patients who underwent curative surgery did not require further intervention. Moreover, targeted agents such as MEK inhibitors are not yet considered a first-line therapy and are often reserved for rapidly progressing tumors or clinical trials.” (opens the source at this quote in a new tab)
“Importantly, for most patients, including ones who underwent a complete resection, a targeted agent has been identified for consideration at recurrence.” (opens the source at this quote in a new tab)

Tovorafenib (DAY101)

Place in treatment, anticipated use, and care setting