{"product_id":"braf-inhibitors-for-brain-tumors-a-practical-guide-to-side-effects-treatment-resistance-and-what-comes-next","title":"BRAF Inhibitors for Brain Tumors: A Practical Guide to Side Effects, Treatment Resistance, and What Comes Next","description":"\u003cp\u003eThis review explains how BRAF inhibitor drugs are used to treat gliomas (brain tumors) that carry a BRAF gene alteration. Two targeted therapies are FDA-approved for these tumors: dabrafenib plus trametinib, and tovorafenib. Both are effective but cause side effects that often require dose changes, and many adults — especially those with high-grade glioma — develop resistance to treatment over time. The article describes practical strategies for managing toxicity, choosing the right drug for each mutation type, and emerging approaches to overcome resistance.\u003c\/p\u003e\n\n\u003ch1\u003eBRAF Inhibitors for Brain Tumors: A Practical Guide to Side Effects, Treatment Resistance, and What Comes Next\u003c\/h1\u003e\n\n\u003ch2\u003eTable of Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"#ddn-key-points\"\u003eKey Points\u003c\/a\u003e\u003c\/li\u003e\n\n  \u003cli\u003e\u003ca href=\"#background\"\u003eBackground: Why BRAF-Targeted Therapy Matters for Brain Tumors\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#approved\"\u003eFDA-Approved BRAF Therapies for Glioma\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#tolerability\"\u003eManaging Side Effects: Optimizing Tolerability\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#guidance\"\u003eAnticipatory Guidance and Monitoring\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#dose\"\u003eDose Reduction Strategies\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#timing\"\u003eTiming of Treatment: Why Continuous Dosing Matters\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#choice\"\u003eChoosing the Right Agent\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#discontinuation\"\u003eStopping Treatment at Progression\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#emerging\"\u003eEmerging Approaches for Resistant Disease\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#firstline\"\u003eFirst-Line BRAF Inhibitor Therapy in HGG and LGG\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#radiation\"\u003eCombining BRAF Inhibitors with Radiation for HGG\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#trials\"\u003eOngoing Clinical Trials\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#implications\"\u003eWhat This Means for Patients\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#limitations\"\u003eLimitations and Open Questions\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#recommendations\"\u003eRecommendations for Patients and Caregivers\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"#ddn-faq\"\u003eFrequently Asked Questions\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#source\"\u003eSource Information\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ddn:keypoints:start --\u003e\n\u003ch2 id=\"ddn-key-points\"\u003eKey Points\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eTwo BRAF-targeted therapies are FDA-approved for gliomas: dabrafenib plus trametinib, and tovorafenib.\u003c\/li\u003e\n\u003cli\u003eAbout 90 percent of patients have drug-related side effects, but most are low grade and manageable with supportive care and dose adjustment.\u003c\/li\u003e\n\u003cli\u003eContinuous dosing matters; brief holds can lead to rapid progression, especially in high-grade glioma.\u003c\/li\u003e\n\u003cli\u003eTherapy should be chosen by mutation type: type 1 inhibitors do not work against BRAF fusions, while tovorafenib does.\u003c\/li\u003e\n\u003cli\u003eResistance is common in adults and high-grade glioma; clinical trials are testing new drugs and combinations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ddn:keypoints:end --\u003e\n\n\n\u003ch2 id=\"background\"\u003eBackground: Why BRAF-Targeted Therapy Matters for Brain Tumors\u003c\/h2\u003e\n\n\u003cp\u003eBrain cancer treatment has seen few breakthroughs over the past 20 years. This is true even though small molecule inhibitors and immunotherapy have transformed care for many other solid tumors. The major exception has been gliomas that carry specific targetable gene mutations, such as \u003cstrong\u003eBRAF\u003c\/strong\u003e (v-Raf murine sarcoma viral oncogene homolog B) or \u003cstrong\u003eIDH1\/2\u003c\/strong\u003e (isocitrate dehydrogenase).\u003c\/p\u003e\n\n\u003cp\u003eWhen the BRAF gene is altered, it produces a protein that is constantly active. This constant activity drives uncontrolled cell signaling through a pathway called \u003cstrong\u003eERK signaling\u003c\/strong\u003e, which promotes tumor growth. The most common BRAF alteration in cancer is a single-nucleotide variant called \u003cstrong\u003ep.V600E\u003c\/strong\u003e. This mutation gives the BRAF protein constant kinase activity without needing to pair up with another molecule (a process called dimerization).\u003c\/p\u003e\n\n\u003cp\u003eOther common BRAF alterations are called \u003cstrong\u003erearrangements\u003c\/strong\u003e (also known as fusions). These are especially common in pediatric low-grade glioma (pLGG). Rearrangements produce kinase activity that depends on dimerization but does not depend on upstream RAS activation.\u003c\/p\u003e\n\n\u003cp\u003eSmall molecule inhibitors of mutant BRAF (called \u003cstrong\u003eBRAFi\u003c\/strong\u003e), used alone or combined with inhibitors of the downstream kinase MEK (called \u003cstrong\u003eMEKi\u003c\/strong\u003e), successfully block ERK signaling and tumor growth across many cancers.\u003c\/p\u003e\n\n\u003cp\u003eTargetable BRAF alterations occur in several glioma subgroups. The most notable is pLGG, where \u003cstrong\u003e72% of tumors\u003c\/strong\u003e harbor a BRAF alteration. In adult low-grade glioma (LGG), BRAF alterations are found in \u003cstrong\u003e2–5%\u003c\/strong\u003e of cases. In high-grade glioma (HGG), approximately \u003cstrong\u003e3% of adult\u003c\/strong\u003e and \u003cstrong\u003e5–10% of pediatric\u003c\/strong\u003e tumors demonstrate a BRAF alteration.\u003c\/p\u003e\n\n\u003cp\u003eThe \u003cstrong\u003eBRAF V600E\u003c\/strong\u003e alteration is the most prevalent BRAF alteration in adult gliomas and in HGG. BRAF rearrangements, most commonly \u003cstrong\u003eKIAA1549-BRAF\u003c\/strong\u003e, are more prevalent in pLGG. Despite their relative rarity overall, BRAF alterations are enriched in certain glioma subgroups. These include pilocytic astrocytoma, pleomorphic xanthoastrocytoma, ganglioglioma, and epithelioid glioblastoma.\u003c\/p\u003e\n\n\u003cp\u003eBRAF-targeted therapy is FDA-approved for gliomas based on positive clinical trials in patients with pLGG, adult LGG, and HGG. The BRAFi dabrafenib, combined with the MEKi trametinib, is effective as first-line treatment for people with pLGG. It is also effective for those with recurrent or refractory LGG and HGG that has a BRAF V600E mutation.\u003c\/p\u003e\n\n\u003cp\u003eA second BRAFi\/MEKi combination, encorafenib with binimetinib, has shown positive responses in patients with treatment-refractory BRAF V600E-mutant HGG. This provides a potential off-label option for clinical use. Vemurafenib monotherapy has also demonstrated benefit in children and adults with HGG and LGG.\u003c\/p\u003e\n\n\u003cp\u003eUnfortunately, dabrafenib and other BRAFi in the same class (encorafenib, vemurafenib) are largely ineffective for gliomas with other BRAF point mutations or for BRAF rearrangements\/fusions. This is due to their specificity. Tovorafenib, a type 2 BRAF inhibitor, can bind to and inhibit BRAF V600 mutants and also disrupt dimerization. It demonstrates clinical responses and benefit in children with relapsed or recurrent pLGG with BRAF V600E or rearrangements.\u003c\/p\u003e\n\n\u003cp\u003eWhile a substantial step forward, BRAFi are not curative, and resistance can occur. Resistance to targeted therapy can occur from the start of treatment (\u003cstrong\u003ede novo\u003c\/strong\u003e or intrinsic resistance) or emerge over the course of treatment, even after a durable response. Resistance can develop through additional genomic alterations that evade ERK suppressive therapy (\u003cstrong\u003eacquired resistance\u003c\/strong\u003e). It can also develop through changes in signaling networks that evade or overcome targeted therapy (\u003cstrong\u003eadaptive resistance\u003c\/strong\u003e).\u003c\/p\u003e\n\n\u003cp\u003eResistance has been observed more commonly in adults and in patients with HGG. This is likely due to other co-occurring alterations that confer resistance (such as NF1, KRAS, or PI3CA mutations) or overall poor prognosis (such as CDKN2A\/B alterations).\u003c\/p\u003e\n\n\u003ch2 id=\"approved\"\u003eFDA-Approved BRAF Therapies for Glioma\u003c\/h2\u003e\n\n\u003cp\u003eCurrently, there are two BRAF-targeted therapies specifically approved for brain tumors. The combination therapy of dabrafenib and trametinib carries a tumor-agnostic approval for unresectable or metastatic solid tumors with BRAF V600E mutations in patients aged 6 years or older. It also has an approval for LGG in patients aged 1 year or older in both the USA and Europe.\u003c\/p\u003e\n\n\u003cp\u003eResponse rates to dabrafenib\/trametinib range from \u003cstrong\u003e33 to 69%\u003c\/strong\u003e in children and adults with LGG. In HGG or glioblastoma, response rates range from \u003cstrong\u003e31 to 56%\u003c\/strong\u003e in adults and children, respectively.\u003c\/p\u003e\n\n\u003cp\u003eTovorafenib, a type II RAF inhibitor, is effective at inhibiting oncogenic BRAF V600 mutations and BRAF rearrangements. It demonstrated a response rate of \u003cstrong\u003e53%\u003c\/strong\u003e in patients aged 0–21 with relapsed or refractory pediatric low-grade gliomas. This response rate included minor responses. Tovorafenib is approved by the FDA for individuals aged 6 months or older with BRAF-altered, relapsed or refractory LGG. Authorization in Europe (EMA) is pending.\u003c\/p\u003e\n\n\u003cp\u003eNotably, tovorafenib shows efficacy for patients who received a prior BRAFi or MEKi as well, with a \u003cstrong\u003e71% response rate\u003c\/strong\u003e. Its efficacy in HGG or adult patients with LGG is unclear.\u003c\/p\u003e\n\n\u003cp\u003eWhile BRAF inhibitors benefit patients with LGG and HGG, a patient's experience while on therapy is likely affected by adverse drug reactions. Dabrafenib\/trametinib is commonly associated with:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003ePyrexia (fever)\u003c\/li\u003e\n  \u003cli\u003eChills\u003c\/li\u003e\n  \u003cli\u003eFatigue\u003c\/li\u003e\n  \u003cli\u003eRash\u003c\/li\u003e\n  \u003cli\u003eNausea and vomiting\u003c\/li\u003e\n  \u003cli\u003eDiarrhea\u003c\/li\u003e\n  \u003cli\u003eAbdominal pain\u003c\/li\u003e\n  \u003cli\u003ePeripheral edema (swelling)\u003c\/li\u003e\n  \u003cli\u003eHeadache\u003c\/li\u003e\n  \u003cli\u003eArthralgia (joint pain)\u003c\/li\u003e\n  \u003cli\u003eNight sweats\u003c\/li\u003e\n  \u003cli\u003eDecreased appetite\u003c\/li\u003e\n  \u003cli\u003eConstipation\u003c\/li\u003e\n  \u003cli\u003eMyalgia (muscle pain)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThese side effects are also seen in patients with HGG and LGG. In a clinical trial of adults with glioma, adverse events led to dose reduction in \u003cstrong\u003e8%\u003c\/strong\u003e of patients, dose interruptions in \u003cstrong\u003e41%\u003c\/strong\u003e of patients, and permanent discontinuation in \u003cstrong\u003e9%\u003c\/strong\u003e of patients.\u003c\/p\u003e\n\n\u003cp\u003eFor pediatric patients with HGG, response rates can be as high as \u003cstrong\u003e56%\u003c\/strong\u003e. This reflects the overall clinical experience in solid cancers with dabrafenib\/trametinib. In that broader experience, \u003cstrong\u003e57%\u003c\/strong\u003e of patients experience dose interruptions, \u003cstrong\u003e28–65%\u003c\/strong\u003e experience dose reductions, and \u003cstrong\u003e12–24%\u003c\/strong\u003e discontinue the drug for toxicity. In a pediatric study, \u003cstrong\u003e79%\u003c\/strong\u003e of patients underwent dose adjustments or interruptions for toxicity.\u003c\/p\u003e\n\n\u003cp\u003eOf note, the incidence of adverse events generally does not correlate with response to treatment or outcome.\u003c\/p\u003e\n\n\u003cp\u003eTovorafenib is associated with similar toxicities. The most common are rash, hair color changes, fatigue, viral infections, vomiting, headache, hemorrhage, pyrexia, dry skin, constipation, nausea, dermatitis acneiform, upper respiratory tract infection, and reduced growth velocity. There is also a rare risk of intratumoral hemorrhage (\u003cstrong\u003e7%\u003c\/strong\u003e).\u003c\/p\u003e\n\n\u003cp\u003eThese adverse events led to dose reduction in \u003cstrong\u003e24%\u003c\/strong\u003e of patients and dose interruptions in \u003cstrong\u003e37%\u003c\/strong\u003e of patients on study. Drug discontinuation due to toxicity occurred in \u003cstrong\u003e7%\u003c\/strong\u003e of patients. Given its recent FDA approval, real-world data on tovorafenib tolerability are still emerging.\u003c\/p\u003e\n\n\u003ch2 id=\"tolerability\"\u003eManaging Side Effects: Optimizing Tolerability\u003c\/h2\u003e\n\n\u003cp\u003eWhile \u003cstrong\u003e90%\u003c\/strong\u003e of patients on BRAF-targeted therapy experience drug-related toxicities, the bulk of these are low grade (CTCAE Grade 1–2). These low-grade toxicities can be managed supportively, enabling patients to remain on therapy.\u003c\/p\u003e\n\n\u003cp\u003eAnticipatory guidance and close follow-up are critical to maximize tolerability, particularly early in treatment. Judicious dose reductions can reduce toxicity while maintaining benefit. Switching between agents within a class can also be effective at improving particularly challenging toxicity.\u003c\/p\u003e\n\n\u003ch2 id=\"guidance\"\u003eAnticipatory Guidance and Monitoring\u003c\/h2\u003e\n\n\u003cp\u003eGiven the known toxicity profiles for dabrafenib and trametinib, patients should be provided with anticipatory guidance and resources to guide them during treatment. For example, pyrexia with or without associated features such as hypotension, dehydration, or renal failure has a different treatment paradigm.\u003c\/p\u003e\n\n\u003cp\u003ePyrexia without associated systemic features requires only a drug hold. The drug can be resumed once the fever resolves. However, a drug hold and dose reduction is necessary when there are concurrent associated features.\u003c\/p\u003e\n\n\u003cp\u003eAnti-inflammatory drugs can help with symptom management. In the setting of recurrent pyrexia, corticosteroids can help reduce symptoms and prevent further dose reductions. In addition to fevers, dabrafenib\/trametinib cause additional inflammatory toxicities. For all of these, aggressive early management is key for tolerability.\u003c\/p\u003e\n\n\u003cp\u003eAnticipatory guidance regarding additional consultants and surveillance monitoring can improve compliance and help avoid some toxicities. Key monitoring recommendations include:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDermatologic and ophthalmologic evaluations\u003c\/strong\u003e every 3–6 months to establish a baseline and identify early signs of complications or toxicity\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBaseline echocardiogram\u003c\/strong\u003e to document left ventricular ejection fraction, with repeat evaluation 1 month after treatment initiation and every 2–3 months while on treatment as appropriate\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe National Health Service (NHS) provides useful leaflets for patients to remain informed about their therapy. The Canadian Consensus Statement also provides further guidance, specifically for dabrafenib and trametinib-induced pyrexia.\u003c\/p\u003e\n\n\u003ch2 id=\"dose\"\u003eDose Reduction Strategies\u003c\/h2\u003e\n\n\u003cp\u003eDose reductions can help improve tolerability, though this must be balanced against a potential for decreased efficacy. In some cases, re-escalation may be warranted once a patient adjusts to the medication.\u003c\/p\u003e\n\n\u003cp\u003eFor combination therapies such as dabrafenib\/trametinib, providers should first consider reducing the dose of the agent most likely responsible for the intolerable side effect. The FDA package inserts include guidance for specific dose reductions. However, if dosing goes below \u003cstrong\u003e1 mg daily of trametinib\u003c\/strong\u003e or \u003cstrong\u003e50 mg twice daily of dabrafenib\u003c\/strong\u003e, the drugs should be discontinued. This is because the risk of resistance without any benefit is presumed to be high at those levels. Tovorafenib can also be reduced for toxicity per manufacturer's instructions.\u003c\/p\u003e\n\n\u003ch2 id=\"timing\"\u003eTiming of Treatment: Why Continuous Dosing Matters\u003c\/h2\u003e\n\n\u003cp\u003eIt is clear that drug cessation or drug holds, even briefly, can lead to rapid disease progression in HGG. Even in the setting of severe toxicity, prolonged cessation of more than a week should be avoided when possible.\u003c\/p\u003e\n\n\u003cp\u003eIn patients with melanoma, several randomized phase II studies evaluated the role of intermittent versus continuous dosing. These studies found that continuous dosing shows superior efficacy and progression-free survival. This was true across multiple drug combinations. One study demonstrated a progression-free survival of \u003cstrong\u003e9 months versus 5.5 months\u003c\/strong\u003e for continuous versus intermittent dosing.\u003c\/p\u003e\n\n\u003cp\u003eWhile intermittent versus continuous dosing has not been evaluated in gliomas, these results suggest that intermittent treatment regimens should not be used as a means to improve tolerability. Intermittent dosing promotes resistance.\u003c\/p\u003e\n\n\u003cp\u003eFollowing targeted therapy discontinuation for toxicity, rechallenging with BRAFi\/MEKi at disease progression is an effective approach in some solid cancers. A systematic review and meta-analysis found that \u003cstrong\u003e65%\u003c\/strong\u003e of patients with advanced melanoma will achieve disease control (partial response and stable disease) when rechallenged following progression during a dose-hold. An objective response rate as high as \u003cstrong\u003e43%\u003c\/strong\u003e can be achieved with a rechallenge of therapy. Responses to re-challenge have also been documented in patients with gliomas.\u003c\/p\u003e\n\n\u003ch2 id=\"choice\"\u003eChoosing the Right Agent\u003c\/h2\u003e\n\n\u003cp\u003eBRAF-targeted therapy should be selected in a mutation-specific fashion. Type 1 BRAFi (such as dabrafenib) are not effective against BRAF fusions and can result in paradoxical activation and tumor progression.\u003c\/p\u003e\n\n\u003cp\u003eTovorafenib is effective in recurrent pLGG with BRAF V600 or BRAF fusions, while dabrafenib is ineffective in tumors with BRAF fusions. Notably, tovorafenib shows efficacy in patients with pLGG who had received prior BRAF or MEK inhibitor therapy. This suggests it can be used as a salvage therapy in the setting of progression.\u003c\/p\u003e\n\n\u003cp\u003ePreliminary study results suggest benefit in adults with BRAF or CRAF fusion-positive HGG as well. However, there are no published efficacy data on patients with BRAF-V600 mutant HGG. Further studies will be necessary to define the role of tovorafenib in patients with HGG.\u003c\/p\u003e\n\n\u003cp\u003eBRAF-targeted therapy may also be modulated based on toxicity. Successful intra-class switching for toxicity has been described in several solid cancers. Should a patient have pyrexia secondary to dabrafenib and trametinib that interferes with continuous dosing, one could consider switching to encorafenib and binimetinib. This combination is not approved for brain tumors or for a tumor-agnostic indication.\u003c\/p\u003e\n\n\u003cp\u003eWhen comparing the published studies on melanoma brain metastases, encorafenib and binimetinib had similar outcomes to dabrafenib and trametinib. In a small study examining encorafenib and binimetinib for patients living with glioma, there were no grade 3 or 4 treatment-related adverse events for pyrexia. These data suggest that in some cases, intraclass switching of BRAF\/MEKi could be an option for symptom management.\u003c\/p\u003e\n\n\u003ch2 id=\"discontinuation\"\u003eStopping Treatment at Progression\u003c\/h2\u003e\n\n\u003cp\u003eThe time and mechanism for BRAFi discontinuation is unclear. In patients with HGG who progress on therapy, withdrawal may result in rapid progression and clinical decline. As a result, the time to transition to a new regimen should be minimized, or therapies may be overlapped.\u003c\/p\u003e\n\n\u003cp\u003eIn patients with pLGG, rapid radiographic progression can occur as well. Some cases represent true disease progression, and others represent establishment of a new stable baseline. The appropriate duration of therapy in pLGG is unclear. The pediatric community is working to develop data-driven guidelines for V600E and fusion-altered pLGG.\u003c\/p\u003e\n\n\u003cp\u003eIn the authors' single-institution experience, many adults with HGG progress after drug is held in the recurrent setting. This suggests that BRAF-targeted therapy may be a chronic therapy until resistance emerges. There is room for a well-designed pre-irradiation clinical trial in order to identify the potential efficacy of this approach.\u003c\/p\u003e\n\n\u003ch2 id=\"emerging\"\u003eEmerging Approaches for Resistant Disease\u003c\/h2\u003e\n\n\u003cp\u003eResistance to BRAF-targeted therapy is common in patients with HGG and adult patients with LGG, even those whose cancers respond for a period of time. Emerging strategies focus on therapeutic approaches under evaluation in clinical trials, as well as emerging practices for treatment-refractory or high-risk patients.\u003c\/p\u003e\n\n\u003cp\u003eThese strategies include:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eCombination with radiation therapy\u003c\/li\u003e\n  \u003cli\u003eAutophagy inhibitors\u003c\/li\u003e\n  \u003cli\u003eAdditional targeted agents\u003c\/li\u003e\n  \u003cli\u003eNext-generation BRAF inhibitors, including paradox breakers, dimer disruptors, and protein degraders\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"firstline\"\u003eFirst-Line BRAF Inhibitor Therapy in HGG and LGG\u003c\/h2\u003e\n\n\u003cp\u003eGiven the efficacy of BRAFi in the recurrent setting, there is interest in identifying whether earlier treatment with BRAFi would provide more durable responses. Based on a randomized phase 2 study in children with newly diagnosed pediatric LGG requiring therapy, dabrafenib\/trametinib is superior to standard chemotherapy.\u003c\/p\u003e\n\n\u003cp\u003eOverall response was higher (\u003cstrong\u003e47% versus 11%\u003c\/strong\u003e, p\u0026lt;0.001) and progression-free survival was longer (\u003cstrong\u003e20.1 versus 7.4 months\u003c\/strong\u003e, HR 0.31; 95% CI 0.17 to 0.55) in those treated with targeted therapy compared to chemotherapy. This trial included children with LGG in whom therapy was clinically indicated. The results do not generalize to patients in whom treatment may extend to under 39 years of age. An ongoing clinical trial of tovorafenib is also evaluating its role in first-line therapy for RAF-altered pLGG.\u003c\/p\u003e\n\n\u003cp\u003eIn HGG, the majority of case reports and retrospective cohort studies describe first-line treatment with BRAF inhibitors in combination with or following radiation. There are two reports in the literature of adults with anaplastic PXA treated with BRAF-targeted therapy alone in the first-line setting after progression from low-grade disease. There are also several cases of pediatric patients with HGG treated with BRAF-targeted therapy in the first-line setting.\u003c\/p\u003e\n\n\u003cp\u003eFor patients with secondarily progressive or relatively indolent HGG, there may be some reluctance to start with radiotherapy. This reluctance may be due to widely disseminated disease or a relatively indolent clinical course. In these patients, first-line treatment with BRAF\/MEK targeted inhibitors may be reasonable. Patients should be counseled regarding the tolerability of this approach.\u003c\/p\u003e\n\n\u003ch2 id=\"radiation\"\u003eCombining BRAF Inhibitors with Radiation for HGG\u003c\/h2\u003e\n\n\u003cp\u003ePreclinical data in a variety of models demonstrate that BRAFi have a radiosensitizing effect on BRAF-mutant cancer cells. Murine intracranial HGG models also show synergy between BRAFi\/MEKi and radiotherapy.\u003c\/p\u003e\n\n\u003cp\u003eA retrospective study of children with HGG treated with BRAFi, primarily in combination with radiotherapy, showed improvement in survival compared to historical controls. There were no serious toxicities attributable to combination with radiotherapy.\u003c\/p\u003e\n\n\u003cp\u003eSimilar data do not exist for adults with HGG. Adults with HGG are known to have inferior overall survival and decreased response to BRAF-targeted therapy compared to children. An ongoing study in the Children's Oncology Group is evaluating dabrafenib and trametinib following radiation therapy. The study is for children and young adults (under 26 years) with BRAF V600E mutant HGG (NCT03919071).\u003c\/p\u003e\n\n\u003ch2 id=\"trials\"\u003eOngoing Clinical Trials\u003c\/h2\u003e\n\n\u003cp\u003eSeveral clinical trials are currently enrolling patients with BRAF-altered gliomas. These trials are testing new drugs and combinations:\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePlixorafenib\u003c\/strong\u003e (NCT06610682, Phase I, ages over 18): A BRAF paradox breaker for glioma\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePlixorafenib\u003c\/strong\u003e (Phase 0, ages over 18): A BRAF inhibitor for recurrent glioma\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDabrafenib, Trametinib, and Nivolumab\u003c\/strong\u003e (NCT06712875, Phase I\/II, ages 1–26): A MAPK inhibitor plus anti-PD-1 antibody\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNST-628\u003c\/strong\u003e (NCT06326411, Phase I, ages 1–30): A pan-RAF\/MEK molecular glue for solid tumors with MAPK alterations\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUlixertinib\u003c\/strong\u003e (NCT04566393, Expanded Access, ages over 12): A MEK inhibitor for solid tumors with MAPK alterations\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePF-07799933\u003c\/strong\u003e (NCT05355701, Phase I, ages over 16): A BRAF inhibitor for BRAF-altered solid tumors\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eIK-595\u003c\/strong\u003e (NCT06270082, Phase I, ages over 18): A MEK\/RAF inhibitor for RAS- or RAF-altered solid tumors\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBDTX-4933\u003c\/strong\u003e (NCT05786924, Phase I, ages over 18): A pan-RAF inhibitor for solid tumors harboring BRAF mutations\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBelvarafenib\u003c\/strong\u003e and others (NCT04589845, Phase II, all ages): A pan-RAF inhibitor for solid tumors\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2 id=\"implications\"\u003eWhat This Means for Patients\u003c\/h2\u003e\n\n\u003cp\u003eBRAF-targeted therapies represent a significant advance for patients with BRAF-altered gliomas. However, these treatments require careful management to maximize both quality of life and treatment duration.\u003c\/p\u003e\n\n\u003cp\u003eFor patients with low-grade glioma, especially children, responses can be durable. For adults with LGG and patients with HGG, resistance and disease progression during treatment are common challenges.\u003c\/p\u003e\n\n\u003cp\u003eThe key takeaway is that proactive management of side effects is essential. Patients should expect that dose adjustments may be needed. These adjustments do not necessarily mean the treatment is failing. In fact, the incidence of adverse events generally does not correlate with response to treatment or outcome.\u003c\/p\u003e\n\n\u003cp\u003ePatients should also understand that continuous dosing is important. Brief treatment interruptions can lead to rapid disease progression, especially in high-grade glioma. If side effects are severe, the treatment plan should be modified rather than stopped for prolonged periods.\u003c\/p\u003e\n\n\u003ch2 id=\"limitations\"\u003eLimitations and Open Questions\u003c\/h2\u003e\n\n\u003cp\u003eSeveral important questions remain unanswered. The appropriate duration of therapy in pediatric low-grade glioma is unclear. The pediatric community is working to develop data-driven guidelines for V600E and fusion-altered pLGG.\u003c\/p\u003e\n\n\u003cp\u003eThe time and mechanism for discontinuing BRAF inhibitors at progression is also unclear. In patients with HGG who progress on therapy, withdrawal may result in rapid progression and clinical decline.\u003c\/p\u003e\n\n\u003cp\u003eThere are no published efficacy data on tovorafenib in patients with BRAF-V600 mutant HGG. Further studies will be necessary to define its role in this population.\u003c\/p\u003e\n\n\u003cp\u003eSimilar data on combining BRAF inhibitors with radiation do not exist for adults with HGG. Adults with HGG are known to have inferior overall survival and decreased response to BRAF-targeted therapy compared to children.\u003c\/p\u003e\n\n\u003cp\u003eIntermittent versus continuous dosing has not been evaluated specifically in gliomas. The evidence favoring continuous dosing comes from melanoma studies.\u003c\/p\u003e\n\n\u003ch2 id=\"recommendations\"\u003eRecommendations for Patients and Caregivers\u003c\/h2\u003e\n\n\u003cp\u003eBased on this review, patients and caregivers should consider the following:\u003c\/p\u003e\n\n\u003col\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUnderstand your mutation type.\u003c\/strong\u003e BRAF-targeted therapy should be selected based on the specific BRAF alteration. Type 1 BRAFi such as dabrafenib are not effective against BRAF fusions. Tovorafenib is effective for both BRAF V600 mutations and BRAF fusions.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eExpect side effects and plan for them.\u003c\/strong\u003e About 90% of patients experience drug-related toxicities, but most are low grade and manageable. Anticipatory guidance and close follow-up are critical.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eReport fevers promptly.\u003c\/strong\u003e Pyrexia (fever) is common and has a specific management approach. Fever without other symptoms may only require a drug hold. Fever with dehydration, low blood pressure, or kidney problems requires a drug hold and dose reduction.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eKeep monitoring appointments.\u003c\/strong\u003e Regular dermatologic and ophthalmologic evaluations every 3–6 months can identify early signs of complications. Echocardiograms at baseline and during treatment monitor heart function.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDo not stop treatment without discussing it with your care team.\u003c\/strong\u003e Even brief drug holds can lead to rapid disease progression in high-grade glioma. If side effects are severe, your care team may reduce the dose or switch to a different agent rather than stopping treatment.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAsk about clinical trials.\u003c\/strong\u003e Several trials are testing new BRAF inhibitors and combination approaches for patients with resistant disease.\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eKnow that rechallenge may be an option.\u003c\/strong\u003e If treatment is stopped for toxicity and disease progresses, some patients respond to restarting BRAF inhibitor therapy.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003c!-- ddn:faq:start --\u003e\n\u003ch2 id=\"ddn-faq\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eWhich BRAF-targeted drugs are FDA-approved for gliomas?\u003c\/h3\u003e\n\u003cp\u003eTwo are approved for brain tumors. Dabrafenib plus trametinib is approved for low-grade glioma in patients aged 1 year and older, and has a tumor-agnostic approval for BRAF V600E solid tumors from age 6. Tovorafenib is approved for BRAF-altered, relapsed or refractory low-grade glioma from age 6 months.\u003c\/p\u003e\n\u003ch3\u003eHow likely is my tumor to respond to BRAF-targeted therapy?\u003c\/h3\u003e\n\u003cp\u003eResponse rates vary by tumor and drug. Dabrafenib plus trametinib produced responses in 33 to 69 percent of children and adults with low-grade glioma, and 31 to 56 percent in high-grade glioma. Tovorafenib produced a 53 percent response rate in patients aged 0 to 21 with relapsed or refractory pediatric low-grade glioma.\u003c\/p\u003e\n\u003ch3\u003eWhat side effects should I expect, and how often do they lead to dose changes?\u003c\/h3\u003e\n\u003cp\u003eAbout 90 percent of patients experience drug-related toxicities, but most are low grade and manageable. In a trial of adults with glioma, side effects led to dose reduction in 8 percent, dose interruptions in 41 percent, and permanent discontinuation in 9 percent. Fever, rash, fatigue, nausea and joint pain are common.\u003c\/p\u003e\n\u003ch3\u003eIf I get a fever on dabrafenib and trametinib, what should I do?\u003c\/h3\u003e\n\u003cp\u003eReport fevers promptly. Fever without other symptoms may only require holding the drug until it resolves. Fever with dehydration, low blood pressure, or kidney problems requires a drug hold and a dose reduction. Anti-inflammatory drugs can help, and corticosteroids may help with recurrent fever.\u003c\/p\u003e\n\u003ch3\u003eCan I take a break from treatment if side effects are severe?\u003c\/h3\u003e\n\u003cp\u003eBrief drug holds can lead to rapid disease progression, especially in high-grade glioma, so prolonged cessation of more than a week should be avoided when possible. If side effects are severe, your care team may reduce the dose or switch to a different agent rather than stopping treatment.\u003c\/p\u003e\n\u003ch3\u003eWhy does my mutation type matter when choosing a BRAF inhibitor?\u003c\/h3\u003e\n\u003cp\u003eTherapy should be selected based on the specific BRAF alteration. Type 1 inhibitors such as dabrafenib are not effective against BRAF fusions and can cause paradoxical activation and tumor progression. Tovorafenib is effective for both BRAF V600 mutations and BRAF fusions, including in patients who had prior BRAF or MEK inhibitor therapy.\u003c\/p\u003e\n\u003ch3\u003eWhat happens if my tumor progresses on BRAF-targeted therapy?\u003c\/h3\u003e\n\u003cp\u003eResistance is common in adults and in high-grade glioma. If treatment is stopped for toxicity and disease progresses, restarting BRAF inhibitor therapy is an option; in a review of advanced melanoma, 65 percent of patients achieved disease control after rechallenge. Several trials are testing new drugs and combinations for resistant disease.\u003c\/p\u003e\n\u003ch3\u003eMy child has a BRAF-altered low-grade glioma and was offered dabrafenib plus trametinib — when should we get a second opinion?\u003c\/h3\u003e\n\u003cp\u003eBecause treatment is chosen in a mutation-specific way, a second opinion can help confirm which BRAF alteration is present. Type 1 inhibitors such as dabrafenib are not effective against BRAF fusions and can cause paradoxical activation and tumor progression, while tovorafenib works for both BRAF V600 mutations and BRAF fusions. A second review can also address dose adjustments, since most patients experience low-grade toxicities and dose changes do not necessarily mean treatment is failing. Diagnostic Detectives Network provides independent expert second opinions.\u003c\/p\u003e\n\u003c!-- ddn:faq:end --\u003e\n\n\u003ch2 id=\"source\"\u003eSource Information\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eOriginal article title:\u003c\/strong\u003e Practical management of BRAF inhibitors in glioma: toxicity and resistance.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAuthors:\u003c\/strong\u003e Bazer D, Ayanlaja AA, Schreck KC.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAuthor affiliations:\u003c\/strong\u003e Department of Neurology, Cooper University Health Care, Camden, NJ, USA; Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA; Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD, USA\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePublication:\u003c\/strong\u003e CNS Oncology, 2026, Volume 15, No. 1, article 2711620\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDOI:\u003c\/strong\u003e https:\/\/doi.org\/10.1080\/20450907.2026.2711620\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eArticle type:\u003c\/strong\u003e Review Article\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDates:\u003c\/strong\u003e Received 30 June 2026; Accepted 27 July 2026\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eThis patient-friendly article is based on peer-reviewed research.\u003c\/em\u003e\u003c\/p\u003e","brand":"DiagnosticDetectives.Com","offers":[{"title":"Default Title","offer_id":47816857419932,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"url":"https:\/\/diagnosticdetectives.com\/fr\/products\/braf-inhibitors-for-brain-tumors-a-practical-guide-to-side-effects-treatment-resistance-and-what-comes-next","provider":"DiagnosticDetectives.Com","version":"1.0","type":"link"}