Plixorafenib For High-Grade Glioma

  • The FDA has granted plixorafenib a Breakthrough Therapy Designation for BRAF V600E-mutated high‑grade gliomas based on strong early response rates, a move that’s inspiring growing enthusiasm among neuro‑oncology experts.
  • Early clinical data, which include a 67% overall response rate in BRAF V600-mutated tumors, suggest that plixifarnib may offer a safer, more effective option than prior treatments, though larger trials are still needed to confirm its benefits.
  • Clinicians emphasize that the rise of actionable mutations such as BRAF V600E reinforces the need for ongoing molecular profiling beyond the initial diagnosis, as well as consideration of clinical trials as new therapies rapidly emerge.

The U.S. Food and Drug Administration (FDA) has granted the emerging cancer drug plixorafenib a Breakthrough Therapy Designation for high‑grade brain tumors with the BRAF V600E mutation.

“This is a promising targeted agent with the ability to address different BRAF alterations and offer a new therapeutic option for patients with molecularly defined high‑grade gliomas,” Dr. Nicholas Gonzales Castro, a neuro‑oncologist at Dana‑Farber Cancer Institute, tells SurvivorNet Connect.

With the Breakthrough Therapy Designation, the drug development is now fast-tracked to address serious unmet needs for these patients. Plixorafenib is an oral therapy designed to shut down cancers driven by abnormal BRAF proteins.

“This designation is a big step for targeted therapies in high‑grade glioma patients with actionable molecular markers,” adds Dr. Jacob Young, a neurosurgeon at UCSF Health.

The findings will require validation in larger clinical trials, Dr. Juan Pablo Ospina, a neurologist at the University of Pennsylvania Health System, tells SurvivorNet Connect, but “the early signals are notable and support the FDA’s designation of plixorafenib as a breakthrough therapy.”

The update also underscores the importance of continued molecular profiling, including next-generation sequencing, for glioma patients “beyond the initial diagnosis,” Dr. Ospina adds.

Promising Results & Favorable Side Effect Profile

Plixorafenib was a key focus during phase 1/2a and the ongoing Phase 2 FORTE clinical trial.

Data presented at the 2023 Society for Neuro-Oncology (SNO) conference showed that patients with BRAF V600-mutated tumors had a “67% overall response rate” after taking plixorafenib.

Dr. Young called the phase 1/2 trial results for patients with BRAF V600E-mutated high-grade glioma “very encouraging.”

Early data also suggest “an improved side effect profile compared with prior alternatives and promising response rates,” Dr. Ospina notes, suggesting plixorafenib could address a serious unmet need for effective and better-tolerated treatments.

Some of the side effects experienced by patients using plixorafenib included:

  • Fatigue
  • Nausea
  • Diarrhea
  • Vomiting
  • Liver disruptions (such as inflammation)

In the phase 1/2 trial, plixorafenib did demonstrate a favorable safety and tolerability profile, with treatment related adverse events leading to treatment discontinuation in less than 2% of patients.