BRAF/MEK Dual Inhibitors Therapy in Progressive and Anaplastic Pleomorphic Xanthoastrocytoma: Case Series and Literature Review

J Natl Compr Canc Netw. 2022 Nov;20(11):1193-1202.e6. doi: 10.6004/jnccn.2022.7046.

Abstract

Recurrent and anaplastic pleomorphic xanthoastrocytoma (r&aPXA) is a rare primary brain tumor that is challenging to treat. Two-thirds of PXA tumors harbor a BRAF gene mutation. BRAF inhibitors have been shown to improve tumor control. However, resistance to BRAF inhibition develops in most cases. Concurrent therapy with MEK inhibitors may improve tumor control and patient survival. In this study, we identified 5 patients diagnosed with BRAF-mutated PXA who received BRAF and MEK inhibitors over a 10-year interval at our institution. Patient records were evaluated, including treatments, adverse effects (AEs), outcomes, pathology, next-generation sequencing, and MRI. The median age was 22 years (range, 14-66 years), 60% male, and 60% anaplastic PXA. Median overall survival was 72 months (range, 19-112 months); 1 patient died of tumor-related hemorrhage while off therapy, and the other 4 experienced long-term disease control (21, 72, 98, and 112 months, respectively). Dual BRAF/MEK inhibitors were well tolerated, with only grade 1-2 AEs, including rash, neutropenia, fatigue, abdominal discomfort, and diarrhea. No grade 3-5 AEs were detected. A literature review was also performed of patients diagnosed with BRAF-mutated PXA and treated with BRAF and/or MEK inhibitors through August 2021, with a total of 32 cases identified. The median age was 29 years (range, 8-57 years) and the median PFS and OS were 8.5 months (range, 2-35 months) and 35 months (range, 10-80 months), respectively. The most common AEs were grade 1-2 fatigue and skin rash. Results of this case series and literature review indicate that dual-drug therapy with BRAF and MEK inhibitors for r&aPXA with BRAF V600E mutation may delay tumor progression without unexpected AEs.

Keywords: BRAF V600E mutation; BRAF inhibitors; MEK inhibitors; Targeted drug therapy; pleomorphic xanthoastrocytoma (PXA); rare brain tumors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Astrocytoma* / drug therapy
  • Astrocytoma* / genetics
  • Brain Neoplasms* / pathology
  • Fatigue
  • Female
  • Humans
  • Male
  • Middle Aged
  • Mitogen-Activated Protein Kinase Kinases / genetics
  • Mitogen-Activated Protein Kinase Kinases / therapeutic use
  • Mutation
  • Neoplasm Recurrence, Local
  • Protein Kinase Inhibitors / adverse effects
  • Proto-Oncogene Proteins B-raf / genetics
  • Young Adult

Substances

  • BRAF protein, human
  • Mitogen-Activated Protein Kinase Kinases
  • Protein Kinase Inhibitors
  • Proto-Oncogene Proteins B-raf