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Updated: Jan 1, 2026
An Orthotopic Sciatic Nerve Xenograft for Neurofibromatosis Type 1 Neurofibromas
Published on: October 10, 2025
A VEGF receptor vaccine demonstrates preliminary efficacy in neurofibromatosis type 2
Ryota Tamura1, Masato Fujioka2, Yukina Morimoto1
1Department of Neurosurgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
Abstract:
The anti-VEGF antibody bevacizumab has shown efficacy for the treatment of neurofibromatosis type 2 (NF2). Theoretically, vascular endothelial growth factor receptors (VEGFRs)-specific cytotoxic T lymphocytes (CTLs) can kill both tumor vessel cells and tumor cells expressing VEGFRs. Here we show an exploratory clinical study of VEGFRs peptide vaccine in seven patients with progressive NF2-derived schwannomas. Hearing improves in 2/5 assessable patients (40%) as determined by international guidelines, with increases in word recognition scores. Tumor volume reductions of ≥20% are observed in two patients, including one in which bevacizumab had not been effective. There are no severe adverse events related to the vaccine. Both VEGFR1-specific and VEGFR2-specific CTLs are induced in six patients. Surgery is performed after vaccination in two patients, and significant reductions in the expression of VEGFRs in schwannomas are observed. Therefore, this clinical immunotherapy study demonstrates the safety and preliminary efficacy of VEGFRs peptide vaccination in patients with NF2.
Insights
This study explored a VEGFRs peptide vaccine for neurofibromatosis type 2 (NF2), showing potential hearing improvements and tumor volume reduction. The VEGFRs vaccine demonstrated safety and preliminary efficacy in NF2 patients.
Area of Science:
- Oncology
- Immunology
- Genetics
Background:
- Neurofibromatosis type 2 (NF2) is a genetic disorder characterized by schwannomas.
- Bevacizumab, an anti-VEGF antibody, has shown some efficacy in NF2 treatment.
- VEGFRs-specific cytotoxic T lymphocytes (CTLs) theoretically target tumor vessels and VEGFRs-expressing tumor cells.
Purpose of the Study:
- To evaluate the safety and preliminary efficacy of a VEGFRs peptide vaccine in patients with progressive NF2-derived schwannomas.
- To assess the induction of VEGFRs-specific CTLs following vaccination.
- To observe any clinical improvements, such as hearing or tumor volume changes.
Main Methods:
- An exploratory clinical study involving seven patients with progressive NF2-derived schwannomas.
- Administration of a VEGFRs peptide vaccine.
- Assessment of hearing using international guidelines and word recognition scores.
- Measurement of tumor volume changes.
- Monitoring for adverse events.
- Analysis of VEGFR1- and VEGFR2-specific CTL induction.
- Examination of VEGFRs expression in schwannomas post-vaccination in two patients who underwent surgery.
Main Results:
- Hearing improved in 2 out of 5 assessable patients (40%), with increased word recognition scores.
- Tumor volume reductions of ≥20% were observed in two patients.
- One patient who did not respond to bevacizumab showed tumor volume reduction with the vaccine.
- VEGFR1-specific and VEGFR2-specific CTLs were induced in six out of seven patients.
- No severe adverse events related to the vaccine were reported.
- Significant reductions in VEGFRs expression were observed in schwannomas of two patients after surgery post-vaccination.
Conclusions:
- The VEGFRs peptide vaccine is safe and shows preliminary efficacy in patients with NF2.
- The vaccine successfully induces VEGFRs-specific CTLs.
- Further clinical studies are warranted to confirm the efficacy of VEGFRs peptide vaccination for NF2 treatment.
