• Age: patients must be ≥18 years of age at the time of study entry.

• Diagnosis: Patients must have inoperable and symptomatic plexiform neurofibromas(PN), and patients must have NF1 mutation or meet at least 1 of the following NF1 diagnostic criteria:

• ① ≥6 cafe-au-lait macules ;

• ② Axillary freckling or freckling in inguinal regions;

• ③ ≥2 Lisch nodules (iris hamartomas);

• ④ A distinctive bony lesion such as dysplasia of the sphenoid bone or dysplasia or thinning of long bone cortex);

• ⑤ An optic pathway glioma;

• ⑥ First-degree relative with NF1.

• Patients must have a measurable lesion, defined as at least 3 cm in length, amenable to MRI for efficacy assessment.

• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.

• Patients are able to understand and voluntarily sign a written informed consent form.

• Patients must be willing and able to complete study procedures and follow-up examinations.