HL-085 in Adults With Neurofibromatosis Type 1 (NF1) and Inoperable Plexiform Neurofibromas

Inclusion Criteria: * 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. Exclusion Criteria: * Patients who are unable to undergo MRI scans (prosthesis, prosthesis, braces, etc.) or patients with lesions that cannot be evaluated by MRI. * Patients do not have adequate organ function. * Patients who are unable to take drugs orally, have difficulty swallowing or anything that may lead to inadequate drug absorption. * Prior treatment with MEK 1/2 inhibitors. * Patients known to be allergic to the ingredients or analogues of the study drug. * Patients with previous or current retinal diseases such as retinal vein occlusion (RVO), retinal pigment epithelium detachment (RPED), central serous retinopathy (CSR), etc. (except retinopathy caused by research diseases). * With infections or other uncontrolled disease. * Strong CYP2C9 inhibitors or inducers within 7 days before treatment of the study drug. * Patients who received surgery within 4 weeks or radiotherapy within 6 weeks before enrollment. * Patients who participated in any other clinical study treatment within 4 weeks before enrollment. * Patients treated with anti-NF1 treatment with unresolved chronic toxicity. * Clinical judgment by the investigator that the patient should not participate in the study.