Plexiform Neurofibroma

Plexiform neurofibromas (PN) are known to cause significant morbidity in children with NF1. The recent FDA approval for selumetinib in children 2 years and older with inoperable symptomatic PN was based on the finding that selumetinib shrinks the majority of PN in children with NF1 and results in clinically meaningful benefit such as improvement in pain or range of motion. However, many morbidities, such as blindness or nerve damage, cannot be fully reversed with PN shrinkage. Therefore, there remains a critical need in this patient population to determine if young participants with PN in high-risk locations may benefit from early medical intervention prior to the development of clinical problems. This study will determine whether participants with asymptomatic PN in high-risk locations can potentially benefit from early treatment with selumetinib.

This study aims to demonstrate that in subjects with symptomatic, inoperable plexiform neurofibromas associated with neurofibromatosis type 1, TQ-B3234 capsules significantly improve the objective response rate at Week 24 compared to placebo.

Based on the clinical activity of both selumetinib and cabozantinib as monotherapies in clinical trials, the demonstrated activity of these agents in reduced doses in preclinical studies, and the non-overlapping toxicity profiles, the study will assess the tolerability and efficacy of selumetinib and cabozantinib in combination in participants with NF1 ≥16 years old with progressive and/or symptomatic PN in a phase 1/1b/2 clinical trial. Trial Design Phase 1 This will be an open label, dose escalation phase. Dose level escalation will be determined by a rolling six design. In this design, up to 6 participants can be enrolled at a given dose level and then evaluated for dose limiting toxicity (DLT) within the DLT window. The DLT window is defined as 16 weeks in this study based on the long half-life of cabozantinib and the desire to have maximum confidence about long-term tolerability of the combination prior to proceeding to the next dose level. Phase 1b Once the recommended phase 2 dose has been determined in phase 1, an expanded cohort of 12 participants will be enrolled in phase 1b portion of the study. Phase 2 This will be an open label, single-arm phase using the recommended phase 2 dose.

The goal of this observational study is to determine if a liquid biopsy (i.e. blood test) is an effective clinical tool for monitoring the development of malignant peripheral nerve sheath tumor (MPNST) among adults (18 years and older) with Neurofibromatosis Type 1 (NF1), compared to the current standard of care. The main questions it aims to answer are: How effective is liquid biopsy compared to the current standard of care (clinical surveillance and imaging) for early detection of MPNST development among people with NF1? Can liquid biopsy offer a cost-effective method for early detection of MPNST in people with NF1? Also, can liquid biopsy provide earlier detection that potentially leads to better outcomes? Also, can offering liquid biopsy improve access to care for people experiencing barriers to access (such as minority populations or people in rural areas)? At baseline, participants will be asked to: * Complete surveys to provide their demographic and NF1-related health information. * Report whether or not they are experiencing MPNST-related symptoms. * Provide blood samples (15 mL blood total between three tubes, which is approximately one tablespoon). Every six months during the five-year follow-up period, participants will be asked to: * Complete additional surveys to report whether or not they are experiencing MPNST-related symptoms and/or if they have been diagnosed with a new MPNST. * Provide an additional blood sample (10 mL blood total in one tube). If diagnosed with an MPNST by their healthcare provider during the follow-up period, participants will be asked to: * Complete an additional survey regarding their diagnosis and symptoms. * Provide an additional blood sample (10 mL blood in one tube). * In parallel, the study team will request a sample of tumor tissue from the care provider, if available.

FCN-159 (Luvometinib Tablets), an orally available and highly potent selective inhibitor of MEK1/2,demonstrated good tolerability and exhibited notable anti-tumor activity in pediatric pts with NF1-related PN in study NCT04954001.This study is a 5-year long-term follow-up of the FCN-159-002 study, involving all enrolled patients to further assess safety, growth and development effects, and treatment efficacy.