BMC Medicine (Jul 2023)

Phase 1 dose-escalation study to evaluate the safety, tolerability, pharmacokinetics, and anti-tumor activity of FCN-159 in adults with neurofibromatosis type 1-related unresectable plexiform neurofibromas

  • Xiaojie Hu,
  • Wenbin Li,
  • Kang Zeng,
  • Zhongyuan Xu,
  • Changxing Li,
  • Zhuang Kang,
  • Shenglan Li,
  • Xin Huang,
  • Pu Han,
  • Hongmei Lin,
  • Ai-Min Hui,
  • Yan Tan,
  • Lei Diao,
  • Ben Li,
  • Xingli Wang,
  • Zhuli Wu,
  • Xiaoxi Lin

DOI
https://doi.org/10.1186/s12916-023-02927-2
Journal volume & issue
Vol. 21, no. 1
pp. 1 – 10

Abstract

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Abstract Background Surgery is a common treatment strategy for patients with neurofibromatosis type 1 (NF1)-related plexiform neurofibroma (PN) and has limited efficacy. FCN-159 is a novel anti-tumorigenic drug via selective inhibition of MEK1/2. This study assesses the safety and efficacy of FCN-159 in patients with NF1-related PN. Methods This is a multicenter, open-label, single-arm, phase I dose-escalation study. Patients with NF1-related PN that was non-resectable or unsuitable for surgery were enrolled; they received FCN-159 monotherapy daily in 28-day cycles. Results Nineteen adults were enrolled in the study, 3 in 4 mg, 4 in 6 mg, 8 in 8 mg, and 4 in 12 mg. Among patients included in dose-limiting toxicity (DLT) analysis, DLTs (grade 3 folliculitis) were reported in 1 of 8 patients (16.7%) receiving 8 mg and 3 of 3 (100%) patients receiving 12 mg. The maximum tolerated dose was determined to be 8 mg. FCN-159-related treatment-emergent adverse events (TEAEs) were observed in 19 patients (100%); most of which were grade 1 or 2. Nine (47.4%) patients reported grade 3 study-drug–related TEAEs across all dose levels, including four experiencing paronychia and five experiencing folliculitis. Of the 16 patients analyzed, all (100%) had reduced tumor size and six (37.5%) achieved partial responses; the largest reduction in tumor size was 84.2%. The pharmacokinetic profile was approximately linear between 4 and 12 mg, and the half-life supported once daily dosing. Conclusions FCN-159 was well tolerated up to 8 mg daily with manageable adverse events and showed promising anti-tumorigenic activity in patients with NF1-related PN, warranting further investigation in this indication. Trial registration ClinicalTrials.gov, NCT04954001. Registered 08 July 2021.

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