2. Academic Validation
  3. Safety and Efficacy of Obinutuzumab β (MIL62), a Novel Glycoengineered Type II Anti-CD20 Monoclonal Antibody, in Patients with Neuromyelitis Optica Spectrum Disorder: A Multicenter, Single-Arm, Phase Ib Clinical Trial

Safety and Efficacy of Obinutuzumab β (MIL62), a Novel Glycoengineered Type II Anti-CD20 Monoclonal Antibody, in Patients with Neuromyelitis Optica Spectrum Disorder: A Multicenter, Single-Arm, Phase Ib Clinical Trial

  • Neurol Ther. 2026 May 24. doi: 10.1007/s40120-026-00960-w.
Lei Wu # 1,  Min Wei # 2,  Feng Gao 3,  Hua Zhang 4,  Jiawei Wang 5,  Feng Xiang 1,  Sai Gao 1,  Ran Liu 3,  Jian Yin 4,  Yanjun Guo 5,  Xifang Liu 2,  Jinjin Liang 2,  Sijun Liu 2,  Feng Li 6,  Dehui Huang 7
Affiliations

Affiliations

  • 1 Department of Neurology, The First Medical Center of Chinese People's Liberation Army General Hospital, 28# Fuxing Road, Beijing, 100853, People's Republic of China.
  • 2 Beijing Mabworks Biotech Co., Ltd., Beijing, 100176, China.
  • 3 Department of Neurology, Peking University First Hospital, Beijing, 100034, China.
  • 4 Department of Neurology, Beijing Hospital, Beijing, 100005, China.
  • 5 Department of Neurology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
  • 6 Beijing Mabworks Biotech Co., Ltd., Beijing, 100176, China. [email protected].
  • 7 Department of Neurology, The First Medical Center of Chinese People's Liberation Army General Hospital, 28# Fuxing Road, Beijing, 100853, People's Republic of China. [email protected].
  • # Contributed equally.
PMID: 42177718 DOI: 10.1007/s40120-026-00960-w
Abstract

Introduction: To evaluate the safety, pharmacokinetics, pharmacodynamics, and efficacy of obinutuzumab β, a novel glycoengineered type II anti-CD20 monoclonal antibody, in patients with neuromyelitis optica spectrum disorder (NMOSD).

Methods: In this multicenter, open-label, single-arm, phase Ib trial (NCT05314010), 11 Aquaporin protein-4 (AQP4)-IgG-positive patients with NMOSD received obinutuzumab β at 500 mg or 1000 mg on days 1 of weeks 1 and 3. Patients in the 500-mg group could escalate to 1000 mg after 24 weeks if tolerated. Evaluations occurred at specified weeks (24-208), with 1000-mg doses on days 1 of weeks 25, 27, and every 26 weeks thereafter in patients who are relapse-free. Safety, efficacy, pharmacokinetics, pharmacodynamics, and immunogenicity were assessed.

Results: All participants with 500 mg (n = 3) transitioned to 1000 mg after 24 weeks. During the entire study period, all 11 participants experienced at least one treatment-emergent adverse event (TEAE); 90.9% had treatment-related adverse events (TRAEs). Serious adverse events were reported in 54.5%, with 27.3% related to obinutuzumab β. No TEAEs or TRAEs led to treatment discontinuation, withdrawal, or death. Two patients had early relapses on days 26 and 27 post-first dose, respectively; one withdrew immediately, while the Other remained on treatment for 1 year. The 2-year disease relapse-free rate was 81.8% [95% confidence interval (CI): 44.7%, 95.1%], and the annualized relapse rate (ARR) declined from 1.3 before 2-year treatment to 0.2 (95% CI: 0.1, 0.2) after obinutuzumab β, representing an 87.7% reduction.

Conclusion: Obinutuzumab β demonstrated manageable safety and may have promising efficacy against NMOSD. Despite the lack of a comparator group, the results support evaluation in phase III trials.

Clinical trial registration: https://clinicaltrials.gov/ (#NCT05314010).

Keywords

Anti-CD20 monoclonal antibody; Efficacy; Neuromyelitis optica spectrum disorder; Obinutuzumab β; Phase Ib; Safety.

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