Lupus & antiphospholipid syndrome
Phase Ib, multicentre, open-label, dose-escalation study to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of subcutaneously administered mosunetuzumab in participants with systemic lupus erythematosus
Authors' conclusion
Mosunetuzumab demonstrated dose-dependent peripheral B-cell depletion and a safety profile consistent with prior studies in follicular lymphoma.
Study context
- Population
- Active autoantibody-positive systemic lupus erythematosus (SLE) with SLEDAI-2K ≥4 at screening; enrolled January 2022 through December 2023
- Participants
- 15 participants
- Comparison
- Fixed-dosing dose-finding cohorts vs Step-up dose-escalation cohorts
- Outcome
- Safety
Methodological detailsmulticentre, open-label, fixed-dosing dose-finding cohorts and step-up dose-escalation cohorts
- Multicentre
- Open-label
- Fixed-dosing dose-finding cohorts and step-up dose-escalation cohorts
Main finding
As reported in the abstract
Safety (primary objective)
Discontinued treatment due to treatment-emergent adverse events (AEs)
2
Grade ≥3 AEs
13.3%
Serious AEs
6.7%
Further findings
Pharmacodynamics (PD): peripheral B cells
- Dose-dependent depletion below the lower limit of quantification (cells/µL)
- 0.441
- CD4+ and CD8+ T-cell activation across all tested doses
SLEDAI-2K
- Scores improved, especially with higher baseline scores and higher doses
Pharmacokinetics (PK)
- Consistent with that observed in relapsed or refractory follicular lymphoma
Safety
- Discontinued treatment due to treatment-emergent AEs
- 2
- Grade ≥3 AEs
- 13.3%
- Serious AEs
- 6.7%
- No immune effector cell-associated neurotoxicity syndrome events or high-grade cytokine release syndrome events reported
Original publication
Phase Ib, multicentre, open-label, dose-escalation study to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of subcutaneously administered mosunetuzumab in participants with systemic lupus erythematosus. Lupus Sci Med. Published 17 June 2026. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →