Efficacy and Safety of Lenabasum, a Cannabinoid Type 2 Receptor Agonist, in a Phase 3 Randomized Trial in Diffuse Cutaneous Systemic Sclerosis

INTRODUCTION Efficacy and safety of lenabasum, a cannabinoid type 2-receptor agonist, was tested in a Phase 3 study in patients with diffuse cutaneous systemic sclerosis (dcSSc). METHODS A multi-national double-blind study was conducted in 365 dcSSc patients who were randomized and dosed 1:1:1 with lenabasum 20 mg, lenabasum 5 mg, or placebo, each twice daily and added to background treatments including immunosuppressive therapies (IST). RESULTS The primary endpoint, ACR Combined Response Index in dcSSc (ACR-CRISS) score at Week 52, lenabasum 20 mg BID versus placebo, was not met, with ACR-CRISS scores of 0.888 versus 0.887, P = 0.4972, mixed models repeated measures (MMRM). Change in modified Rodnan Skin Score (mRSS) at Week 52 was -6.7 versus -8.1 points for lenabasum 20 mg BID versus placebo, P = 0.1183, MMRM. Pre-specified analyses showed higher ACR-CRISS scores, greater improvement in mRSS, and less decline in forced vital capacity in subjects on background mycophenolate and those receiving IST for ≤ 1 year duration. No deaths or excess in serious or severe adverse events related to lenabasum were observed. CONCLUSIONS A benefit of lenabasum in dcSSc was not demonstrated. The majority of patients were treated with background IST, and treatment with MMF in particular was associated with better outcomes. This supports the use of IST in the treatment of dcSSc, and highlights the challenge of demonstrating a treatment effect when investigational treatment is added to standard of care IST. These findings have relevance to trial design in SSc, as well as clinical care. This article is protected by copyright. All rights reserved