Corbus Pharmaceuticals, Inc.

The Total Improvement Score (TIS), which is used as the primary efficacy measure in dermatomyositis (DM) clinical trials, lacks a skin-specific measure. However, skin is a defining feature of DM. In this study, data were analyzed from the phase 3 trial of lenabasum in DM. Cutaneous Dermatomyositis Disease Area and Severity Index-Activity scores and all components of the TIS were collected at baseline and weeks 16, 28, 40, and 52. From these assessments, a composite outcome was developed, named Dermatomyositis Outcomes for Muscle and Skin, which includes certain components of the TIS and the Cutaneous Dermatomyositis Disease Area and Severity Index-Activity scores. The relative sensitivities of the TIS and Dermatomyositis Outcomes for Muscle and Skin to detect improvement in DM skin and muscle disease activity were analyzed. A total of 174 patients with DM were included, 82% were female, and 75% were White. Mean (SD) age was 51.9 (12.20) years. Treatment effect using the TIS ranged between 17.6 and 21.7 points for muscle and skin responders versus nonresponders across time points. The Dermatomyositis Outcomes for Muscle and Skin score displayed a statistically significantly greater treatment effect of 25.9-40.0 points for responders than for nonresponders, depending on the response assessed and the time point. Dermatomyositis Outcomes for Muscle and Skin is a more sensitive composite measure that reflects improvement from baseline in both skin and muscle disease activity, suggesting usefulness for use in future DM clinical trials.

This study utilizes data from the open-label extension (OLE) phase of the lenabasum phase 2 trial and additional post-OLE follow-up data. Key aims include evaluating the drug's long-term effectiveness and assessing disease manifestation recurrence.

The phase 2 lenabasum trial enrolled patients with treatment-resistant, skin-predominant DM. The OLE consisted of a 3-year period during which 20 patients were on the drug for the entire duration, with assessments every 8 weeks to evaluate drug safety and efficacy. Subsequently, a follow-up retrospective chart review was performed on patients who completed the OLE as well as on control subjects with DM who did not participate in the lenabasum trial.

By week 68, patients exhibited reductions in Cutaneous Dermatomyositis Disease Area and Severity Index activity score (-21.8), Patient Skin Activity Visual Analog Scale (-3.0), and Skindex-29 (-28.0) from OLE baseline. After OLE, 58.3% maintained stable disease, significantly higher than controls (P = .035), with 41.7% not experiencing flares compared with 91.6% of controls. In addition, 50% of patients reported sustained pruritus improvement.

Data from OLE and subsequent follow-up periods demonstrate lenabasum's efficacy in maintaining disease stability, reducing flares, and improving DM symptoms, suggesting that it is a promising option for patients with treatment-resistant skin-predominant DM.

This study was registered at clinicaltrials.gov, with NCT02466243. Study registration was first submitted on June 2, 2015.

Endocannabinoids, which are present throughout the central nervous system (CNS), can activate cannabinoid receptors 1 and 2 (CB1 and CB2). CB1 and CB2 agonists exhibit broad anti-inflammatory properties, suggesting their potential to treat inflammatory diseases. However, careful evaluation of abuse potential is necessary. This study evaluated the abuse potential of lenabasum, a selective CB2 receptor agonist in participants (n = 56) endorsing recreational cannabis use. Three doses of lenabasum (20, 60, and 120 mg) were compared with placebo and nabilone (3 and 6 mg). The primary endpoint was the peak effect (E_max) on a bipolar Drug Liking visual analog scale (VAS). Secondary VAS and pharmacokinetic (PK) endpoints and adverse events were assessed. Lenabasum was safe and well tolerated. Compared with placebo, a 20-mg dose of lenabasum did not increase ratings of Drug Liking and had no distinguishable effect on other VAS endpoints. Dose-dependent increases in ratings of Drug Liking were observed with 60 and 120 mg lenabasum. Drug Liking and all other VAS outcomes were greatest for nabilone 3 mg and 6 mg, a medication currently approved by the US Food and Drug Administration (FDA). At a target therapeutic dose (20 mg), lenabasum did not elicit subjective ratings of Drug Liking. However, supratherapeutic doses of lenabasum (60 and 120 mg) did elicit subjective ratings of Drug Liking compared with placebo. Although both doses of lenabasum were associated with lower ratings of Drug Liking compared with 3 mg and 6 mg nabilone, lenabasum does have abuse potential and should be used cautiously in clinical settings. SIGNIFICANCE STATEMENT: This work provides evidence that in people with a history of recreational cannabis use, lenabasum was safe and well tolerated, although it did demonstrate abuse potential. This work supports further development of lenabasum for potential therapeutic indications.