FDA Grants Orphan Drug Designation to Dermatomyositis Treatment, Lenabasum

A treatment for dermatomyositis, a rare and serious systemic autoimmune disease has just been granted an orphan drug designation by the US Food and Drug Administration (FDA).

The treatment in question? Lenabasum.

Lenabasum, developed by Corbus Pharmaceuticals Holdings, Inc., is a synthetic, oral, small-molecule, endocannabinoid-mimetic, selective cannabinoid receptor type 2 (CB2) agonist that preferentially binds to CB2 expressed on activated immune cells and fibroblasts. Since CB2 activation triggers physiologic pathways that resolve inflammation, speed bacterial clearance, and halt fibrosis, it also causes the production of specialized pro-resolving lipid mediators that activate an endogenous cascade responsible for the resolution of inflammation and fibrosis, while reducing production of multiple inflammatory mediators.

Following closely behind the FDA’s first marijuana-derived drug approval for the treatment of Lennox-Gastaut syndrome and Dravet syndrome, lenabasum joins the ranks of other developing drugs that are based from cannabidiol (CBD) and are being tested in rare diseases like fragile x syndrome.

Lenabasum is currently being tested in a 2-part, double-blind, randomized, placebo-controlled phase 2 clinical trial to assess safety, tolerability, and efficacy in patients with dermatomyositis.

The trial consists of 2 arms; those in the experimental arm are receiving lenabasum 20 mg once-daily on days 1 to 28, then 20 mg twice-daily on days 29 to 84 in Part A and lenabasum 20 mg twice daily on days 1 to 365 of the open-label extension (OLE) in Part B, while those in the placebo arm are receiving placebo once-daily on days 1 to 28, then twice daily on days 29 to 84 in Part A and placebo twice-daily on days 1 to 365 of the OLE in Part B.

Primary outcomes include the number of participants with treatment emergent adverse events as a measure of safety and tolerability as measured in the time frame of 112 days and follow-up period, the change in cutaneous dermatomyositis disease area and severity index (CDASI) from baseline in Part A as measured in the time frame of 84 days, and the number of participants with treatment emergent adverse events as a measure of safety and tolerability and the change in cutaneous dermatomyositis disease area and severity index (CDASI) from baseline in Part A as measured in the time frame of 343 days and follow-up period.

The current estimated completion date for the trial is September 2019.

Dermatomyositis is characterized by distinct skin lesions that can be accompanied by erosions, photosensitivity, itch, ulcers, calcinosis and hair loss along with other abnormalities. The disease involves the skin and muscles and is known to primarily affect more women than men.