The FDA has granted orphan drug designation to lenabasum for the treatment of dermatomyositis, a systemic autoimmune condition characterized by skin and muscle involvement, according to a press release from Corbus Pharmaceuticals.
An estimated 1 in 100,000 individuals in the United States are affected by dermatomyositis, according to the National Organization for Rare Disorders, with women disproportionately affected more than men and black, Asian and Native American populations exhibiting more severe morbidity.
Often characterized by distinct skin lesions accompanied by erosions, photosensitivity, itch, ulcers, calcinosis and hair loss, dermatomyositis has also been linked to muscle inflammation and atrophy which can manifest as weakness.
Unlike standard of care treatments, which include antimalarial drugs and potent immunosuppressive agents, lenabasum is intended to “turn off” chronic inflammation and fibrotic processes by binding to the cannabinoid receptor type 2 (CB2) expressed on activated immune cells and fibroblasts. Additionally, CB2 activation induces the production of specialized proresolving lipid mediators that activate an endogenous cascade responsible for the resolution of inflammation and fibrosis, which may impact fibroblasts to reduce tissue scarring.
The FDA based its decision in part on a phase 2 double-blind, randomized, placebo-controlled trial examining the safety and efficacy of lenabasum in dermatomyositis, as well as preclinical and human clinical studies that showed favorable safety, tolerability and pharmacokinetic profile. According to study findings, the mean improvement in the Cutaneous Dermatomyositis Disease Area and Severity Index activity score was 9.3 points for lenabasum at the conclusion of the study compared with 3.7 points for placebo (P = 0.04).
Additionally, researchers found that lenabasum was well-tolerated with no associated severe or serious side effects.
The FDA’s Office of Orphan Products Development assigns orphan drug designation to novel drugs and biologics that are intended for safe and effective treatment, diagnosis or prevention of rare diseases or disorders that affect less than 200,000 people nationwide.