Resunab Granted Orphan Drug Status in EU as Potential Therapy for Systemic Sclerosis

The European Commission (EC) has designated Corbus Pharmaceuticals’ product Resunab (JBT-101) an Orphan Drug for the potential treatment of systemic sclerosis (SSc).

Orphan Drug status is attributed to therapeutic drugs intended to prevent and treat rare life-threatening or chronically debilitating conditions that affect no more than five in 10,000 people, and for which there are no, or only unsatisfactory, prevention and treatment options. It also boosts the development of the drug and the start of clinical trials and protects the product from competition when it reaches the market.

“We are pleased to receive our second Orphan Designation in the EU for JBT-101,” Corbus CEO Yuval Cohen said in a press release. “We look forward to the continued advancement of our global clinical and regulatory development strategy for [Resunab] for the treatment of serious and rare inflammatory and fibrotic diseases.”

Resunab is a synthetic oral drug that activates a group of proteins called CB2 receptors that are expressed on activated immune cells and that trigger molecular pathways which resolve inflammation and halt fibrosis.

A Phase 2 trial (NCT02465437) is currently evaluating the safety, tolerability, and effectiveness of Resunab in 42 patients with SSc for up to six years and under immunosuppressive medication.

Resunab is given in different doses during the first month of the study (5 mg once-daily, 20 mg once-daily, or 20 mg twice-daily), after which patients receive 20 mg twice-daily for two months. At the end of the study, all patients are followed-up from weeks 13 to 16.

Improvement is assessed using the American College of Rheumatology (ACR) Combined Response Index in the diffuse cutaneous Systemic Sclerosis (CRISS) score (a measure of improvement in SSc).

This measure includes the modified Rodnan skin score (mRSS, it evaluates skin thickening); physician global assessment (MDGA); patient global assessment (PtGA); Health Assessment Questionnaire – Disability Index (HAQ-DI); and forced vital capacity (FVC, a measure of lung function).

Top-line results showed that 33 percent of patients on Resunab improved significantly in the ACR CRISS score, whereas patients in the placebo group showed no changes. Resunab also induced positive changes in the five individual domains of the CRISS score since baseline, observed as soon as week 4 or week 8. No serious adverse effects have been reported.

Resunab has also been designated an Orphan Drug as a potential treatment for people with cystic fibrosis (CF) in the EU, and was granted Fast Track status for the treatment of both SSc and CF by the U.S. Food and Drug Administration (FDA).