Corbus Pharmaceuticals says a Phase 3 clinical trial of anabasum for diffuse cutaneous scleroderma will start in the fourth quarter of 2017, putting the treatment a step closer toward regulatory approval after a Phase 2 trial that improved patients’ disease.
According to the company’s second-quarter financial report, the trial’s launch is the result of meetings between the company and the U.S. Food and Drug Administration as well as meetings with the European Medicines Agency. The discussions covered results of the Phase 2 study and the design of the Phase 3 trial.
The global trial will recruit about 350 adults with diffuse scleroderma who will be randomized to receive one of two anabasum doses or a placebo. After 52 weeks of treatment, researchers will analyze patients’ modified Rodnan Skin Score, which measures skin fibrosis and thickening. This measure will constitute the study’s main outcome.
Anabasum, formerly known as Resunab or JBT-101, improved patients’ symptoms in the Phase 2 trial (NCT02465437), as measured by the mRSS. Corbus presented the results at the annual meeting of the European League Against Rheumatism.
Other disease features also improved, as shown by improvements in patients’ scores on the American College of Rheumatology Combined Response Index in diffuse cutaneous Systemic Sclerosis (ACR CRISS). This tool measures several disease parameters, including lung function and global health assessments.
Anabasum is a synthetic oral drug that mimics endocannabinoids. Its binding to the CB2 receptor on immune cells and on skin cells called fibroblasts triggers changes in activity in nearly 1,940 genes.
Additional analyses, presented at the 15th International Workshop on Scleroderma Research, showed that the treatment reduced inflammation and fibrosis in patients’ skin samples.
The treatment is currently being evaluated in an open-label extension study that includes patients from the Phase 2 trial. The extension trial, originally scheduled for one year, will now run for two more years.
The European Commission in 2017 granted anabasum orphan drug status as a treatment for scleroderma and cystic fibrosis — another condition marked by inflammation and fibrosis development. In 2015, the FDA granted it both orphan drug and fast track status for the treatment of scleroderma.