It’s not looking good for Corbus Pharmaceuticals and the autoimmune disease treatment lenabasum.
Corbus disclosed another in a long string of failures for the synthetic oral cannabinoid type 2 agonist, this time in a late-stage trial in the rare autoimmune disease dermatomyositis.
Patients with the disease experience distinctive skin rashes and muscle weakness, plus pulmonary, cardiac, gastrointestinal and joint complications.
Back in September, Corbus revealed that lenabasum had failed a phase 3 trial in cutaneous systemic sclerosis and another midstage study aimed at reducing pulmonary exacerbations in cystic fibrosis patients. The hits led the company to downsize its staff a month later to free up some cash to make it through mid-2022.
The earlier trial failures sent Corbus’ shares from $9.25 down 75% to the $2 range. Shares dropped again by more than 11% to $1.77 on the latest setback Thursday afternoon.
Corbus certainly was hoping for better results here, but CEO Yuval Cohen, Ph.D., urged calm: “With our strong cash position, we have the resources to both advance our now diversified pipeline while also planning next steps for lenabasum.”
The company has a few other products in development, but lenabasum is by far the furthest along in studies for dermatomyositis and lupus.
In the dermatomyositis study, lenabasum missed the main goal of improving patients’ condition. Patients received either the drug and background therapy or background therapy alone.
Patients with the condition are typically split into two distinct subgroups: classic dermatomyositis, or patients with both muscle weakness and skin involvement, and dermatomyositis with no significant muscle weakness but with skin involvement. Corbus noted a slight improvement in the former group.
The biotech also noted a “trend of beneficial effect” on other pre-specified analyses of the therapy’s overall effect, which included an analysis of improvement in inflammatory skin involvement in the patients without weakness and improvements in lung function.
On the skin involvement endpoint, Corbus found that patients without muscle weakness had an improvement in their skin condition compared to the control group. This goal was also incorporated in another phase 2 study of lenabasum.
As for improvements in lung function, investigators saw no benefit from the drug at Week 28.
Treatment-related adverse events occurred fairly frequently in both the treatment and control groups, but at similar rates. The lenabasum group had a higher rate of serious adverse events at 11.5% compared with 5.6%.
Cohen said the company will discuss the results from the phase 2 and 3 studies with regulatory authorities to determine next steps. The skin involvement results in the group without muscle involvement are encouraging, although the company is generally disappointed in the results, Corbus Chief Medical Officer Barbara White, M.D., said in a statement.
If Corbus wants to pursue this subgroup of patients in further testing, an expert quoted in the same statement suggested that finding a large enough population will be challenging.