Another Corbus program hits the skids after late-stage flop, plummeting the small biotech's shares
Corbus Pharmaceuticals’ plans to position lenabasum as a pipeline-in-a-product aren’t going so well.
After shelving a program in scleroderma, the Norwood, MA-based biotech has revealed that its lead candidate failed both the primary and secondary endpoints in another Phase III trial.
Lenabasum failed to show a statistically significant difference in total improvement compared with placebo in treating dermatomyositis, a rare disease that causes muscle inflammation and skin rash, the company said Thursday. The news sent Corbus’ $CRBP stock spiraling around 30% early Thursday morning.
Participants in the study received one of two doses of lenabasum (20 mg or 5 mg) twice a day, or a placebo, all in addition to background treatments. At week 28, those in the 20 mg group saw a mean total improvement score (TIS) of 28.3, versus 26.7 in the placebo group. However, the p-value came in at 0.1965, which is far over the golden 0.05 number often used in drug trials to measure statistical significance.
“We are disappointed that the trial did not meet the primary endpoint of TIS at Week 28,” CMO and head of research Barbara White said in a statement.
Lenabasum is a small molecule that binds to and activates CB2, which is expressed on activated immune cells. The Phase III study, dubbed DETERMINE, enrolled patients with two types of dermatomyositis: those who have both muscle weakness and skin involvement, and those with skin involvement but no significant muscle weakness.
In an attempt to look on the bright side, Corbus said higher TIS scores were seen in participants who had muscle weakness and were treated with two 20 mg doses compared to placebo, with a nominal p-value of 0.0302. And patients with skin symptoms but no muscle weakness showed greater improvements on the Cutaneous Dermatomyositis Activity and Severity Index (CDASI), which measures inflammatory skin involvement, with a nominal p-value of 0.0166.
However, the drug flopped on another secondary endpoint: effect on lung function. No statistically significant difference was seen at week 28 compared to the control group, according to Corbus.
CEO Yuval Cohen told Endpoints News that the company will have a discussion with regulators, and if the next step is to conduct another study, they’ll discuss which patients and which endpoints to focus on.
“While, again, we did not hit on the primary, it’s the second time that we’re seeing signs of what we think is clear: clinical activity,” he said. “What we’re also waiting for are the biomarker data from skin biopsies. In our Phase II, the biomarker data was very encouraging.”
Lenabasum is the company’s only clinical candidate, according to their website. It has other CB2 agonists in the works for solid tumors, as well as CB1 inverse agonists for metabolism diseases and two monoclonal antibodies for solid tumors and fibrosis.
Corbus spent years building up investors’ hope in lenabasum. But back in September, the drug failed a Phase III study for a rare autoimmune condition called scleroderma. The following month, it announced it would shave its workforce by 54%. The company, which once had hopes for lenabasum as a pipeline in a product, said it would refocus on programs in dermatomyositis and systemic lupus erythematosus, and its preclinical candidates.