Supernus tweaks ADHD studies to boost chances of success
- Maryland-based Supernus Pharmaceuticals said Monday it would drop a lower dose of its experimental drug for impulsive aggression in children with attention deficit hyperactivity disorder (ADHD) and continue with only a higher dose in two Phase 3 studies testing the treatment.
- The decision was made after a planned interim analysis of the first study of Supernus' drug, called SPN-810. Based on predefined criteria, the lower 18 mg dose will be cut and all patients will now be randomized to either a 36 mg dose or placebo.
- Supernus said eliminating the lower dose would "maximize the probability of reaching a statistically significant outcome for the 36 mg dose." Enrollment is currently at about 64% for the first trial and 56% for the second study, and recruitment to both is expected to continue through mid-2018.
Supernus had planned to conduct the interim analysis of the first of its two Phase 3 studies in order to build in flexibility to drop a dose arm, increase its recruitment targets or halt the study early in case of futility.
After analysis by an independent statistician, Supernus decided to eliminate the 18 mg dose arm, likely increasing the statistical powering of the study, according to Cowen & Co. analyst Ken Cacciatore.
"We note that the total number of patients in the trials will not change, but since the 18mg dose arms were re-randomized, the number of patients in both the 36mg and placebo arms arm will increase, which in turn, likely increases the statistical powering and chance of success," Cacciatore wrote in a Sept. 19 note.
There are currently no approved options for impulse aggression control in children with ADHD.
SPN-810 (molindone hydrochloride) was originally marketed as Moban by Endo Pharmaceuticals for the treatment of schizophrenia, but at a higher dose and in a different formulation. Endo halted sales in January 2010 but the drug is still available as a generic.
Shares in Supernus fell by 15% in Tuesday morning trading, possibly prompted by an analyst downgrade of the stock from "Buy" to "Hold."
- Supernus Pharmaceuticals Press release
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