Alcobra says its ADHD drug works--as long as you don't compare it to placebo

Alcobra ($ADHD) is touting the benefits of its in-development ADHD treatment, saying the drug provided a statistically significant benefit over placebo--but only after the company removed data from four "extreme" responders from its analysis. Investors were unconvinced by the modified results, however, sending the biotech's shares down nearly 50% on Monday morning.

The company's lead drug is metadoxine (MDX), a nonstimulant GABA modulator the company bills as free of the abuse potential that plagues other treatments for ADHD. In a Phase III trial on 300 adult patients, the drug improved symptoms of the disorder among patients in the treatment arm, but whether it can be said to have significantly topped placebo is the subject of some controversy.

In full results from all 300 patients, MDX "yielded a positive trend" versus placebo, notching a p value of 0.15--well short of the industry standard 0.05 threshold for statistical significance. However, if you remove four placebo patients who fared particularly well in the trial--as Alcobra did in a post hoc analysis--the p value comes down to a healthy 0.03, and the company is confident the results from its modified intent-to-treat (mITT) population best reflect MDX's true potential.

Jonathan Rubin

"We conducted the mITT analysis after observing the disproportional effect of a few extremely large placebo responses which were inconsistent with what has been reported in previous ADHD trials of MDX or other agents," Alcobra Chief Medical Officer Jonathan Rubin said in a statement. "We plan to take the complete findings of this and other MDX studies to the FDA to determine the next steps on the path to potential regulatory approval for MDX."

The market doesn't seem to like MDX's chances, however, as the news of Alcobra's Phase III miss dealt a blow to the company's shares.

Alcobra disclosed only top-line results from its Phase III trial, saving detailed data on safety and efficacy for future scientific and medical conferences.

The Israeli biotech is in the midst of midstage studies testing MDX on pediatric ADHD and Fragile X syndrome, a genetic disorder suspected to play a role in autism development.

- read the results

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