Why DBV Technologies SA Plummeted and Aimmune Therapeutics Inc Skyrocketed Today

DBV Technologies (NASDAQ: DBVT) is down 45% at 12:48 p.m. EDT after announcing that its peanut allergy treatment, Viaskin Peanut, failed -- albeit not by much -- a phase 3 trial. The results caused Aimmune Therapeutics (NASDAQ: AIMT), which has a peanut allergy treatment of its own, to shoot up 35%.

In the phase 3 trial called PEPITES, 35.3% of patients responded to Viaskin Peanut after 12 months of treatment compared to 13.6% of patients who received placebo. While the 21.7% difference in response rate was substantial, the trial was set up so that it would only pass if the lower end of the 95% confidence interval was above 15%. Unfortunately, the 95% confidence interval -- a statistical measurement of where the difference in response rate would likely read out if the trial was repeated multiple times -- was 12.4% to 29.8%, just missing the 15% threshold.

DBV Technologies noted that the secondary endpoint, the cumulative reactive dose, which measures the amount of peanut protein a patient can have before reacting, showed patients who took Viaskin Peanut tolerated an average of 900 mg of peanut protein compared to 360 mg for patients who received placebo. Unfortunately, the Food and Drug Administration generally doesn't care about secondary endpoints in trials that don't pass the primary endpoint.

Source: Fool.com