An experimental vaccine meant to combat peanut allergy came up short on Friday in a large clinical trial, but the company developing it blames the failure on a surprising placebo effect — and believes it still might win Food and Drug Administration approval.

The treatment, called Viaskin Peanut, is a patch designed to gradually train a patient’s immune system to tolerate peanuts. In a trial on more than 300 children with peanut allergies, about 35 percent of patients responded to Viaskin, but the overall results didn’t beat placebo by enough to meet the study’s primary goal.

Despite that failure, DBV Technologies, the firm that developed Viaskin, is planning to move forward with plans to file for FDA approval. The FDA has seen the trial data, the company said, and encouraged management to propose a path forward. DBV provided few other details about its plans, promising only to delve further into the study results.

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Whether the FDA will consider approving Viaskin remains to be seen. Under Dr. Scott Gottlieb, President Trump’s choice to lead the agency, the FDA has promised to loosen its standards for new therapies that might improve the lives of patients with severe conditions.

Investors, however, were less than optimistic Friday. DBV’s share price fell by about 45 percent on the news, erasing more than $1 billion of the company’s value.

DBV blamed the trial outcome on better-than expected results from placebo. In the study, about 13 percent of patients on placebo saw their peanut allergies improve, a rate that was roughly double what DBV saw in earlier trials, according to Dr. Hugh Sampson, the company’s chief scientific officer.

A second trial, focused on Viaskin’s safety, is expected to read out later this month.

This article is reproduced with permission from STAT. It was first published on Oct. 20, 2017. Find the original story here.