UPDATE 1-FDA approves Aimmune's peanut allergy drug

Aimmune Therapeutics Inc said on Friday the U.S. Food and Drug Administration had approved its drug to reduce, and potentially eliminate, allergic reactions to peanuts in children aged 4 to 17.

Shares of the company were up 15% at $35.74 in extended trading . The treatment, called AR101 and to be sold under the brand name Palforzia, was designed to gradually reduce sensitivity to peanuts by exposing patients to a highly refined version of peanut flour over the course of several months.

The oral drug will be the first in the market to offer relief from peanut allergy symptoms for those who previously had to avoid all contact with peanuts in any form or risk a reaction requiring emergency treatment with an EpiPen or another epinephrine shot. The goal, the company says, is to get allergic children and teens to the point where accidental exposure to small amounts of peanuts do not trigger a potentially life-threatening immune response.

Some 1.6 million U.S. children aged 4 to 17 live with peanut allergies, Aimmune says, creating an opportunity for peak annual sales in excess of $1 billion. Symptoms can range from red, swollen skin to potentially deadly airway constriction. The FDA-approved label for Palforzia includes a warning of its potential to trigger a possibly dangerous allergic response.

Aimmune said each dose increase will be done under the supervision of an allergist who is prepared to treat any allergic reactions that arise. Palforzia may soon face competition from French drugmaker DBV Technologies SA, which has filed for U.S. approval of a once-daily skin patch to reduce sensitivity to peanut exposure.

The FDA is expected to make its approval decision for DBV's Viaskin Peanut patch by August 2020.