DUBLIN – Shares in DBV Technologies Inc. plunged on news that its Viaskin peanut allergy therapy failed to reach statistical significance in a pivotal phase III trial in children. The most immediate beneficiary was Aimmune Therapeutics Inc., of Brisbane, Calif., whose stock rose by more than one-third Monday, with investor attention switching to its AR-101 oral desensitization therapy, which is currently undergoing a phase III trial in children and adults.