By Toni Clarke
WASHINGTON (Reuters) - U.S. health regulators have declined to approve an inhaled migraine drug from Allergan Inc, citing manufacturing concerns related to the canisters used to dispense it.
The U.S. Food and Drug Administration had previously expressed concerns related to Exemplar Pharma LLC, a business that fills the drug canisters for Allergan. In a move to ensure its supply chain, Allergan acquired Exemplar for what it said was less than $20 million and appointed members of its own team to oversee the facility.
Allergan said it expects the U.S. Food and Drug Administration will require a re-inspection of the Exemplar facility prior to approval. The company said the FDA also had concerns about the manufacturing process for the final filled canisters. Allergan said it has already responded to this concern but the agency has not yet had time to respond.
The drug, Levadex, is an inhaled version of an existing drug, dihydroergotamine, which is typically given by nasal spray or by injection at a headache center or hospital. The drug was reformatted into a more convenient form by MAP Pharmaceuticals Inc. Allergan acquired MAP in January for about $958 million.
Dihydroergotamine is in a class of drugs called ergot alkaloids that work by tightening blood vessels in the brain. Analysts on average expect Levadex to generate sales of nearly $300 million by 2015 according to Thomson Reuters data.
Data from a Phase III clinical trial, the last needed before a drug is submitted for U.S. approval, showed the drug met all four of the trial's main goals of reducing pain, mitigating sensitivity to light and sound and relieving nausea.
Migraine is an often debilitating neurological disorder that affects around 30 million people in the United States, according to the National Headache Foundation.
Migraine therapies on the market include a class of drugs called triptans, such as GlaxoSmithKline Plc's Imitrex, Johnson & Johnson and Almirall's Axert and AstraZeneca Plc's Zomig.
Allergan's injectable wrinkle-filler Botox was approved for headaches in October 2010.
The company said it will "vigorously address" the concerns raised by the FDA in its so-called "complete response letter," the type of letter issued by the agency to convey that it cannot approve a drug application in its current form.
Allergan said that based on its assessment of the FDA's response, it expects the agency to make its next ruling by the end of the fourth quarter. It said its financial earnings per share forecast remains unchanged, saying 2013 sales of Levadex would have been minimal even had the FDA approved it.
The company's shares on Tuesday were trading $1.69 lower in price, or down about 1.48 percent, at $112.34 a share.
(Reporting By Toni Clarke in Washington; Editing by Chris Reese)