FDA Queries AstraZeneca Drug's Efficacy
By REUTERS (copyright). Filed at 8:54 a.m. ET
LONDON (Reuters) - Officials at the U.S. Food and Drug Administration have questioned both the efficacy and safety of AstraZeneca Plc's new anti-stroke pill Exanta, according to documents posted on the agency's Web site on Thursday.
Shares in the Anglo-Swedish drug maker fell 4.2 percent to 25.08 pounds as the news shook widespread confidence among investors that the potential blockbuster would be recommended for approval.
A briefing note, posted on the FDA Web site one day ahead of an committee meeting on the drug, said the company may have been "too liberal'' in the way it assessed the effectiveness of Exanta against warfarin, the standard treatment.
One industry analyst said the efficacy of the product had been taken as a given and that the questions about its effectiveness against warfarin amounted to a setback for approval hopes.
FDA officials also questioned the drug's possible toxic effects on the liver and said the company's risk plan for the product did not address some possible concerns.
The FDA was expected to focus on safety, since Exanta has been associated with raised liver enzymes in some patients, although AstraZeneca argues the benefits outweigh the risks.
Exanta is the first new anticoagulant pill since the introduction of warfarin, a notoriously difficult drug to use, 60 years ago.
Along with Crestor, the cholesterol-lowering drug launched last year, Exanta is a pivotal product for AstraZeneca, which needs to make up for declining sales of its aging ulcer pill Losec/Prilosec, now facing generic competition.
The consensus peak annual sales forecast for Exanta is $3.7 billion, according to pharmaceutical consultancy Evaluate.
Exanta is already on sale in Europe as a treatment to prevent blood clotting after orthopedic surgery. But the big commercial opportunity -- estimated by analysts to account for over 80 percent of sales -- lies in preventing stroke in patients with atrial fibrillation, or an irregular heartbeat.
The FDA's Cardiovascular and Renal Drugs Advisory Committee will consider both uses of the drug at the Sept. 10 meeting.
Thursday, September 09, 2004
Forthcoming Meeting: Exanta and Stroke Prevention
Reuters reports that the FDA will be holding a meeting tomorrow to discuss Exanta and its use as an anti-stroke medication. Here is the text of the FDA announcement about this meeting: FDA Announcement and the text of the FDA Briefing Note: FDA Briefing Note. Here is the report as published on the New York Times website (free registration required):