FDA Sued by Consumer Group Over Alzheimer Drug Dosage

Higher doses of a drug sold by Eisai Co. Ltd. (4523) and Pfizer Inc. (PFE) to treat Alzheimer’s disease should be halted because of potentially life-threatening side effects, a consumer group claimed in a lawsuit filed today in Washington.

Public Citizen Inc. of Washington sued the Food and Drug Administration seeking to force the agency to accept or reject its request to remove the 23-milligram dose of Aricept from the U.S. market. The group cited an Eisai-produced study that it claims showed the higher dosage didn’t enhance the effectiveness in treating moderate to severe Alzheimer’s.

“Although the study failed to show that the 23 mg dose has any clinically meaningful benefit, the study demonstrated that, in comparison with the 10 milligram dose, the use of a 23- milligram dose of donepezil is associated with a significant increase in risk to patient safety,” according to the complaint.

U.S. regulators approved a 23 milligram dose in July 2010, four months before a patent on Aricept’s 10 milligram dose expired. Patients taking the larger amount had more side effects than the 10 milligram level, including nausea, vomiting and gastrointestinal bleeding, according to the complaint.

Public Citizen on May 18, 2011, asked the FDA to pull the pills from the U.S. market and add a label to lower dosages of Aricept and generic donepezil warning of “increased toxicity associated with higher dosages.” The agency hasn’t acted on its petition, according to the lawsuit.

‘Acted Unlawfully’

“To protect public safety and prevent needless death and injury, Public Citizen seeks a declaration that the FDA has acted unlawfully by withholding action on Public Citizen’s petition,” according to the complaint.

Sandy Walsh, an FDA spokeswoman, said the agency doesn’t comment on pending litigation.

In a Dec. 1 letter to Public Citizen, the agency said it had yet to reach a decision on the group’s request because of the “significant issues” raised in the petition.

“We stand by the FDA’s decision to approve Aricept 23 milligram as a safe and effective treatment of moderate-to- severe Alzheimer’s disease,” Marcia Diljak, a spokeswoman for Tokyo-based Eisai, said in an e-mail.

She declined to comment on the lawsuit.

Christopher Loder, a spokesman for New York-based Pfizer, declined to comment on the lawsuit.

The case is Public Citizen Inc. v. Food and Drug Administration, 12-cv-01461, U.S. District Court, District of Columbia (Washington).

To contact the reporter on this story: Tom Schoenberg in Washington at tschoenberg@bloomberg.net

To contact the editor responsible for this story: Michael Hytha at mhytha@bloomberg.net