As Medicare officials review evidence about Biogen’s (NSDQ:BIIB) Aduhelm (aducanumab) to determine if and how it will cover the drug, two high-level House Democrats are asking Biogen about its dealings with FDA. 

Yesterday, Carolyn Maloney (D-N.Y.) and Frank Pallone, Jr. (D-N.J.) sent a letter to Biogen CEO Michel Vounatsos asking for details about the company’s communications with FDA staff before it filed a Biologics License Application for aducanumab. Maloney chairs the House Committee on Oversight and Reform, while Pallone chairs the House Committee on Energy and Commerce.

The House isn’t alone in its push for such information regarding the drug, which could cost patients $56,000 annually in out-of-pocket expense. Acting FDA Commissioner Dr. Janet Woodcock recently asked the Office of Inspector General to launch an independent review of the agency’s dealings with Biogen during the Aduhelm approval process. 

Public Citizen recently filed a letter to Christi Grimm, principal deputy inspector general at the Office of the Inspector General (OIG), asking that the Office of Inspector General investigate Dr. Woodcock as part of its probe.

Analysts expect Aduhelm to be an eventual blockbuster drug, but the company does face risks related to Aduhelm pushback and potential U.S. drug pricing reform. Roughly 60% of its sales are in the U.S., but such concerns are not material to the firm’s valuation, according to an analysis from Morningstar healthcare strategist Karen Andersen. 

CMS anticipates that it will make a coverage decision on Aduhelm in the next six months. Once it reaches a conclusion, it will allow the public to submit comments for 30 days. 

The agency’s decision will also likely serve as a model for other potential drugs that target amyloid, a protein found in the brains of Alzheimer’s patients.