Biogen has terminated a large study evaluating its marketed treatment for Alzheimer's disease, a decision the company says was made in response to a recent ruling from Medicare.
Known as "ICARE AD," the study was meant to gather years of real-world data on patients prescribed Biogen's drug, which is sold under the brand name Aduhelm. Biogen designed ICARE AD — together with two other clinical trials, one of which is required to keep Aduhelm on the market — to generate more evidence of the drug's effects following its controversial approval last year. With ICARE AD, the company had hoped to enroll as many as 6,000 patients across approximately 200 centers in the U.S.
But eight months after it officially began, the study had just 29 participants, according to a federal clinical trials database. Only 22 trial sites were listed on the study’s database entry.
Biogen says the low enrollment was due to a policy decision from Medicare, the government insurance program expected to cover the bulk of patients eligible to receive Aduhelm. In April, Medicare confirmed it would not pay for Aduhelm or other drugs that work like it, unless the patients getting these treatments were enrolled in randomized, controlled clinical trials. ICARE AD is an observational study, not a randomized trial.
Both Biogen and Wall Street analysts predicted that Medicare's policy would sharply limit the number of patients who could ultimately access Aduhelm. Indeed, early sales figures indicate the drug has been prescribed to a tiny fraction of the millions of Alzheimer's patients living in the U.S.
The lack of prescribing has, as a result, made enrolling ICARE AD much more difficult, leading Biogen to shutter the study altogether.
"Unfortunately, because of the national policy for coverage, there will be limited Aduhelm prescription and usage in routine clinical practice and therefore Biogen will not be able to further pursue the study," a company spokesperson wrote in an email to BioPharma Dive.
Participants in the study were meant to be followed for five years, and assessed for changes in cognition and function at regular visits every six to 12 months.
The spokesperson added that Biogen made the decision in mid-May to end ICARE AD early. Around that time, the company announced plans to lay off most of the commercial team supporting Aduhelm. A notice of the study termination was posted on the federal database record of the trial this week.
Biogen's required confirmatory trial, meanwhile, remains ongoing. Named ENVISION, it's slated to enroll around 1,500 patients with mild Alzheimer's or mild cognitive impairment from the disease, who also test positive for the toxic brain protein Aduhelm is supposed to block. ENVISION kicked off earlier this month and should wrap up in four years' time — sooner than the FDA and Biogen had originally agreed to at the time of Aduhelm's approval.