Based on the available data, I’m not clear and skeptical at this moment,” said Yale professor Reshma Ramachandran. “I would have a lot of reservations about prescribing this. “I do think one of the things that have given us a lot of pause…is the risk and the death issue. Nobody wants to be the clinician prescribing a drug that could potentially harm our patients,” she added.” That is just the tip of the problem.

Patients, doctors, and insurers still have to decide whether using the drug to slow the disease’s progression is worth the associated hassle, cost, and safety risks. These decisions will ultimately decide the overall uptake and commercial success.

Leqembi, a new Alzheimer’s drug developed by Eisai and Biogen, may have passed muster with the FDA last week, but experts say it’s still an open question how much it will improve the quality of patients’ lives.

Leqembi’s accelerated approval was based on data showing patients taking the drug saw a statistically significant reduction in brain amyloid plaque that’s thought to contribute to the disease. But data published in November — which was not used for the accelerated approval — found that the drug also provides a clinical benefit. But clinicians caution that such a modest benefit may not be very noticeable to patients and comes with significant tradeoffs.

It also requires patients to overcome significant hurdles before starting treatment, including testing to confirm they have a buildup of amyloid and an MRI within the last year. The treatment consists of one-hour infusions every two weeks, and patients must receive MRIs throughout the process.

The upfront requirements for patients who do want to receive the drug will likely present broad challenges to the health system.

What’s not being discussed is Biogen’s previous reputation with their failed Alzheimer’s drug. Will physicians welcome Biogen reps with open arms?