After a full FDA approval last week triggered Medicare coverage of Eisai and Biogen’s Leqembi, doctors are still trying to work out the logistics of testing and reimbursement. But at least two experts remain positive about the drug’s efficacy and safety profile.The new Leqembi label carries a boxed warning about the risks of brain bleeding and swelling known as amyloid-related imaging abnormalities (ARIA). But two Alzheimer’s opinion leaders suggested the side effect is manageable typically by extensive monitoring in the first six months, Leerink Partners analysts said in a Wednesday note.

But the two experts were split on whether they intend to treat patients with the ApoE ε4 genetic trait. The FDA label requires testing for that biomarker before initiating Leqembi to inform the risk of ARIA. While one expert felt comfortable giving Leqembi to APOE4 carriers as long as the patients are informed of the risk, the other was against the idea, according to the Leerink team.

Overall, both experts believed that the phase 3 Clarity AD data have proven Leqembi’s benefit. The two pointed to a greater treatment effect over time in the data, suggesting Leqembi may have greater benefit with longer treatment duration.

Discontinuation will likely be driven by side effects or lack of treatment effect, the two experts said. But both argued that a maintenance dosing regimen should be developed. Eisai doesn’t have data on whether or when patients can stop treatment. And U.S. lawmakers and government officials have raised concerns over Leqembi’s cost burden, especially if the $26,500-per-year drug means endless treatment.

By comparison, Eli Lilly’s rival drug donanemab could offer doctors the ability to stop dosing. One of the experts view that as an advantage. But the design is not a reflection of donanemab’s efficacy; rather, chronic treatment of the Lilly drug may simply not be feasible because patients tend to form neutralizing agents that could make the antibody ineffective.

The Lilly drug has also shown it could slow cognitive decline in a phase 3 trial, and both experts were positive about its overall profile as well, according to Leerink.

All told, one expert slightly favors Leqembi over donanemab, with no strong distinction between the two. The other one suggested he will use Leqembi more for younger patients who would require chronic use while allocating older patients to donanemab.

Leqembi got its initial accelerated approval in January with limited Medicare coverage. Now, the Centers for Medicare & Medicaid Services has opened a registry as a reimbursement pathway.

Doctors are still learning the ropes of how to properly screen and select patients, administer the drug, monitor for ARIA and seek reimbursement. Paul Schulz, M.D., a neurologist at UTHealth in Houston, told Bloomberg he will use Leqembi on a few patients to make sure reimbursement isn’t a problem before introducing the drug to more patients.

Eisai is amping up its commercialization activities spanning sales reps, medical affairs liaisons and reimbursement agents, Alex Scott, Eisai’s executive vice president of government affairs, said in a recent interview with Fierce Pharma.

“This is not a fast build,” Scott said. “This is a slow and careful build that we’re being very conscious about.”

Source: cnbc.com