(Bloomberg) -- Eisai Co.’s sales of the Alzheimer’s drug Leqembi in the US are “ahead of expectations” despite the steps required to administer it, said Ivan Cheung, the company’s global Alzheimer’s disease officer.

Eisai and partner Biogen Inc. made their first sales to pharmacies in the US on Jan. 18. The first prescription was written on Jan. 23 and the initial administration of the drug was conducted on Feb. 3, Cheung told reporters and analysts at post-earnings briefing Monday. Patients taking Leqembi are part of a program to support uninsured and under-insured patients, or are paying the full cost out of pocket, he said.  

The fast start runs contrary to an earlier Alzheimer’s treatment introduced by the two companies. That medicine, Aduhelm, faced controversy after it won accelerated approval in 2021. Outside medical experts advised US regulators not to allow the medicine on the market because results from two big trials conflicted on how it impacted brain function. 

Eisai also said it aims to file data on a subcutaneous version of Leqembi to regulators in fiscal 2023.

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