(Bloomberg) -- Biogen Inc. was accused by a managed-care provider of illegally boosting sales of its pricey multiple sclerosis drugs by providing them free to patients on a temporary basis and then funneling money to them for co-payments so they can keep taking the medications.The first part of the scheme involves “seeding” the drugs -- Tysabri, Avonex, and Tecfidera -- to multiple sclerosis sufferers who lacked medical insurance, according to the lawsuit filed Friday by Humana Inc.After a few months, Biogen encourages the patients to sign up for government-funded healthcare and then funnels “illegal copayment assistance to those same patients under the guise of unrestricted charitable giving,” Humana said.The money is funneled through a large specialty pharmacy and two medical charities who provide co-pay assistance, according to the suit. “Given the high costs of the MS drugs here, copays can be thousands of dollars for any single patient,” Humana says in the suit.“But they are a tiny fraction of the total expense for the drugs. This means that if the manufacturer pays the copays itself, it can earn a major return from a minor investment.”

The drugs cost $50,000 to $80,000 a year, according to the suit. Biogen didn’t respond after regular business hours to a request for comment.

The case is Humana Inc. v. Biogen Inc., 21-cv-11578, U.S. District Court, District of Massachusetts.

©2021 Bloomberg L.P.