Brand manufacturer Acorda is fending off at least six different generic challenges filed in the last few weeks to its multiple sclerosis drug Ampyra.

Acorda confirmed the first Paragraph IV ANDA against Ampyra (dalfampridine) in a June 26 statement that vowed to defend the company’s intellectual property rights against all challenges.

As of Friday, Acorda had filed separate infringement lawsuits in the U.S. District Court for the District of Delaware against the following ANDA filers: Actavis on June 24, Aurobindo Pharma on June 26, Roxane Laboratories on July 1, Alkem Laboratories on July 2, Accord Healthcare on July 7, and Mylan on July 9.

Most of the ANDA filers are challenging all five of Ampyra’s patents: the ’938, ’826, ’437, ’703 and ’685, based on court filings.

The last of Ampyra’s patents expires in 2027, according to the Orange Book. An Acorda spokesman said the FDA was able to start accepting challenges to the patents in January. “The timing of the ANDA filers is impacted by a number of factors which include the FDA review timelines,” Jeff Macdonald said.

Acorda is joined in the lawsuit by Irish drugmaker Alkermes, which owns the ‘938 patent and has licensed it exclusively to Acorda, according to court filings. Acorda owns the rest of the patents.

Ampyra is the first drug authorized for helping MS patients to improve walking, and has Orphan Drug status that extends until 2017, Acorda has said. The drug also has new chemical entity exclusivity until January 2015, according to the Orange Book.

The drug, which is Acorda’s flagship product, generated net revenues of $72.5 million in the first quarter of this year, according to the firm’s most recent earnings statement. — Bryan Koenig

Originally appeared in Drug Industry Daily, the pharmaceutical industry’s number one source for regulatory news and information. Click here for more information.