Eisai filed litigation against the US Drug Enforcement Agency (DEA) Monday in a US Court of Appeals to compel the agency “to promptly schedule” its epilepsy drug Fycompa (perampanel), which was approved by the FDA in October last year. The drugmaker alleges the DEA “unreasonably” and “egregiously” delayed the scheduling of Fycompa, for which the FDA submitted its scheduling recommendation in January.

The company added that “the DEA’s delay continues to harm Eisai” even though it demonstrated to the FDA’s satisfaction that Fycompa was safe and effective when used according to its labelling. Eisai noted that the scheduling process once a new chemical entity receives FDA clearance has lengthened from an average of 49 days between 1997 and 1999, to an average of 237 days between 2009 and 2013. However, the drugmaker’s obesity drug Belviq (lorcaserin) was not classified by the DEA until 315 days after FDA approval.

Allen Waxman, general counsel for Eisai, mentioned that it expected the DEA to have completed its scheduling process in time to permit a July 1 launch, which he says would have allowed the therapy to generate sales of around $8 million by the end of August. He indicated that the drugmaker made “frequent calls” to the agency and written letters to receive updates on the process. In a letter provided to Eisai last week, DEA Chief Counsel Wendy Goggin mentioned the agency is in the “final stages” of the scheduling process, although she could not specify a timeline or deadline.

The Pharmaceutical Research and Manufacturers of America (PhRMA) also expressed “serious concerns” about the delayed scheduling and called on the DEA to conduct “expeditious” reviews. “Excessive delays in DEA review can not only negatively impact patient access, but also discourage biopharmaceutical research companies from pursuing the types of medical innovation that may lead to medicines requiring DEA scheduling,” remarked PhRMA general counsel Mit Spears. A DEA spokesperson declined to comment on the matter due to the pending litigation.

Separately, Eisai asked the FDA in late July to grant Fycompa and Belviq their five years of marketing exclusivity starting on the date that the DEA’s classifications take effect, rather than from the day of FDA approval. An agency spokeswoman said the FDA is reviewing the petition and will respond directly to Eisai.