The FDA has denied citizen's petitions filed by Eisai Inc. and UCB Inc. to change how the agency sets the five-year exclusivity clock for new chemical entities (NCEs) that require Controlled Substances Act (CSA) scheduling, stating that the approach the petitioners suggested is unworkable under current regulations.

Growing delays in the time it takes the U.S. Drug Enforcement Administration (DEA) to schedule new prescription drugs – a required step before starting sales – is impeding timely patient access to important therapies, the companies and their allies have argued. (See BioWorld Today, April 9, 2014.)

The delay cuts into the fixed five-year exclusivity window granted to NCEs, shortening the amount of time during which a company can sell its drug before facing competition, Eisai said in its July 2013 petition. Citing similar concerns, UCB pointed to Eisai's rationale in its own citizen's petition, seeking to extend exclusivity for its epilepsy drug, Vimpat (lacosamide), in November 2013. To resolve the issue, Eisai proposed that the FDA should look at the effective approval date – when the DEA finalizes the scheduling of a drug – as the exclusivity trigger.

In the FDA's consolidated response to the petitions, the agency declined to make changes and said that "the legal and regulatory framework on exclusivity and drug approvals contemplate only a single date of approval for determining when exclusivity begins for an NDA . . . the date that FDA completes its review and issues an approval letter."

In their petitions, both Eisai and UCB pointed out that delays in DEA scheduling had eaten into exclusivity periods. Eisai, for example, gained approved for its epilepsy drug Fycompa (perampanel) CIII in October 2012.

But the drug wasn't launched until January 2014 because the DEA did not schedule the drug until December 2013, after Eisai took legal action. A similar delay cost Eisai and partner Arena Pharmaceuticals Inc. as much as a year of market exclusivity for obesity drug Belviq (lorcaserin), the company said in its July petition.

UCB also said it stood to lose out. With at least 16 abbreviated new drug applications seeking FDA's approval to market generic versions of Vimpat, it was also eager to gain extended exclusivity by pushing the start date of its five-year window ahead to compensate it for the 223 days it "lost" pending CSA scheduling.

In declining to make changes, the FDA took issue with Eisai's argument that Congress intended sponsors to enjoy a full five years of NCE exclusivity, starting once a sponsor is able to begin marketing.

"Congress tied the start of the exclusivity to the date of approval, not to the date of first marketing of the product," the FDA wrote, seeming to suggest that if legislators wanted things done differently, they would have said so.

Some legislative change may be in store. The Improving Regulatory Transparency for New Medical Therapies Act, introduced as H.R. 4299, sponsored by Rep. Joseph Pitts (R-Pa.), would give the DEA 45 days after receiving a U.S. Health and Human Services recommendation to pass an interim final rule scheduling a new drug, but will likely face resistance in an environment in which current DEA review can take up to 11 months, depending on the drug, and additional resources to speed up the process are scarce.

In concluding the denial, FDA Commissioner Margaret Hamburg wrote that the "FDA understands that petitioners have lost valuable marketing time during the five-year NCE exclusivity period," but reiterated the agency's stance that the legal and regulatory framework on exclusivity and drug approvals "contemplate only a single date of approval for determining when exclusivity begins for an NDA."

It's unclear what will come next. "From a policy perspective," wrote the the Pharmaceutical Research and Manufacturers of America in a March letter to the agency, the "FDA's apparent policy decision to calculate NCE exclusivity periods for controlled substances using the date of the approval letter – yet before legal marketing is allowed – significantly devalues the incentives that Congress created to reward innovation, which will harm the public health."

If Eisai, UCB or another similarly situated company feels that the current process devalues its incentives enough, it could take the matter to court. But neither company has indicated a plan to do that just yet. When contacted by BioWorld Today, UCB declined to comment. Eisai did not respond to a request for its take on the letter.