In 17 suits against FDA in the last two years, firm seeks to block generics of its sleep-wake disorder drug and gain a jet lag indication. CEO Mihael Polymeropoulos tells the Pink Sheet that FDA has retaliated against Vanda for its first suit challenging a partial clinical hold on another drug.

More sponsors are submitting applications around the same time requiring the agency to make complicated decisions about exclusivity and whether approval of subsequent applications is barred, FDA attorney says.

Lawsuit argues FDA wrongly determined that Avadel’s Lumryz is ‘clinically superior’ to Xywav because of once-nightly dosing. FDA’s Division of Neurology revised its initial opinion based on views of CDHR’s sleep team and additional input from the agency’s orphan drug office.

US FDA will continue to tie orphan exclusivity to uses or indications for which the drug was approved. Attorneys say this buys agency time to sort out complex policy and legal questions and continue to seek legislative fix. Additional litigation is also possible, as happened in Depomed case.