UCB has suffered a setback at the hands of US regulators who have issued a not approvable letter for lacosamide, its treatment for diabetic neuropathic pain in adults.

The Belgian company is keeping its cards close to its chest as to why the US Food and Drug Administration has turned down its New Drug Application for Vimpat (lacosamide). Eimear O'Brien, global CNS communications manager for the Brussels-headquartered firm simply told PharmaTimes World News that UCB is to “seek clarification” from the agency in order to determine what extra information may be required to obtain marketing approval.

Vimpat, the first agent of its kind to be clinically studied for the treatment of DNP, which is often characterised by a stabbing or burning sensation in the legs, feet and hands, has been under review at the European Medicines Agency since August last year. Ms O’Brien declined to speculate as to when the latter body will reveal its final decision.

However Vimpat has also been filed in Europe and the USA for the adjunctive treatment of partial onset seizures in adults with epilepsy and last month the EMEA’s Committee for Medicinal Products for Human Use granted lacosamide a positive opinion in that indication. UCB is also considering whether to file the drug as a potential treatment for fibromyalgia.

The bad news was announced after the markets closed yesterday but this morning UCB’s shares had fallen 12.5% by 9am UK time to 20.46 euros. Vimpat is seen as vital, along with the Parkinson’s disease/restless legs syndrome treatment Neupro (rotigotine) and the anti-tumour necrosis factor alpha drug Cimzia (certolizumab pegol) in plugging the gap in sales resulting from the loss of patent protection on the allergy drug Zyrtec (cetirizine) last year and the antiepileptic Keppra (levetiracetam) next year.