Spain's Faes Farma says it is unsure whether the US partner for its investigational oral allergy drug bilastine, Inspire Pharmaceuticals, intends to continue their pact once their existing agreement runs out at the end of the year.

In a statement to the Spanish Securities and Exchange Commission (CNMV), the Bilbao-headquartered company confirmed that it will complete additional trials of bilastine, as suggested by the US Food and Drug Administration, in the second quarter of 2008. The news, initially disclosed in June, means that Inspire will not pay out $8 million, the first of agreed fees from the $89 million agreement the firms signed last October, until the drug gets approval from the FDA.

The problem is that the deal with Inspire could end on December 1 this year and Faes said in the CNMV statement that it cannot unilaterally resolve issues arising from the said contract. However the Spanish firm also pointed out that it still hopes to fully complete the terms of the Inspire agreement, though the US group has the option to discontinue.

Bilastine is a selective antihistamine receptor antagonist which has successfully completed Phase III trials for the prevention of allergic rhinitis and is expected to be launched in Europe in 2008. Faes said in April that it was close to signing an agreement with an unnamed “multinational pharmaceutical company” to market what many analysts believe is a potential blockbuster but no name has been forthcoming.