Optimer Pharmaceuticals, Inc. ( OPTR - Analyst Report ) recently announced that it is set to receive €10 million in milestone payments from Astellas Pharma, Inc. for the first sales of Dificlir (fidaxomicin) tablets in Europe. As per the 2011 agreement, Astellas was granted the rights to develop and commercialize Dificlir in Europe and certain other countries.

Optimer is eligible to receive milestone payments of up to $224 million including a $68 million upfront cash payment as per the 2011 collaboration and license agreement with Astellas. Astellas will pay tiered double-digit royalties on net sales of Dificlir. As per the deal, Astellas will bear all costs related to the development, manufacturing and commercialization of the product in the covered areas.

Dificlir was approved in Europe in December 2011 for the treatment of adults with clostridium difficile infections (CDI). The product is sold in the US under the trade name, Dificid, for treating patients suffering from clostridium difficile-associated diarrhea (CDAD) and is currently under priority review in Canada. In the first quarter of 2012, Optimer recorded Dificidsales of $14.4 million.

In March 2012, Optimer entered into another collaboration and license agreement with Astellas Japan. Astellas was granted exclusive, royalty-bearing license and intellectual property to develop and commercialize Dificlir in Japan.

Our Take

The sole marketed product at Optimer is Dificid. Even though the European approval of the drug should aid sales, we remain concerned about Optimer’s dependence on a single product for growth. We believe the company lacks a decent pipeline candidate.

Currently, we have a Neutral stance on Optimer in the long run. The company carries a Zacks #3 Rank (“Hold” rating) in the short run.