Federal Circuit Affirms Prometheus’s Alosetron Use Patent Was Obvious

On November 10, 2015, in Prometheus Labs v Roxane Labs (Fed Cir 2015), the Federal Circuit upheld the District Court’s decision that Prometheus’s US Patent No. 6,284,770 (the ‘770 patent) was invalid for obviousness. The asserted claims of the ‘770 Patent are directed to a method of treating diarrhea-predominant female irritable bowel syndrome (IBS-D) with alosetron (Prometheus’s LOTRONEX®).

The District Court had found that the claims of the ‘770 patent were obvious because the claimed elements were found in the prior art with insubstantial differences and also when considering the secondary considerations.  In particular, a prior genus patent taught treating IBS with alosetron but not particularly treating female IBS-D.

On appeal, the Federal Circuit recognized that the genus-species distinction may have particular relevance in the field of personalized medicine and that a particular species with new limitations may be patentable (e.g. species effective with respect to one patient subset and ineffective or harmful to another subset), despite the existence of a prior art genus disclosing the treatment to patients generally.  Nevertheless, the Federal Circuit agreed with the District Court that the asserted species claims in this case were obvious, as the new limitations were directed to a known type of IBS and to treating the gender (female) that predominantly experiences IBS and the prior art suggested that females would have a greater response to the proposed treatment than males.  The Federal Circuit also agreed with the District Court’s analysis of secondary considerations, in particular that the commercial success could not be attributed to the ‘770 patent but rather was due to Prometheus’s marketing and sales practices.