FOREST LABORATORIES, LLC v. SIGMAPHARM LABORATORIES, LLC
- Mar 14 2019 |
- Category: CAFC Updates
Sigmapharm Laboratories and others (“Appellants”) filed Abbreviated New Drug Applications (ANDAs) seeking to market generic versions of Saphris, a sublingually administered, atypical antipsychotic containing asenapine maleate sold by Forest Laboratories. Forest sued for patent infringement, asserting that Appellants’ proposed generic products would infringe certain claims of U.S. Patent No. 5,763,476. Following a bench trial, the district court held Appellants had not established the claims to be invalid and held Forest had not established infringement. Appellants appeal the district court’s construction of claim 1 and its determination that the claims have not been established to be invalid. Forest cross-appeals, arguing the district court’s finding of no infringement is clearly erroneous. The CAFC holds the district court properly construed claim 1 to be limited to buccal and sublingual formulations and does not, therefore, reach Appellants’ validity challenges based on its proposed alternative construction. On the issue of motivation to combine, the CAFC notes that the district court failed to make an express finding as to whether compliance concerns for patients with trouble swallowing would provide a motivation to combine prior art that teaches oral formulations of asenapine with sublingual formulations of other drugs and thus remands for the district court to address this question. The CAFC further holds that: 1) while the fact that existing antipsychotics had debilitating negative side effects which are reduced in Saphris may not be a particularly strong demonstration of long-felt need, the district court did not clearly err in finding such need weighs in favor of non-obviousness; 2) the district court erred in its analysis of unexpected results because at the time of the claimed invention, a person of ordinary skill could not have been surprised that the sublingual route of administration did not result in cardiotoxic effects because the person of ordinary skill would not have been aware that other routes of administration do result in cardiotoxic effects; and 3) while Appellants cite evidence that the properties of asenapine free base make it unsuitable for use in pharmaceutical development, the district court did not clearly err in finding that Appellants had not established invalidity for lack of written description by clear and convincing evidence. Finally, because the district court erred in treating “excitation” as being limited to “excitation disorders,” the CAFC vacates the district court’s finding of non-infringement, construes “excitation” to refer to a symptom, and remands for the district court to assess infringement in light of the CAFC’s construction.