Recently, the PTAB denied Gilead Sciences, Inc.’s (Gilead) request to institute an inter partes review of two patents relating to HIV-prevention, U.S. Patent No. 9,044,509 (the ’509 patent) and U.S. Patent No. 9,579,333 (the ’333 patent). One key reason for the denial was because Gilead failed to adequately address unexpected results in its Petition.

The ’509 and ’333 patents are directed to a prophylactic combination therapy of emtricitabine (“FTC”) and tenofovir disoproxil fumarate (“TDF”) for treating HIV. During the prosecution of the patent, the examiner rejected the then-pending claims as obvious. In response, the applicant presented evidence of unexpected results using post-filing publications. The applicant thereafter discussed the unpredictability of the HIV art. The examiner noted after the interview that the “claims are allowable in view of the high unpredictability of chemoprophylaxis against HIV infection and the supe[r]ior and unexpected results shown in the application and exhibits.”  In the “statement for reasons for allowance” the examiner  noted the “the record has shown the claimed combination has clinically significant results, which would have not been expected in the view of the prior art as a whole.” Thus, the unexpected results played a critical role in the allowance of the claims.

Gilead failed to address the unexpected results in its Petitions. Gilead instead made conclusory statements about the unexpected results simply stating, “there are no unexpected results because there is no nexus to the invention.” The PTAB found the statements to be insufficient. The PTAB acknowledged that it sometimes “puts off” exploration into alleged indicia of nonobviousness, especially when the indicia are raised for the first time in the patent owner’s preliminary response. The PTAB clarified, however, the same timing does not apply when specific evidence of unexpected results “prompted allowance of the challenged claims.”

This decision emphasizes the importance of petitioners addressing objective indicia of nonobviousness in their petitions, especially when the issue was addressed during prosecution and provided a basis for allowance.