A Non-limiting Preamble Strikes Again

The PTAB found that methods for treating patients using the chemotherapy drug Jevtana were unpatentable in light of references that taught administering the drug, but were silent on the drug’s clinical efficacy.¹ The Board disagreed with Aventis that the claim’s preamble required clinical efficacy, and indeed found the preamble to be non-limiting.

Representative independent claims of the Jevtana recite:

1. A method for treating a patient with prostate cancer that has progressed during or after treatment with docetaxel, comprising administering to said patient a dose of 20 to 25 mg/m2 of cabazitaxel, or a hydrate or solvate thereof, in combination with a corticoid.
27. A method of increasing the survival of a patient with a castration resistant or hormone refractory, metastatic prostate cancer that has progressed during or after treatment with docetaxel, comprising administering a dose of 20 to 25 mg/m2 of cabazitaxel, or hydrate or solvate thereof, to the patient in combination with prednisone or prednisolone. .²

Aventis argued that claim 1’s preamble, “a method for treating,” should be construed to mean “a method that produces a therapeutic effect in a patient” and that claim 27’s preamble, “a method of increasing the survival for a patient,” should be construed to mean “a method that prolongs the life of a patient as compared to no treatment or palliative treatment, where that method has been demonstrated to provide a statistically significant increase in overall survival.”³ In each instance, the Board maintained its construction of the preamble as non-limiting for the reasons given in its Institution Decision.⁴

Whether the preamble is a claim limitation was important to the obviousness determination. The cited art taught clinical trial protocols that were found to meet all the non-preamble claim limitations, but did not teach clinical efficacy. Aventis argued that the unpredictability associated with this class of drugs precluded a finding of a reasonable expectation of success. The Board disagreed, emphasizing that the claim recited no requirement for clinical efficacy not only because of the non-limiting preambles, but also because reference to clinically effective amount had been deleted from the claims during prosecution.⁵ (“As indicated by patent applicant’s final claim language, achieving a clinically effective treatment is not a limitation of the ‘592 method claims.”).

Aventis argued that secondary indicia outweighed the obviousness of the invention. The PTAB again disagreed. For instance, regarding Jevtana’s commercial success, the Board noted that several patents covered the drug, some of which had expired. It said that Aventis failed to explain why commercial success of Jevtana was attributable to the methods of treatment in this patent, rather than other Orange Book listed patents.