On June 11, 2015, the Patent Trial and Appeal Board (PTAB) denied a petition for Inter Partes Review (IPR) filed by Cepheid against patent owners Roche Molecular Systems and Mayo Foundation for Medical Education and Research in connection with US patent number 5,643,723 (Case IPR2015-00255). The ’723 patent “is directed to methods based on the polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis (MTB) and concurrent determination of its drug susceptibility, utilizing the appropriate oligonucleotide primers.” Claim 1 is representative.
1. A method for detecting Mycobacterium tuberculosis in a biological sample suspected of containing M. tuberculosis comprising:
(a) subjecting DNA from the biological sample to polymerase chain reaction using a plurality of primers under reaction conditions sufficient to simplify a portion of a M. tuberculosis rpoB gone to produce an amplification product, wherein the plurality of primers comprises at least one primer that hybridizes under hybridizing conditions to the amplified portion of the gone at a site comprising at least one position-specific M. tuberculosis signature nucleotide selected, with reference to FIG. 3 (SEQ D NO:1), from the group consisting :
a G at nucleotide position 2312,
a T at nucleotide position 2313,
an A at nucleotide position 2373,
a G at nucleotide position 2374,
an A at nucleotide position 2378,
a G at nucleotide position 2408,
a T at nucleotide position 2409,
an A at nucleotide position 2426,
a G at nucleotide position 2441,
an A at nucleotide position 2456, and
a T at nucleotide position 2465; and
(b) detecting the presence or absence of an amplification product, wherein the presence of an amplification product is indicative of the presence of M. tuberculosis in the biological sample and wherein the absence of the amplification product is indicative of the absence of M. tuberculosis in the biological sample.
The patent also includes product claims directed towards primers for use in this diagnostic method.
The petition for IPR was prompted by a lawsuit that Roche Molecular Systems filed on July 16, 2014, alleging that Cepheid’s XpertMTB/RIFAssay infringes the patent (Roche Molecular System v. Cepheid, Docket No. C-14-3228, N.D. Cal.). The district court stayed the litigation on January 7, 2015, pending the outcome of the IPR. The magistrate judge that entered the stay noted that the PTAB has invalidated at least one patent claim in approximately 84% of its final written decisions, and that this “data reflects a relatively high probability that at least some of the claims at issue in this litigation will be selected for IPR and eventually canceled. Accordingly, a stay has the potential to greatly simplify these Court proceedings, weighing in favor of a stay.”
Now that the stay will presumably be lifted and the infringement litigation resumed, the issue of patent eligibility will likely take center stage. IPR is limited by statute to invalidation challenges based on prior art, i.e., for lack of novelty or obviousness, and thus patent ineligibility under 101 cannot be raised as a basis to invalidate claims in IPR. However, the patent claims at issue in this case clearly implicate patent eligibility concerns. Cepheid has already raised the issue of patent eligibility in the district court prior to the stay, arguing that the patent “contains claims that are not patent-eligible in light of the Supreme Court’s recent significant decision [in Myriad] that a naturally occurring DNA segment is a product of nature and not patentable.”While Myriad calls into serious question the validity of the primer claims, it is the Supreme Court’s decision in Mayo v. Prometheus, and the Federal Circuit’s recent interpretation of Mayo in Ariosa, that will provide Cepheid with its strongest basis for arguing that the method claims are patent ineligible. Thus, somewhat ironically, there is a good change that one of Mayo’s own patents will be brought down by the Mayo decision.