by Dennis Crouch
Merck Sharp & Dohme Corp. v. Microspherix LLC (Fed. Cir. 2020)
The Federal Circuit here affirms the PTAB IPR final determination that Merck failed to prove the Microspherix claims invalid. US9636401; US9636402; US8821835. Microspherix sued Merck — accusing Merck’s implantable contraceptive of infringing. Merck responded with the three IPR petitions.
The patents here cover implantable therapeutic/diagnostic devices that also have a radiopaque marker that helps find the device after insertion. As originally filed, the claims were directed to “brachytherapy” — slow release of radioactive agents to treat cancer. However, the claims were expanded in various continuation applications to broadly claim any “therapeutic, prophylactic, and/or diagnostic agent”
The interesting legal question on appeal has to do with the timing of the asserted prior art reference Zamora. The chart below shows the patent filings in question, and each party argued that the opposing non-provisional applications could not properly claim priority to their respective provisional applications.
Question 1: Does 102(e) (pre-AIA) apply in inter partes review?: 35 U.S.C. 311 limits IPR validity challenges “the basis of prior art consisting of patents or printed publications.” Under 102(e), Zamora’s 2001 non-provisional application became prior art once the resulting patent issued. However, as of its 2001 filing date, the application was neither a “patent or printed publication.” In its decision here, the court simply assumed that 102(e) prior art counts under the IPR statute (as it has done in prior cases as well) See In re Cuozzo Speed Techs., LLC, 793 F.3d 1268, 1281 (Fed. Cir. 2015), aff’d sub nom. Cuozzo Speed Techs., LLC v. Lee, 136 S. Ct. 2131 (2016). Post-AIA 102(a)(2) does not have the same problem because the statute makes clear that it is the patent / published application that is the prior art.
Question 2: Does Zamora’s provisional date allow for further back-dating of the 102(e) date?: Here, the court explains that Zamora would get the 2000 prior art date of its provisional “if it was entitled to the date of the Zamora provisional.” The court quoted Drinkware, LLC v. Nat’l Graphics, Inc., 800 F.3d 1375, 1381 (Fed. Cir. 2015) in explaining that the “‘reference patent is only entitled to claim the benefit of the filing date of its provisional application if the disclosure of the provisional
application provides support for the claims in the reference patent in compliance with’ the written description requirement.” Here, the court noted that 2001 Zamora claimed three options for placement of a radiopaque medium, but one of those was not present in the provisional application. That failure of written decription meant that Zamora’s prior art date was 2001, not Jan. 2000.
Question 3: Does Microspherix’s provisional date work as a priority date?: In considering priority claims, the courts generally operate on a claim-by-claim basis. Thus, in a complex patent family, a single patent may include claims with a variety of priority dates. One problem with our current system is that a patent only tells us the earliest claimed priorty date — not the actual priority date. The actual date is only realized and determined through ex post litigation. Here, Merck argued that some of the claims went beyond the provisional disclosure. On appeal, the Federal Circuit disagreed — explaining that the the written description requirement requires the disclosure to “reasonably convey” possession of the invention.
Here, the particular written description argument focused on the length of the claimed strands that were inserted into a body. The original provisional disclosed a variety of strand lengths, but none of them were longer than 1 cm (10 mm). Some of the patent claims claim strands without any length limitation, and Merck argued that Microspherix was not in possession of such a broad range of strand lengths. On appeal, the Federal Circuit agreed with the PTAB that the description found int he provisional “adequately supports the claimed strand recited in Microspherix’s patent