Mometasone hydrate (NASONEX) patent valid but not infringed

mometasone furoate monohydrate

On June 15, 2012, the District Court for the District of New Jersey released its redacted opinion in litigation between Schering and Apotex involving mometasone furoate monohydrate (NASONEX) and US. Patent No. 6,127,353.  The ‘353 patent is generally directed to the monohydrate form of mometasone furoate and aqueous nasal sprays containing the same.

 Non Infringement

In its infringement arguments, Schering did not contend that Apotex used the claimed monohydrate at the time of manufacture, but rather that the anhydrous form of mometasone furoate in Apotex’s proposed product converts to the claimed monohydrate within the two year shelf-life of Apotex’s product. The primary issue at trial was whether this conversion from the anhydrous form to the patented monohydrate occurred.  Whereas Schering’s expert found that conversion begins to occur as soon as the Apotex ANDA product is manufactured, Apotex’s expert provided evidence that the “Apotex formulation would be stable against conversion for around 800 years.”  The Court accepted Apotex’s criticisms of how certain samples were handled by Schering’s expert and concluded that Schering had failed to demonstrate infringement on a balance of probabilities in respect of experimental samples that had been shaken or vortexed.  In respect of the remaining samples, the Court concluded that Schering’s analysis of the x-ray powder diffraction (XRPD) patterns, relying on only one or two XRPD peaks, “was insufficient upon which to find a match” to the XRPD pattern depicted in Figure 2 of the ‘353 patent.

Schering’s infringement theory also sought to rely on three other items that were supportive of conversion to the monohydrate: (1) preferred orientation; (2) Raman spectroscopy and (3) an XRPD report produced by a close Apotex affiliate that, according to Schering, showed conversion in several mometasone furoate formulations within seven weeks of production.  The Court gave little weight to Schering’s preferred orientation theory and Raman spectroscopy testing, the latter of which is not mentioned in the ‘353 patent.  The Court concluded that while the XRPD report prepared by the Apotex affiliate was relevant, the report was not supported by any first hand evidence by a person performing or overseeing the testing and did not add much weight to the evidence of the Schering expert in light of Apotex’s criticisms.

Having concluded that Schering had failed to carry its burden on a preponderance of evidence, the Court dismissed Schering’s infringement claim.

Validity – Anticipation

While the Court concluded that Apotex had waived the issue of anticipation by failing to raise this issue in the pretrial order, it also found that Apotex had failed to demonstrate, on the clear and convincing standard, that an earlier patent directed to mometasone furoate anticipates the ‘353 patent.  The Court concluded that Apotex was not able to rebut evidence provided by the patentee to the USPTO that infrared testing of the compound generated during the development of the prior art compound demonstrated that that the prior art compound was not a hydrate.  Further, as the prior art patent did not disclose a monohydrate it was not subject to an analysis under section 102(b).

Validity – Obviousness

Apotex’s obviousness attack was based on the reference cited for anticipation and four additional prior art documents that disclose compounds structurally similar to mometasone furoate. The Court accepted Schering’s position that the skilled person would not need to have a specific experience in the development of aqueous nasal suspensions and concluded that Apotex had failed to meet their burden to establish that the skilled person would have been motivated to develop a nasal spray of mometasone furoate, in part because of the uncertainty in the liver metabolism of mometasone furoate.  Having determined that Apotex had failed to establish a prima facie case of obviousness, the Court concluded that there was no need to review evidence of the secondary indicia of obviousness.

A copy of the Court’s redacted opinion may be found here.