Wednesday, January 15, 2014

Patent for Form I Efavirenz Not Infringed on the Facts

Bristol-Myers Squibb & Gilead Sciences v Teva / efavirenz (NOC) 2014 FC 30 Barnes J
             2,279,198 / efavirenz / ATRIPLA

In this NOC proceeding Barnes J dismissed Merck’s application for an order of prohibition in respect of Teva’s generic version of ATRIPLA on the basis that Merck had failed to establish infringement. The decision turns entirely on the facts, and raises no new issue of law.

ATRIPLA is an anti-viral used in treating HIV/AIDS which contains efavirenz as one of its three active ingredients. The ‘198 patent claims a particular crystalline form of efavirenz, Form I, and a process for producing it. It was common ground that Teva’s starting medicinal compound, “Form Teva,” does not contain Form I efavirenz [7]. It was also undisputed that
Form I is the most stable crystal form of efavirenz and, “with the input of sufficient energy, all metastable crystal forms of efavirenz, including Form Teva, will convert to Form I” [9]. The question on infringement is “whether Form Teva will convert in some measure to Form I during Teva’s tablet manufacturing process” [7]. In particular Barnes J held that “Claims 1 and 2 would be infringed if any detectable amount of Form I is found in Teva’s efavirenz product. It does not matter that the amount may be so small that it provides no medicinal advantage” [16].

The resolution of this question turned on the facts. Merck manufactured a sample of the Form Teva efavirenz and asked a Dr Taylor to subject it to processing intended to mimic the commercial manufacturing process. Dr Taylor’s process resulted in a very small amount of Form I being produced [35] and “The central issue in dispute between the parties is whether the mortar and pestle grinding carried out in Dr. Taylor's laboratory is a reliable proxy for the [omitted] that Teva employs in its manufacturing process” [38]. Barnes J concluded that the process used by Dr Taylor was sufficiently different from Teva’s tabletting process that it could not be inferred that any amount of Form I would be present in Teva’s tabletted product [45]. The process used by Dr Taylor would result in significantly more energy being put into the product than commercial tabletting, with the result that Form I was less likely to be created during Teva’s process. Consequently, Merck failed to meet its burden of proving that Teva's tablets would infringe [46].

A couple of notes. The applicants were Bristol-Myers Squibb & Gilead Sciences, the licensees, and Merck, the patentee. Barnes J used “Merck” as including all the applicants, which is why the decision refers to Merck while the abbreviated style of cause does not.

The ‘198 patent had previously been before Barnes J in Bristol-Myers Squibb Co. v. Mylan / efavirenz (NOC) 2012 FC 1142, which concerned SUSTIVA, which contains only efavirenz, in contrast to the ATRIPLA combination product. The same question of infringement was at issue in the SUSTIVA decision, and Merck lost there as well, but the evidence before Barnes J was substantially different and the reasoning was not the same. SUSTIVA is blogged here in respect of the ‘198 patent and here in respect of the other patent at issue.

Teva’s NOA also alleged the ‘198 patent was invalid, as did Mylan in SUSTIVA. Barnes J did not find it necessary to address these allegations in light of his conclusions regarding infringement, but he did say that "Teva presented a stronger case for invalidity on the ground of obviousness than was before me in the Mylan proceeding” [6].

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