TAKEAWAY: Life science companies should employ strategies to avoid double-patenting in their patent portfolios, including taking advantage of the safe harbor of USPTO restrictions and selecting the patent(s) to be extended by patent term extension (PTE) early in prosecution.

The Federal Circuit recently decided two precedential cases that address important nuances in double-patenting: Novartis v. Breckenridge (Fed. Cir. 2018) and Novartis v. Ezra (Fed. Cir. 2018). These cases help to clarify under what circumstances a patent can serve as a reference for obviousness-type double patenting (ODP).

Double patenting is a judicial doctrine intended to prevent patentees from an unjustified extension of patent rights through multiple patents on the same or closely similar subject matter. Applicants can face ODP rejections in cases of a common inventor or applicant, common ownership, or a joint research agreement. Filing a terminal disclaimer is often the easiest way to overcome the rejection, whereby patentees give up any term that would extend beyond the lifetime of a reference patent. But some patents can be most valuable towards the end of their lifetimes, including those for drugs and medical devices that undergo expensive clinical trials and lengthy FDA regulation. In such cases, patentees can avail themselves of patent term extension (PTE) under 35 U.S.C. § 156 to compensate for the effective loss of patent term due to regulatory delay. Only one patent may be extended by PTE per FDA-approved product.

In the life sciences, a common scenario is to patent the therapeutic or device first, and then file a continuation on related methods of use or formulations. Depending on the prosecution timeline and availability of term extensions, the method or formulation patent could expire before the product patent. In Gilead v. Natco, 735 F.3d 1208 (Fed. Cir. 2014), the Federal Circuit held that a patent’s expiration date is decisive for ODP. That is, a later-filed but earlier-expiring patent on methods of use or formulations can serve as an ODP reference against a patent on the therapeutic or device itself. Notably, the patents in question in Gilead v. Natco were filed after June 8, 1995, when the patent term calculation was changed from 17 years from the issue date to 20 years from the earliest effective filing date by the Uruguay Round Agreements Act (URAA), harmonizing U.S. patent term with that of other countries as part of creating the World Trade Organization. ODP analysis under the pre-URAA regime had focused on the patent issue date.

This was the backdrop for Novartis v. Breckenridge, concerning a Novartis patent on the compound everolimus. The patent was filed under the pre-URAA regime, which provided a 2014 expiration date. (While not relevant to the court’s analysis, Novartis applied for and obtained the maximum 5-year PTE, extending the term to 2019.) The defendants argued that the patent was invalid under ODP over a later-filed, post-URAA divisional on methods of treatment that expired in 2013, before the original expiration date of the compound patent. The Federal Circuit held that the pre-URAA status of the compound patent necessitated a pre-URAA approach to ODP analysis. Because the method patent issued after the product patent, it could not serve as an ODP reference.

Novartis v. Ezra presents similar facts for a pre-URAA patent on the compound fingolimod. While the patent’s original expiration date was in 2014, Novartis applied for, and obtained, 5 years of PTE to extend the patent term to 2019. The defendants argued that the patent was invalid under ODP over a later-filed, post-URAA patent on methods of treatment expiring in 2017. Unlike Breckenridge, the compound patent would have expired before the method patent but for the PTE. The Federal Circuit considered the statutory language and purpose of PTE to find that ODP does not invalidate a patent, so long as the requirements for PTE are met. Importantly, the court observed that ODP could apply to patents extended by PTE if the reference patent expires before the original expiration date of the patent in question.

These cases emphasize the need for a strategy that takes into account the potential for double-patenting issues. Applicants should keep ODP in mind whether or not the examiner raises it. One strategy is to take advantage of the 35 U.S.C. § 121 safe harbor by filing multiple types of claims to prompt a restriction requirement, and filing divisional applications within the scope of the restricted groups. In this way, restricted inventions made the subject of divisional applications cannot serve as ODP references against other inventions subject to the same restriction. Applicants also may wish to cancel claims withdrawn due to a restriction to avoid having them inadvertently rejoined at allowance and giving up the safe harbor protections. Filing terminal disclaimers remains an option to overcome ODP rejections, one that patentees should carefully consider before applying for PTE. Companies should decide which patent(s) to extend early on, in order to anticipate and resolve possible ODP issues well before applying for PTE.