Amgen’s Enbrel (etanercept), a blockbuster biologic treatment for a number of autoimmune diseases, including rheumatoid arthritis and psoriasis, has been an attractive target for biosimilar makers. Sandoz, the maker of Zarxio (filgrastim-sndz), the only biosimilar launched in the US to date, is also first in line with an Enbrel biosimilar in the US. Last October, Sandoz announced that FDA accepted its regulatory application for a proposed Enbrel biosimilar for review. Sandoz is seeking marketing approval for all of Enbrel’s medical indications. The European Medicines Agency (EMA) also accepted Sandoz’s application for review last year. But Sandoz will not be first with a biosimilar of Enbrel in Europe. In January 2016, Biogen and Samsung Bioepis secured marketing approval for their biosimilar from the European Commission, marking the first approval of an Enbrel biosimilar in Europe.

In the United States, Sandoz’s proposed Enbrel biosimilar is governed by the US biosimilars statute, the Biologics Price Competition and Innovation Act of 2009 (BPCIA). Sandoz initially attempted to bypass the BPCIA’s patent dispute resolution procedures and to seek a declaratory judgment that two patents owned by Hoffman-La Roche and exclusively licensed to Amgen were invalid, unenforceable, and would not be infringed if Sandoz were to market a biosimilar of Amgen’s Enbrel. Sandoz brought its lawsuit in 2013, long before submitting its regulatory application to FDA. The district court dismissed the case on jurisdictional grounds, among others. The Federal Circuit affirmed the dismissal of Sandoz’s suit noting that it had never found a case or controversy prior to the filing of a regulatory application with FDA.

One of the two patents at issue in Sandoz’s dismissed complaint was later challenged before the Patent Trial and Appeal Board (PTAB). In August 2015, a few months prior to the acceptance of Sandoz’s regulatory application for review by FDA, hedge fund owner Kyle Bass jumped into the game and challenged one of the two patents in a petition for inter partes review (IPR). In proceedings before the PTAB, unlike those in federal court, a case or controversy is not required to litigate the validity of a patent, making such challenges possible. In March 2016, the PTAB rejected the challenge to the patent and did not institute IPR on any of the challenged claims.

In February 2016, shortly before the denial of the petition for IPR, Amgen (along with Hoffman-La Roche and Immunex) sued Sandoz on that patent and four others that protect Enbrel. Three of the five patents relate to methods of treating psoriasis and/or psoriatic arthritis by administering etanercept and were not part of Sandoz’s 2013 lawsuit. One only issued in 2014. The complaint states that Amgen has an exclusive licensee or sublicense under all of the patents. Plaintiffs sued after Sandoz allegedly cut short the BPCIA’s patent dispute resolution procedures triggered by the acceptance of its regulatory application for review.

In their complaint, Plaintiffs allege that Sandoz is “piggybacking on the fruits of [their] trailblazing efforts” while seeking to avoid the obligations imposed by the BPCIA. The BPCIA states that the abbreviated Biologics License Application (aBLA) and any other information describing the processes to manufacture the proposed product are to be provided in 20 days from acceptance of the aBLA for review. 42 U.S.C. § 262 (l)(2)(A). The complaint states that although Sandoz provided its aBLA and manufacturing information to Immunex, a subsidiary of Amgen Inc, in that time frame (in October 2015), Sandoz did not provide the aBLA in unaltered form, with all associated data, until afterwards. According to the complaint, Sandoz’s disclosure of manufacturing information was also incomplete and Sandoz provided further information in November 2015.

The complaint states that although Plaintiffs believed Sandoz did not fully comply with 42 U.S.C. § 262 (l)(2)(A) given its late disclosures, Immunex provided Sandoz with a list of the patents for which a claim of infringement could be asserted. 42 U.S.C. § 262 (l)(3)(A). The complaint goes on to say that in January 2016 Sandoz provided “even more” information relating to the manufacture of its product. On the same day, Sandoz also responded with its patent contentions under 42 U.S.C. § 262 (l)(3)(B) but stated that it was “waiving” its right to receive contentions from Immunex, that further BPCIA procedures, i.e., 42 U.S.C. § 262 (l)(4) and (5) were “unnecessary,” and that it “agree[d]” to be sued under the patents in Immunex’s list. (Sandoz took a similar approach in its lawsuit with Amgen involving Sandoz’s proposed biosimilar of Neulasta.) The complaint states that Sandoz also “insisted” that Immunex file an immediate patent infringement suit pursuant to 42 U.S.C. § 262 (l)(6) within 30 days, by February 26, 2016. 42 U.S.C. § 262 (l)(6) requires suit within 30 days after the completion of 42 U.S.C. § 262 (l)(4) or (5), the selection of the patents to be litigated immediately in order to be able to recover lost profits damages or obtain an injunction. Although those procedures were not completed, Plaintiffs filed this patent infringement suit on February 26 in the District of New Jersey as requested by Sandoz.. The case is Immunex Corp. et al. v. Sandoz Inc. et al., 16-cv-01118-CCC-JBC (D.N.J.).

Plaintiffs brought claims for patent infringement under 35 U.S.C. § 271 (e)(2)(C) due to Sandoz’s submission of an aBLA to obtain approval to market its proposed biosimilar prior to the expiration of the patents protecting Enbrel. They also brought declaratory judgment claims for patent infringement under 42 U.S.C. § 262 (l)(9) due to Sandoz’s refusal to participate in 42 U.S.C. § 262 (l)(4) or (5). The complaint contends that Sandoz, by contrast, lost its ability to seek a declaratory judgment under 42 U.S.C. § 262 (l)(9) due to its failure to participate in 42 U.S.C. § 262 (l)(4) or (5).