Amgen And Sanofi: What Does It Take To Patent An Antibody?

Author:Mr Mark S. Cohen
Profession:Pearl Cohen Zedek Latzer Baratz

The next steps and lessons learned from the latest chapter in the dispute between Amgen and Sanofi: What does it now take to patent an antibody?

Biologics are an increasing share of the pharmaceutical market, and many of them are monoclonal antibody drugs. For broad claims to such antibodies, satisfying the written description and enablement requirements is becoming more difficult, as can be seen in an ongoing patent dispute between Amgen and Sanofi for their monoclonal PCSK9 inhibitor antibody drugs for lowering cholesterol.

Amgen and its PCSK9 rivals Sanofi and Regeneron have been battling over their US patents for years. Here we discuss the most recent developments in that dispute.

What is PCSK9?

In October 2014, Amgen asserted its REPATHA patents against Sanofi's PRALUENT.

The protein PCSK9 (proprotein convertase subtilisin kexin type 9) binds and promotes degradation of low-density lipoprotein (LDL) receptors (LDLR), which clear circulating LDL, or "bad" cholesterol. PCSK9 lowers LDLR levels resulting in higher LDL cholesterol (LDL-C). Thus, one approach to lower LDL-C is to inhibit PCSK9 binding to LDLR. The FDA has approved two monoclonal PCSK9 inhibitor antibodies for reducing LDL-C, Amgen's REPATHA (evolocumab) and Sanofi's PRALUENT (alirocumab), both bind PCSK9 and inhibit LDLR binding.

When did it all begin?

In October 2014, Amgen asserted its REPATHA patents against Sanofi's PRALUENT. In March 2016, a jury found the patents valid. The court issued and then stayed a permanent injunction against marketing PRALUENT. Sanofi appealed and the case was remanded for a new trial on written description and enablement. Amgen Inc. v. Sanofi, 872 F.3d 1367 (Fed. Cir. 2017). Amgen sought en banc rehearing and Supreme Court review; both were declined.

The February 2019 jury verdict found claims 19 and 29 of US8,829,165 ('165) and claim 7 of US8,859,741 ('741) satisfied the written description and enablement requirements, and as a result, are valid. Sanofi moved for Judgment as a Matter of Law that those claims are Invalid.

Claims 1, 19 and 29 of the '165 patent read as follows:

An isolated monoclonal antibody, wherein, when bound to PCSK9, the monoclonal antibody binds to at least one of the following residues: SI53, 1154, P155, R194, D238, A239,1369, S372, D374, C375, T377, C378, F379, V380, or S381 of SEQ ID NO:3, and wherein the monoclonal antibody blocks binding of PCSK9 to LDLR. The isolated monoclonal antibody of claim 1 wherein the...

To continue reading