Antibody Patents: Use of the Written Description and Enablement Requirements at the Patent & Trademark Office

Abstract

Antibody patents form the basis of some of the most valuable biotechnology products on the market. In 2020 alone, the sales of the top three drugs exceed 10 billion dollars. Two of those three drugs are monoclonal antibodies (Humira and Keytruda). In the past, patent law offered broad protection for monoclonal antibodies. As time has progressed, however, courts have narrowed the scope of antibody patents. However, very little research has been done to see how patent examiners are applying the rules of patentability to these valuable antibody patents.

We examine approximately two decades worth of antibody patents to determine how the US Patent Office has dealt with antibody patents. Specifically, we examine every patent directed to an antibody composition of matter from 2001-present. We find that patent examiners have steadily increased the use of 112(a) enablement and written description rejections while slightly decreasing the use of anticipation and obviousness rejections. Accordingly, these data suggest that 112(a) plays a greater role in policing claim scope than prior art rejections, which is the most frequently used rejection type for every other technology center. Correspondingly, patent applicants have also changed the type of claims they are drafting. Claims have moved from broad claims based only on function to narrow claims based on antibody structure.

We also find that the number of antibody composition patents has dramatically increased, while the number of claims per patent has decreased. Additionally, the number of words in each independent claim has increased three-fold. These data present an interesting evolution for antibody patents that mirrors the changing nature of antibody technology and offers some insights for improving antibody patent prosecution.

Keywords: patent, antibody, USPTO, PTO, written description, enablement, patent examiner, prosecution, litigation