Humanized Antibodies: CIPO Picks Up the Pace

By Claire Palmer and Jessica Sudbury, September 15t^h, 2016

Keeping pace with science and technology that evolves at lightning speed is a challenge for any government institution. The Canadian Intellectual Property Office (CIPO) has a lot of catching up to do, but is not out of the race just yet. Arcane patent office examination practices grounded in habit can never justifiably replace a proper fact-driven determination of patentability. Commissioner’s Decision 1398 (CD 1398, issued on May 5, 2016)[1] reminds us that CIPO is not completely asleep behind the wheel and shows that the applicant who fights to the bitter end can win it all.

At issue in CD 1398 were a set of dependent claims (5, 10, 15 and 20) in patent application 2,451,493 (published on January 3, 2003)[2] over a genus of humanized murine monoclonal antibodies directed against a human glypican-3 epitope. The epitope sequence was adequately disclosed; however the application did not disclose the corresponding complementarity determining regions (CDRs) for the humanized embodiments, nor any evidence that such humanized embodiments were actually made from the process described. In the Final Action issued by the Examiner on February 4, 2014, these dependent claims were found to be incompliant with section 84 of the Patent Rules for lack of support in the description, and that the specification was in violation of subsection 27(3) of the Patent Act for lack of adequate enablement.

The Examiner largely grounded rejection of these claims based on a previous decision issued by the Commissioner concerning humanized antibodies (CD 1296, Re: Sloan-Kettering Institute for Cancer Research),[3] finding that it created a bright-line rule requiring disclosure of CDR amino acid sequences to fulfill support requirements in the absence of evidence pointing to an actual carrying-out of the invention in the application. This, despite the fact that adequate support for generic monoclonal antibodies has generally been found upon disclosure of a fully characterized antigen capable of binding the antibody claimed (e.g., see the CD 1302 Immunex decision and MOPOP directive 17.08.01b).[4]

Since the CD 1296 Sloan-Kettering decision was issued in 2009, similar reasoning has been repeatedly applied to justify rejections of similarly-supported claims over humanized antibodies by CIPO examiners in disregard of submitted evidence. The Patent Appeal Board noticed this problem when it recommended an upholding of the dependent claims for the humanized genus of anti-glypican-3 antibodies to the Commissioner in CD 1398.

The Board identified several problems with the Examiner’s line of reasoning in the 2014 Final Action. First, it commented that no specific guidance concerning humanized antibodies existed at the time in Canadian jurisprudence (paragraph 23). Secondly, the Board noted that “the enablement requirement of paragraph 27(3)(b) of the Patent Act entails fact-specific determinations that take into account the common general knowledge (CGK) and the ordinary skills possessed by the person of ordinary skill in the art (POSITA) at the publication date of the patent application,” and that the relevant CGK had significantly evolved over the 11 years since (paragraph 35). Nonetheless, the evidence put before the Board was convincing to establish that antibody humanization techniques were “routine” in 2003 (paragraph 42). Thus, the relevant POSITA would have been adequately enabled to carry out the invention as described at the publication date (paragraph 44). Finally, the Board reasoned that the CD 1296 Sloan-Kettering decision “cannot impose a rigid rule” applicable to variable factual situations and that it had limited applicability to the present case (paragraph 39). Accordingly, the Board did not find that disclosure of the CDRs for humanized antibodies was a requirement to comply with the Patent Act.

While the institutional checks and balances on display in the CD 1398 decision may bring comfort to some, the decision may also serve as a reminder to others that baseless CIPO examination practices can present a serious obstacle to inventors seeking otherwise justified ownership rights over rapidly-developing technology. Pushing through these barriers with a well-supported patent application can clearly be worth the trouble and expense, however. Examiners should always bear in mind that the relevant CGK “undergoes continuous evolution and growth” (CD 1398, paragraph 36) and that only the CGK that was available to the relevant POSITA at the publication date can be considered in light of Patent Act requirements. An evidence-driven analysis of application claims in in light of the CGK at time of filing would catch a situation where the relevant POSITA had become practiced enough in brand-new technologies to not require inventiveness in carrying out an invention as described. Considerations, such as the current relevant CGK or previous Commissioner decisions analyzing similar patent applications, have no justifiable bearing on an examiner’s assessment of a patent application.

Thankfully, it appears that CIPO retains self-awareness and recognizes when it is stuck in a rut spinning its wheels. While consistency in examination practices may lead to increased certainty over time to the benefit of the public, our innovation institutions cannot carry out mandates without leaving room for flexibility and growth in internal procedures. Further, unlike courts, tribunals in Canada are not bound by stare decisis. Therefore, CIPO is not held to apply any body of rules except those found within case law, the Patent Act or the Patent Rules. Previous Commissioner’s Decisions are not determinative, and the public is entitled to decisions issued by CIPO that are assessed according to the relevant factual matrix in disregard of existing examination practices. Hopefully, the CD 1398 decision reflects a new lasting habit embarked on by CIPO to continually oversee and make internal adjustments to ensure it stands a fighting chance of keeping pace with our swift innovators.