In the examination of inventive step in US patents, one of the critical factors in determining whether an invention is “obvious” is establishing the “level of ordinary skill in the art.”

Why is it necessary to set this level to make a judgment on inventiveness? Can’t the examiner simply make the determination directly?

In fact, the purpose of establishing a third-party perspective level is to ensure fairness and objectivity, preventing patent examination from being influenced by personal subjective opinions.

However, in practice, the “person of ordinary skill in the art” can easily be idealized by examiners. In their view, this “person” seems capable of creating anything.

If the standard of this idealized person is applied to patents, then every invention might appear to lack inventiveness. This contradicts the original intention of establishing the “level of ordinary skill in the art” to ensure fair examination.

How to Ensure Maximum Fairness and Impartiality?

In our previous article, “Factors to Consider When Determining the Level of Ordinary Skill in the Art in US Patent Examination,” we discussed how MPEP §2141.03 outlines the factors to be considered when determining the level of ordinary skill in the art. These factors include the types of problems encountered in the art, the existence of solutions in the prior art, the rate of innovation in the field, the complexity of the technology, and the educational level of active practitioners in the field.

These factors help standardize the subjective behavior of examiners, ensuring that the examination results are as reasoned and justified as possible.

In different case contexts, not all of these factors may be present, and sometimes one or more factors may dominate depending on the situation.

How Does the Determination of Ordinary Skill Level Function in Patent Practice?

This article, based on an analysis of the patent invalidation case Daiichi Sankyo Co. v. Apotex, Inc., reveals who the “person of ordinary skill in the art” really is.

In this case, the differing perspectives of “ordinary skill in the art” held by various judges nearly led to Apotex paying millions of dollars in patent infringement damages!

PART 1: Case Background

Litigation History

In March 2003, Daiichi sued Apotex, alleging that Apotex’s generic ofloxacin ear drops intentionally infringed on US Patent No. 5,401,741 (the “’741 patent”).

The ‘741 patent pertains to a method of treating bacterial ear infections by locally administering the well-known antibiotic ofloxacin into the ear. This method, involving the topical application of ofloxacin to the external auditory canal and middle ear, significantly reduces the risk of ototoxicity and antimicrobial resistance.

Two years after the ‘741 patent was granted, the U.S. Food and Drug Administration (FDA) approved Daiichi’s FLOXIN® Otic product. Subsequently, Apotex, a Canadian generic drug manufacturer, submitted an Abbreviated New Drug Application (ANDA) to the FDA for an ofloxacin ear solution.

Daiichi argued that Apotex’s ofloxacin ear solution was a generic “copy” of its FLOXIN® Otic product, thus initiating an infringement lawsuit. During the trial, Apotex contended that its generic product did not infringe and that Daiichi’s ‘741 patent was invalid due to obviousness.

The district court conducted an obviousness analysis, establishing the qualifications of a person of ordinary skill in the art as someone with a medical degree, experience in treating ear infections, some understanding of the pharmacological uses of antibiotics, and a background as a pediatrician or general practitioner. From the perspective of this defined person of ordinary skill in the art, the ‘741 patent was not obvious. Based on this analysis, the district court concluded that the ‘741 patent was valid and that Apotex had infringed upon it.

Dissatisfied with the ruling, Apotex appealed to the Federal Circuit, arguing that the district court had erred in its definition of the “person of ordinary skill in the art.”

Focus of the Dispute

The key issue in this case was whether the ‘741 patent was obvious to a person of ordinary skill in the art.

Court Ruling

The Federal Circuit overturned the district court’s decision, redefining the level of ordinary skill in the art as that of a person engaged in the development of ear drug formulations and treatment methods, or an ear treatment specialist, rather than a pediatrician or general practitioner. Consequently, the ‘741 patent was declared invalid due to obviousness.

This case highlights the critical importance of accurately defining the level of ordinary skill in the art when determining obviousness in patent litigation.

Part 2: Case Analysis

Divergent Perspectives of District and Federal Circuit Courts

Why did the district court and the Federal Circuit have such different views? Which court’s perspective on the level of ordinary skill in the art is more reasonable?

To answer this, we must consider the prior art provided by Apotex, specifically the Ganz reference. Before the filing date of the ‘741 patent, Ganz had already disclosed another member of the same antibiotic family, ciprofloxacin, demonstrating similar efficacy. Apotex argued that Ganz provided guidance and motivation towards the ‘741 patent (teaching that ciprofloxacin, when applied topically, does not exhibit ototoxicity). However, this was not acknowledged by the district court judge.

The district court emphasized that “Ganz’s article reported that this antibiotic should only be used in difficult cases and exclusively by otologists.” The expertise of an otologist exceeded the ordinary skill level defined by the district court. Therefore, the district court held that the method claimed in the ‘741 patent would not be obvious to a pediatrician or general practitioner, who possesses basic pharmacological knowledge but lacks specialized experience in ear treatment and cannot extrapolate the safety profile of one antibiotic to another.

In essence, the district court perceived that the person of ordinary skill in the art in the context of the ‘741 patent was a doctor with fundamental pharmacological knowledge (such as a primary care physician or general practitioner) without specialized experience in ear treatment. This level of skill does not reach the medical expertise of Ganz, and thus would not readily think to use one antibiotic’s safety profile to infer another’s.

The district court and the Federal Circuit’s differing views on the level of ordinary skill in the art underscore the importance of accurately defining this skill level in patent litigation. The district court’s definition was more restrictive, considering the practical application by generalists in medicine, while the Federal Circuit adopted a broader perspective, considering specialists in the relevant field. This case illustrates how the definition of the level of ordinary skill in the art can significantly impact the determination of obviousness and the ultimate validity of a patent.

The district court’s logic is quite comprehensible: when people experience ear infections, they typically consult their community doctors for antibiotics, as these doctors often serve as the “first line of defense” against ear infections. These general practitioners are unlikely to think about administering antibiotics topically to reduce ototoxicity.

In essence, the district court and Daiichi argued that Ganz’s method was beyond the scope of ordinary doctors’ expertise and thus not instructive. For these general practitioners, understanding Ganz’s teachings would be challenging, making it unlikely that someone with ordinary skill in the art would develop the invention claimed in the ‘741 patent. Hence, the ‘741 patent was considered inventive within its field.

However, Apotex provided expert testimony indicating that there was significant interest among ENT (ear, nose, and throat) specialists in developing a solution using ofloxacin to treat ear infections while reducing ototoxicity. This highlighted that the problem addressed by the ‘741 patent was already recognized in the ENT field, and Ganz had provided a similar solution.

Given this context, the Federal Circuit ultimately ruled that the district court’s judgment was “clearly erroneous.” The Federal Circuit redefined the person of ordinary skill in the art as: “a person engaged in the development of new drugs, formulations, and treatment methods, or an expert in ear treatment such as an otologist or an ENT specialist, who also has training in drug formulation.”

The Federal Circuit emphasized that a person of ordinary skill in the art “would not possess the training or knowledge to develop the compound claimed without some specialized training, such as that possessed by the inventors of the ‘741 patent.” Therefore, the Federal Circuit concluded that the appropriate level of skill for someone in the ‘741 patent’s field was that of an individual engaged in developing ear drug formulations and treatment methods or an ear treatment specialist, rather than a pediatrician or general practitioner.

In summary, the Federal Circuit determined that the individuals addressing the issue of antibiotic ototoxicity should be ear specialists. These specialists represent the “person of ordinary skill in the art” for the ‘741 patent. An otologist would be able to derive technical guidance from Ganz’s teachings and substitute locally administered ciprofloxacin with ofloxacin to achieve the same goal: avoiding ototoxicity.

The Federal Circuit dismissed the district court’s assertion that “the safety of one antibiotic cannot be extrapolated to another” as unsubstantiated.

Ultimately, the decision on the patent’s invalidity heavily relied on considering the inventors’ educational background, all being ear specialists. By recognizing this, the Federal Circuit redefined the person of ordinary skill as someone in the otology field, making it clear that such a person would find no difficulty in applying Ganz’s teachings to the ‘741 patent. Consequently, the Federal Circuit declared the ‘741 patent invalid due to a lack of inventive step.

This case illustrates the profound impact of defining the person of ordinary skill in the art. The district court and the Federal Circuit adopted completely different perspectives, which led to the reversal of the decision. The district court considered a broader medical field, while the Federal Circuit focused on the more specific field of otology, which is more relevant to the ‘741 patent. This approach demonstrates that taking into account the specific educational background and expertise within the relevant field is crucial for a fair and reasonable determination of the ordinary skill level in patent cases.

Further Insights

This case provides an important takeaway: never underestimate the significance of the “person of ordinary skill in the art”! Although termed “ordinary,” this individual is far from ordinary when examined within the context of different case scenarios. It is crucial to recognize that the level of this “person” is not static but can elevate depending on the circumstances. The definition of ordinary skill can directly influence the assessment of a patent’s inventiveness.

Conclusion

In practice, understanding and defining the ordinary skill level by considering relevant factors can have a significant impact on the determination of obviousness and, consequently, the validity of a patent. By advocating for a definition of ordinary skill that is favorable to your case, you can greatly influence the outcome of patent disputes. After reading this article, you should have a deeper understanding of the concept of ordinary skill in the art.