Obviousness is assessed based on the path a person having ordinary skill in the art (PHOSITA) would take in light of prior art, not the path the inventor actually followed. The following case highlights this principle, where the inventor’s exploration of a known process resulted in a new, nonobvious compound.
Case Background: Millennium Pharmaceuticals, Inc. v. Sandoz
In Millennium Pharmaceuticals, Inc. v. Sandoz Inc. (Fed. Cir. 2017), Millennium developed a stable version of a known compound, bortezomib, for effectively treating cancer. Previously, the FDA had not approved bortezomib because no stable formulation existed for storage, transportation, and administration under clinical conditions.
Millennium initially attempted to stabilize the drug using a liquid formulation, but these efforts failed. They then pursued an alternative process: lyophilization (freeze-drying) with a known bulking agent, mannitol. During this process, Millennium unexpectedly discovered that a new compound, the D-mannitol ester of bortezomib, was formed. This compound stabilized bortezomib, enabling its commercialization.
Known Process, New Compound: The Obviousness Debate
The key issue was whether the resulting compound was obvious despite being created through a known process. Sandoz argued that lyophilization with mannitol was an obvious alternative to a liquid formulation, making the resulting compound “inevitable” and therefore not inventive. However, the Federal Circuit disagreed, emphasizing that obviousness is determined by the path suggested by prior art, not hindsight based on the inventor’s approach.
Obviousness and the Path of PHOSITA
Obviousness analysis considers many factors, including the path a PHOSITA would follow based on prior art teachings. The Federal Circuit clarified that the inventor’s specific path is irrelevant to this determination, as hindsight cannot be used to conclude obviousness.
In its reasoning, the court stated:
“The inventor’s own path itself never leads to a conclusion of obviousness; that is hindsight. What matters is the path that the person of ordinary skill in the art would have followed, as evidenced by the pertinent prior art.” – Otsuka Pharmaceutical Co. v. Sandoz, Inc., 678 F.3d 1280, 1296 (Fed. Cir. 2012).
Furthermore, the court highlighted that while lyophilization with mannitol was a known method, no evidence showed that a PHOSITA would have expected or predicted the formation of the stabilizing ester compound.
Federal Circuit’s Findings
The court evaluated the entirety of the record, considering factors like:
- Unexpected results: The formation of a new, stable compound was unforeseen.
- Long-felt need: The solution addressed a longstanding challenge in cancer drug formulation.
- Expert testimony: No experts testified that they anticipated the ester formation or its stabilizing properties.
Based on these factors, the Federal Circuit concluded that the resulting compound was nonobvious and therefore patentable.
Key Takeaways for Patent Prosecution
This case underscores an important point: the path the inventor took is irrelevant to the obviousness inquiry. Instead, the focus should be on the path a PHOSITA would take based on the prior art. Even when the components used in an invention are known, if the prior art does not suggest combining them in the claimed manner, the result may be patentable.
When prosecuting patents, consider emphasizing this distinction to USPTO examiners. Highlight the inventive step as it relates to the prior art’s teachings rather than the inventor’s methodology. By doing so, you can strengthen your arguments for nonobviousness.
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