“Understanding the Genus/Species Framework in Patent Law: A Focus on Solid-Form Patents in the Pharmaceutical Industry”

Understanding the Concept of Genus and Species in Patent Applications

In the realm of patent law, the concept of genus and species plays a significant role, particularly in the pharmaceutical industry. The case of In re Baird illustrates this concept, demonstrating that the disclosure of a genus in the prior art does not necessarily equate to the disclosure of every species within that genus. This concept can be leveraged by patentees when applying for solid-form patents.

The Significance of Solid Forms in Pharmaceuticals

Pharmaceutical products can be dosed in various forms, including solids, liquids, and gases. The solid-state properties of a drug can significantly affect its delivery, such as the speed and quantity of the active ingredient delivered from ingestion to the site of action. This is particularly relevant in the case of crystalline solids, where the same chemical compound can exist in different forms depending on how it is crystallized. This phenomenon, known as polymorphism, can result in significantly different drug solubility and dissolution properties, making it a common subject of patent applications in the pharmaceutical arts.

Case Study: Solid Forms and the Wakix® Example

A prime example of the application of solid forms in patent law is the case of Pitolisant hydrochloride, marketed as Wakix®. The patentees hold U.S. Patent No. 7,169,928, which covers the composition of matter directed to the pitolisant molecule and its various forms. A second patent, U.S. Patent No. 8,207,197, is also directed to pitolisant but is limited to the hydrochloride salt and contains additional limitations. This example illustrates how multiple patents can cover the same compound but with different scope, enabling a solid-form patent strategy.

The Genus/Species Framework in Patent Law

The ability to obtain multiple drug substance patents covering the same compound is based on how patent law views the scope of claims, particularly the genus-species relationship. In re Baird is a case that highlights this relationship, where a patentee attempted to claim an invention directed to a specific compound. The court ruled that the disclosure of a genus in the prior art does not necessarily mean a disclosure of every species within that genus.

This ruling illustrates that patentees can use the concept of genus and species to their advantage when applying for solid-form patents. The prior art compound becomes the genus, and the solid form becomes the species. This relationship allows for the patentability of later-filed solid form patents, providing a strategic advantage in the pharmaceutical industry.

Conclusion

The concept of genus and species in patent law provides a strategic advantage for patentees, particularly in the pharmaceutical industry. The ability to obtain multiple patents covering the same compound, but with different scope, allows for a solid-form patent strategy. This strategy, illustrated by the case of In re Baird and the Wakix® example, demonstrates the potential for innovation and advancement in the field of pharmaceuticals.

For more information on this topic, consider viewing IPWatchdog’s webinar, “Pharmaceutical Salts and other Complexes – A Solid Form Strategy,” sponsored by Barash Law.