IP Law Daily, PATENT—Fed. Cir.: District court’s finding of non-infringement in CBD patent dispute affirmed, (Apr 24, 2023)

By George Basharis, J.D.

The district court’s construction of terms used in the CBD patent was supported by both the ordinary meaning of those terms and the patent’s prosecution history.

The U.S. Federal Circuit Court of Appeals has upheld the dismissal of a patent infringement lawsuit filed by Canopy Growth Corp. against GW Pharma Ltd. The lawsuit alleged that GW Pharma had infringed on Canopy’s patented extraction process, which is used to manufacture the FDA-approved CBD drug Epidiolex. The lawsuit was dismissed by the federal district court in Waco, Texas, after the parties agreed that based on the court’s construction of Canopy’s claimed method of extracting CBD using liquified carbon dioxide (CO2), Canopy would not have been able to prove infringement at trial (Canopy Growth Corp. v. GW Pharma Ltd., April 24, 2023, Taranto, R.).

Canopy owns U.S. Patent 10,870,632 (the ’632 patent). The ’632 patent describes and claims processes for producing an extract containing THC and/or CBD from cannabis using liquid CO2, which can exist in the solid, liquid, and gas phases. Solid and gas CO2 can be converted to liquid form under certain temperature and pressure conditions. When temperature and pressure are high enough, CO2 enters a supercritical fluid state. When either temperature or pressure is below the critical point, CO2 is subcritical and can form either a liquid or a gas depending on specific temperature and pressure ranges.

The ’632 patent claims a process of extracting CBD by subjecting the cannabis plant to “CO2 in liquified form under subcritical pressure and temperature conditions.” The patent then lists ranges of temperature and pressure conditions for CO2. During prosecution of the ’632 patent, Canopy disclaimed two alternative methods of extracting CBD via CO2: one method employing supercritical pressure and temperature conditions and another using a subcritical temperature range and a supercritical pressure. The two alternative methods were removed from Canopy’s application because they were claimed by prior art.

Relying on the claim’s use of “and” instead of “or,” the district court concluded that the phrase, “CO2 in liquefied form under subcritical pressure and temperature conditions,” required that both the pressure and temperature be subcritical. The lower court found the use of the plural “conditions” did not change the meaning of the plain language. The court also viewed the prosecution history as not providing any additional insight. Based on the district court’s construction, the parties stipulated to non-infringement, and the court entered final judgment in favor of GW Pharma on infringement.

The Federal Circuit agreed with the district court that the ordinary meaning of “subcritical pressure and temperature conditions” is that both pressure and temperature must be subcritical for the claim limitation to be satisfied.

Canopy argued that, despite the claim language, a person of ordinary skill in the art would not be able to distinguish between liquid CO2 with both subcritical pressure and temperature, and liquid CO2 with subcritical temperature and supercritical pressure. However, Canopy disclaimed two of the three alternative methods of extracting CBD using liquid CO2. The court explained that if the claim was not limited to having both subcritical temperature and pressure, one of the two disclaimed conditions (CO2 with subcritical temperature and supercritical pressure) would be redundant. Therefore, subcritical temperature and supercritical pressure were not simply subsets of the claimed extraction method, as Canopy claimed. Rather, the prosecution history disclosed three distinct embodiments, and Canopy chose to claim only one of the three options. Consequently, the plain language of the claim, along with the prosecution history, made it clear that the ’632 patent disclosed three non-overlapping embodiments while claiming only one of them: the one in which both pressure and temperature must be subcritical.

The Case is No. 22-1603.

Attorneys: Kurt M. Pankratz (Baker Botts, LLP) for Canopy Growth Corp. Gerald J. Flattmann, Jr. (Cahill Gordon & Reindel, LLP) for GW Pharma Ltd. and GW Research Ltd.

Companies: Canopy Growth Corp.; GW Pharma Ltd.; GW Research Ltd.

Cases: Patent Cannabis FedCirNews TexasNews GCNNews