We have been monitoring the patent showdown between Canadian corporation Canopy Growth and its suit against UK-based specialty pharmaceutical company GW Pharmaceuticals before Judge Albright in the Western District of Texas.1 GW is known for its FDA-approved cannabinoid therapy for treating certain forms of epilepsy (Epidiolex). Canopy Growth owns U.S. Patent No. 10,870,632, entitled “Process for producing an extract containing tetrahydrocannabinol and cannabidiol from cannabis plant material, and cannabis extracts.”

In this patent infringement suit, filed by Canopy Growth one year ago on December 20, 2020, Judge Albright conducted a Markman hearing on October 9, 2021, and issued a claim construction order on November 27, 2021. According to the claim construction order, only one term was disputed, namely, the meaning of “CO2 in liquified form under subcritical pressure and temperature conditions.” According to the order, GW contended that “subcritical pressure and temperature conditions” means that “both” the pressure and temperature need to be below the critical pressure and critical temperature, respectively, whereas Canopy Growth contended that “subcritical” simply means “not supercritical.” In a decision considering each party’s arguments regarding the intrinsic and extrinsic evidence in turn, Judge Albright ultimately adopted a form of GW’s proposed construction: the plain-and-ordinary meaning wherein the plain-and-ordinary meaning is “CO2 in liquified form under both subcritical pressure and temperature conditions.”

Judge Albright’s claim construction order emphasizes that “while the Court essentially adopts Defendants’ proposed construction, the Court does not do so based on lexicography or a finding of a prosecution disclaimer,” noting “the Court bases its decision on the plain language of the claims and the specification, and to a lesser degree, the prosecution history.” The order explains that “because the extrinsic evidence is not directed to claim term at issue, it does not outweigh the intrinsic evidence.” That the subject matter of the patent relates to extraction of cannabinoids, including THC, did not feature substantively or specifically in the analysis.

We will continue to monitor this case for further developments, as it represents an example of cannabis patent litigation between two important industry players, including a leader in cannabinoid therapeutics, and is unfolding in a popular and fast-moving venue.

[1] CBD Extraction Showdown: Canopy Growth Sues GW Pharma (Jan. 2020), available at

This article appeared in the December 2021 issue of MarkIt to Market®. To view our past issues, as well as other firm newsletters, please click here.