Canopy Growth Corp. v. GW Pharma Ltd.

1

CANOPY GROWTH CORPORATION, Plaintiff-Appellant v. GW PHARMA LIMITED, GW RESEARCH LIMITED, Defendants-Appellees

No. 2022-1603

United States Court of Appeals, Federal Circuit

April 24, 2023

This disposition is nonprecedential.

Appeal from the United States District Court for the Western District of Texas in No. 6:20-cv-01180-ADA, Judge Alan D Albright.

DAVID G. WILLE, Baker Botts LLP, Dallas, TX, argued for plaintiff-appellant. Also represented by MELISSA MUENKS, KURT M. PANKRATZ, CLARKE STAVINOHA; MICHAEL HAWES, Houston, TX.

GERALD J. FLATTMANN, JR., Cahill Gordon & Reindel LLP, New York NY, argued for defendants-appellees. Also represented by JESSE SNYDER, AMY R. UPSHAW, King & Spalding LLP Washington, DC.

Before LOURIE, TARANTO, and STARK, Circuit Judges.

TARANTO, CIRCUIT JUDGE

Canopy Growth Corp. sued GW Pharma Ltd. and GW Research Ltd. (collectively, GW) in the United States District Court for the Western District of Texas, alleging infringement of at least claims 1-25 of its U.S. Patent No. 10,870,632. The district court issued an order construing the sole disputed claim limitation: "CO₂ in liquefied form under subcritical pressure and temperature conditions." Canopy Growth Corp. v. GW Pharmaceuticals PLC, No 20-cv-01180, 2021 WL 8015834, at *4-15 (W.D. Tex. Nov. 27, 2021). Based on the district court's construction, the parties stipulated to non-infringement, and the court then entered final judgment in favor of GW on infringement and dismissed GW's remaining affirmative defenses and counterclaims without prejudice. Canopy appeals. Because the phrase "subcritical pressure and temperature conditions," as used in the claims here, requires both pressure and temperature to be subcritical, we affirm.

I

The '632 patent describes and claims processes for producing an extract containing tetrahydrocannabinol (THC) and/or cannabidiol (CBD) from cannabis using liquid carbon dioxide (i.e., CO₂). CO₂ can exist in the solid, liquid, and gas phases. But when temperature and pressure are high enough, CO₂ can transition from the liquid or gas phase into a supercritical fluid state. The lowest combination of temperature and pressure at which this transition can occur is the critical point; only if both temperature and pressure are above the critical point will CO₂ enter the supercritical fluid state.

CO₂ can be described as subcritical when either its temperature or its pressure is below the critical point, and, putting aside its solid phase (which is not relevant here), CO₂ can be in the subcritical state as either a liquid or a gas, depending on the specific temperature and pressure of the CO₂. When its temperature is supercritical but its pressure is subcritical, CO2 will form a gas because the pressure is not sufficient to force the CO₂-expanding due to the high temperature-to liquify. In contrast, when its temperature is subcritical but its pressure is supercritical, the CO₂ will form a liquid. And when both temperature and pressure are subcritical, CO₂ can form either a liquid or a gas, depending on the specific temperature and pressure. The critical-point temperature for CO₂ is 31°C, and the critical-point pressure for CO₂ is 73.8 bar (or 72.8 atm). The parties do not dispute any of those principles, which are depicted in the CO₂ phase diagram below.^[1]

(Image Omitted)

J.A. 90.

Independent claim 1 of the '632 patent recites

1. A process for producing an extract containing Tetrahydrocannabinol (THC) and/or cannabidiol (CBD), and optionally the carboxylic acids thereof, from a cannabis plant material or a primary extract thereof, said process comprising:

(1) subjecting the cannabis plant material or primary extract thereof to CO₂ in liquefied form under subcritical pressure and temperature conditions to extract cannabinoid components; and

(2) reducing the pressure and/or temperature to separate tetrahydrocannabinol and/or cannabidiol, and optionally the carboxylic acids thereof, from the CO₂.

'632 patent, col. 14, lines 30-41 (bolding added for emphasis). The only other independent claim, claim 14, is relevantly similar, and all claims of the '632 patent include the limitation at issue.

The '632 patent's specification lists the phrase at issue among itemized temperature and pressure conditions for CO₂ that are "[i]n accordance with the invention." Id., col. 5, lines 6-20. Specifically, it provides that extraction can occur

with the aid of CO₂ under supercritical pressure and temperature conditions at a temperature in the range of approx[.] 31° C. to 80° C. and at a pressure in the range of approx. 75 bar to 500 bar, or in the subcri[t]i[c]al range at a temperature of approx. 20° C. to 30° C. and a supercritical pressure of approx. 100 bar to 350 bar; or extracted under subcri[t]i[c]al pressure and temperature conditions; and the obtained primary extract is separated under subcri[t]i[c]al conditions, or under conditions that are subcri[t]i[c]al in terms of pressure and supercritical in terms of temperature.

Id.

The limitation at issue, with the other possible CO₂ conditions quoted above, also appears in the prosecution history. The '632 patent issued from a continuation of Application No. 10/399,362. During prosecution of that application, the applicant sought claims to these conditions in a claimed process that it described as reciting three "alternative steps," J.A. 372 (emphasis omitted), depicted below:

1 5. (Currently amended) A process for producing an extract containing tetrahydrocannabinol, cannabidiol and optionally the carboxylic acids thereof from dried comminuted Cannabis plant material, comprising

- extracting said plant material by means of CO₂

(a) under supercritical pressure and temperature conditions at a temperature in a range of approx. 31 °C to 80°C and at a pressure in a range of approx. 75 bar or 500 bar, or

(b) in liquefied form in the subcritical subericital range at a temperature of approx. 20°C to 30°C and a supercritical pressure of approx. 100 bar to 350 bar; or

(c) in liquefied form under subcritical subericital pressure and temperature conditions; and

- separating the obtained primary extract out under subcritical subcrioital conditions or under conditions subcritical subcricital in terms of pressure and supercritical in terms of temperature.

J.A. 366. As described by the applicant during prosecution, these alternative steps permitted extraction via CO₂ under "(a) supercritical pressure and temperature conditions; or (b) subcritical temperature range and a supercritical pressure; or (c) subcritical pressure and temperature conditions." J.A. 372-73. The '362 application issued with claims directed to these steps as U.S. Patent No. 8,895,078.

For the application that gave rise to the '632 patent, Application No. 14/276,165, the prosecution history starts off similarly, in that the applicant began by seeking claims directed to the same three alternative steps. J.A. 399. But in response to an examiner rejection of the claims over prior art that discloses the use of supercritical fluid CO₂ for extraction, Webster (U.S. Patent No. 6,403,126), J.A. 40405, the applicant amended the pending claims to remove the first of the alternative steps-"under supercritical pressure and temperature conditions at a temperature in a range of approx. 31°C to 80°C and at a pressure in a range of approx. 75 bar or 500 bar," J.A. 420. Then, in response to the examiner's continued rejection based on Webster's disclosure of supercritical fluid CO₂ and Webster's statement that temperature and pressure can be adjusted, J.A. 431-33; J.A.445-48, the applicant amended the claims to also remove the second alternative step-"in liquefied form in the subcritical range at a temperature of approx. 20°C to 30°C and a supercritical pressure of approx. 100 bar to 350 bar," J.A. 437. This amendment left the applicant with claims directed only to the third of the alternative steps- "in liquefied form under subcritical pressure and temperature conditions," though further limited through amendment to "a pressure of 70 bar or less and a temperature of approx. 20°C to 30°C." Id. The applicant ultimately canceled the claims, J.A. 152, but the issued claims now in dispute include this same phrase (without the numerical pressure and temperature limits).

The district court concluded that the phrase "CO₂ in liquefied form under subcritical pressure and temperature conditions," requires that both the pressure and temperature be subcritical. Canopy, 2021 WL 8015834, at *15. The court relied on the claim's use of "and" instead of "or," which it viewed as indicating that the claim required both pressure and temperature to be subcritical. Id. at *4. The court concluded that the use of "conditions" (a plural) does nothing to change this. Id. Looking next to the specification, the court viewed the above-quoted passage, in column 5, as listing three alternative options, rejecting Canopy's argument that the second, which includes subcritical temperature and supercritical pressure, is a subset of the third, which is defined by the "subcritical pressure and temperature conditions" phrase at issue. Id. at *8-10. Finally, the court viewed the prosecution history as not "provid[ing] any additional insight . . . beyond the plain language of the claims and the specification." Id. at *14. The prosecution history statements, the court determined, "mirror those in the specification, namely, that the claims in the parent patent and the as-filed/amended claims in the asserted patent recite three pressure and temperature conditions." Id. The court likewise deemed extrinsic evidence, involving the use of similar but notably different phrases, to be "not directly relevant" and not sufficient to "outweigh the intrinsic...