Update on Claim Interpretation from the Courts

In another precedential opinion, the Federal Circuit Court of Appeals continued its focus on defining claim term meanings in light of the specification and prosecution history.[i] At issue was Auerbach, et al. (U.S. Pat. 8,822,438), which involves the use of a CYP17 enzyme inhibitor with an anticancer or steroid to treat prostate or breast cancer.[ii] Notably, the patent provides using the anti-androgen abitraterone acetate, seen below, and prednisone.[iii]

Abitraterone acetate is an oral anti-androgen used in prostate cancer treatment, designed to inhibit enzymes involved in androgen steroid synthesis.[iv] The patent was asserted against Amneal Pharmaceuticals LLC, Dr. Reddy’s Labs, Inc., Wockhardt Bio AG, Mylan Pharmaceuticals Inc., and more.[v] Pat. ‘438 was challenged, via Inter Partes Review and through litigation, as obvious.

A group of references were relied upon to establish obviousness. Gerber & Chodak disclose studies of metastatic prostate cancer patients treated with ketoconazole and prednisone.[vi] Ketoconazole inhibits enzymes involved in androgen steroid synthesis,[vii] and prednisone is a steroid. O’Donnell, et al. discloses use of abitraterone acetate to inhibit CYP17 enzyme activity in prostate cancer patients.[viii] O’Donnell also notes abitraterone acetate and ketoconazole, among other compounds, inhibit androgen production.[ix]

The Federal Circuit noted that there was sufficient evidence to support combining these references to show replacing ketoconazole with abitraterone acetate in ketoconazole and prednisone treatment.[x] In support of its finding, and addressing arguments by BTG, the Court noted that the definition of “treatment” must include the therapeutic agent’s effects as disclosed in the specification.[xi] The specification states that a “therapeutic agent” can be either “an anti-cancer agent or a steroid” and this language- with use of “or”- suggests that a steroid is not necessarily the same thing as an anti-cancer agent.[xii] Prednisone is listed as an antibiotic agent, and antibiotic agents are one example of anti-cancer agents.[xiii] The specification therefore provides that prednisone may be used as both a steroid and an anti-cancer agent.[xiv] Because prednisone includes anti-cancer agent and steroidal effects, “treating” with prednisone must include more than just anti-cancer effects, namely steroid effects of palliation and reduction of side effects and the claims must include the steroidal effects of palliation and the reduction of side effects caused by the co-administration of arbiraterone.[xv] Because O’Donnell confirms Gerber’s findings and notes it is common to use supplementary hydrocortisone and that abiraterone is a more selective inhibitor of CYP17 than ketoconazole.[xvi] The Court also noted that BTG’s reliance on commercial success to show nonobviousness, which assisted in obtaining the ‘438 patent originally, was inappropriate due to BTG’s patent (Barrie, U.S. Patent) that prevented others from developing treatment regimens using abiraterone for the treatment of prostate cancer.[xvii]

The case shows the importance of determining the appropriate scope of the claims, and drafting claim language that is reflective of the appropriate claim scope. Further, the use of information in the specification is useful in assisting in determining claim scope, but can be a double-edged sword. In this case, the very broad language used in the specification, and the broad definitions used, were used by the courts in invalidating the patent.



[i] See, BTG Int’l Ltd. v. Amneal Pharma. LLC, No. 2019-1147 , 2019-1148, 2019-1323, 2019-1324, 2019-1325 (Fed. Cir. May 14, 2019).

[ii] BTG Int’l Ltd., slip opinion at 8.

[iii] BTG Int’l Ltd., slip opinion at 9.

[iv] http://www.janssenlabels.com/package-insert/product-monograph/prescribing-information/ZYTIGA-pi.pdf, last accessed May 29, 2019; Zytiga (abiraterone acetate) tablet Prescribing Information insert, Janssen Biotech, Inc. (April 2018); Section 12, page 5.

[v] BTG Int’l Ltd., slip opinion at 5-7.

[vi] BTG Int’l Ltd., slip opinion at 9.

[vii] Lo, et al., Prospective evaluation of low-dose ketoconazole plus hydrocortisone (HC) in docetaxel pre-treated castration-resistant prostate cancer (CRPC) patients. Prostate Cancer Prostatic Dis. 2015 Jun; 18(2): 144-8; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4430382/, last accessed May 29, 2019.

[viii] BTG Int’l Ltd., slip opinion at 10.

[ix] BTG Int’l Ltd., slip opinion at 10.

[x] BTG Int’l Ltd., slip opinion at 21-22.

[xi] BTG Int’l Ltd., slip opinion at 16.

[xii] BTG Int’l Ltd., slip opinion at 16 citing col. 10 ll. 54–55 (emphasis added).

[xiii] BTG Int’l Ltd., slip opinion at 17 (citing to col. 9; col. 30–44; col. 7 l. 46).

[xiv] BTG Int’l Ltd., slip opinion at 17.

[xv] BTG Int’l Ltd., slip opinion at 17, 19.

[xvi] BTG Int’l Ltd., slip opinion at 23.

[xvii] BTG Int’l Ltd., slip opinion at 25-26.