Cabazitaxel – USA

Cabazitaxel – USA

On Jan 15, 2021, Federal Circuit affirmed (Rule 36 judgment) PTAB which found amended claims patentable over prior arts.

 

Background:

Mylan filed IPR (2016-00712) on Mar. 15, 2016 against US 8,927,592. US’592 relates to method of treating prostate cancer with combination therapy including cabazitaxel & prednisone/prednisolone. PTAB issued final decision (reported here) on Sep 21, 2017 finding claims claims 1–5 and 7–30 unpatentable over prior arts & denied motion by Sanofi (Patentee) to amend claims 27-30. Sanofi appealed to Federal Circuit over denial of claim amendment. Federal Circuit on Feb 05, 2019 remanded case (reported here) back to PTAB finding that the board improperly placed the burden of proof on Sanofi to establish that its proposed claims were patentable and applied the wrong claim construction in its analysis. Back in PTAB, on Oct 22, 2019 board issued final decision finding proposed amended claims 31-34 (which replaced claims 27-30) patentable over prior arts.

 

Subject matter of claims 31 t 34 basically relate to ‘method of increasing survival’ in prostate cancer patients.  The proposed claim 31 recited:

31. A method of increasing survival comprising administering to a patient in need thereof (i) an antihistamine, (ii) a corticoid, (iii) an H2 antagonist, and (iv) a dose of 20 to 25 mg/m2 of cabazitaxel, or a hydrate or solvate thereof, wherein said antihistamine, said corticoid, and said H2 antagonist are administered prior to said dose of 20 to 25 mg/m2 of cabazitaxel, or hydrate or solvate thereof, in combination with prednisone or prednisolone, wherein said patient has castration resistant or hormone refractory, metastatic prostate cancer that has progressed during or after treatment with docetaxel.

 

On remand, Federal Circuit asked PTAB to treat the preamble of claim 31 “as an additional limitation of” the claim that “require[s] ‘increasing survival’” as the “intentional purpose . . . for which the [recited] method must be performed.” PTAB applied the limitation & then reviewed whether now amended claims are obvious or not over prior arts. The main issue was with respect to “reasonable expectation of success” in view considering the term ‘increasing survival’ as the ‘intentional purpose’ of claim. Specifically, the claim at issue required performing the recited method steps with the intended purpose. Mylan argued that a reasonable expectation of success would be shown if the evidence of record proves that a person of ordinary skill in the art reasonably would have expected to be able to carry out the recited method steps with the intent of increasing survival. Sanofi argued that a reasonable expectation of success would be shown only if the evidence of record proves that a person of ordinary skill in the art reasonably would have expected carrying out the recited method steps to result in increased survival. PTAB agreed with Sanofi. PTAB citing precedent said that showing a reasonable expectation of success required proving that a person of ordinary skill in the art “would . . .have had a reasonable expectation that [the recited method] would reduce the risk of cardiovascular hospitalization.” [Sanofi v. Watson Labs. Inc., 875 F.3d 636, 647 (Fed. Cir. 2017)]. Mylan argued that applying the Sanofi standard would “impermissibly engraft” increased survival results onto the scope of claims that merely require an intended purpose, not results.” PTAB, however, said that Sanofi did not require proof of such result. Accordingly, what is required is not a proof that the recited method would actually bring about the recited result, but rather proof that a person of ordinary skill in the art would have had a reasonable expectation that performing the recited method would bring about the recited result.

 

TROPIC study which was cited as one of the prior arts, was phase III protocol. PTAB said that this study was seeking to test the hypothesis that treatment with cabazitaxel would increase overall survival, rather than reasonably suggesting that an increase in overall survival was to be expected. PTAB said that there is some evidence of record that supports a finding that a person of ordinary skill in the art would have expected the treatment method recited in the proposed claims to have resulted in an increase in survival. But, overall evidences & expert testimony say opposite. Dr. Sartor, Patent Owner’s declarant, testified that, at the time of the effective filing date of the ’592 patent, clinicians ‘hoped’ that treatment with cabazitaxel would extend their patients’ lives & clearly disagreed with the statement that he ‘intended’ the treatment to have that effect. Because the results of the TROPIC study showing an increase in survival was “surprised, delighted, [and] shocked” him. Thus, given the evidence of record here, the fact that a person of ordinary skill in the art would have hoped that the method recited in the proposed claims would increase survival does not support a conclusion that that person also would have expected such a result. [OSI Pharms., LLC v. Apotex Inc., No. 2018-1925, 2019 WL 4892078, at *8 (Fed. Cir. Oct. 4, 2019) (“[H]ope that a potentially promising drug will treat a particular cancer is not enough to create a reasonable expectation of success. . . .”)]

 

PTAB, thus, concluded that the preponderance of evidence of record does not show that, POSA reasonably would have expected the treatment regimen recited in the proposed claims to have resulted in an increase in patient survival. Therefore, proposed claims 31 to 34 are not obvious over cited prior arts. PTAB also denied other invalidity attacks such as 35 USC 102 (anticipation) & 35 USC 101 (patentable subject matter).

 

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