In Re Montgomery: Inherently Therapeutic

17 May 2012 PharmaPatents Blog

In In re Montgomery, the Federal Circuit addressed the issue of anticipation by inherency in the therapeutic context. This case illustrates the difficult doctrine of inherency and the potential importance of claim language—and claim construction—to an inherency analysis.

The Patent Application At Issue

The patent application at issue was U.S. Patent Application 11/118,824, filed April 29, 2005, as the U.S. national stage of a PCT application filed October 19, 1998, that claimed priority to two UK applications filed May 20, 1998 and October 17, 1997, respectively.

As described in the Federal Circuit opinion, the application was “directed to inhibitors of the renin-angiotensin system (“RAS”), which is ‘important in the maintenance and control of blood pressure as well as the regulation of salt and water metabolism.’” The opinion characterizes the specification as being “largely directed to treating wasting diseases such as cachexia, and to improving cardiovascular fitness and physical endurance,” but notes that it does disclose “[s]troke treatment and prevention,” although no clinical data is provided.

There were three claims at issue:

42. A method for the treatment or prevention of stroke or its recurrence, wherein said method comprises administering, to a patient diagnosed as in need of such treatment or prevention, an inhibitor of the rennin-angiotensin system, said inhibitor having a ClogP of greater than about 1.

43. The method as claimed in claim 42, wherein the inhibitor of the rennin-angiotensin system comprises at least one inhibitor of angiotensin-converting enzyme.

45. The method as claimed in claim 43, wherein the inhibitor of angiotensin-converting enzyme comprises ramipril.

The Board had construed claim 42 as having two elements:

  1. “to administer an inhibitor of the rennin-angiotensin system” and
  2. “the patient population receiving the inhibitor . . . encompasses patients diagnosed as required stroke treatment or prevention.”

According to the Federal Circuit, although “the Board did not rule directly on whether Montgomery’s claims required that the administration be effective at treating or preventing stroke, it appeared to assume that they did include such a requirement.”

The Prior Art

The USPTO Examiner had rejected the claims as anticipated by four prior references, and the USPTO Board of Patent Appeals and Interferences affirmed the rejections. On appeal, the Federal Circuit focused on the “HOPE” reference.

The HOPE Study Investigators, The HOPE (Heart Outcomes Prevention Evaluation) Study: The Design of a Large, Simple Randomized Trial of an Angiotensin-Converting Enzyme Inhibitor (Ramipril) and Vitamin E in Patients at High Risk of Cardiovascular Events, 12 Can. J. Cardiology 127 (1996)

According to the Federal Circuit opinion:

HOPE describes the design of “a large, simple randomized trial of . . . ramipril . . . and vitamin E . . . in the prevention of myocardial infarction, stroke, or cardiovascular death,” which recruited “[o]ver 9000 [patients] at high risk for cardiovascular events such as myocardial infarction and stroke.” HOPE at 127. HOPE discloses that at the time of its publication, all 9541 patients had been randomized and had been receiving ramipril or a placebo for at least one month. (The HOPE study ultimately found that patients receiving ramipril had a statistically significant reduction in the risk of stroke, but these results were not published until after Montgomery’s priority date and thus are irrelevant to an anticipation analysis.)

The Board found that “each reference teaches administration of ramipril to stroke-prone patients,” and characterized the HOPE study as being “clearly enabled to treat patients, including patients with previous stroke, with ramipril.”

The Federal Circuit Decision 

The Federal Circuit opinion was authored by Judge Dyk and joined by Judge Prost. Judge Lourie wrote a dissenting opinion.

With regard to the rejection based on the HOPE reference, the only “contested” claim element was the administration of ramipril “for the treatment or prevention of stroke or its recurrence.” 

The court first considered whether the claims include “an efficacy requirement,” and expressed skepticism that they did. The court found it more likely that the language “expressed . . . a purpose . . . rather than requiring a particular result.” Interestingly, the court found that this construction was supported by the lack of experimental data in the specification:

Nothing in the ’824 specification suggests that a narrower construction is appropriate: the specification does not describe any studies that show that RAS inhibitors are effective for stroke treatment or prevention, see J.A. 224-52, thus also suggesting that the claims do not incorporate such a requirement . . . .

 The court determined that it did not have to decide the issue, however, because “even if the claim includes an efficacy requirement, efficacy is inherent in carrying out the claim steps.” The court explained:

 We have repeatedly held that “[n]ewly discovered results of known processes directed to the same purpose are not patentable because such results are inherent.” . . . . “It matters not that those of ordinary skill heretofore may not have recognized the[] inherent characteristics of the [prior art].”

HOPE discloses a protocol for the administration of ramipril to stroke-prone patients, and administering ramipril to stroke-prone patients inevitably treats or prevents stroke. See HOPE at 127. Thus, HOPE inherently anticipates the claims at issue.

The court also emphasized that it did not matter whether the HOPE trial actually had been carried out:

[A]nticipation “requires only an enabling disclosure,” not “actual creation or reduction to practice,” so that “actual administration . . . to patients [in the prior art] is irrelevant”—the prior art patent inherently anticipated as long as it “disclose[d] in an enabling manner the administration . . . to patients.”

The court acknowledged the principle that “[a]n invitation to investigate is not an inherent disclosure,” but characterized the HOPE reference as providing a detailed protocol, “far from an abstract theory.” Indeed, the court noted that “[i]n all relevant respects, HOPE is identical to the patent itself, which does not disclose actual results from the administration of ramipril for these purposes.”

Judge Lourie’s Dissent

Judge Lourie dissented from the majority opinion and wrote separately to emphasize the care with which the doctrine of inherency must be applied.

Inherency is a very tricky concept in patent law. Its salutary goal is to prevent subject matter that is effectively in the public’s possession from being retrieved by a patent and withdrawn from the public domain. On the other hand, its downside is withholding patent protection from that which the public knew nothing about until a later inventor found it.

According to Judge Lourie, one safeguard against the liberal use of “inherency” is the requirement of inevitability:

The keystone of the inherency doctrine is inevitability. For anticipation by inherency, a later-claimed invention must have necessarily resulted from the practice of a prior art reference. Our precedent has been steadfast in this strict requirement of inevitability.

Judge Lourie found the HOPE reference to fall short in this regard.

The HOPE paper . . . describes a plan designed to administer a combination of ramipril and vitamin E to patients at risk of a major vascular event including myocardial infarction, stroke, or death from cardiovascular disease. But HOPE . . . truly expresses only a hope, not achievement of that hope. . . . The results of a proposed study . . . are neither predictable nor inevitable. . . . Inherency follows from the carrying out of an activity that inherently produces what is claimed; inherency does not arise from a plan whose description does not indicate its realization.

A description of a process, even if not carried out, is an anticipation of that process. But a mere description of a process that, if it had been carried out, might yield a particular undisclosed result is not an inherent anticipation of that result. Stated somewhat differently, inherency requires description of action that inevitably produces a result, not merely description of action that might have been carried out, but was not, and might have yielded a particular result, but did not.

The Court’s Claim Construction

I find it odd that the court considered it feasible—even probable—that the claims do not embody a requirement for efficacy. Wouldn’t the claims lack utility if they did not recite an effective method?

Would the outcome have been any different if the claims had recited administering “an effective amount” of a RAS inhibitor? With that claim language, would the USPTO have to have shown that the doses of the HOPE protocol were indeed effective for preventing stroke?

Was the applicant unable to include such claim language in the claims because the specification did not include experimental data demonstrating efficacy at a specific dose? The specification does include one paragraph that at least proposes a specific dose to use to prevent stroke.

Are there any claim construction arguments that the applicant could have made that might have affected the outcome?

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