District Court Applies Mayo To Treatment Claims But Denies Motion To Dismiss BMS Keytruda Litigation

The U.S. District Court for the District of Delaware accepted Merck’s arguments that method of treatment patents asserted by BMS against its Keytruda product “touch[] upon a natural phenomenon” such that they should be analyzed under the Mayo/Alice patent eligibility framework. However, in view of disputed issues of fact, the presumption of validity, and other presumptions arising from the Rule 12(b)(6) context, the court denied Merck’s motions to dismiss the Keytruda litigation. 

The Patents At Issue

The patents at issue are assigned to Ono Pharmaceutical Co., Ltd. and Tasuku Honjo, and exclusively licensed to Bristol-Myers Squibb Co. BMS asserted that Merck’s Keytruda® (pembrolizumab) product infringes U.S. Patent No. 9,067,999. and U.S. Patent No. 9,073,994.

Claim 1 of the ‘999 patent recites:

1. A method of treating a lung cancer comprising administering a composition comprising a human or humanized anti-PD-1 monoclonal antibody to a human with the lung cancer, wherein the administration of the composition treats the lung cancer in the human.

Claim 1 of the ‘994 patent recites:

1. A method of treating a metastatic melanoma comprising intravenously administering an effective amount of a composition comprising a human or humanized anti-PD-1 monoclonal antibody and a solubilizer in a solution to a human with the metastatic melanoma, wherein the administration of the composition treats the metastatic melanoma in the human.

The Mayo/Alice Analysis

The district court rendered similar decisions in DED-1-15-cv-00560 (involving the ‘999 patent) and DED-1-15-cv-00572 (involving the ‘994 patent), providing its analysis in footnotes in three-page orders denying Merck’s motions to dismiss.

With regard to step 1 of the Mayo/Alice framework, the court agreed with Merck that that claims involve a “natural phenomenon”, providing similar explanations for both patents:

[T]he court concludes that, contrary to Bristol-Myers contention, the ‘999 patent touches upon a natural phenomenon by using T cells to activate the immune system. The inventors relied on the fact that inhibiting “signals of PD-1, PD-L 1 or PD-L2 inhibit cancer proliferation through the mechanism of the recovery and activation of immune function.” This interaction is a natural phenomenon.

[T]he court concludes that, contrary to Bristol-Myers contention, the ‘994 patent touches upon a natural phenomenon by using T cells to activate the immune system. The ‘994 patent relies on the known scientific fact that blocking activation of the PD-1 pathway causes this effect in the body, which enables the patient’s T cells to perform their normal biological activity of removing cancer cells. This interaction is a natural phenomenon.

With regard to step 2, the court summarized the parties arguments as follows:

Merck contends that the process method consists of administering a synthetic agent through a single step to induce a natural reaction. Bristol-Myers insists that administering anti-PD-1 antibodies is not a diagnostic step as in Mayo, but provides the treatment itself.

Merck contends that the process method consists of administering a synthetic substance through a single step to induce a natural reaction. Bristol-Myers insists that administering anti-PD-1 antibodies is not a diagnostic step, but provides the treatment itself.

In both cases, the court determined:

Whether the claims amount to an implementation step is a complicated factual determination that the court could better resolve after discovery.

The court also noted that the patents were entitled to a presumption of validity, including a presumption that “the determination of the Patent Office that the [patents are] patent-eligible” is correct.

Overall, the court determined that “there is not clear and convincing evidence that ineligibility is the only plausible reading of the patent,” and so denied Merck’s motions to dismiss.

Ignoring Guidance Or Just Dicta?

While I am glad that the court did not grant Merck’s motions to dismiss, it is disappointing that the court believes that it needs to conduct an in-depth inquiry into whether these method of treatment claims amount to “significantly more” than a natural phenomenon. We all know that the Supreme Court expressly distinguished method of treatment claims in Mayo, and also distinguished method claims in Myriad. While some might say that language is dicta, ignoring it altogether defies the guidance the Supreme Court itself provided for applying its patent eligibility jurisprudence.