Prometheus Labs., Inc. v. Roxane Labs., Inc. (D.N.J.)

The asserted claim was obvious because all of its elements were in the prior art.

Summer 2014

GENERICally Speaking

Case Name: Prometheus Labs, Inc. v. Roxane Labs, Inc., Case Nos. 11-230 (FSH), 11-1241 (FSH), Unpublished (D.N.J. May 21, 2014) (Hochberg, J.)

Drug Product and Patent(s)-in-Suit: Lotronex® (alosetron hydrochloride); U.S. Pat. No. 6,284,770 (“the ’770 patent”)

Nature of the Case and Issue(s) Presented:  Lotronex was initially launched in 2000, but was subsequently removed from the market in light of serious side effects attributed to the drug. It was re-launched in 2002 with a new label. At the time, the ’770 patent was listed in the Orange Book along with U.S. Patent No. 5,360,800 (“the ’800 patent”). In 2005, the ’770 patent was de-listed from the Orange Book. In 2007, Prometheus acquired the Lotronex franchise and initiated a reexamination of the ’770 patent. The USPTO issued the reexamination certificate in 2010. Prometheus re-listed the ’770 patent in the Orange Book.

In December 2010, Roxane submitted its ANDA with a paragraph IV certification to the FDA, and Prometheus filed suit against Roxanne and its API manufacturer. Prometheus asserted three method claims against defendants. The method claims are directed to treating a diarrhea-predominant female irritable bowel syndrome (IBS-D) patient by assessing whether the patient has experienced symptoms for at least six months and administering an effective amount of alosetron. The court identified the following invalidity issues for trial: (i) obviousness; (ii) obviousness-type double patenting; (iii) lack of written description; and (iv) lack of patentable subject matter. After trial, the court issued its findings of fact and conclusions of law finding that the ’770 patent was invalid as obvious and invalid for obviousness-type double patenting in light of the claims of the ’800 patent. The court also found that the patent contained adequate written description and did not lack patentable subject matter.

Why Roxane Prevailed:  The court found the asserted claims obvious because all of the elements were disclosed in the prior art. The prior art disclosed using alosetron to treat IBS, which would include women with IBS-D who had symptoms for more than six months. One reference disclosed that alosetron slowed colonic transit and alleviated pain. The side effects of alosetron were known and a gastroenterologist would be cautious in administering the drug, therefore the six-month symptom duration would have been a substantially expected result. It would have also been obvious to assess patients for at least moderate pain and administer alosetron to treat moderate pain. The court also found that treating female patients as opposed to male patients fails to impart novelty because, first, the prior art would have included women patients, and, second, the patent-in-suit does not affirmatively claim the exclusion of men. The claims do not contain a negative limitation and the Court refused to import one.

The court also found the ’770 patent invalid for obviousness-type double patenting in light of the claims in the ’800 patent. While the ‘800 patent was listed in the Orange Book, it was never considered by the Patent Examiner during the prosecution or the reexamination of the ’770 patent. The court determined that any elements added by the ’770 patent were simply obvious variants of the ’800 patent which every good doctor would execute. The differences between the ’770 patent and the ’800 patent are the relevant population, or object of the method claims, rather than the method itself.

The dispute concerning the written description requirement centered on whether the ’770 patent demonstrated that the inventors possessed “assessing” whether a patient had IBS-D (rather than simply IBS symptoms) for six months or more. Plaintiffs argued that since the reported clinical trials only included patients with diarrhea-predominant IBS or alternating constipation/diarrhea, one of ordinary skill would read this passage as requiring IBS-D symptoms. The parties’ experts disagreed. The court noted that having mixed symptoms (constipated and diarrhea) included in the population muddies the situation. Nonetheless, defendants failed to provide clear and convincing evidence that the description was inadequate.

Finally, the court rejected defendants’ argument that the asserted claim covered unpatentable subject matter. Defendants argued since the claim included assessing whether the patient had symptoms for six months, it was attempted to cover a law of nature. The court was not persuaded because routine activities or mental steps alone would not render the asserted claim unpatentable subject matter.

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