Clinical trials have been used to invalidate patents as a public use. Whether it is the patentee who is trying to avoid its own clinical trials from being held a public use, or a third party's clinical trials, the circumstances and parameters of when such trials may be considered a public use raise important issues for the pharmaceutical industry. In the most recent case on this topic, Dey L.P. v. Sunovion Pharm. Inc., 2012-1428 (Fed. Cir., May 20, 2013), the alleged infringer uses its own clinical trial as a weapon to attack the validity of the asserted claims. Dey follows recent cases which support the exception to clinical trials as a public use.


In 2007, Dey L.P., Dey Inc., and their parent company Mylan, Inc. (collectively, "Dey") sued Sunovion Pharmaceutical, Inc. ("Sunovion"; formerly known as Sepracor, Inc.) for infringement of five of Dey's patents. Both parties sell products that treat chronic obstructive pulmonary disease ("COPD"), and both products provide the compound formoterol in an aqueous solution to be administered through a nebulizer. Dey brought suit shortly before Sunovion launched its product.

Sunovion moved for partial summary judgment conceding that "the formulation fell within the scope of the asserted claims." Sunovion also claimed that the formulation was in public use more than one year before the priority date of Dey's patents through Sunovion's clinical trial, therefore anticipating Dey's asserted claims according to the pre-AIA Section 102(b). The district court agreed that Sunovion's clinical trial constituted a public use of Dey's invention and invalidated Dey's asserted claims. Dey appealed.

Same "Public Use" Analysis for Prior Use by a Third Party

Determining "public use" requires analysis of the following factors: the nature of the activity that occurred in public; the public access to and knowledge of the public use; and whether there was any confidentiality obligation imposed on persons who observed the use. Bernhardt, L.L.C. v. Collezione Europa USA, Inc., 386 F.3d 1371, 1379 (Fed. Cir. 2004). In addition, "an agreement of confidentiality, or circumstances creating a similar expectation of secrecy, may negate a 'public use' where there is not commercial exploitation." Invitrogen Corp. v. Biocrest Mfg. L.P., 424 F.3d 1374, 1382 (Fed. Cir. 2005). The court in Dey made clear that the same analysis applies to prior use by an unaffiliated third party, and public availability of the third-party use is required. Secret or confidential third-party uses cannot invalidate later-filed patents. By way of example, the Federal Circuit contrasted the circumstances in Dey to other cases where third-party uses invalidated later-filed patents because the third-party user "made no attempt to maintain confidentiality or to deliberately evade disclosure," made no "discernible effort to maintain the [invention] as confidential," or "made no efforts to conceal the device or keep anything about it secret." See Eolas Techs. Inc. v. Microsoft Corp., 339 F.3d 1325 (Fed. 2005), Baxter Int'l, Inc. v. COBE Labs., Inc., 88 F.3d 1054 (Fed. Cir. 1996), and Beachcombers v. WildeWood Creative Prods., Inc., 31 F.3d 1154 (Fed. Cir. 1994).

These guidelines seem clear-cut, but in practice, third-party uses may cause confusion in legal standards. In fact, the district court in Dey relied on the language of a Federal Circuit case not involving third-party uses to hold that public use may involve any use with no limitation, restriction or obligation of secrecy to the inventor. The Federal Circuit however pointed out the inapplicability of the language in the third-party use situations because a third-party use by definition is made by persons not owing a duty of secrecy to the inventor. Rather, for third-party uses, the Federal Circuit directed parties to instead examine the adequacy of the confidentiality guarantees to the party in control of the allegedly invalidating prior use.

Solid Base to Argue that Clinical Trials Are Not Public Use

Applying these standards, the panel reversed the district court's grant of summary judgment to Sunovion. The court found the Sunovion clinical trial sufficiently controlled and restricted, and the confidentiality obligations imposed in the clinical trial were sufficiently strict. As such, a judgment of invalidity was not justified. Judge Newman went a step further in dissent stating that in her opinion the court should have entered judgment for Dey.

More specifically, the court provided useful guidelines for determining whether a clinical trial constitutes public use. First, confidentiality agreements signed by the test subjects are not required to negate public use, although a strict confidentiality agreement signed by the investigators is strongly favored. Second, patients in the clinical trials may be aware of the active ingredient of the tested drug, where as here, the claimed invention includes a delivery formulation, as long as more specific information about the drug formulation is withheld. Third, self-administration of the tested drug at the patient's home and not returning all unused test products is common and should not render a clinical trial a public use. Finally, the fact that a tiny fraction of the thousands of vials were lost without penalizing the responsible test subject(s) does not preclude a reasonable jury from concluding that the clinical trial is not public use.

"The core issue is not public knowledge of the invention, but the public use of it." The district court relied on this language from New Railhead Mfg. L.L.C. v. Vermeer Mfg. Co., 298 F.3d 1290 (Fed. Cir. 2002) to determine the nature of the prior use. The Federal Circuit found this reliance misplaced because the quoted language from New Railhead derives from an "experimental use" case. Interestingly, the Court went on to state that a court must decide whether the claimed features of the patents were placed in the public's possession, and if the public is not informed of and cannot readily discern the claimed features, i.e.,not having adequate knowledge, the invention is not in the public's possession. In this way, the Federal Circuit seems to be saying that, for public use, the core issue is not public use of the invention, but the public knowledge of it.

The holding in Dey provides a solid base for the position that a properly conducted clinical trial is not a public use. It is worth noting that the new Section 102(a)(1) of the America Invents Act includes a new provision that requires an invention not to be "otherwise available to the public." This provision should maintain the current law on what constitutes a public use. However, the AIA broadens public use on two fronts. First, use is no longer restricted to use in the U.S. Second, no grace period applies to public uses conducted by third parties. In addition, new standards being imposed by the FDA may also affect whether a clinical trial constitutes a public use, that is, the FDA may now require a clinical trial to be registered on, which may serve as a publicly accessible index of clinical trials, thereby making the trial more "public". It will take time to see how the Federal Circuit's Dey ruling plays out in the post-AIA world on the nature of clinical trials.