Even in the case of third-party uses, being “accessible to the public” still requires public availability; “secret or confidential third-party uses do not invalidate later-filed patents.” A formal confidentiality agreement, however, is not required to show non-public use. “[I]n the absence of such an agreement, we simply ask whether there were ‘circumstances creating a similar expectation of secrecy.’” In clinical trials in particular, it is apparently routine for investigators to sign strict confidentiality agreements while the patients do not. Such an arrangement does not necessarily strip the trial of confidentiality protection or render it accessible to the public.

Background / Facts: The parties here are competitors in the pharmaceutical industry and were simultaneously developing pharmaceutical products to treat lung disease at the time that the patents-in-suit were filed. It turns out that a particular drug formulation tested by the accused infringer in one of its own clinical trials was the same as the claimed invention of the patents-in-suit. These clinical trials pre-dated the filing of the patents-in-suit by more than one year.

Issue(s): Whether a clinical trial in which a third party tests its own products constitutes a prior public use of the invention within the meaning of 35 U.S.C. § 102(b).

Holding(s): No. The policies underlying the public use bar are aimed at “discouraging the removal, from the public domain, of inventions that the public reasonably has come to believe are freely available.” The key inquiry is therefore not an “enablement-type inquiry,” but whether the “claimed features of the patents [were placed] in the public’s possession.” Thus, if members of the public are not informed of, and cannot readily discern, the claimed features of the invention in the allegedly invalidating prior art, the public has not been put in possession of those features. Here, the clinical trial participants were permitted to discuss the study with their doctors and therefore not required to execute formal confidentiality agreements, but “they were not in a position to reveal the composition of the allegedly invalidating prior art, because they were unaware of the specifics of the inventive formulations.” “[T]he fact that no formal obligation of secrecy was imposed on the study subjects does not automatically transform [the accused infringer’s] clinical trial into a public use.”

Full Opinion