When do clinical trial consent disclosures render a patent invalid?

As part of Good Clinical Practice (GCP) and local regulatory requirements, participants in clinical trials must provide informed consent.  To ensure participants can provide informed consent, trial organisers must provide them with a participant information sheet and consent form.  These documents must disclose enough detail about the objective of the study, type of treatments to be administered and possible effects to allow prospective participants to make an informed decision about whether to participate or not. 

Although detailed and accurate disclosure is an essential requirement for the conduct of clinical trials, there is a risk that publication of this information may adversely affect the novelty of subsequent patents.  A recent decision of the Federal Court of Australia in the case of InterPharma Pty Ltd v Hospira Inc (No 5) [2019] FCA 960 provides an interesting insight into the extent to which clinical trial participant information sheets and consent forms could damage patent novelty.

Background to the case

The case concerned a challenge to the validity of Australian Patent 754484, which was held by Pfizer and Hospira and was directed to the "use of dexmedetomidine for ICU sedation" (Pfizer patent).  Dexmedetomidine is a sedative belonging to the class of α2-receptor agonists.  The compound was not novel, having been disclosed in US patent 4910214 in 1987 as a general sedative. The Pfizer patent claimed new uses and methods of treatment for dexmedetomidine in the specific area of intensive care unit (ICU) sedation. 

InterPharma intended to supply a generic version of dexmedetomidine for sale in Australia, including for use in ICU sedation, and challenged the validity of the Pfizer patent on a variety of grounds.  These included that the patent was not a patentable manner of manufacture, was not novel, lacked an inventive step and the claims were not described with sufficient clarity.  Hospira and Pfizer cross-claimed that InterPharma threatened to infringe by supplying the generic product and were granted an interlocutory injunction preventing the sale of the generic product until the Pfizer patent expired in March 2019.

The court ultimately found in Pfizer's favour, rejecting all the grounds of invalidity argued and holding that InterPharma had threatened to infringe Pfizer's patent by the sale of the generic product.

Clinical trial consent forms as prior art

In arguing that the Pfizer patent lacked novelty, InterPharma, in part, relied on patient information consent (PIC) forms from two clinical trials conducted by Abbott Laboratories, as Pfizer's predecessor in the development of the Pfizer patent.  InterPharma argued that the PIC forms amounted to prior art information which anticipated Pfizer's patent, making it not novel under s 7(1) of the Patents Act 1990 (Cth) (Patents Act).

The test for anticipation requires the information to have been "made available to at least one member of the public, who was, in that capacity, free in law and equity, to make use of it" (Insta Image Pty Ltd v KD Kanopy Australasia Pty Ltd [2008] FCAFC 139) and that it discloses "explicitly or implicitly all of the essential features of the invention, as claimed" (AstraZeneca AB v Apotex Pty Ltd [2014] FCAFC 99).

The two PIC forms discussed in this case related to clinical trials of dexmedetomidine conducted at Duke University in North Carolina (Duke study) and in the Netherlands (249 study).  Both studies were completed before the priority date of the Pfizer patent on 1 April 1998. 

Justice Kenny found the PIC forms had been made publically…