Prior published information in clinical trials can invalidate Australian patents

 

The long running litigation of Mylan’s Lipidil™ (fenofibrate) patents has now finally come to a close.  The High Court[1] has refused a special leave application by Mylan Health Pty Ltd to appeal the Full Federal Court decision[2]  handed down on 3 July 2020, finding that its fenofibrate patents are invalid. This means that the decision of the Full Federal Court stands.

This Full Federal Court decision is of particular significance for pharmaceutical patentees/applicants in Australia, who seek to protect their inventions by way of method of treatment and Swiss-style claims.  As many readers would be aware, Swiss-style claims are directed to use of a known substance in the manufacture of a medicament for a new therapeutic treatment.

The Full Federal Court found that Swiss-style claims are purpose-limited, highlighting differences between the Australian and European approach to construction of these claims. Therefore, a manufacturer will only infringe a Swiss-style claim if it can be clearly shown that a product was made specifically for use to treat the claimed indication(s), regardless of the manufacturer’s intentions.  Under European law, the achievement of the therapeutic effect is a functional technical feature of the claim.

The Full Federal Court also found that method of treatment and Swiss-style claims can lack novelty in light of clinical trial protocols that include a “reasoned hypothesis” but that have not been scientifically validated.  This is of course considered on a case-by-case basis, but may occur as long as the disclosure is sufficiently specific and complete enough to be considered equivalent to the claimed invention.

Finally, the Full Federal Court found that an invention is considered obvious if a person skilled in the art would be directly led to try it as a matter of routine, in the expectation that it might produce a useful result – even if the person skilled in the art cannot say with certainty that the outcome will be produced.

 

Implications of the decision

This decision reinforces the importance of including both Swiss-style claims and method of medical treatment claims when seeking to protect a therapeutic use of a medicament in Australia, since each of these will capture a different infringer.  Specifically, a pharmaceutical manufacturer will only be deemed to infringe a Swiss-style claim if it can be shown that a product was made specifically to treat the claimed indication. For example, this may be the case if the medical condition is specifically listed as an approved indication on any labelling or associated product information sheets. Where this cannot be demonstrated, use of the product to treat the medical condition may still be considered to infringe a method of treatment claim – as long as there is a claim present that is directed to such.

The Full Federal Court decision also confirms that scientific speculation (or unproven reasoned hypothesis) in prior art documents, including clinical trial protocols, may be detrimental to a finding of novelty.  This is even the case for double-blind clinical trials. Thus, careful consideration  should be given to any disclosures made prior to, or in relation to clinical trials, which could later be construed as directly teaching the use of a medicament for the treatment of a particular disease, even when the certainty of the treatment outcome is not yet known.   It is advisable to seek advice before publication.  Existing pharmaceutical patent holders should also be mindful that their patent could be challenged on the basis of such prior published clinical data.

The Full Federal Court also provided further guidance on assessing obviousness. The ‘modified Cripps question’ asks whether a person skilled in the art would have been led directly as a matter of course to try something falling within the claim with an expectation of success[3].  The decision further explains that this question can be answered in the affirmative, even if the person skilled in the art cannot say with certainty that the outcome will be produced by following a series of routine steps, as long as the person skilled in the art can be led to try the invention as claimed.

This article was written by Vanessa Yeung and Sarah Couper.

If you have any specific enquiries about this article, please contact Paul Jones or Debra Tulloch.

Jones Tulloch’s articles are provided as general information only, current at the date of publication. They do not constitute professional (patent and trade mark attorney) advice and should not be relied upon as such. If you need specific professional advice, for example in relation to a matter of interest arising from this communication, please contact us.

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[1] Mylan Health Pty Ltd v Sun Pharma ANZ Pty Ltd [2020] HCASL 234
[2] Mylan Health Pty Ltd v Sun Pharma ANZ Pty Ltd [2020] FCAFC 116
[3] Aktiebolaget Hässle v Alphapharm Pty Ltd (2002) 212 CLR 411 at [50]-[53]]