GSK’s extended release paracetamol patent 2

In addition to dismissing GSK’s appeal against the construction of “basket” (noted here), the Full Court also dismissed Apotex’ cross-appeals on fair basis and best method.

Fair basis

Apotex and Generic Partners also lost their appeals against the trial judge’s ruling that GSK’s patent was fairly based and there had been no failure to disclose the best method.

On fair basis, the claims were consistent with the consistory clauses, but Apotex argued the body of the specification showed that the invention was narrower than the broad consistory clauses. This appears to have been an attempt to read the claims down to two specific formulations discussed in the specification, Formulations C and D.

A key point was whether the trial judge had impermissibly taken into account information in an FDA report to ascertain if the claims travelled beyond the disclosure in the specification. Apotex argued this was excluded by the High Court’s decision in the first Lockwood decision, where it had said at [48]:

If all that is essential in assessing a fair basing objection is recourse to the contents of the specification, there is no call, for example, for an examination (except on construction questions) of common general knowledge (which is essential when considering an objection based on want of an inventive step), or of prior art (which is essential when considering novelty (s 7(1))) …

The Full Court, however, rejected this attack; concluding that the information in the FDA Report (which was common general knowledge) informed how the skilled addressee would understand the claims. At [166], the Full Court said:

What is critical to the pharmacokinetic behaviour of the many formulations within the claims is the dissolution profile (or release rate) of the formulation. The primary judge accepted that the FDA Report recognised that a variation of ±10% percentage points in the release rate was acceptable to the FDA even where no IVIVC had been established. This provides evidentiary support for the finding that the skilled addressee would know that various formulations within the claims apart from Formulations C and D were likely to have similar pharmacokinetic properties. This also provides a complete answer to Apotex’s argument that the skilled addressee (equipped with the common general knowledge) would approach the Patent with an understanding that there would be no reason to think that other formulations within the claims would have a similar pharmacokinetic profile to Formulations C and D in the absence of any established IVIVC.

The Full Court also rejected Apotex’ argument that a claim could not be fairly based unless the specification explained why the claims worked. Making it clear that they were dealing only with the position before the Raising the Bar Act reforms, the Full Court said at [170]:

Of course, it is important to note that s 40(2)(a) requires that the complete specification “describe the invention fully”. A complete specification may still “describe the invention fully” without explaining why the invention works. After all, the inventor, who presumably believes that the invention described works, may not understand why it works. But this does not prevent him or her from obtaining patent protection for the invention.

Best method

For best method, the argument built on the Servier ruling to argue there had been a failure to disclose the best method because the specification did not disclose the particular grade or viscosity of the high viscosity HPMC or the granulation end points used to make Formulations C and D.

At [192], the Full Court accepted that there could be a failure of best method if information was withheld even though it could be ascertained by routine experiment. The Full Court rejected the best method attack, however, finding that the information omitted was inessential manufacturing and production information. According to the Full Court at [201]:

It does not follow merely because the patent applicant uses a particular manufacturing process or a particular excipient in formulating its commercial embodiment that it will form part of the best method. The patent applicant may have adopted a particular process, or used a particular excipient, for reasons that are associated with its own particular circumstances rather than because it believes that they reflect the best method. The best method known to the patent applicant may be one that allows for the optimisation of a formulation by the skilled addressee rather than one that adheres to one specific formulation that the patent applicant seeks to commercialise.

Those preparing specifications might want, first, to note the reservation that the Full Court was not dealing with the “new” post-Raising the Bar regime. Secondly, [192] appears to carry with it the warning that, if one leaves something out, one does so at one’s own peril.