Does Mr Justice Arnold's decision in Teva v MSD show just how large a role patent law has come to play in assessing SPC validity?

The AmeriKat facing the wind of
combo SPC validity

A cool wind seems to be blowing from the Patents Court, especially if you are an SPC owner for a combination product.  In the past three months, Mr Justice Arnold has decided three SPC cases - Teva v Gilead [2017] EWHC 13, Abraxis v Comptroller General of Patents [2017] EWHC 14 and, last week, Teva v MSD [2017] EWHC 539.  The first two cases were subject to references to the CJEU (see previous IPKat post here), with the latest decision keeping to the UK's shores...at least for now.  The headline point seems to be that SPC owners will have a tough time trying to maintain their combination product SPCs.  So how does the decision in Teva v MSD fit into this?  The AmeriKat summarizes the decision below.  

What was the SPC?  

MSD's SPC/GB08/022 ("the SPC")  - a combo SPC covering the anti-retroviral medication used in the treatment of HIV sold as Atripla by BMS and Gilead.  Atripla is a fixed-dose combination of three active ingredients which are inhibitors of a viral enzyme known to reverse transcriptase - efavirenz ("EFV"), tenofovir in the form of disoproxil fumarate ("TDF") and emtricitabine ("FTC").

FTC is a NRTI (nucleoside reverse transcriptase inhibitor).  EFV is a NNRTI (a non-nucleoside reverse transcriptase inhibitor).  Tenofovir, a NtRTI (i.e. a nucleotide RT inhibitor), is a nucleotide analogue.  

The rationale of Atripla is that it simplifies HIV-treatment regimens by improving patient compliance (one pill being easier to take than three separate ones).
 
The SPC described the product as

"A combination of efavirenz, emtricitabine or a pharmaceutically acceptable salt or ester thereof, and tenofovir or a pharmaceutically acceptable prodrug, salt or ester thereof, particularly tenofovir disoproxil, especially tenofovir disoproxil fumarate" 

The marketing authorization ("MA") for Atripla was granted on 13 December 2007.  An MA for EFV was granted in 20 November 1998.  This MA was used as the basis to obtain an earlier SPC - SPC/GB00/35 - for EFV, alone ("the EFV mono SPC") which expired on 19 November 2013.  The MAs for TDF and FTC were granted on 5 February 2002 and 24 October 2003, respectively.

What was the problem?

Teva argued that the SPC was invalid under Article 3(a) and 3(c) of the SPC Regulation.  Article 3(c) demands that the product subject to the SPC be protected by a basic patent in force at the date of the SPC application.  Article 3(c) requires that the product not already be subject to an SPC.   Teva argued that the SPC was invalid under:

• Article 3(a) as the product was not protected by the basic patent - EP(UK) 0 582 455.  Interestingly, MSD amended its patent to include a new claim 17 upon which it relied to protect the product for the purposes of obtaining the SPC, but didn't rely upon it at trial (c.f with the position in Actavis v Boehringer [2013] EWHC 2927 at [10]).  Only claim 16 was relied upon at trial.  Claim 16 is in the following terms:

"A combination of the compound of claim 12 or a pharmaceutically acceptable salt thereof with a nucleoside analog having biological activity against HIV reverse transcriptase."

•  Article 3(c) as MSD already obtained an SPC for EFV based on the basic patent.  Because it was agreed that the basic patent disclosed and claimed EFV specifically and as part of a class of compounds, Teva argued that the Atripla product had already been subject to an SPC (the EFV mono SPC) which compensated MSD for the delay in exploiting the invention.  

What is the legal test?

On Article 3(c), after an exhaustive review of the case law under Article 3(c), including referring to the Explanatory Memorandum (COM (90) 101 final), the judge concluded that:

• Article 3(c) precludes the grant of SPCs for a combination of active ingredients where one of those active ingredients embodies the "core inventive advance" (at [30] of Actavis v Sanofi) or "sole subject-matter of the invention" (at [39] of Actavis v Boehringer) of the basic patent and that active ingredient has already been the subject of an SPC based on that patent.  This is irrespective of whether the patent contains one of more claims which protect the combination itself.  

• But an SPC can be granted if the combination is a distinct invention - it will not matter whether its protected by the same patent or by a different patent.  In those circumstances, one of those active ingredients could not be said to be the "sole subject-matter of the invention".

To determine whether the combination is a "distinct invention", the correct question to be considered is not a "conventional patent law" question.  The question is instead:

"whether, given the invention of efavirenz [which was accepted by the parties], claim 16 represents a distinct invention such that it could in principle form the subject-matter of a separate patent."

What was the answer?

The judge first decided under the Article 3(a) objection.  With the aid of expert evidence, Mr Justice Arnold held that the construction of Claim 16 would include tenofovir (MSD successfully argued that it could be described as a nucleoside analog).  However, he held that the "a" in front of " a nucleoside analog" meant that Claim 16 was limited to a duel combination product, but not a combination of all three of EFV, TDF and FTC.    For that reason, since the "minimum requirement" is that all three must fall within a claim of a basic patent, the SPC was held to be invalid under Article 3(a).  It was on the basis of this construction which meant that the SPC did not meet this "minimum requirement" that the question of a reference to the CJEU did not arise, as it had in Teva v Gilead.  

The judge then turned to Article 3(c).  In answering the question posed above, he considered that Claim 16 was not independently valid over the claims which protect efavirenz and 

"does not represent a distinct invention. There is nothing in the Patent to suggest that claim 16 represents a distinct invention. Given the need for a simple and transparent system for the grant of SPCs, it seems to me that that should ordinarily be the end of the matter and that it should not be necessary to adduce expert evidence on this question."

He went on to acknowledge that if (note the word "if") it was appropriate to have regard to expert evidence: 

"I consider that the evidence establishes that, given efavirenz, it would have been obvious to combine it with a NRTI in vitro because that would have been an obvious thing to try and the skilled person would have had a fair expectation of success. This is for the following combination of reasons."

This conclusion pulled support from an earlier finding made by the judge at paragraphs 136-140 where he concluded that it was CGK that combinations of NRTIs and NNRTIs were at least worth considering.  This was because emerging research showed that NNRTIs were unlikely to be efficacious alone and given the different mode of action to NRTIs, there were potential advantages in combining the two.  The judge held that the skilled person would have considered that there was a reasonable likelihood that a combination of a NRTI and a NNRTI would be either synergistic or additive, in vitro.  Further, there was a "reasonable possibility" that the effect would be synergistic, although tests would have to prove this.  The SPC was therefore invalid under Article 3(c).

Conclusion

So a combination SPC bites the dust.  The AmeriKat is struck by the detail in which the parties went into expert evidence on construction for the purposes of Article 3(a) which was then employed to establish CGK for the purposes of a somewhat fall-back assessment of "distinct invention" under Article 3(c).   This assessment was essentially that the combination was obvious over the CGK alone (which in normal patent proceedings is a pretty risky move).  On one view, the "distinct invention" test is just an SPC-neutral way of disguising a conventional patent law inventive step test into SPC law. Arnold J's comments about the appropriateness of the use of expert evidence seems to suggest a tacit recognition of this nervousness to adopt conventional patent law tests and practice in the SPC space (or maybe it does no such thing!).  Further, given that the correctness and scope of the use of expert evidence in assessing validity under Article 3(c) has not been clarified, will this lead to mini-patent trials inside of SPC proceedings?  

If patent law assessments start creeping into SPC assessments of "distinct invention" then this must call into question whether the SPC Regulation (and the CJEU's interpretations of Article 3(c)) is doing justice to the teleological interpretation of the SPC Regulation.  Further, how will patent offices be expected to assess the CGK for the purposes of determining Article 3(c) objections - this is not the straightforward, administrative assessment that the SPC regime was meant to embody.  But here, we have the CJEU to thank for their Article 3(c) jurisprudence.  "Perhaps post-Brexit UK laws will be a bit kinder to combo SPCs" muses Merpel.  Well, on that happy note...