Home > Insights > Hospira successfully challenge further Herceptin follow-on patents
2 April, 2015

In April 2014 we reported on the outcome of a dispute between Hospira UK Limited and Genentech Inc. Here the High Court revoked two of Genentech’s follow-on patents for Trastuzumab (Herceptin®), an anti-HER2 antibody which heralded the start of a targeted approach to the treatment of cancer. The court battles have continued between these two parties with Hospira seeking revocation of two further Genentech follow-on patents in order to clear their way to market biosimilar lyophilised Trastuzumab. In November 2014 the UK High Court handed down its judgment deciding in favour of Hospira, revoking one of the patents in dispute and ordering amendment of the second patent to delete the challenged subject matter (please click here for the judgment).

The two patents at the heart of the most recent dispute (EP1516628 referred to herein as the ‘628 patent, and EP2275119 referred to herein as the ‘119 patent) are divisionals derived from the same parent application and relate to a lyophilised (freeze-dried) formulation of Trastuzumab (the patent for Trastuzumab itself and related SPC having expired on 29 July 2014).

In the proceedings, Genentech did not defend the validity of the claims as granted but instead sought to replace the granted claims with amended claims and argued in favour of their validity. Hospira challenged the amended claims offered by Genentech on the grounds that the amendments would (i) extend the scope of protection afforded by the claims, (ii) add matter, (iii) lack clarity, (iv) lack an inventive step and (v) be insufficiently disclosed.

Of particular interest, the claims as granted and the amended claims offered by Genentech were drafted as “product-by-process” claims (i.e. claims to a product which is defined, in whole or in part, by reference to the process by which it is or can be made). For instance, claim 1 as amended of the ‘628 patent read:

A formulation comprising a lyophilized mixture of a lyoprotectant, a buffer, a surfactant and an antibody, wherein the lyoprotectant is trehalose, wherein the buffer is histidine, wherein the surfactant is polysorbate 20 and wherein the antibody is huMAb4D5-8, obtainable by lyophilizing a solution containing 25 mg/ml huMAb4D5-8, 5mM histidine pH 6.0, 60 mM trehalose and 0.01% polysorbate 20.

When considering the extension of scope attack put forward by Hospira, Mr Justice Birss considered the UK and EPO authorities regarding product-by-process claims and particularly Kirin-Amgen, the leading UK judgment decided by the House of Lords in 2004. During his consideration, the judge noted from Kirin-Amgen that “a product not made by the claimed process [was] found not to infringe because it was not made by the claimed process while another product not made by the process [was] found to render the claim lacking novelty despite the fact it was not made by the process. This is a little paradoxical but it shows the difficulties one can get into with product-by-process claims”.

Following his consideration, Mr Justice Birss put forward the following derived principles in relation to product-by-process claims:

“(i) A new process which produces a product identical to an old product cannot confer novelty
on that product. To be novel a product obtained or obtainable by a process has to have some
novel attribute conferred on it by the process as compared to the known product.
(ii) This rule is a rule of the law of novelty. It is not a principle of claim construction. Although
in effect the rule treats “obtained by” language as “obtainable by” language, nevertheless as
a matter of claim construction a claim to a product “obtained by” a process means what
it says. That will be the relevant scope of the claim as far as infringement and sufficiency
are concerned.
(iii) Although normally a patent is drafted by the inventor “in words of his own choosing”,
the EPO will not permit overt product by process language unless there is no other alternative
available. By no other alternative, they mean no other way of defining a particular
characteristic of the product in question.”

Applying these principles to the claims in dispute, Mr Justice Birss decided that the “obtainable by” language used by Genentech did not accurately specify the product characteristic the process clause was meant to define, nor was this clear to the skilled person from reading the specification as a whole. Thus, it was held that the claim language left the skilled reader with “the impossible task” of having to try and define (without certainty) all the attributes of the product to which the process feature could apply. On this basis, the judge refused amended claim 1 of the ‘628 patent and new claims 1-3 of the ‘119 Patent proposed by Genentech.

In addition, the judge held that all of the claims in dispute added matter beyond the disclosure as originally filed and lacked an inventive step over prior art brought forward at trial. As a consequence, the judge made no findings in respect of the allegation of insufficiency.

In summary, patentees should take special care when considering drafting or amending claims in the so-called product-by-process format. Consistent with current EPO guidance, this judgment makes it clear that use of product-by-process language must be the sole means available to claim a novel technical attribute of a product. This attribute needs to be clearly identifiable to the skilled reader from the specification. This High Court decision is on appeal to the Court of Appeal. We will, of course, keep you informed of the development of this dispute in due course.

If you need further information please contact Matthew Spencer or your usual Boult Wade Tennant advisor.