IP & IT Bytes: Patents - guidance on product by process claims and obviousness



The High Court, applying the European Patent Office's (EPO) approach to the allowability of product by process claims, has refused to allow proposed amendments to the claims of two patents for a breast cancer drug.


If the invention is a process, a person infringes the patent for that invention if he disposes of, offers to dispose of, uses, imports or keeps (for disposal or otherwise) any product obtained directly by means of that process (section 60(c), 1977 Act) (1977 Act).

In considering whether or not to allow a proposed amendment, the court or the comptroller shall have regard to any relevant principles applicable under the European Patent Convention (section 75(5), 1977 Act).


G's patents related to formulations of the breast cancer drug known as Herceptin, whose active ingredient is trastuzumab. Patent protection for trastuzumab itself had expired. The patents related to lyophilised (freeze-dried) formulation of antibodies, one of which was trastuzumab. G applied to amend both patents and did not defend the validity of the relevant claims as granted.

H argued that all of the claims as amended were obvious, or, if not obvious, were insufficient. H also contended that none of the amendments proposed should be allowed, on four grounds: extension of scope; a point on product by process claims; clarity; and added matter.


The court held that the proposed amendments were not allowable under the EPO principles relating to product by process claims, also that they introduced added matter, and that all of the claims in issue lacked inventive step.

There are two kinds of product by process claims: products obtained by a process; and products obtainable by a process.

A new process that produced a product identical to an old product could not confer novelty on that product. To be novel a product obtained or obtainable by a process had to have some novel attribute conferred on it by the process as compared to the known product. This rule was a rule of the law of novelty, not a principle of claim construction. Although, in effect, the rule treated “obtained by” in the same way as “obtainable by”, as a matter of claim construction a claim to a product “obtained by” a process meant what it said. That would be the relevant scope of the claim as far as infringement and sufficiency were concerned.

Although normally a patent was drafted by the inventor in words of his own choosing, the EPO would not permit overt product by process language unless there was no other way of defining a particular characteristic of the product in question.

Here, the proposed amendments were unallowable because they did not state which characteristic of the product conferred by the process is being referred to. The skilled reader would not know, from the claim or the specification as a whole, which one was intended. Unless it is possible to identify all the attributes to which the language applies, amendments to this type of claim cannot be permitted.  

In relation to obviousness, the law could not be accurately summarised simply by stating that the question was whether the skilled person would have arrived at the claimed invention, not whether they could have. The issue depended on the facts. Sometimes asking simply if a skilled person would do something risked placing too much weight on minor or irrelevant factors like cost, instead of focusing on the technical issues. The fact that the claimed invention was not something a skilled person would in practice make was not relevant. It was more accurate to say that it was not patentable because the skilled person could make it without any inventive step. However, in other cases the difference between “could” and “would” was important. If the outcome rested on the result of a single experiment, the fact the skilled person could carry it out did not usually mean the invention was obvious: the question may be whether they would carry out the test in the expectation of a positive result. 

Here, it was not true that a real team would arrive at the claimed formula. However, the claimed formula could be reached by applying nothing other than the routine approaches applied to excipients that were part of the skilled team's common general knowledge. This was not a case where the invention was not obvious because it was only arrived at after a series of steps involving the cumulative application of hindsight, that is where it was only the hindsight knowledge of the invention as the target that could motivate a skilled person to take each step without knowledge about the next one. So, all of the claims lacked inventive step.


Applying EPO principles relating to amendment of product by process patents, the UK court refused amendments that did not allow the reader to identify all the attributes of the product conferred by the process conditions. To identify one attribute was not sufficient if the reader would understand there was likely to be an indefinite class of further attributes to which the product by process language also applied.       

This decision also addresses the law of validity and infringement in relation to product by process claims, which are typically in the form of “obtained by” or “obtainable by”. 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.  However, for an “obtainable by” claim to be infringed if a different process is used, it must have every single characteristic that is the inevitable consequence of that process. If one attribute is missing then it is not “obtainable by”. In practice, it may be difficult if not impossible to demonstrate infringement of an “obtainable by” form of claim if a different process is involved from that specified in the claim.

The court's analysis of obviousness in the context of a drug formulation case is also interesting. The relevant approach may depend on the facts: in an empirical field the skilled team will, without hindsight, want to test a range of ingredients that are all part of the common general knowledge, and this will not necessarily involve an inventive step.       

Case: Hospira UK Ltd v Genentech Inc [2014] EWHC 3857 (Pat).

First published in the December 2014 issue of PLC Magazine and reproduced with the kind permission of the publishers. Subscription enquiries 020 7202 1200.