IP Review Autumn 2017

Patentability The ability to obtain patent protection is critical in the pharmaceutical sector, as pharmaceutical companies need to be able to recoup the huge costs involved in developing effective new drugs. This is perhaps even more important in precision medicine. Identifying biomarkers that correlate with a disease is hard enough. Identifying biomarkers that predict how a drug will affect a disease is a much more daunting prospect for a pharmaceutical company. It is therefore critical that suitable incentives prompt researchers to undertake this expensive but potentially life-saving work. An important issue affects the patentability of such developments, however. There is likely to be overlap between the patient groups defined by a biomarker and the more traditional patient groups defined by the disease in general. Using the Merck example previously mentioned, Keytruda was already known as a treatment for non- small cell lung cancer. Therefore, it is inevitable that certain patients with a MSI-H or dMMR variant of non-small cell lung cancer tumour would already have been treated with Keytruda. Can a patent claim covering treatment of a patient group that overlaps with a patient group that was already being treated be allowable? Patentability options Consider an example where drug D has previously been used for treating patients with condition C. It is then determined that drug D is actually only effective in the subgroup of patients with biomarker B. What, then, is patentable? Drug D is known and its use in patients with condition C is known. The biomarker itself was already present in the bodies of certain patients. What is new is the identification of how biomarker B is predictive of drug D’s effect on condition C, and applying this in determining the treatment approach. One option is claiming a method of testing a patient for biomarker B. While there are ways to draft suitable diagnosis claims that cover these test methods, product claims covering the drug are usually more valuable. This is because it is typically easier to identify and stop an infringing supply of the drug, as opposed to policing the carrying out of a diagnostic test. In many countries around the world, medical use type claims are available. These claims confer patentability in situations where there is a novel and inventive use of the drug. With medical use type language, the following claim may appear suitable: “Drug D for use in the treatment of condition C in a patient with biomarker B”. However, drug D has already been used in all patients with condition C, so the use in patients with biomarker B has inevitably already been performed. Would this claim be allowable? According to the European Patent Office (EPO), for a claim’s novelty to rely on the new patient group, the selection cannot simply be arbitrary. The Technical Board of Appeal of the EPO stated that “the use of the same compound in the treatment of the same disease for a particular group of subjects, could nevertheless represent a novel therapeutic application, provided that it is carried out on a new group of subjects which is distinguished from the former by its physiological or pathological status.” Therefore, the biomarker must be linked to the way in which the human body responds to a condition or the way in which the condition operates within the human body. It was confirmed that this applies even where the new patient group overlaps with known patient groups. For an inventive step to be acknowledged, a functional relationship between the biomarker and the improved technical effect should be established. Evidence of the relationship between the biomarker and how the treatment acts upon the condition is critical. Where the relationship can be described at the biochemical level (for example if the biomarker is part of a pathway involved in the disease), in vitro or preclinical data may be sufficient. If a relationship has been established without any biochemical understanding (for example if the correlation was established through statistical analysis), clinical data is more likely to be required. It therefore appears that the above claim language should be allowable at the EPO. However, in other jurisdictions, further distinction may be required. Example claim language to achieve this could be: “Drug D for use in the treatment of condition C in a patient that has been characterised as having biomarker B.” or even: “Drug D for use in the treatment of condition C in a patient that has been characterised as having biomarker B using method M.” It would, of course, be advisable to push for the broadest claim in any given jurisdiction, but ensure there is basis for these additional limitations if needed. Conclusions The European Patent Office has recognised the importance of developments in precision medicine and is paving the way for the incentive of patent protection to drive research. Crucially, even in situations where there is overlap between a known patient population and a new patient population, the possibility for obtaining patent protection still exists. This is important news for innovators, physicians and patients, as we should see more research in this area leading to more effective treatments. 15 Andrew Evitt aevitt@withersrogers.com To find out more contact Nicholas Jones njones@withersrogers.com