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Accord Healthcare Ltd v Medac Gesellschaft für Klinische Spezialpräparate mbH [2016] EWHC 24 (Pat)

This case concerned a revocation action brought by Accord Healthcare to revoke a EP(UK) 2046332 owned by Medac.

The patent related to a specific concentration of methotrexate solution, used in the treatment of autoimmune diseases, including rheumatoid arthritis. The solution was administered by subcutaneous injection.
Methotrexate itself was well known, having been originally developed and used in much higher doses for the treatment of cancer. The use of methotrexate for the treatment of autoimmune diseases was also known. The only novel aspect of the claimed invention was the concentration of the product used. Previously methotrexate had been administered when treating auto immune diseases as at concentrations of between 7.5-25 mg/ml. The patent proposed utilising a solution of about 50 mg/ml, much higher than the conventional concentrations used when treating autoimmune diseases but still significantly lower than the concentrations used when treating cancer.

The Court found the patent lacked inventive step and revoked the patent. The judge (Birss J), accepted Accord’s arguments that the relevant skilled person for considering inventive step would involve both a clinician and a formulator.

The judge considered that the clinician, on reading of the cited prior art, would be concerned with the pain which was caused in the administration of methotrexate. The clinician would in turn encourage the formulator to look for a formulation to counteract the pain caused. The formulator would think it obvious to optimise the formulation to minimise pain, even if there were other factors which may contribute to the pain (eg shape of the needle).
Even though this was not apparently in any text books of the time, it was found as a fact that it was part of the common general knowledge that smaller dosage volumes, particularly volumes under 1 ml caused less pain than larger volumes. Although a clinician on his or her own might not suggest increasing the concentration of the solution used to minimise volume and hence reduce pain of administration, this would be obvious for the formulator.
The judge also considered the secondary evidence – why had it not been done before? – and found that, because some clinicians had asked for a higher concentration, the reason it had never been done was not because it wasn’t obvious.

Having concluded that the patent lacked inventive step over one of the cited items of prior art, other objections based on more remote art were dismissed without being considered in depth, other than the judge noting the difficulty of trying to establish lack of inventive step on the basis of common general knowledge alone, due to the danger of such arguments being based on hindsight

Read the judgment here.

Head note: Nicholas Fox, Simmons & Simmons