The High Court revoked one of Merck’s patents (EP(UK) 0724444) which related to the drug finasteride for treating male and female pattern baldness. The main claim was a second medical use or “Swiss” claim, as follows:

“The use of [finasteride] for the preparation of a medicament for oral administration useful in the treatment of androgenic alopecia in a person and wherein the dosage amount is about 0.05 to 1.0 mg”.

Finasteride was previously known to be useful in the treatment of androgenic alopecia but was used at a much higher dose than that claimed. Therefore, it was the dosage regimen of the claim that was new.

The Court revoked this patent as it considered that, in order for a second medical use claim to be patentable, the novelty of the claim must lie in the new therapeutic application; novelty could not reside in a new dosing regimen for treatment of the same disorder as previously treated. Therefore, the court considered this claim to lack novelty.

Further, the Court considered that the claim related to a method of treatment since the novel aspect of the claim was the new dosing regimen. Under UK law, methods of treatment of the human body are specifically excluded from patentability as not being industrially applicable. Therefore, the patent was also revoked as relating to a method of treatment of the human body.

The UK Courts have now made a number of decisions on patent claims of this type all following the “Taxol” decision ([2001] RPC 1).

A significant gap in the interpretation of the law has now opened up between the UK Courts and the European Patent Office (EPO). The EPO considers that such second medical use claims in which the novelty of the claim lies in a new dosage regimen are patentable in principle. Further, the EPO does not consider that such claims relate to a method of treatment of the human body. This is demonstrated in the EPO decision T1020/03 (see our earlier article Dosage Regimen Claims Deemed Patentable by EPO Board of Appeal).

However, some other European countries have also taken a similar stance to the UK on claims relating to new dosage regimens. For example, the German Courts have recently revoked a European patent (DE) which claimed a new dosage regimen of the beta blocker carvedilol. Therefore, the EPO is granting patents which appear to be unenforceable in the UK and some other European countries. This position seems unlikely to change in the immediate future as it will require a shift in interpretation from the national courts or the EPO. In the UK it seems that this will require consideration by the House of Lords which is not currently foreseen. For the EPO, an opinion of the Enlarged Board of Appeal may be required. Again, this is not foreseen at present. Furthermore, this situation is unlikely to change under EPC 2000.

Justin Wilson
Life Sciences & Chemistry Group
June 2007