Monday, 11 June 2012

T 611/09 – Non-Therapeutic

The opponent filed an appeal against the maintenance of the opposed patent in amended form.

Claim 1 of the main request before the Board read:
1. The use of a citrate salt solution having a concentration to eliminate infection and to reduce the likelihood of subsequent infection for the manufacture of a medicament in the form of a catheter lock solution for infusion into the lumen of an in-dwelling intravascular catheter of a patient for the treatment of an infection or a substantial risk of infection related to the presence of the catheter wherein the lock solution comprises the citrate salt in a concentration range, in weight percent, of between 10% and 50%.
The discussion of this request by the Board contains some interesting statements:

Preliminary considerations

[4.1] Claim 1 of the main request, which is drafted in the “Swiss type” format, refers to two alternative uses of the lock solution, namely to the treatment of an infection and to the treatment of a substantial risk of infection, which in the view of the board is equivalent to a prevention.

[4.1.1] Regarding therapy the board notes that according to the established jurisprudence of the boards of appeal, this term comprises any treatment designed to cure, alleviate, remove or lessen the symptoms of a disorder or malfunction or the human or animal body. This definition also includes a retardation in the progression of a disease, as for example in cancer therapy. All these aspects of therapy have one thing in common: the majority of the patients having undergone a treatment must be in a better physical and/or mental state than those without a treatment.

A further important aspect in connection with therapy via medicaments is that the medicament is brought into contact with the body where it delivers the active agent(s) in order to obtain the desired pharmacological effect. Active agents exercising their activity outside the human or animal body (e.g. disinfection of surgical instruments in order to avoid infections) are not considered to be therapeutic.

[4.1.2] In the present case it is therefore important to evaluate whether the lock solution exerts its antibacterial activity within the human or animal body or outside of it. According to paragraphs [0013] and [0024] of the contested patent, the lock solution is used for infusion into the lumen of an in-dwelling intravascular catheter, i.e. a catheter which is typically inserted into a vein or artery and therefore in intimate contact with the human or animal body. However, this does not necessarily mean that the lock solution is also directly in contact with or even active within it.

Paragraph [0042] of the contested patent indicates that the lock solution, once infused into the lumen of the catheter, is allowed to remain until the catheter or lumen is desired to be accessed again. The lock solution can be removed from the catheter prior to infusion or removal of additional fluid for further treatment or, alternatively, it can be flushed directly into the patient without the necessity of removing it before infusing fluids for subsequent treatment. In the latter case, the lock solution enters of course into contact with the human or animal body. However, in that case, the citrate in the lock solution is inactivated by calcium in the blood or calcium derived from body stores (see column 9, lines 18-20 of the contested patent) and can therefore not exert any therapeutic effect within the human or animal body.

In this context, it is noted that it is irrelevant whether the bacteria are located at the tip of the catheter (see last three sentences of paragraph [0008] of the contested patent) and therefore very close to the lumen of the catheter or freely circulating in the bloodstream. The important point is that no antibacterial activity can take place within the human or animal body as a consequence of this inactivation. Therefore, the antibacterial activity will only take place in the lumen, which is a part of the catheter that is located outside of the human or animal body, which means that it is not therapeutic in the sense of A 52(4) EPC 1973.

Sufficiency of disclosure

[4.2] A logical consequence of the finding that the citrate containing lock solution does not show any therapeutic activity within the human or animal body is that it does not constitute a medicament which would be suitable for treating a bacterial infection of the human or animal body (see the second paragraph of point [4.1.1] above). It can certainly prevent or reduce the invasion of further microorganisms into the human or animal body by preventing contamination of fluids administered via the catheter as a preventive measure, but it is not able to inactivate pathogenic microorganisms which are already there. In other words, the citrate containing lock solution can at best eliminate the source of an infection - which is comparable to the disinfection of surgical instruments - but it cannot alleviate or cure an already existing infection, which is claimed in claim 1 of the main request. As a consequence, the use claimed in claim 1 of the main request lacks sufficiency so that the requirements of A 83 are not met.

[4.3] In view of this finding, an evaluation of the further objections raised by the appellant is not necessary.

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