T 1824/08 – Do It Yourself

This case, which an anonymous commentator has invited me to report (here), concerns an appeal against the decision of the Examining Division (ED) to refuse an application for lack of inventive step.

Claim 1 of the application on which the decision was based read:

1. A compound of the formula:

wherein

Ring A is benzo;

Z1 and Z2 independently are S or O;

R1 and R2 independently are H, optionally substituted aliphatic, optionally substituted aryl, hydroxyl, halogen, alkoxy, heterocycle, cyano, amino, or, are taken together to form an optionally substituted cycloaliphatic or optionally substituted aryl;

R3 represents H, optionally substituted aliphatic, and optionally substituted aryl;

R4 and R5 independently are H, optionally substituted aliphatic, optionally substituted aryl, heterocycle, aryloxy, carboxy, or, are taken together to form an optionally substituted heterocycle or optionally substituted heteroaryl;

R6 represents H, optionally substituted aliphatic, optionally substituted aryl, alkoxy, carboxy, amino, heterocycle, aryloxy, and optionally substituted therewith a targeting agent;

L represents a linker group;

and L is connected to the quaternary amine by a hydrolyzable bond.

Together with its statement of grounds of appeal, the applicant filed amended claims. The product claims were replaced by product-by-process claims.

The ED did not grant interlocutory revision.

Claim 1 of the main request before the Board read:

A compound which is obtainable by a process comprising reacting Compound 2

wherein,

Z1 and Z2 are S or O;

R1 and R2 independently are H, optionally substituted aliphatic, optionally substituted aryl, hydroxyl, halogen, alkoxy, heterocycle, cyano, amino, or, are taken together to form an optionally substituted cycloaliphatic or optionally substituted aryl;

R3 represents H, optionally substituted aliphatic or optionally substituted aryl;

R4 and R5 independently are H, optionally substituted aliphatic, optionally substituted aryl, heterocycle, aryloxy, carboxy, or, are taken together to form an optionally substituted heterocycle or optionally substituted heteroaryl;

with a halomethyl ester of formula

where hal is a halogen atom, R7 is -CH2-, -CH(CH3),

-CH(Ph), C(CH3)(COOH) or CH(CH(CH3)2, Z3 and Z4 are O and

R6 represents H, optionally substituted aliphatic, optionally substituted aryl, alkoxy, carboxy, amino heterocycle, aryloxy, any of which are optionally substituted with either a targeting agent to form a group R6-T, or second functional group which can covalently bond to a targeting agent,

and thereafter if required, covalently linking any second functional groups present to a targeting group to form a group R6-T.

The Board is not very happy to have to deal with the appeal:

[2] In the decision under appeal the sole ground for refusing the application was lack of inventive step of the claimed N-alkylated compounds of the following formula:

In particular, the ED held that the N-alkylated benzo(thio)pyranones or benzo(thio)pyranthiones according to the formula of claim 1 were obvious in view of document (1), which disclosed a benzopyranone compound (LY294002) of the following formula

and document D8 which referred to the designing of prodrugs and bioprecursors. According to the ED, document D8 gave a clear hint to the skilled person to use soft quaternary ammonium salts, i.e. N-alkylated compounds, which can be easily cleaved in the body, in order to solve the underlying technical problem of providing “pro-compounds” having improved pharmacokinetik and pharmacodynamic properties.

[3] The amended main and auxiliary requests filed with the statement setting out the grounds of appeal are no longer directed to N-alkylated benzo(thio)pyranones or benzo(thio)pyranthiones. Claim 1 of both requests refers instead to a compound obtainable by the reaction of a benzo(thio)pyranone or benzo(thio)pyranthione compound with a halomethylester. The reason for changing the form of the claims was the [applicant’s] recent finding that the compounds it had prepared using this method starting from LY294002 or a LY294002 derivative (emphasis added by the Board) corresponded in fact to “O- or S-alkylated” compounds illustrated by the following formula

and that N-alkylated compounds were not obtained.

[4] The [applicant’s] realisation that an incorrect formula had been used to define the compounds it had prepared and its attempt to remedy this deficiency by characterising the obtained compounds by their process of production have altered the case in such a way that the reasons for the decision based on the obviousness of the N-alkylated compounds are no longer relevant. Compounds wherein the C=O or the C=S group of the benzo(thio)pyranone or benzo(thio)pyranthione had been alkylated were never considered by the ED. It is not even apparent to the Board whether or not these compounds were properly covered by the search. One is therefore faced with a fresh case concerning subject-matter which was not considered before by the ED and which may not have been properly searched. In these circumstances, the Board judges it appropriate to exercise its power under A 111(1) and remit the case to the ED for further prosecution.

[5] In its preliminary opinion, the Board raised the question whether or not the product by process claims are, in the absence of any reaction conditions, in compliance with A 123(2). This issue was never addressed by the ED, which did not rectify its decision, although it could and, therefore, should have done so (T 139/87). Furthermore, the Board appreciates that in order to address fully the question whether or not and in what form a product by process claim in the present case may be considered allowable, further investigations into the scientific literature and further experimental work by the [applicant] appear to be necessary. Depending on these results, further substantive examination may be required, and this is normally the task of the ED. The Board further notes that the outcome of a further search, which might turn out to be necessary, may well influence the answer to this question.

[6] In these circumstances and in order to give the [applicant] a fair chance to defend its whole case before two instances, the Board considers it appropriate to allow the [applicant’s] request for remittal of the case to the ED without deciding on the issue of A 123(2).

Should you wish to download the whole decision, just click here.

The file wrapper can be found here.

NB: This decision has been commented on Le blog du droit européen des brevets.