In the absence of any tangible proof in the patent specification that the claimed concept can be put into practice, post-published documents can be used as evidence whether the invention merely disclosed at a general conceptual level was indeed reproducible without undue burden at the relevant filing date (T 994/95 and T 157/03). In T 1262/04, the board considered that this principle applied at least to cases such as the one at issue, where the technical teaching as disclosed in the application was credible. In T 1205/07, the post-published documents were considered, as the evidence they provided was not aimed at "curing" any alleged insufficiency of disclosure, but rather at confirming the teachings of the application. See also T 1547/08.
If a disclosure is seriously insufficient in that it provides no guidance for performing a particular aspect of the invention, a reference to later documents showing how such performance was accomplished at a later date is manifestly incapable of curing the insufficiency (T 222/00). Sufficiency of disclosure must, in principle, be shown to exist at the effective date of a patent. If the description of the patent specification provides no more than a vague indication of a possible medical use for a chemical compound yet to be identified, later more detailed evidence cannot be used to remedy the fundamental insufficiency of disclosure of such subject-matter (T 609/02).
See also 6.2 below, "Level of disclosure required for medical use".