definiens: means the occurrence of any of the events described in clauses ( A ), ( B ) or ( C ): ( A ) the reasonable determination of [COMPANY], at any stage 9 in the patent procedure after receipt of the Europe an search report and the first official letter from the European Patent Offi ce referred to in Section 11.4, that it is not reasonably likely that a Europ ean patent will be granted on PPI-149 or the formulation, respectively, substanti ally as described in the respective European equivalents of patent applicati ons PCT / US96/09852 or US 08/762,747, respectively ( the ) ; ( B ) the lack of any valid or enforceable patent issued substantiall y as described in the Material Patent Applications as the individual or c ombined result of ( i ) no such patents having issued and the unrevivable abandonme nt of any of the Material Patent Applications, ( ii ) all such patents having b een finally and unappealably declared invalid or unenforceable, or ( iii ) all suc h patents having prematurely expired for failure to pay maintenance fees or annu ities ; or ( C ) a timely filed action by a Third Party to annul, cancel or revoke a patent issued substantially as described in the Material Patent Applications, o ther than any such action which has no reasonable likelihood of success on th e merits