definiens: means [COMPANY] 's receipt of written confirmation from the FDA that the partial clinical hold on BB - IND 13178 . as described in the December 22, 2006 letter from the FDA to [COMPANY] . has been lifted and that [COMPANY] is permitted to initiate Phase III trials of CDX-110 under such IND . Each Event Milestone Payment in the table above in this Section S.3(a ) shall be payable one time only even if the corresponding Event Milestone occurs or is achieved with respect to more than one Licensed Product containing CDX - II0 . Each Event Milestone Payment in the table above in this Section S.3(a ) corresponding to an Event Milestone that is described as shall be payable one time only even if the corresponding Event Milestone occurs or is achieved with respect to more than one Second Indication . For the avoidance of doubt : ( i ) each Event Milestone Payment in the table above in this Section S.3(a ) shall be payable only on the first occurrence of the corresponding Event Milestone ; ( ii ) none of the Event Milestone Payments in the table above in this Section S.3(a ) shall be payable more than once ; ( iii ) should a Licensed Product containing CDX-110 for GBM or a Second Indication, as the case may be, be replaced or succeeded in development by another Licensed Product containing CDX-11 0 for such indication, then no additional Event Milestone Payments shall be due for Event Milestones already met with respect to any Licensed Product containing CDX - II0 for such indication ; and ( iv ) the reference to within an Event Milestone means the first Licensed Product containing CDX - l1 0 to reach such Event Milestone . Each Event Milestone Payment in the table above in this Section S.3(a ) shall be irrevocable, non - refundable and, except as provided in Section IS.S, non - creditable toward any other payment due [COMPANY] under this Agreement