Momenta Pharmaceuticals, Inc. (MNTA)

[DewDiligence]

For 180-day Hatch-Waxman exclusivity, first-filer status goes to the first company to submit an ANDA—provided that the ANDA is "substantially complete". (This is the actual phrase used in the text of the H-W legislation.)

If an ANDA submission is not substantially complete, the FDA does not accept it for review and the original submission date becomes irrelevant for the H-W first-filer determination. This may be what happened to the the (undisclosed) ANDA filer who made a submission on 2/26/14 (the date in the table you posted).

(I do not understand how the undisclosed company mentioned above could have submitted a Paragraph-IV challenge on 40mg Copaxone before TEVA's 40mg-Copaxone patents were entered into the Orange Book, but that's a question for another day.)