This is directly from their website where students were directed to complete secondaries:
On first review, about 450 applicants are invited to interview and about 200 applicants are put on hold for a second review at a later date. Of these, about 50 are ultimately invited to interview. Should you be placed on hold for a second review, we advise you to mail any new information (reasons for interest in Pritzker, grade reports, abstracts, other publications, honors, awards or any special recognition) to the Committee. All applicants held for a second review will be notified by February 1, 2005, if they are going to be invited for interviews.
Good luck.