Exhibit 10.4

RELOCATION/SIGN-ON BONUS REPAYMENT AGREEMENT

I, Jordan Siegel, agree that I will reimburse Nabi Biopharmaceuticals for
relocation expenses and/or a sign-on bonus paid on my behalf, if I voluntarily
terminate my employment with Nabi Biopharmaceuticals or I am terminated for
cause within twelve (12) months after my start date. The following pro-rated
repayment schedule will apply:

 

1st Month   92%   7th Month   44% 2nd Month   84%   8th Month   36% 3rd Month  
76%   9th Month   28% 4th Month   68%   10th Month   20% 5th Month   60%   11th
Month   12% 6th Month   52%   12th Month      4%

 

/s/ Jordan Siegel

  

4/29/06

Employee Signature    Date

/s/ Thomas H. McLain

  

April 29, 2006

HR Representative Signature    Date