Heparin has been shown to modulate binding of palifermin to the KGF receptor. Therefore, as part of a post-marketing regulatory commitment with the Food and Drug Administration (FDA), the purpose of this study is to characterize the potential pharmacokinetic and pharmacodynamic drug-drug interaction between a continuous IV infusion of heparin and an IV bolus injection of palifermin. If an interaction is observed during co-administration, it is expected that the outcome would be modulation of clearance of palifermin or a change in heparin activity. Although not commonly conducted, the literature describes heparin drug-drug interaction studies conducted in healthy subjects using both subcutaneous (Grimaudo et al,1988; Kroon et al, 1992) and intravenous (Caplain at al, 1999; Noveck & Hubbard, 2004; Spowart et al, 1988) formulations. Based on these experiences, it is appropriate to investigate heparin drug-drug interactions in healthy subjects.