Palifermin DDI (Drug Drug Interaction)

• To evaluate the effect of a continuous intravenous (IV) infusion of unfractionated heparin on the single-dose pharmacokinetics (PK) of palifermin in healthy subjects.
  

• To evaluate the effect (activated partial thromboplastin time, aPTT) of a single dose of palifermin on unfractionated heparin pharmacodynamics [(PD), AUCaPTT, 0-6, AUCaPTT, 0-24].
  
• To evaluate the safety and tolerability of a single 60 µg/kg intravenous dose of palifermin with or without a continuous IV infusion of heparin.
  

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.

In this study, subjects will receive a single 60 mcg/kg dose of palifermin either as monotherapy or in conjunction with a continuous heparin infusion. The 60 mcg/kg dose of palifermin explored in this study is identical to the current recommended daily dosage for patients with hematologic malignancies who were undergoing autologous PBPC transplantation after receiving total body irradiation and high-dose chemotherapy: 3 consecutive days administered in two cycles with a 5-day non-dosing interval.