The lymphatic route. VIII. Distribution and plasma clearance of recombinant human interleukin-2 after SC administration with albumin in patients

It has been postulated that favouring the absorption of interleukin-2 via lymphatics rather than venous capillaries after subcutaneous administration may improve its therapeutic index. We have now evaluated in 12 cancer patients the plasma pharmacokinetic of interleukin-2 either dissolved in water or in 20% albumin solution with an internal cross-over after at least three days. Our data show that when albumin is present, the plasma concentrations of interleukin-2 versus time is increased and swelling at the injection sites is reduced. It remains to be seen whether efficacy improves during a prolonged treatment.