Phase I trial of low-dose interleukin 2 therapy in patients with Wiskott-Aldrich syndrome.

Background: Low dose IL-2 can restore the function of T and NK cells from Wiskott-Aldrich (WAS) patients. However, the safety of in vivo IL-2 in WAS is unknown.
Objectives: A phase-I study to assess safety of low dose IL-2 in WAS.
Methods: Patients received 5 daily subcutaneous IL-2 injections, every 2months, for three courses. A "3+3" dose escalation method was used.
Results: 6 patients received the 0.5millionunits/m ² /day dose without serious adverse events. However, 2 of 3 patients receiving the 1millionunits/m ² /day dose developed thrombocytopenia requiring platelet transfusions. A statistically significant platelet increase occurred in patients receiving the 0.5millionunits/m ² /day dose. A trend toward higher T, B and NK cell numbers and higher T regulatory cell percentages was observed.
Conclusion: We have identified a safe IL-2 dose for WAS patients. Additional trials are indicated to study the efficacy of this immunostimulant as a therapy for WAS.
(Copyright © 2017 Elsevier Inc. All rights reserved.)