Systemic administration of interleukin-2 in humans

Area of Science:

• Immunology
• Pharmacology
• Oncology

Background:

• Interleukin-2 (IL-2) is a cytokine with potential therapeutic applications.
• Previous research on IL-2 efficacy in cancer and acquired immunodeficiency syndrome (AIDS) was limited.
• The JURKAT cell line provided a source for purified human IL-2.

Purpose of the Study:

• To evaluate the safety, tolerability, and pharmacokinetic profile of JURKAT-derived IL-2 in humans.
• To assess the in vivo immunologic effects of IL-2 in patients with advanced cancer or AIDS.
• To determine the impact of IL-2 on tumor response and chronic immunodeficiency.

Main Methods:

• A Phase I clinical trial involving twelve patients with cancer or AIDS.
• Administration of purified human IL-2 (JURKAT-derived) at doses of 0.25, 2.5, or 25 micrograms/kg via bolus or continuous infusion weekly for 4 weeks.
• Monitoring of serum half-life, acute and chronic toxicity, and various immunologic parameters including immune cell activity and counts.

Main Results:

• JURKAT IL-2 exhibited a rapid serum half-life of approximately 6 minutes, with a secondary clearance component observed at higher doses.
• Acute toxicity was generally mild, including headache, nausea, malaise, and fever/chills. Transient hyperbilirubinemia occurred in two patients.
• No significant anti-tumor activity or improvement in chronic immunodeficiency (AIDS) was observed. No consistent chronic immunologic effects were detected, though acute changes in lymphokine responsiveness and macrophage populations were noted.

Conclusions:

• Purified JURKAT IL-2 is well-tolerated in humans with minimal acute toxicity and a short serum half-life.
• The study did not demonstrate efficacy against tumors or chronic immunodeficiency in the studied patient populations.
• Further investigation into the acute immunologic effects of IL-2 may be warranted.