PII-155 - SAFETY, TOLERABILITY AND PHARMACOKINETICS OF SINGLE INTRAVENOUS ADMINISTRATIONS OF LENZILUMAB IN HEALTHY KOREAN SUBJECTS

J. Song¹, J. Park¹, S. Bae¹, D. Lee¹, S. Oh², J. Kang², J. Kim², S. Lee³; ¹Seoul National University College of Medicine and Hospital, ²Telcon RF Pharmaceutical Inc., ³Seoul National University Hospital.

Background: Lenzilumab is a recombinant monoclonal antibody neutralizing human granulocyte macrophage-colony stimulating factor. By modulating immune-mediated hyperinflammation, lenzilumab improved ventilator-free survival in hospitalized patients with COVID-19. This study aimed to assess the safety, tolerability, and pharmacokinetics (PKs) after a single intravenous administration of lenzilumab in healthy Korean subjects

Methods: A randomized, double-blind, placebo-controlled, single intravenous administration study was conducted. The subjects were randomized into three dosage group with 1, 3, 10 mg/kg. Four subjects in the lowest dose group and eight in each remaining groups received lenzilumab or placebo in a 3:1 ratio. Adverse events and other safety variables including vital signs were monitored to evaluate the safety/tolerability profile of lenzilumab. Serial blood samples were collected up to 70 days post-dose for estimating PK parameters using noncompartmental analysis, and PK dose-proportionality was assessed.

Results: A total of 20 subjects completed the study. Treatment-emergent adverse events (TEAE) occurred in nine cases in the six subjects receiving lenzilumab and five cases in the three subjects receiving placebo. All were mild and spontaneously recovered. Lenzilumab demonstrated 1st-order elimination profile as the average half-life was similar in all dosing groups, ranging from 25.33 to 31.21 days. Lenzilumab exhibited dose-proportional pharmacokinetics.

Conclusion: A single intravenous administration of lenzilumab was safe and well tolerated in the dose range between 1 and 10 mg/kg. The pharmacokinetic characteristics were dose-proportional.