Safety and Pharmacokinetics of a Four Monoclonal Antibody Combination Against Botulinum C and D Neurotoxins.

Abstract

Botulism is caused by botulinum neurotoxin (BoNT), the most poisonous substance known. BoNTs are also classified as Tier 1 biothreat agents due to their high potency and lethality. The existence of seven BoNT serotypes (A-G), which differ between 35% to 68% in amino acid sequence, necessitates the development of serotype specific countermeasures. We present results of a Phase 1 clinical study of an anti-toxin to BoNT serotypes C and D, NTM-1634, which consists of an equimolar mixture of four fully human IgG1 monoclonal antibodies (mAbs), each binding to non-overlapping epitopes on BoNT serotypes C and D resulting in potent toxin neutralization in rodents. This first-in-human study evaluated the safety and pharmacokinetics of escalating doses of NTM-1634 administered intravenously to healthy adults (NCT03046550). Three cohorts of eight healthy subjects received a single intravenous dose of NTM-1634 or placebo at 0.33 mg/kg, 0.66 mg/kg or 1 mg/kg. Follow-up examinations and pharmacokinetic evaluations were continued up to 121 days post-infusion. Subjects were monitored using physical examinations, hematology and chemistry blood tests, and electrocardiograms. Pharmacokinetic parameters were estimated using noncompartmental methods. The results demonstrated that the materials were safe and well-tolerated with the expected half-lives for human mAbs and with minimal anti-drug antibodies detected over the dose ranges and duration of the study.

• Authors: Doris M Snow, Kathryn Riling, Angie Kimbler, Yero Espinoza, David Wong, Khanh Pham, Zachary Martinez, Carl N Kraus, Fraser Conrad, Consuelo Garcia-Rodriguez, Ronald R Cobb, James D Marks, Milan T Tomic
• Journal: Antimicrobial agents and chemotherapy (Antimicrob Agents Chemother) Vol. 63 Issue 12 (09 09 2019) ISSN: 1098-6596 [Electronic] United States
• PMID: 31591130 (Publication Type: Journal Article)
• Copyright: Copyright © 2019 Snow et al.