Phase 2 Randomized Trial of the Safety and Efficacy of MHAA4549A, a Broadly Neutralizing Monoclonal Antibody, in a Human Influenza A Virus Challenge Model

Antimicrob Agents Chemother. 2017 Oct 24;61(11):e01154-17. doi: 10.1128/AAC.01154-17. Print 2017 Nov.

Abstract

MHAA4549A, a human monoclonal antibody targeting the hemagglutinin stalk region of influenza A virus (IAV), is being developed as a therapeutic for patients hospitalized with severe IAV infection. The safety and efficacy of MHAA4549A were assessed in a randomized, double-blind, placebo-controlled, dose-ranging study in a human IAV challenge model. One hundred healthy volunteers were inoculated with A/Wisconsin/67/2005 (H3N2) IAV and, 24 to 36 h later, administered a single intravenous dose of either placebo, MHAA4549A (400, 1,200, or 3,600 mg), or a standard oral dose of oseltamivir. Subjects were assessed for safety, pharmacokinetics (PK), and immunogenicity. The intent-to-treat-infected (ITTI) population was assessed for changes in viral load, influenza symptoms, and inflammatory biomarkers. MHAA4549A was well tolerated in all IAV challenge subjects. The 3,600-mg dose of MHAA4549A significantly reduced the viral burden relative to that of the placebo as determined by the area under the curve (AUC) of nasopharyngeal virus infection, quantified using quantitative PCR (98%) and 50% tissue culture infective dose (TCID50) (100%) assays. Peak viral load, duration of viral shedding, influenza symptom scores, mucus weight, and inflammatory biomarkers were also reduced. Serum PK was linear with a half-life of ∼23 days. No MHAA4549A-treated subjects developed anti-drug antibodies. In conclusion, MHAA4549A was well tolerated and demonstrated statistically significant and substantial antiviral activity in an IAV challenge model. (This study has been registered at ClinicalTrials.gov under identifier NCT01980966.).

Keywords: MHAA4549A; influenza A virus; monoclonal antibodies.

Publication types

  • Clinical Trial, Phase II
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies, Monoclonal / adverse effects
  • Antibodies, Monoclonal / pharmacology*
  • Antibodies, Neutralizing / pharmacology
  • Antiviral Agents / adverse effects*
  • Antiviral Agents / pharmacokinetics
  • Antiviral Agents / pharmacology*
  • Drug Resistance, Viral / drug effects
  • Healthy Volunteers
  • Hemagglutinin Glycoproteins, Influenza Virus / immunology
  • Humans
  • Influenza A Virus, H3N2 Subtype / pathogenicity
  • Influenza, Human / drug therapy*
  • Influenza, Human / virology
  • Male
  • Nasopharyngeal Diseases / virology
  • Treatment Outcome
  • Viral Load
  • Virus Shedding
  • Young Adult

Substances

  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • Antiviral Agents
  • Hemagglutinin Glycoproteins, Influenza Virus

Associated data

  • ClinicalTrials.gov/NCT01980966