C1. Clinical trials (abstracts submitted to C1 should choose a secondary category that describes the subject matter of the trial)
Late Breaking Abstract Submission
Andrea L. Cox, MD;PHD
Professor of Medicine and Oncology
Johns Hopkins University
Baltimore, MD
Disclosure: Nothing to disclose
Michael Melia, MD
Assoc. Professor
Johns Hopkins University
Baltimore, Maryland
Disclosure: Gilead Sciences, Inc.: Research Grant
Rebecca Veenhuis, PhD
Research Assitant
Johns Hopkins University
Baltimore, MD
Disclosure: Nothing to disclose
Guido Massaccesi, BS
Technician
Johns Hopkins University
Baltimore, MD
Disclosure: Nothing to disclose
William Osburn, PhD
Assistant Professor
Johns Hopkins University
Baltimore, MD
Disclosure: Nothing to disclose
Katherine Wagner, MPH
Reserach Assistant
The University of New Mexico
Albuquerque, NM
Disclosure: Nothing to disclose
Linda Giudice, MD,PhD
Professor
The University of California, San Francisco
San Francicso, CA
Disclosure: Nothing to disclose
Ellen Stein, MPH
Reserach Coordinator
The University of California, San Francisco
San Francisco, CA
Disclosure: Nothing to disclose
Alice K. Asher, PhD
Research Coordinator
The University of California, San Francisco
San Francisco, CA
Disclosure: Nothing to disclose
Ventzislav Vassilev, PhD
Director
GlaxoSmithKline Vaccines
Wavre, Brussels Hoofdstedelijk Gewest, Belgium
Disclosure: GlaxoSmithKlein Vaccines: Employee
Lan Lin, MD
Medical Director
GlaxoSmithKline Vaccines
Wavre, Brussels Hoofdstedelijk Gewest, Belgium
Disclosure: GlaxoSmithKlein Vaccines: Employee
Alfredo Nicosia, PhD
Director
5ReiThera, srl
Rome, Piemonte, Italy
Disclosure: ReiThera: Employee, Shareholder
Antonella Folgori, PhD
Scientist
5ReiThera, srl
Rome, Piemonte, Italy
Disclosure: ReiThera: Employee
ReiThera: Employee, Shareholder
Richard Gorman, MD
Medical monitor
The National Institute of Allergy and Infectious Diseases
Rockville, MD
Disclosure: Nothing to disclose
Soju Chang, MD
Medical monitor
The National Institute of Allergy and Infectious Diseases
Rockville, MD
Disclosure: Nothing to disclose
Peter Wolff, MHA
Trial Coordinator
The National Institute of Allergy and Infectious Diseases
Rockville, MD
Disclosure: Nothing to disclose
T. Jake Liang, MD
Scientist
The National Institute of Diabetes and Digestive and Kidney Diseases
Bethesda, MD
Disclosure: Nothing to disclose
Marc Ghany, MD
Scientist
The National Institute of Diabetes and Digestive and Kidney Diseases
Bethesda, MD
Disclosure: Nothing to disclose
Paula Lum, MD, MPH
Associate Professor
The University of California, San Francisco
San Francisco, CA
Disclosure: Nothing to disclose
Background:
The development of a safe and effective vaccine to prevent chronic hepatitis C virus (HCV) infection is a critical component of elimination efforts, providing the rationale for the first HCV vaccine efficacy trial.
In a randomized, multicenter, double-blind, placebo-controlled efficacy trial (NCT01436357), we evaluated a recombinant chimpanzee adenovirus 3 vector vaccine prime followed by a recombinant modified vaccinia Ankara boost, both encoding nonstructural proteins of HCV. HCV-uninfected adults 18-45 years old at-risk for HCV infection due to injection drug use were randomized to receive the prime-boost regimen or placebo at Days 0 and 56. Trial participants were monitored for vaccine reactogenicity, adverse events, and HCV viremia. Vaccine safety, immunogenicity, and efficacy against progression to chronic HCV infection were assessed.
A total of 455 subjects received the prime-boost regimen or two doses of placebo, with 202 and 199 in the respective groups included in the according-to-protocol efficacy cohort. Overall incidence of infection was 14.1 infections per 100 person-years. There were no differences in development of chronic infection between vaccine and placebo arms, with 14 chronically infected subjects in each group. Specifically, the vaccine efficacy in preventing chronic infection was -0.53 (95% confidence interval [CI], -2.5 to 0.34). Of vaccinated subjects, 78% generated T cell responses to ≥1 vaccine-encoded HCV antigens. The vaccine was generally safe and well tolerated with no serious vaccine-related adverse events. There were more solicited reports of adverse events after either injection in the vaccine group (81%) than in the placebo group (59%), with the difference mainly due to injection-site reactions. Serious adverse events and deaths occurred with similar frequencies in the two groups.
A randomized, placebo controlled, Phase I/II trial of a prime-boost vaccine to prevent chronic HCV infection was completed in an at-risk population, demonstrating the feasibility of conducting rigorous vaccine research in people who inject drugs. The regimen elicited robust immune responses without evident safety concerns, but did not provide protection against chronic HCV infection.