Johnson & Johnson COVID-19 vaccine candidate Interim Phase 1/2a data are published

Jan. 21, 2021

Johnson & Johnson announced its Interim Phase 1/2a data were published in the New England Journal of Medicine demonstrating that the company’s single-dose investigational COVID-19 vaccine candidate (JNJ-78436735) – being developed by the Janssen Pharmaceutical Companies of Johnson & Johnson – provided an immune response that lasted for at least 71 days, the duration of time measured in this study in participants aged 18 to 55 years.

A preview of part of these interim data was posted on medRxiv in September 2020.

The Phase 1/2a interim analysis showed that the company’s COVID-19 vaccine candidate induced an immune response and was generally well-tolerated across all study participants. Data demonstrated that, after a single vaccination, neutralizing antibodies against COVID-19 were detected in over 90 percent of study participants at Day 29 and 100 percent of participants aged 18 to 55 years at Day 57. These neutralizing antibodies remained stable through Day 71, currently the latest timepoint available in this ongoing study, in all participants aged 18 to 55 years. Data on durability of immune responses in trial participants aged over 65 years will be available in late January and longer-term follow-up to one year is planned.

The company anticipates announcing topline Phase 3 data for its single-dose Janssen COVID-19 vaccine candidate in late January 2021; however, as this trial is dependent on disease events, the timing is approximate. If the single-dose vaccine is shown to be safe and effective, the company expects to submit an application for Emergency Use Authorization with the U.S. Food and Drug Administration shortly afterwards, with other regulatory applications around the world to be made subsequently.

This Phase 1/2a study has been funded in whole or in part with Federal funds from the Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, under Contract No. HHSO100201700018C.

This ongoing Phase 1/2a multi-center, randomized, double-blind, placebo-controlled trial aims to evaluate the safety, reactogenicity, and immunogenicity of Janssen’s COVID-19 vaccine candidate at two dose levels (5x1010 or 1x1011 viral particles), administered intramuscularly as single-dose or two-dose schedules, eight weeks apart, in healthy adults (aged 18 to 55 years; n=405 or >65 years; n=405). The study is ongoing at multiple clinical sites in Belgium and the United States. The full set of results for this Phase 1/2a study will be published once the complete trial data are available.

The interim analysis also included unblinded safety data which showed that injection site (local) and systemic reactions to vaccinations either occurred on the day of immunization or the next day, and generally resolved within 24 hours. The most frequent solicited adverse events (mild-to-moderate side effects typically associated with vaccinations) in the vaccine study arms were fatigue, headache, myalgia and injection site pain. Reactogenicity was lower in the older age group. The study also evaluated a two-dose regimen, in which reactogenicity was observed to be lower after the second vaccine dose.

Five serious adverse events were reported; one participant visited the hospital for a fever that was associated with vaccination (the participant recovered within 12 hours); the remaining four were confirmed by study investigators as unrelated to the vaccine candidate.

The interim data show that, following a single vaccination, neutralizing antibodies (VNA) titers – a laboratory test measuring the presence of antibodies in blood – against COVID-19 were detected in over 90 percent of participants at Day 29. In participants aged 18 to 55 years, this increased to 100 percent at Day 57 – irrespective of vaccine dose or age group. VNA titers then remained stable until at least Day 71 (currently the latest available time point in this ongoing study). Data on durability of immune responses in trial participants aged over 65 years after Day 29 will be shared in late January. The interim analysis showed the safety profile and immunogenicity after a single dose of the COVID-19 vaccine candidate were supportive of further development.

The study also evaluated a two-dose regimen, in which the data showed that a second dose of the vaccine candidate, administered 56 days apart, was less reactogenic while it triggered more than a two-fold increase in antibodies against COVID-19.

The investigational Janssen COVID-19 vaccine candidate leverages the company’s AdVac vaccine platform, which was also used to develop and manufacture Janssen’s European Commission-approved Ebola vaccine regimen and construct its Zika, RSV, and HIV investigational vaccine candidates. Janssen’s AdVac technology has been used to vaccinate more than 200,000 people to date.

Janssen is investigating multiple doses and dosing regimens of its COVID-19 vaccine candidate to evaluate long-term efficacy. The company is studying a single-dose of its vaccine candidate in the Phase 3 ENSEMBLE trial, which completed enrollment on Dec. 17, 2020, and a two-dose regimen in the Phase 3 ENSEMBLE 2 study which is ongoing.

Johnson & Johnson continues to develop and test its COVID-19 vaccine candidate in accordance with ethical standards and sound scientific principles. The company is committed to transparency and sharing information related to its ongoing clinical studies – including the ENSEMBLE study protocol.

ENSEMBLE was initiated in collaboration with the Biomedical Advanced Research and Development Authority (BARDA), part of the Office of the Assistant Secretary for Preparedness and Response at the U.S. Department of Health and Human Services (HHS) under Other Transaction Agreement HHSO100201700018C, and the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH) at HHS.

Johnson & Johnson has the announcement.

More COVID-19 coverage HERE.