Johnson & Johnson COVID-19 vaccine candidate demonstrates robust protection in pre-clinical studies

Johnson & Johnson announced that its lead vaccine candidate for COVID-19 elicited a robust immune response as demonstrated by “neutralizing antibodies” in pre-clinical studies.

The data, published in Nature, showed that the company’s investigational adenovirus serotype 26 (Ad26) vector-based vaccine successfully prevented subsequent infection and completely protected the lungs from the SARS-CoV2 virus in non-human primates (NHPs) during the pre-clinical study.

“We are excited to see these pre-clinical data because they show our SARS-CoV-2 vaccine candidate generated a strong antibody response and provided protection with a single dose,” said vice chairman of the executive committee and Chief Scientific Officer Paul Stoffels.

“The findings give us confidence as we progress our vaccine development at and upscale manufacturing in parallel, having initiated a Phase 1/2a trial in July with the intention to move into Phase 3 trials in September,” he added.

The pre-clinical studies were conducted by researchers from Beth Israel Deaconess Medical Center (BIDMC) in collaboration with the Janssen Pharmaceutical Companies of Johnson & Johnson and others as part of its ongoing collaboration to accelerate the development of a SARS-CoV-2 vaccine.

In the studies, researchers first immunized the NHPs with a panel of vaccine prototypes, and then challenged them with SARS-CoV-2 infection.

The scientists found that, of seven vaccine prototypes tested in the study, Ad26.COV2.S elicited the highest levels of neutralizing antibodies to SARS-CoV-2.

The level of antibodies correlated with the level of protection, confirming previous observations and suggesting that they could be a potential biomarker for vaccine-mediated protection.

The six NHPs that received a single immunization with Ad26.COV2.S showed no detectable virus in the lower respiratory tract after exposure to SARS-CoV-2, and only one of six showed very low levels of the virus in a nasal swab at two time points.

Dan Barouch, director of the Center for Virology and Vaccine Research at BIDMC and the Ragon Institute, said “the pre-clinical data, generated in partnership with the Johnson&Johnson team, highlights the potential of this SARS-CoV-2 vaccine candidate. Moreover, the data suggest that antibody levels may serve as a biomarker for vaccine-mediated protection.”

The robust Janssen COVID-19 clinical trial program, including the Phase 1/2a clinical trials and the Phase 3 clinical trial program, will evaluate both one- and two-dose regimens of Ad26.COV2.S in parallel studies.

The Phase 1/2a trial will evaluate the safety, reactogenicity (expected reactions to vaccination, such as swelling or soreness), and immunogenicity of Ad26.COV2.S in over 1,000 healthy adults aged 18 to 55 years, as well as adults aged 65 years and older.

Based on the strength of the data, a Phase 1/2a first-in-human clinical trial of the vaccine candidate, Ad26.COV2.S, in healthy volunteers, has now commenced in the United States and Belgium.

Plans are also underway for a Phase 2a study in the Netherlands, Spain and Germany and a Phase 1 study in Japan.

As the company plans its COVID-19 Phase 3 clinical development program, discussions are underway with partners with the objective to start a pivotal Phase 3 clinical trial of the single vaccine dose versus placebo in September, pending the interim data of the Phase 1 and 2 trials and approval of regulators.

Simultaneously, the company is also planning to start a parallel Phase 3 clinical trial of a two-dose regimen versus placebo.

Johnson & Johnson also shared that they will emphasize representation of populations that have been disproportionately impacted by the pandemic as it designs and implements its COVID-19 Phase 3 trial program.

In the United States, this would include significant representation of Blacks, Hispanic/Latinx and participants over 65 years of age.

“As we collectively battle this pandemic, we remain deeply committed to our goal of providing a safe and effective vaccine to the world. Our pre-clinical results give us reason to be optimistic as we initiate our first-in-human clinical trial, and we are excited to enter the next stage in our research and development toward a COVID-19 vaccine,” said Mathai Mammen, Global Head for Janssen Research & Development, Johnson & Johnson.

“We know that, if successful, this vaccine can be rapidly developed, produced on a large scale and delivered around the world,” Mammen added.