Johnson & Johnson COVID-19 Vaccine Candidate Demonstrates Robust Protection in Pre-Clinical Studies

In the studies, the 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, the vaccine candidate, 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 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. 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.

Based on the strength of the data, the company has now commenced a Phase 1/2a first-in-human clinical trial of Ad26.COV2.S in healthy volunteers, in the US and Belgium. The robust Janssen COVID-19 clinical trial program, including the Phase 1/2a clinical trial 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. Planning also is 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.

“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. The findings give us confidence as we progress our vaccine development and upscale manufacturing in parallel, having initiated a Phase 1/2a trial in July with the intention to move into a Phase 3 trial in September,” said Paul Stoffels, M.D., Vice Chairman of the Executive Committee and Chief Scientific Officer, Johnson & Johnson.

“The pre-clinical data, generated in collaboration 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,” said Dan Barouch, M.D., Ph.D., Director of the Center for Virology and Vaccine Research at BIDMC and the Ragon Institute.

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