Novavax announced positive phase 1 data from a trial investigating its coronavirus disease 2019 (COVID-19) vaccine candidate, NVX-CoV2373.

NVX-CoV2373 is engineered from the genetic sequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the Company’s recombinant nanoparticle technology to generate antigen derived from the coronavirus spike (S) protein. The vaccine candidate contains the Company’s saponin-based Matrix-M™ adjuvant technology. The incorporation of an adjuvant may allow for greater production of vaccine doses, as the amount of protein required per dose would be reduced. Vaccine adjuvants are also used to enhance and prolong immune responses.

The randomized, observer-blinded, placebo-controlled phase 1/2 trial consists of a phase 1 portion assessing the immunogenicity and safety of NVX-CoV2373 (5mcg and 25mcg doses), both with and without Matrix-M adjuvant, in 131 healthy adults aged 18 to 59 years. The phase 2 portion will assess immunity, safety and COVID-19 disease reduction in a broader age range.

Findings from the phase 1 portion showed that NVX-CoV2373 induced neutralization titers in all patients, with a peak geometric mean titer (GMT) of 3906 (95% CI, 2556-5970) in the 5mcg adjuvanted dose group. After a single dose, all patients developed anti-spike IgG antibodies and many developed wild-type virus neutralizing antibody responses. After a second dose, all patients developed wild-type virus neutralizing antibody responses. 

Additionally, the antibody responses were observed to be numerically superior to those seen in human convalescent sera. The adjuvanted vaccine also induced robust polyfunctional CD4+ T cell responses.

As for safety, NVX-CoV2373 was found to be well tolerated and generally mild reactogenicity events were reported. The most frequent local symptoms were tenderness and pain. There were no serious adverse events reported.

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“The phase 1 data demonstrate that NVX-CoV2373 with our Matrix-M adjuvant is a well tolerated COVID-19 vaccine with a robust immunogenicity profile,” said Gregory M. Glenn, MD, President, Research and Development at Novavax. “Using a stringent wild-type virus assay performed by investigators at the University of Maryland School of Medicine, NVX‑CoV2373 elicited neutralizing antibody titers greater than those observed in a pool of COVID‑19 patients with clinically significant disease.”

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