A month after scoring $1.6 billion from the U.S. government, Novavax is posting the first human data from its COVID-19 vaccine. The early results, from the phase 1 part of a phase 1/2 study, show that two dose levels of the recombinant vaccine triggered an immune response similar to those in patients who had recovered from the disease.
The study tested four dose regimens of the vaccine, NVX-CoV2373, against placebo in 131 healthy adults up to 59 years old. Although it tested an unadjuvanted form of the vaccine and a single-dose regimen of the adjuvanted vaccine, all eyes were on two adjuvanted regimens: 5 micrograms and 25 micrograms given in two injections three weeks apart.
All of the patients developed neutralizing antibodies against SARS-CoV-2, the virus that causes COVID-19, but those who received two doses of the adjuvanted vaccine did the best. At the 35-day mark, or two weeks after their second dose, they had neutralizing antibody levels higher than those seen in a group of patients who had recovered from COVID-19. What’s more, the lower dose fared “comparably” to the higher dose.
“You can see there was no difference between the responses in 5 and 25 mcg. In other words, this is a dose sparing regimen,” Novavax R&D chief Gregory Glenn, M.D., said on a conference call on Tuesday.
On the safety side, the most common side effects were headache, fatigue and muscle pain, but the majority were mild and lasted, on average, less than two days. No serious side effects were reported.
Like the first human data for Moderna’s COVID-19 vaccine reported in May, the data have not yet been peer-reviewed. Moderna followed up its early results with a peer-reviewed study in the New England Journal of Medicine that detailed its “robust” results. However, the investigators noted that "correlates of protection from SARS-CoV-2 infection have not been determined." That’s a concern with the vaccines in development—that it's not known yet if high antibody levels actually translate to protection.
Novavax’s candidate uses nanoparticle technology to create an antigen from the coronavirus spike protein, along with the company’s Matrix-M adjuvant to boost patients’ immune response. Although the Maryland-based biotech was initially left off the list of U.S. governments finalists for Operation Warp Speed, it later scored a $1.6 billion deal with the initiative—the project’s largest funding commitment at the time.
Novavax has never brought a product to market, but it's also advancing a late-stage flu vaccine candidate with plans to file for FDA approval soon. It is using the Operation Warp Speed funding to finish late-stage clinical development of its COVID-19 vaccine, including a phase 3 study that would enroll up to 30,000 patients.