Vaxart (NSDQ:VXRT) announced today that the FDA cleared the investigational new drug (IND) application for its oral COVID-19 vaccine.

Upon news of the IND application approval for the S-only protein construct-based vaccine candidate, shares of VXRT were up 16.1% at $8.35 in early-morning trading today.

South San Francisco-based Vaxart’s S+N oral tablet SARS-CoV-2 vaccine candidate demonstrated in a completed Phase 1 clinical trial that it triggered multiple immune responses against SARS-CoV-2 antigens while reaching primary and secondary endpoints of safety and immunogenicity, respectively, according to a news release.

The S-only candidate produced higher serum antibodies than the construct expressing both S and N in a non-human primate study, Vaxart said.

A Phase 2 clinical trial with the S-only construct is expected to start in the second half of this year, with the development of the candidate, along with other S-only constructs, planned to proceed in parallel with the S+N construct.

“This is great news because it allows us to move forward with our first S-only vaccine construct,” Vaxart CEO Andrei Floroiu said in the news release. “As we said at the end of the first quarter, we will explore multiple S-only constructs in clinical trials alongside the S+N construct that has already completed its Phase I trial.

“This new clinical trial will allow us to compare the S-only and S+N vaccine candidates and put us in a position to decide which approach offers the best way forward for our COVID-19 vaccine development program, particularly in the face of emerging variant strains,” added CSO Dr. Sean Tucker.