(Adds comments from conf call)
March 1 (Reuters) - Inovio Pharmaceuticals Inc has paused enrollment for an ongoing late-stage study of its lead COVID-19 vaccine candidate after the shot showed significantly lower levels of antibodies against the Omicron variant in lab testing.
The vaccine, INO-4800, maintained robust T-cell response in the lab tests though, leading Inovio to plan changes to the trial design and forecast a delay in reporting preliminary efficacy data from the study. T-cells are a key part of the immune system's second line of defense.
The company plans to seek regulatory approval to change the main goal of the study to "prevention of severe disease due to COVID-19" from the earlier goal of "prevention of virologically confirmed COVID-19 disease", it said on Tuesday.
"The expectation for vaccination has changed. The highly infectious nature of Omicron has meant that while vaccines currently available in the market may not directly prevent infections, they can significantly protect the vaccinated from severe disease," Chief Executive Officer Joseph Kim said during a call with investors.
An independent data safety monitoring board recommended that Inovio pause enrollment to reflect Omicron's potential impact on the trial. As a result, interim efficacy data from the trial will not be available in the first half of 2022 as previously expected.
In November, Inovio resumed the late-stage trial of its vaccine in the United States after 14 months on clinical hold.
The FDA in September put the study on hold as it sought more information from the company, including details on a delivery device used to inject genetic material into cells.
Inovio then started late-stage trials outside the United States in partnership with China's Advaccine Biopharmaceuticals.
(Reporting by Mrinalika Roy in Bengaluru; Editing by Devika Syamnath)