Coronavirus Prevention Vaccine Reports Positive Dosage Data

A Cambridge Massachusetts biotech company announced positive interim clinical data of mRNA-1273, its vaccine candidate against novel coronavirus (SARS-CoV-2).

This Phase 1 study, led by the National Institute of Allergy and Infectious Diseases (NIAID) and Moderna, Inc., said in a press release published on May 18, 2020, “These interim data, while early, demonstrate that vaccination with mRNA-1273 elicits an immune response of the magnitude caused by natural infection starting with a dose as low as 25 µg.”

Tal Zaks, M.D., Ph.D., Chief Medical Officer at Moderna continued saying “When combined with the success in preventing viral replication in the lungs of a pre-clinical challenge model at a dose that elicited similar levels of neutralizing antibodies, these data substantiate our belief that mRNA-1273 has the potential to prevent COVID-19 disease and advance our ability to select a dose for pivotal trials.”

The immunogenicity data are currently available is for the 25 µg and 100 µg dose level (ages 18-55) after two doses (day 43) and at the 250 µg level (ages 18-55) after one dose (day 29).

Vaccine dose-dependent increases in immunogenicity were seen across the 3-dose levels and between prime and boost within the 25 µg and 100 µg dose levels.

‘At this time, neutralizing antibody data are available only for the first four participants in each of the 25 µg and 100 µg dose level cohorts,’ said the company.

Consistent with the binding antibody data, mRNA-1273 vaccination elicited neutralizing antibodies in all eight of these participants, as measured by plaque reduction neutralization (PRNT) assays against live SARS-CoV-2. 

The levels of neutralizing antibodies at day 43 were at or above levels generally seen in convalescent sera.

mRNA-1273 was generally safe and well-tolerated, with a safety profile consistent with that seen in prior Moderna infectious disease vaccine clinical studies. 

The sole incidence of a grade 3 adverse event in the 25 µg and 100 µg dose cohorts was a single participant at 100 µg who experienced grade 3 erythema (redness) around the injection site. 

To date, the most notable adverse events were seen at the 250 µg dose level, comprising three participants with grade 3 systemic symptoms, only following the second dose. 

All adverse events have been transient and self-resolving. No grade 4 adverse events or serious adverse events have been reported.

Based on the interim Phase 1 data, the Moderna-led Phase 2 study will be amended to study two dose levels, 50 µg and 100 µg, with the aim of selecting a dose for pivotal studies.

The NIAID-led Phase 1 study is being amended to include a 50 µg dose level cohort across each of the three age groups. 

Moderna said it ‘anticipates the dose for the Phase 3 study to be between 25 µg and 100 µg and expects Phase 3 trial initiation in July, subject to finalization of the clinical trial protocol.’

“With today’s positive interim Phase 1 data and the positive data in the mouse challenge model, the Moderna team continues to focus on moving as fast as safely possible to start our pivotal Phase 3 study in July and, if successful, file a BLA,” said Stéphane Bancel, Chief Executive Officer at Moderna. 

“We are investing to scale up manufacturing so we can maximize the number of doses we can produce to help protect as many people as we can from SARS-CoV-2.”

Funding from the Biomedical Advanced Research and Development Authority supported the planning for the Phase 2 and Phase 3 studies of mRNA-1273 and will also support the execution of these studies, as well as the scale-up of mRNA-1273 manufacturing both at the Company’s facilities and that of its strategic collaborator, Lonza Ltd.

Previously, on May 6, 2020, the U.S. Food and Drug Administration (FDA) completed its review of the Company’s Investigational New Drug (IND) application for mRNA-1273 allowing it to proceed to a Phase 2 study.

On May 12th, the FDA granted mRNA-1273 Fast Track designation.

Precision Vaccinations publishes coronavirus vaccine development news.