With eyes on a phase 3 study this summer, Moderna posted promising early data for its COVID-19 vaccine. The jab prompted an immune response similar to those seen in patients who have recovered from the disease.
The study, being run by the National Institute of Allergy and Infectious Diseases (NIAID), is testing three dose levels of the vaccine, mRNA-1273, given in two injections a month apart. Eight patients who received the two lowest dose levels—25 micrograms and 100 micrograms—developed neutralizing antibodies against SARS-CoV-2, the virus that causes COVID-19, two weeks after receiving their second dose.
These antibody levels mirrored those seen in patients who have recovered from infection. The study also found that all 45 patients developed binding antibodies against the virus—so-called because they identify and bind to viruses but do not attack them—within two weeks of receiving the first dose.
The data are early and come from a group of patients aged 18 to 55. The study is testing the vaccine in adults aged 56 to 70 and those 71 and older.
Of the 30 patients who received the two lowest doses, only one reported a side effect considered to be grade 3: redness around the injection site. Three people who got the highest dose, 250 mcg, developed grade 3 “systemic symptoms,” including fever, muscle pain and headache, Moderna Chief Medical Officer Tal Zaks, M.D., Ph.D., said on a call discussing the data. Although the side effects were temporary and went away on their own, Moderna won’t carry the highest dose into future trials.
Based on the data, the company will tweak its phase 2 study to test two dose levels, 50 mcg and 100 mcg, while the NIAID will test a 50-mcg dose in all three age groups. Moderna thinks the phase 3 dose will land somewhere between 25 mcg and 100 mcg.
“These interim Phase 1 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,” Zaks said in a statement. “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 company plans to start its phase 3 study in July. Last week, it picked up fast-track status from the FDA, which will help speed up the time a new drug or vaccine takes to hurdle the normal regulatory barriers.
“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,” Moderna CEO Stéphane Bancel said in the statement. Last month, the Biomedical Advanced Research and Development Authority committed up to $483 million to fund late-stage trials and scale up manufacturing for the vaccine.