Moderna Inc. on Thursday said its closely watched experimental messenger RNA-based influenza vaccine generated a strong immune response against A strains of the flu but failed to show it was at least as effective as an approved vaccine versus less prevalent influenza B.
The results dashed investor hopes that the company might plug its
COVID franchise decline, sending Moderna’s shares down more than 6 percent in after-hours trading.
Moderna, whose only marketed product is its
COVID-19 shot, has high hopes for its flu
vaccine and aims to grab large portions of the respiratory syncytial virus (RSV) and seasonal flu markets with new mRNA
vaccines.
The company said its
vaccine, called mRNA-1010, generated a stronger immune response for the A/H3N2 and A/H1N1 strains than the marketed
vaccine it was tested against in a trial of 6,102 adults aged 18 and over across Argentina, Australia, Colombia, Panama and the Philippines during flu season there.
It failed to meet its goal of non-inferiority compared to the conventional
vaccine for the B/Victoria and B/Yamagata-lineage strains, the drugmaker said.
Cowen analyst Tyler Van Buren said investors had hoped Moderna would replace its
COVID revenue with RSV and flu
vaccine income, especially after it delivered positive RSV
vaccine efficacy results in January.
“But to fill that big
COVID decline, you need RSV and flu. The efficacy results could tell a different story when they come out, but there was no doubt that the most recent
vaccine data was a mixed bag,” he said.
He said physicians and patients might be put off by Moderna’s flu
vaccine’s results for Influenza B and the high rate of side effects.
The US company said it has already updated mRNA-1010 in a way it believes will improve immune responses against Influenza B and will test those changes.
“We have always said our goal is to produce a flu
vaccine, and then to iterate it, and to fine tune it over time to really make it exceptional,” Chief Medical Officer Paul Burton said in an interview.
Dr. David Boulware, an infectious disease specialist at the University of Minnesota Medical School, said he was not overly concerned about the immune response versus Influenza B.
Boulware said the immune response against the A strains demonstrated that the
vaccine probably worked and Moderna’s tweaks to the
vaccine are likely to improve the response against the B strains.
“I consider it pretty positive,” he said.
Seventy percent of those who received Moderna’s shot reported mostly mild adverse reactions compared to 48 percent for the conventional flu
vaccine. Pain and swelling at the injection site as well as headaches and fatigue were among the most commonly reported side effects.
The company also has an ongoing late-stage efficacy study on the mRNA-1010 flu
vaccine, which could have data within weeks.
If that trial reads out soon, Burton said he hopes to have the data prepared and sent to regulators in the first half of this year, which could allow them to review it as soon as late 2023 or early 2024.
The flu, an infection of the nose, throat and lungs, kills 290,000 to 650,000 people worldwide annually.