Ongoing Phase 2/3 Trial Evaluates Efficacy of mRNA-1345 Vaccine for RSV

In a trial conducted by ModernaTX, Inc, investigators are assessing the safety and efficacy of the mRNA-1345 vaccine to target respiratory syncytial virus (RSV) among adults 60 years and older.¹ The phase 2/3 randomized, observer-blind, placebo-controlled study (NCT05127434) is divided in 2 parts — Part A and Part B. The role of Part A is to evaluate the safety and tolerability of mRNA-1345 along with the efficacy of a single dose of mRNA-1345, compared to a placebo 14 days post-infection through 12 months. In Part B, investigators are evaluating the safety, tolerability, and immunogenicity of a booster dose of mRNA-1345 at 24 months after the initial dose.²

Image credit: Artur | stock.adobe.com

The study is focusing on the older population, highlighting the need to address the long-term effects of RSV in this patient population to improve outcomes. Additionally, older individuals are at higher risk of developing more severe complications because of age-related declines in immune function, along with comorbidities, such as chronic lung disease, heart disease, and a weakened immune system. However, the most impacted individuals are those living in institutional settings, as this setting can lead to outbreaks in long-term care facilites.³

The Part A phase 2 section of the study will include up to 2000 individuals that will be randomly assigned to receive a single injection of the mRNA-1345 vaccine or a placebo in a 1:1 ratio. Part A phase 3 of the study will include the same vaccines that will be randomly assigned, but will include 35,000 individuals. Following Part A, the Part B substudy will include 15,000 individuals that previously received a dose of mRNA-1345 in the Part A phase 3 section, and these individuals will be randomly assigned to receive a single booster dose of mRNA-1345 or a placebo.²

The study authors noted that the individuals included will be primarily responsible for self-care and activities of daily living. Additionally, the individuals could have 1 or more chronic medical diagnosis, not excluding chronic heart failure and chronic obstructive pulmonary disease, however, they must be medically stable. Individuals must also have a body mass index from ≥18 kg/m² to ≤35 kg/m², according to study authors.¹

The study authors noted that individuals could be excluded from the study if they participated in a previous clinical study that included an investigational product 6 months before day 1 of the current injection. Other exclusion criteria include participation in research that involved investigational RSV products or received or planned to receive a vaccine that is not included in the current study 28 days before or after day 1 of the current injection. Additionally, individuals with a history of serious reactions to prior vaccinations or Guillain-Barré syndrome 6 weeks prior to any flu infection will be excluded, according to study authors.¹ The trial dates are set from November 2021 – August 2025.¹

REFERENCES

1. A Study to Evaluate the Safety and Efficacy of mRNA-1345 Vaccine Targeting Respiratory Syncytial Virus (RSV) in Adults ≥60 Years of Age. Moderna Clinical Trials. News release. Accessed May 30, 2024. https://trials.modernatx.com/study/?id=mRNA-1345-P301.

2. Clinical Trials.gov. A Study to Evaluate the Safety and Efficacy of mRNA-1345 Vaccine Targeting Respiratory Syncytial Virus (RSV) in Adults ≥60 Years of Age. Accessed May 30, 2024. https://clinicaltrials.gov/study/NCT05127434?rank=1.

3. Respiratory Syncytial Virus in Older Patients: Prevention, Management, and Long-Term Impact. Pharmacy Times. News release. May 11, 2024. Accessed May 30, 2024. https://www.pharmacytimes.com/view/respiratory-syncytial-virus-in-elderly-prevention-management-and-long-term-impact.