Moderna CMV Vaccine: Investing in Latent Virus Prevention

The company's investigational vaccine, which is in a phase 3 study, is an example of its commitment to addressing these viruses.

Cytomegalovirus (CMV) is a common latent virus with over half of Americans infected with it by the age of 40, according to the Centers for Disease Control and Prevention (CDC).1 CMV typically lays dormant in people who do not have compromised immune systems.

For those who are beset with the active virus, they can have more serious symptoms affecting various parts of the body including the eyes, lungs, liver, esophagus, stomach, and intestines. And for babies born with CMV, they can have brain, liver, spleen, lung, and growth issues. Hearing loss is the most common problem in this patient group who are dealing with congenital CMV infection.1

“CMV is the leading infectious cause of birth defects in the United States,” Sandeep Basnet, MD, director, Clinical Development at Moderna.

Clinicians and researchers argue there is a strong need for preventative or treatment modalities for latent viruses such as CMV.

“CMV represents a significant unmet medical need right now,” Basnet explained. “…It can lead to lifelong medical conditions for those with weakened medical conditions or those born with CMV infection.”

There is no FDA approved vaccine to prevent CMV.

During its Vaccines Day back in March, Moderna discussed its commitment to addressing latent viruses and the company’s pipeline includes vaccines for Herpes Simplex Virus-1, Herpes Simplex Virus-2, Varicella zoster virus, Epstein-Barr Virus, and CMV. The company is applying its mRNA technology it used against COVID-19 to develop vaccines for latent viruses. Their CMV investigational vaccine, mRNA-1647, is in its phase 3 registration study, known as CMVictory.

The study is evaluating the safety and efficacy of mRNA-1647 against primary CMV infection in women ages 16-40 years. Moderna is looking to enroll up to 6900 women of child-bearing age, at approximately 150 sites globally, starting with the US. The company has set a goal of enrolling 42% of the participants as persons of color.

The vaccine combines 6 mRNAs in one vaccine, which encode for two proteins located on the surface of CMV: five mRNAs encoding the subunits that form the membrane-bound pentamer complex and one mRNA encoding the full-length membrane-bound glycoprotein B (gB). Both the pentamer and gB are essential for CMV to infect barrier epithelial surfaces and gain access to the body, which is the first step in CMV infection. The mRNA-1647 vaccine is designed to produce an immune response against both the pentamer and gB for the prevention of CMV infection.

Contagion spoke with Basnet about the mRNA-1647 efficacy and safety profile thus far and the mRNA platform’s capability to address latent viral infections.

Reference

1.Cytomegalovirus (CMV) and Congenital CMV Infection. Centers for Disease Control and Prevention. Updated August 18, 2020. Accessed May 12, 2022. https://www.cdc.gov/cmv/overview.html