Moderna initiates Chikungunya vaccine human test, replaces backup Zika candidate

Moderna seldom updates progress made to its pipeline, but when it does, the updates tend to come in batches. Apart from a few advancements in its immuno-oncology programs, the mRNA expert also shared a new peek into its infectious disease efforts Thursday.

First up, the biotech started a phase 1 study of its Chikungunya vaccine candidate dubbed mRNA-1388 in August. This marks the fifth prophylactic vaccine Moderna has pushed into the clinic.

The dose-ranging study will enroll 60 healthy volunteers in the U.S. to evaluate the safety and immunogenicity of the shot, Liz Melone, a media aide with Moderna, told FierceVaccines.

Back in 2013, the U.S. Department of Defense’s Defense Advanced Research Projects Agency (DARPA) awarded Moderna up to $25 million to develop antibody-producing drugs against infectious diseases and other biological threats. The scope of the grant was expanded in 2015 to support vaccines projects, including this Chikungunya candidate.

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The idea behind the company’s infectious diseases vaccines is, instead of immunizing people with the actual virus, they deliver mRNAs that direct cells to produce and express viral antigenic proteins, mimicking a viral infection that could trigger the immune system to produce antibodies.

Moderna’s more advanced Zika vaccine candidate, mRNA-1325, uses the same rationale. The company said a phase 1/2 study on the candidate, backed by a $125 million grant awarded in 2016 by the Biomedical Advanced Research and Development Authority (BARDA), is progressing as planned and will have readouts in the coming months.

According to Melone, mRNA-1325 was brought to the clinic in an expedited time frame of just 12 months, as the global community last year faced intense pressure to advance studies on Zika countermeasures.

"While that program has been moving forward, we have continued to learn a great deal about the biology and behavior of the Zika virus and other flaviviruses, based on both our own research as well as research from the scientific community, including our collaborators at the Washington University School of Medicine," Melone told FierceVaccines.

That knowledge base is continually growing as the company enhances its own mRNA platform—both mRNA-1388 and mRNA-1325 are based on in-licensed formulations—leading to its decision to pursue a backup Zika vaccine.

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Moderna also announced that it has replaced its original backup Zika vaccine with a new one called mRNA-1893, which utilizes one of Moderna’s proprietary formulations, V1GL, a next-generation lipid nanoparticle technology, according to Melone. This new preclinical candidate also has a different API from that included its predecessor and mRNA-1325. A previous study applying viral challenge models found that the new version, which uses a leader sequence from the Japanese encephalitis virus, led to improved immunogenicity and superior protection compared to IgE used in mRNA-1325.

"Given that there is now reduced urgency as a result of the lower infection rate currently being observed, we have an opportunity to advance the best possible vaccine," Melone said. The company said it will first conduct GLP toxicology studies on it.

All together, nine prophylactic vaccine projects currently exist in Moderna’s pipeline: a proof-of-technology H10N8 flu vaccine with interim phase 1 results from May, one against H7N9, two Merck-partnered programs with undisclosed indications, and two other V1GL-based preclinical candidates against cytomegalovirus, and human metapneumovirus and human parainfluenza virus type 3, respectively.