Updated
October 6th, 2019

$51 Million Dollars Raised For RSV Vaccine Development

Icosavax IVX-121 RSV vaccine candidate incorporates a stabilized prefusion F antigen

older woman healthy

 A Seattle based company announced $51 million dollar financing for advancing the company’s first vaccine candidate, IVX-121.

The IVX-121 vaccine is targeted for Respiratory Syncytial Virus (RSV) in older adults through Phase 1b clinical studies.

This is good news since there is no vaccine available today to prevent an RSV infection.

IVX-121 incorporates a stabilized prefusion F antigen licensed from the NIAID/NIH. Extensive preclinical studies suggest that IVX-121 could increase the protective immunogenicity of RSV F compared to the DS-Cav1 antigen alone, said the company.

Adam Simpson, Chief Executive Officer of Icosavax, said in a October 3, 2019, press release, “This support allowed us to assemble a world-class team and to help translate the scientific insights from IPD into IVX-121, our lead candidate for RSV and the application of our Virus-Like Particles (VLP) technology to a whole class of vaccine targets with significant unmet medical needs.”

VLPs enable high-density, multivalent display of antigens in a manner that closely resembles viruses, with an important difference. VLPs contain no genetic material, so they are non-infectious and can provide a safer alternative to live-attenuated or inactivated vaccines. 

Naturally occurring VLPs have delivered successful vaccines, including Gardasil, Cervarix, Engerix-B, and Recombivax HB.

However, VLPs have been difficult to use for the display of complex heterologous antigens, like in the case of RSV.

VLPs are known to induce superior immunological responses compared to traditional soluble antigens, eliciting protective immune responses while reducing the need for strong adjuvants, which in some instances have been associated with side effects.

“Icosavax’s vaccine technology solves the problem of constructing and manufacturing VLPs displaying complex antigens by utilizing computationally designed proteins that separate the folding of individual protein subunits from the assembly of the final macromolecular structure,” said Icosavax co-founder Neil King, Ph.D.

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“The individual proteins are expressed and purified using traditional recombinant technologies, and then self-assemble into VLPs when mixed together.”

Icosavax’s in-licensed computationally designed VLP technology is a product of the IPD’s Translational Investigator Program, which enables entrepreneurial researchers to turn their first working versions of designed proteins into commercially viable assets. 

The license to this technology was negotiated with CoMotion at the University of Washington, UW’s collaborative innovation hub.

Recent RSV vaccine news

Symptoms of RSV infection typically resemble those of a cold. But the infection leads to more than 57,000 hospitalizations a year of children age 5 or younger, according to the Centers for Disease Control and Prevention (CDC). 

An additional 177,000 older adults are hospitalized annually with RSV infection, which kills about 17,000 of them, the CDC says.

Icosavax was founded on breakthrough computationally designed virus-like particle technology, exclusively licensed for a variety of infectious disease indications from the Institute for Protein Design at the University of Washington.

For more information, please visit Icosavax.

RSV Vaccine information published by Precision Vaccinations