30 October 2020 - - US-based Icosavax, Inc. has launched the company's COVID-19 vaccine program with preclinical data on the company's VLP vaccine candidate, IVX-411, which comprises a virus-like particle displaying the SARS-CoV-2 receptor-binding domain in a highly immunogenic array, the company said.

Icosavax also announced that the Bill and Melinda Gates Foundation has provided a USD 10m grant to support the company's COVID-19 vaccine program through the first in human Phase 1 clinical trial in young and older adults, expected to initiate in mid-2021.

In addition, Icosavax received USD 6.5m from Open Philanthropy to support development of the company's vaccine platform technology and COVID-19 vaccine candidate.

The company is currently advancing the necessary studies to support regulatory filings and has initiated GMP manufacturing.

To enable rapid progress of the company's COVID-19 vaccine candidate to the clinic, Amgen has agreed to manufacture a key intermediate for initial clinical studies.

Developed by scientists at the University of Washington School of Medicine using structure-based vaccine design techniques invented at the Institute for Protein Design at the UW Medicine, IVX-411, the lead vaccine candidate for COVID-19, is a self-assembling protein nanoparticle that displays 60 copies of the SARS-CoV-2 spike (S) glycoprotein receptor-binding domain in a highly immunogenic array.

Preclinical data from UW researchers and their collaborators show IVX-411 induces high neutralizing antibody titers in mice after a single administration and further improvement after a second administration (Cell 2020).

Titers after the second administration were ten-fold higher than those seen with the soluble SARS-CoV-2 spike protein that forms the basis of many other vaccine candidates.

The data also show a strong B-cell response after immunization, critical for immune memory and a durable vaccine effect, with antibodies that target multiple distinct epitopes on the RBD, suggesting potential protection from escape mutations.

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.

The high yield and stability of the protein components and assembled nanoparticles suggest that manufacture of the nanoparticle vaccines will be highly scalable.

Icosavax has a worldwide license with an exclusive option for IVX-411 in North America and Europe from the University of Washington.

Icosavax is focused on developing safe and effective vaccines against infectious diseases that cause severe, life-threatening respiratory illnesses.

In addition to the COVID-19 vaccine candidate, Icosavax is also advancing IVX-121 into clinical trials as a potential vaccine for respiratory syncytial virus for older adults.

The company was founded on breakthrough computationally-designed virus like particle technology developed at the Institute for Protein Design and exclusively licensed from the University of Washington. Icosavax is located in Seattle.