Icosavax Secures $51 Million Series A Financing Led by Qiming Venture Partners and Sanofi Ventures to Advance Novel RSV Vaccine Candidate IVX-121

VCBeat (WeChat ID: vcbeat) has learned that biotechnology company Icosavax recently completed a $51 million Series A financing round. The round was led by Qiming Venture Partners USA, with participation from Adams Street Partners, Sanofi Ventures, and NanoDimension. The proceeds will support the Phase 1b clinical study of the company’s first vaccine candidate, IVX-121, for respiratory syncytial virus (RSV) in older adults. Icosavax was founded based on the virus-like particle (VLP) technology developed by the Institute for Protein Design (IPD) at the University of Washington School of Medicine (Cell, 2019, Preview).

Adam Simpson, CEO of Icosavax, stated, “This funding support enables us to build a world-class team and helps translate scientific insights on IPD into our vaccine candidate IVX-121, the lead candidate for RSV. We are highly pleased with the quality of the investor consortium we have assembled, which has provided substantial expertise and financial backing to advance IVX-121 into clinical development and apply our VLP technology to vaccine programs addressing significant unmet medical needs.”

Virus-like particles (VLPs) enable high-density, multivalent antigen display in a manner strikingly similar to viruses, but with one critical distinction. VLPs lack genetic material and are therefore non-infectious, serving as safe alternatives to live-attenuated or inactivated vaccines. Naturally occurring VLPs have already been successfully developed into vaccines, including Gardasil® and Cervarix® against HPV, and Engerix-B® and Recombivax HB® against hepatitis B. However, it remains challenging to employ VLPs for the display of complex heterologous antigens, such as those from respiratory syncytial virus (RSV).

Icosavax Chairman of the Board, Dr. Tadataka (Tachi) Yamada, explained, “RSV can cause life-threatening respiratory infections, with consequences as severe as influenza in older adults. However, an effective RSV vaccine has the potential to transform the lives of millions of people worldwide.”

“Icosavax’s vaccine technology addresses the challenges of constructing and producing virus-like particles (VLPs) that display complex antigens by leveraging computationally designed proteins, which decouple the folding of individual protein subunits from the assembly of the final macromolecular structure. We use conventional recombinant techniques to express and purify individual proteins, which then self-assemble into VLPs when mixed together,” said Neil King, co-founder of Icosavax. “Compared with traditional soluble antigens, VLPs can elicit superior immune responses, thereby inducing protective immunity while reducing the need for potent adjuvants, which can cause side effects in certain cases.”

The company’s RSV candidate vaccine, IVX-121, incorporates the stabilized prefusion F antigen (DS-Cav1; Science 2019) licensed by NIAID/NIH. Extensive preclinical studies conducted by IPD and Icosavax have demonstrated that IVX-121 enhances the protective immunogenicity of the RSV F protein compared to the DS-Cav1 antigen used alone.

Icosavax is a biotechnology company headquartered in Seattle, Washington. Icosavax is dedicated to developing safe and effective vaccines against infectious diseases to address unmet medical needs and reduce healthcare costs. The company was founded based on breakthrough computationally designed virus-like particle technology, which is currently licensed from the University of Washington’s Institute for Protein Design for use in multiple infectious disease indications.

(Compiled by Ning Chen)