IcosavaxThe biopharma Icosavax (Nasdaq:ICVX) has announced positive topline interim results from its Phase 1/1b clinical trial of IVX-121, a vaccine candidate with a prefusion stabilized Respiratory Syncytial Virus (RSV) F antigen.

The Phase 1 portion of the study enrolled 90 healthy young adults between 18 and 45. The Phase 1b portion included 130 healthy adults aged 60 to 75.

IVX-121 had a robust immunologic response to RSV. In addition, Icosovax noted that the vaccine candidate achieved comparable Geometric Mean Titer (GMT) levels at Day 28 in both age groups.

Seattle-based Icosavax noted that the vaccine candidate had a favorable tolerability profile with no vaccine-related serious adverse events.

“Importantly, we believe these Phase 1/1b data provide initial validation of our underlying VLP technology. They also reaffirm our strategy to combine multiple pathogen targets in one vaccine,” said Adam Simpson, CEO of Icosavax, in a news release. “As planned, Icosavax will now progress the development of IVX-121 combined with a human metapneumovirus (hMPV) VLP as our IVX-A12 bivalent vaccine candidate. We believe IVX-A12 could be unique in providing protection against these two leading causes of pneumonia, each of which currently lack an approved vaccine.”

The company intends to file an investigational new drug (IND) application with FDA and launch a Phase 1 study of IVX-A12, a combination bivalent RSV + hMPV VLP candidate, in the second half of 2022.

Many companies are developing vaccines for respiratory syncytial virus (RSV). Earlier this month, Agenus (Nasdaq:AGEN) and its partner GSK (NYSE:GSK) announced positive results from a pre-specified efficacy interim analysis of the AReSVi 006 Phase 3 trial of an experimental RSV vaccine. Last year, Moderna won FDA fast-track designation for RSV vaccine. In addition, Pfizer (NYSE:PFE), GlaxoSmithKline (LON:GSK), Johnson & Johnson (NYSE:JNJ), Novavax (Nasdaq:NVAX) and Bavarian Nordic (CPH:BAVA) are also working on RSV vaccines.

ICVX shares fell 27.43% to $6.11 today.

In early September 2021, its shares were trading close to $40.

The company saw its share price drop by almost two-thirds on March 25 after announcing disappointing interim results from a Phase 1/2 trial of IVX-411, a virus-like particle vaccine candidate against SARS-CoV-2.