Visterra, a US-based antibody therapeutics developer backed by pharmaceutical firm Merck & Co, suspended plans for its $50m initial public offering on Friday.
The company had initially filed for the IPO in January 2016, setting a target of $69m. It subsequently set the range last month for an offering that would have raised between $46.2m and $53.9m, only to withdraw the plans due to unfavourable market conditions.
Founded in 2007, Visterra is working on antibody-based treatments for diseases such as influenza and dengue fever. Its lead product candidate is a flu therapy called VIS410 for which the company planned to initiate phase 2b trials in the first half of 2017.
The company had raised approximately $100m in equity and debt financing from investors including Merck, which provided $10m of the $30m in series B funding it raised in 2014.
Visterra subsequently raised $23.1m in June 2016, according to a regulatory filing, with Merck and the Singapore state-owned Vertex Venture Management each investing $5m while VC firms Polaris Partners and Flagship Ventures each provided $3.5m.
Merck owns a 13.9% stake in Visterra while other notable investors include Polaris (23.4%), Flagship (20.8%), Vertex (7.2%), Bill & Melinda Gates Foundation (7%) and V-Sciences Investment (6.7%). Unnamed existing backers had expressed interest in buying $26.4m of shares in the offering.