San Diego’s Ambrx Withdraws IPO, Citing Market Conditions

Xconomy San Diego — 

Ambrx, a San Diego biotech developing antibody-drug conjugates to treat solid tumors and other diseases, said today it is withdrawing its planned IPO because of current market conditions. The company had planned to raise as much as $86 million in an IPO, according to a confidential filing that was made public in early May.

Ambrx notified the Securities and Exchange Commission of its planned withdrawal in a June 30 letter from the company’s vice president of finance. The 11-year-old biotech has raised more than $106 million from venture investors that include Tavistock BIO, Maverick Capital, Apposite Healthcare Fund, Versant Ventures, 5AM Ventures, Roche, and Merck.

In its IPO filing, Ambrx said it also has raised more than $200 million in non-dilutive funding by collaborating on particular drug development programs with Bristol-Myers Squibb, Merck, Eli Lilly, Zhejiang Medicine, and other strategic pharmaceutical partners.

Ambrx uses recombinant DNA-based protein biosynthesis to insert non-native amino acids at precisely selected sites in native proteins as they are being made within the cells. The company’s new drug pipeline includes a number of anti-cancer compounds, as well as long-acting proteins for growth hormone deficiency, weight management, and other disorders.

Ambrx is one of 21 U.S. companies that have withdrawn their IPOs, according to data available at Renaissance Capital, a Connecticut IPO investment firm that has counted 219 IPO filings so far this year. As of today, Renaissance said it has counted 146 IPOs this year (almost 59 percent more than the 92 IPOs during the first half of 2013) that have raised over $31.4 billion (more than 52 percent than the $20.6 billion raised at this time last year).