Durham antiviral drug developer Chimerix is seeking to raise as much as $50 million with a public stock sale.
The proceeds from the sale will go to the selling stockholders, not the company itself, the company said in a regulatory filing.
Chimerix shares were down about 9 percent Tuesday after the announcement.
Chimerix, a 13-year-old company with no products on the market, raised $117.9 million in April in an initial public offering of stock. The shares, which began trading at $14, opened at $21.91 on Tuesday.
Chimerix is developing a treatment for life-threatening viral infections in patients whose immune systems have been compromised by cancer or by drugs. Its most advanced experimental drug, CMX001, has gone through two patient trials and is scheduled for a third and final test this year.
Chimerix is also developing an experimental HIV treatment, CMX157. Last summer, Merck licensed the rights to the product for a $17.5 million upfront payment plus milestone payments that could reach $151 million. Merck will be responsible for developing and marketing the drug.
The company's major shareholders include Sanderling Venture Partners V, New Leaf Ventures II, Canaan VII and Alta Biopharma Partners III.