Shares of Rigel Pharma fall on stock offering

SOUTH SAN FRANCISCO, Calif. -- Drug developer Rigel Pharmaceuticals Inc. said it priced its public offering of 13.7 million shares of its common stock at $9.50 per share.

The price represents an 8.2 percent discount to Rigel's Tuesday's closing stock price of $10.35. Rigel shares tumbled on the news.

The South San Francisco, Calif.-based company said it expects the offering's gross proceeds to total about $130 million, before deducting underwriting discounts, commissions, and other expenses.

The company plans to use the money to fund research and development. It has no products on the market. Its most advanced experimental drug is called fostamatinib, which is in late-stage trials as a treatment for rheumatoid arthritis. It has several other drugs at various stages of development.

Rigel is selling all of the shares in the offering, which is expected to close on or about Oct. 9. The company also granted the offering's underwriters, Jefferies & Co. and J.P. Morgan Securities LLC, a 30-day option to buy up to an additional 2.1 million shares to cover possible overallotments.

Rigel shares fell 83 cents, or 8 percent, to $9.52 in heavy morning trading, after dipping as low as $9.31 earlier in the session. Over the past 52 weeks, the company's shares have traded between $6.60 and $11.44.