Puma Biotechnology Inc. early Tuesday priced a public offering of 979,592 common shares at $122.50 a share, 2.6 percent below its later closing price.

Before the markets opened, the Westwood cancer drug developer, which has 28.7 million shares outstanding, plans to use net proceeds to pay for upcoming clinical trials of its lead drug candidate, Neratinib, which targets cancers of the breasts and lymph nodes.

Puma, which has a market cap of $3.59 billion, has seen its stock price soar in recent months as the company released encouraging early data on Neratinib.

The company has granted underwriters, including BofA Merrill Lynch and Citigroup, an option to purchase up to 146,938 additional shares to cover overallotments. The offering is expected to close by Friday.

Shares closed up 48 cents, or less than one percent, to $125.75 on the New York Stock Exchange.