Pharmaceutical startup Karyopharm Therapeutics of Natick said underwriters for its initial public offering of common stock have exercised their option to buy more than a million additional shares.
Karyopharm (KPTI), whose stock trades on the Nasdaq exchange, said the underwriters bought 1.02 million shares of stock at $16 per share, minus underwriting discounts. The stock sale gives the company an extra $15.2 million after the discounts.
Gross proceeds from Karyopharm’s IPO, which took place last month, were $125.1 million.
Karyopharm is a clinical-stage startup that is developing drugs that aim to treat cancer and other major diseases by blocking the export of various proteins out of cell nuclei.
