Arrowhead Pharmaceuticals Inc. of Pasadena has reported raising $60 million from selling shares of its common stock.

The biotech company announced on Jan. 22 that it had closed its public offering of 11,500,000 shares priced at $5.25, for gross proceeds of $60.4 million. The underwritten offering was first announced on Jan. 17.

Assisting in the sale were Jefferies LLC and B. Riley FBR Inc. of West Los Angeles, and Barclays Capital Inc. and Cantor Fitzgerald & Co. of New York.

Arrowhead Pharmaceuticals was listed last week as the biggest gainer in the Business Journal index of local businesses, with a 30 percent increase in share value. Its stock on Tuesday was trading above $6.

The 28-year-old firm, which develops drugs to treat stubborn diseases by silencing the genes that cause them, last month reported a fiscal 2017 year-end loss of $34.3 million narrowing its $87.7 million loss in the prior year.

Health business reporter Dana Bartholomew can be reached at [email protected]. Follow him on Twitter @_DanaBart.