Aptose Biosciences Inc. closed its offering of 18,543,750 common shares priced at $4 per share.

The number of shares sold includes the full exercise of underwriters of their option to buy additional shares.

Gross proceeds were about $74.2 million.

Piper Jaffray & Co. acted as sole active book-running manager for the offering, while Canaccord Genuity acted as passive book-running manager. Oppenheimer & Co. was lead manager, while JonesTrading Institutional Services LLC was co-manager for the offer.

Toronto-based Aptose Biosciences develops personalized therapies for cancer in the U.S. Its drug candidate APTO-253 is in a phase 1b clinical trial for treating patients with relapsed/refractory blood cancers, including acute myeloid leukemia and high-risk myelodysplastic syndrome.