Takeda Pharmaceutical Co., Japan's largest drugmaker, expects a 55 percent decline in profit this year from costs related to the $8.8 billion takeover of Millennium Pharmaceutical Inc. last month.

Net income will fall to ¥160 billion for the year ending next March 31, the firm said Friday in a statement to the Tokyo Stock Exchange.

Buying Cambridge, Mass.-based Millennium gives Takeda drugs under trial to treat cancer and inflammation, as well as additional research costs. Osaka-based Takeda needs the products because patents on its Actos diabetes treatment and stomach ulcer medicine Prevaid will expire within three years.