Amgen Inc. has signed an agreement with a Chinese pharmaceutical company for distribution of a colon cancer drug. The Thousand Oaks biopharmaceutical company will work with Zhejiang Beta Co. Ltd., of Zhejiang, to distribute Vectibix, a treatment for metastatic colorectal cancer. Amgen will control 49 percent of the joint venture with Zhejiang having 51-percent majority control. Financial details were not announced. “This joint venture brings us one step closer to providing Chinese patients with Amgen’s medicines and supports our strategy of expanding in key, fast-growing markets,” said Anthony Hooper, executive vice president of Amgen, in a statement. Amgen has been rapidly expanding into the Asian pharmaceutical market, and is constructing a $200 million manufacturing facility in Singapore to support its growth in the region. Shares of Amgen closed up $2.16, or 2 percent, to $106.72 on the Nasdaq.