A traditional Chinese medicine preparation used to treat cancer and boost patients' immunity has been given the go-ahead for a third phase of clinical trials in the US, the last major hurdle for those wishing to launch new drugs in the US market.

The drug, known as Kanglaite Injection, contains anticancer compounds extracted from the seed of coix, a grasslike relative of maize, and has been approved and used as a cancer treatment in China since 1995.

It has been used by more than 200,000 patients and is among the best-selling cancer treatments in the country.