SHANGHAI — One new drug promises to stop cancer from spreading to other organs. Another would treat blood cancer. A third would use the body’s immune system to kill tumors.

All three show encouraging results, and need just one more step to be approved for use in the United States. The drugs have something else in common: They were created in China.

For years, China’s drug industry concentrated on replicating Western medicines. Getting new drugs approved was a frustrating and time-consuming process. Companies thought plowing millions of dollars into research and development was risky and stuck to safer revenue streams.