We have a product which is patented in UK, Europe and USA. Should we try to get it patented in China to stop copying? Is that even possible?

Yes if that is a key market for you and you are still able to extend the patent to China, you would need to take legal advice to see if the timescales still allow this for you. You can find advice from the China IP attache – visit the IP in Export Markets section of your member hub.