Australians are likely to face price rises for their medicines in coming years if intellectual property proposals contained in the Trans-Pacific Partnership agreement go ahead.

The leaked treaty reveals a range of measures that would enhance the ability of drug companies to extend and widen patents on drugs.

It also proposes compensation for companies that face delays in the granting or extension of patents along with measures to ensure data exclusivity for companies so they can prevent competitors, specifically manufacturers of generic medicines, from using past clinic data to support new products.

The leaked TPP negotiations suggest drug companies will also be able to extend patent protection beyond the typical 20-year limit by patenting different aspects of their products, such as an active ingredient for new use further down the track. This is called ''evergreening''.

While these proposals would arguably encourage research and development of new drugs and boost the profits of large drug companies, which are mainly concentrated in the US, they will inevitably delay generic manufacturing of drugs which reduce the price of medicines for consumers.