The restrictions on use of existing drugs in pharmaceutical R&D could be lifted under new laws proposed by the Intellectual Property Office (IPO).

The IPO’s proposed amendments to the Patents Act would rule that the use of a branded drug in a clinical or field trial does not infringe copyright.

This would make it easier for companies to compare a new drug to a branded product that is not their own, or to test a combination of the two drugs.

Current UK law allows limited use of patented drugs in tests required for the regulatory approval of generic drugs, but not of new brands.

The aim of the proposals, now out for consultation, is to create a better environment for pharmaceutical R&D in the UK.

IPO Chief Executive Sean Dennehey said: “Previous discussions with the pharmaceutical industry revealed a widespread appetite for change in the way UK patent law treats clinical or field trials.

“This consultation now offers a formal opportunity to shape the patent infringement provisions so that they can better support growth in this key industry sector.”

The consultation will run for eight weeks, until 19 December.

Sanofi has lost a legal appeal against the decision that Roche and Biogen Idec did not infringe its patent for biologic drug development.

Roche’s Genentech business and biotech specialist Biogen Idec did not steal Sanofi’s IP for genetic medicine to develop the cancer drugs Avastin and Rituxan, a US appeals court determined.

The decision reflects the growing commercial potential of biologics and the tense relationship between big pharma and the biotech sector.

The dispute began in 2008, when Genentech cancelled its long-standing licensing agreement with Sanofi. The genetic medicine specialist was acquired by Roche in 2009.

Sanofi claimed that Genentech and Biogen Idec had used its proprietary techniques to enhance gene expression, improving the efficiency of drug production.

However, the US court upheld the previous decision that in both cases, the drug production methods were different from those covered by Sanofi’s patent.

Avastin and Rituxan, both cancer drugs, are among Roche’s best-selling products: Rituxan achieved sales of $6.6bn, and Avastin $5.81bn, in 2011. Avastin is marketed by Roche, while Rituxan is co-marketed with Biogen in the US.

According to Sanofi spokesperson Carrie Brown, the company is “currently evaluating its options and next steps.”