In a ruling yesterday in London, Justice Colin Birss found two patents held by Roche Holding AG were invalid, according to Bloomberg. The company's patent for its top-selling breast cancer drug Herceptin expires in Europe on July 28, but it had filed two additional patents relating to certain dosages and the composition of the drug in order to prevent generic manufacturers from moving into the market.

Hospira Inc, a U.S.-based drug manufacturer, challenged these two patents in the U.K. High Court of Justice, Chancery Division, and won a ruling that overturned them. As a result, generic drugmakers like Hospira will be able to sell a cheaper competing generic form of the drug in the U.K., which would be known as trastuzumab.

"We are very pleased with this decision, which helps pave the way for our trastuzumab product," Hospira said in a statement.

Hospira is pioneering the development of generic versions of biotech drugs, Reuters reported. This is difficult to accomplish, as biological drugs are complex to make and copies cannot be exact replicas, but only very similar to the original product. Hospira recently made a biosimilar drug for sale in Europe called Inflectra, which is an alternative to Johnson & Johnson's and Merck & Co's drug Remicade for rheumatoid arthritis.