IFN-gamma is currently marketed for the treatment of chronic granulomatous disease and malignant osteopetrosis, and is in clinical trials for the treatment of idiopathic pulmonary fibrosis, certain forms of cancer and tuberculosis.

The novel molecules, developed by Nautilus, are single mutants of IFN-gamma. Experimental studies have shown they have significantly higher resistance to blood and intestinal proteases, while maintaining the native level of biological activity.

"Achieving higher stability is a key objective for the improvement of IFN-gamma, as it will increase the half-life of the molecule in the body and decrease the frequency of repeat treatments," said Nautilus CEO Manuel Vega.

"This is one of the most important clinical criteria for any next generation IFN-gamma with the potential to become the next generation of blockbusters," he added.

In 2003 worldwide sales of therapeutic proteins, including interferons, hormones, growth factors and enzymes, were more than $29 billion (€22.3 billion) The therapeutic proteins market is one of the fastest growing in the pharmaceutical sector, with annual sales growth of 10-15 per cent.