The battle for market share in drugs for Gaucher disease is hotting up after Israel’s Protalix Biotherapeutics reported positive top-line results from a late-stage trial of Uplyso.

The Gaucher market has opened up as the result of a potential shortage of the only US-approved drug for the disease, Genzyme Corp's Cerezyme (imiglucerase). The latter firm temporarily shut down its manufacturing facility in Boston in June after a bioreactor was contaminated with a virus.

Now Protalix says that a Phase III trial of Uplyso (taliglucerase), previously known as prGCD, reduced spleen volume by a statistically significant amount after nine months. Those reductions were experienced by patients who took a higher dose of 60 units/kg, as well as patients who took a lower dose of 30 units/kg.

Interestingly, only 6% of patients developed antibodies to Uplyso, much lower than for Cerezyme. David Aviezer, Protalix chief executive, said the company now expects to complete the ongoing rolling New Drug Application submission with the US Food and Drug Administration before the end of this year.

In addition, “these results further validate our ProCellEx platform for the expression of safe and efficacious human therapeutic proteins in plant cell cultures”, he added, “and sets the ground for many other lucrative opportunities.” Gaucher affects about 5,000 people globally but the market is a lucrative one and sales of Cerezyme reached $1.2 billion last year.

Shire is also hoping to fill the gap created by the shortage of Cerezyme and last month said that it has accelerated its manufacturing timeline by almost 18 months in order to provide velaglucerase alfa, its Gaucher treatment which has been filed with the FDA. Geoffrey Meacham, an analyst at JP Morgan, issued a research note saying that “we see Shire and Protalix as real competitors in the space and remain sceptical that Genzyme will be able to win back all of its patients once its manufacturing issues are resolved".