Shares in UK drugmaker Shire continued their recent upward trend on Friday after US regulators issued a green light for its Type 1 Gaucher disease drug Vpriv.

Marketing approval for the drug was granted in just six months by regulators, who were keen to make available a new treatment option for Gaucher disease given that supply of the only other enzyme replacement therapy - Genzyme Corp’s Cerezyme (imiglucerase) - remains “uncertain and disrupted”, the firm noted.

Gaucher disease is a rare lysosomal storage disorder caused by a hereditary deficiency of the enzyme glucocerebrosidase, which can lead to the build up of fatty substances in organs including the spleen, liver, kidney and brain, resulting in a whole host of complications such as liver malfunction, skeletal disorders anaemia. Vpriv (velaglucerase alfa for injection) is an ERT designed for both adult and paediatric patients, which has, in clinical trials, proven its potential as a long-term therapy for sufferers of the disease.

Shire has been providing its ERT to patients free of charge on both sides of the Atlantic under a compassionate use protocol - which allows patients to be treated with a drug before it becomes commercially available under certain conditions - because of the global supply shortage of Cerezyme, sparked by the temporary shut down of Genzyme’s manufacturing plant last June after a bioreactor was contaminated with a virus disrupting production.

But following the completion of a rolling submission of Phase III clinical trial data, which began back in September, the US Food and Drug Administration has now ruled, in just six months, that Vpriv is indeed safe and clinically effective allowing commercial sales of the drug, which Shire’s chief executive Angus Russell previously noted would be sold at a 15% discount to its rival blockbuster Cerezyme.

Confidence growing
According to Gregory Pastores MD, Associate Professor of Neurology and Pediatrics at the NYU School of Medicine in New York, experience with Vpriv garnered through the compassionate use programme “has helped build confidence in its use, bolstered by data on low frequency of antibody formation”, which should also help the make significant inroads into the Gaucher disease market in a relatively short space of time.

Across the pond, Vpriv’s application has also been granted a speedy review by the European Medicines Agency, and Shire says it expects to launch its therapy within the European Union by the end of the year, as well as other countries beginning in 2011.