Pfizer and partner Protalix BioTherapeutics have received some bad news after the regulator in the USA asked for more information on the latter's new treatment for Gaucher disease Uplyso.
The Israel-headquartered firm has been issued with a complete response letter from the US Food and Drug Administration for Uplyso (taliglucerase alfa). The main questions raised by the agency relate to "clinical and chemistry, manufacturing and controls".
Specifically, the FDA requested additional data from Protalix' switchover trial and long-term extension study, which was not available when the New Drug Application was filed. The agency also wants information regarding testing specifications and assay validation.
David Aviezer, chief executive of Protalix, said the firm is disappointed to get a CRL, but noted that the FDA did not request additional clinical studies. Moreover, the agency inspected the firm's manufacturing facilities, "finding them acceptable," and "did not identify any issues in its audit of our clinical sites”.
David Simmons, head of emerging markets and established products business at Pfizer, which licensed Uplyso in November 2009, said the company "remains dedicated to the Gaucher community worldwide”. He added that “we will work closely with Protalix to address the requests from the FDA in a timely manner by providing technical, analytical and regulatory expertise".
Investors in Protalix reacted badly to the news and the company's shares fell over 18%. However, observers believe that the market may have over-reacted as the FDA has not asked for any new trials and there do not appear to be any safety issues.
Although Gaucher is a rare disease, 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, the market is a lucrative one. It is led by Genzyme Corp's Cerezyme (imiglucerase), which has had manufacturing problems, and Shire's Vpriv (velaglucerase alfa).