Pfizer to pay Protalix up to $115 million in Gaucher's disease treatment deal; Genzyme's Cerezyme supply

World pharmaceutical behemoth Pfizer, furthering its interests in rare diseases, has entered into an agreement with Israel-based Protalix Biotherapeutics to develop and commercialize taliglucerase alfa, a plant-cell expressed form of glucocerebrosidase (GCD) in development for the potential treatment of Gaucher's disease.

The news saw the US firm's share price gain 3% while Protalix' shares dropped 9% to $9.00. Pfizer and the Switzerland, not-for-profit R&D group Drugs for Neglected Diseases initiative (DNDi) recently entered into an accord designed to facilitate advancements in the battle against human African trypanosomiasis, visceral leishmaniasis and Chagas disease, which afflict vulnerable populations in the developing world (The Pharma Letter November 19).

David Simmons, president and general manager of Pfizer's Established Products Business Unit, commented: 'This agreement supports our goal to meet the needs of many patient populations, including those affected by rare diseases, and brings the best minds together to challenge the most feared diseases of our time.'

Under the latest deal, Pfizer will make an upfront payment of $60 million to Protalix. In addition, the latter is eligible to receive further regulatory milestones of up to $55 million. Pfizer and Protalix will share future revenues and expenses for the development and commercialization of taliglucerase alfa on a 60%/40% basis respectively.

In return, Pfizer will receive exclusive worldwide licensing rights for the commercialization of taliglucerase alfa, while Protalix will retain the exclusive commercialization rights in Israel. Taliglucerase alfa is the first enzyme replacement therapy derived from a proprietary plant cell-based expression platform using genetically engineered carrot cells.

Preparing rolling NDA filing with FDA

With the successful completion of Phase III clinical studies, Protalix is preparing to complete a rolling New Drug Application with the US Food and Drug Administration. The FDA has granted Orphan Drug designation and Fast Track status, facilitating the development and expediting the review of drugs to treat rare conditions or diseases, as well as an Emergency Use Authorization. The FDA has also requested, and subsequently approved, an Expanded Access Program (EAP) treatment protocol. Taliglucerase alfa is currently being provided to Gaucher's patients in the USA under the EAP protocol, as well as to patients in the European Union under a compassionate use protocol.

It is thought that the drug could reach the market as early as early as next year, and could provide competition to already troubled Genzyme Gaucher's drug Cerezyme (imiglucerase for injection), which has encountered supply problems and costs about $200,000 a patient per year, but even the small patient population can support sales exceeding $1 billion a year, notes the New York Times.

Genzyme starts supplying Cerezyme for Allston Landing plant

Meantime, Genzyme has begun shipping vials of newly produced Cerezyme manufactured at its Allston Landing plant. The company also provided an update on its progress to restore supplies of Cerezyme and Fabrazyme (agalsidase beta) for patients worldwide.

The initial Cerezyme shipments will provide uninterrupted treatment for the most vulnerable patients under the current supply conservation guidelines. By the end of this month, Genzyme will expand shipments of Cerezyme to patients worldwide who have experienced interruptions in their treatment this year.