By Randall Osborne
West Coast Editor
In a development that caused a market ripple but was not expected to affect Genzyme General's bottom line, the FDA said it had completed its review of the company's biologics license application (BLA) for its enzyme replacement product Fabrazyme, and wants several points clarified.
"This is not any huge, abnormal type of thing," said Caren Arnstein, vice president of corporate communications for Cambridge, Mass.-based Genzyme. "It's a normal part of the review phase, and a lot of this information we already have."
Fabry disease is caused by a deficiency of the enzyme alpha-galactosidase, and afflicts between 2,000 and 4,000 people worldwide. Genzyme, which filed its BLA for Fabrazyme (agalsidase beta) June 23, is racing toward approval with Transkaryotic Therapies Inc. (TKT), also of Cambridge, Mass., which filed its BLA for Replagal (alpha-galactosidase) June 16. The two companies are involved in a patent fight over the products, both of which have been accepted for priority review and potential orphan drug status. (See BioWorld Today, June 19, 2000, and June 26, 2000.)
Genzyme's stock (NASDAQ:GENZ) slid Wednesday, closing at $89.75, down $6.125. TKT's shares (NASDAQ:TKTX) jumped, ending the day at $35.437, up $3.312. The teeter-totter effect is not unusual, Arnstein said, noting that TKT has yet to hear from the FDA.
Before the request for clarification was made, the FDA was expected to take action on Fabrazyme by mid-January. Keeping to that schedule "would be a great goal, but whether it can move that fast, we don't know at this time," Arnstein told BioWorld Today.
The required Phase IV study of Genzyme's drug for Fabry disease is expected to begin on time, with enrollment starting in January. An ongoing open-label extension study of Fabrazyme is confirming the positive findings of the Phase III study on which the BLA was based, and some of the data sought by the FDA is newly analyzed.
"At some point, the FDA looks at data received as of a particular date," she said. "Because of the competitive situation, we really don't want to be very specific [about what the agency has requested]," she added.
Genzyme, which has been given orphan drug status for the drug, said it will launch Fabrazyme immediately after FDA approval, using its sales force for Cerezyme (imiglucerase), another enzyme replacement product.
Arnstein said the FDA is not guaranteeing it won't need still more data, Arnstein said. "I don't know if they ever draw a line that clear for you, but I think we're anticipating they've done a fairly thorough review of the data [already] submitted," she said.