Sanofi's Genzyme hits main target in PhIII study of rare disease drug

Sanofi's Genzyme has advanced a key program for its experimental tablet for patients with Gaucher disease. The Cambridge, MA-based unit of the French drug giant turned in upbeat data from the first Phase III study of the closely watched eliglustat tartrate, an oral drug for the rare genetic disorder that is typically treated with infusions of enzyme therapies.

Genzyme already offers the enzyme-replacement drug Cerezyme for patients with Gaucher, but patients on the treatment need to get ongoing intravenous infusions of the drug. The company, which Sanofi ($SNY) bought last year for $20.1 billion, has been working on the eliglustat tartrate program for more than a decade to provide patients with a new oral option for combatting the disease.

The tablet could provide Sanofi with differentiation in an increasingly crowded market for enzyme replacements for Gaucher. The FDA approved Pfizer ($PFE) and Protalix Biotherapeutics' rival drug Elelyso in May, and Shire ($SHPG) has been nipping at Genzyme's heels with its own enzyme therapy for this disease called Vpriv. The market size is limited, as fewer than 10,000 patients worldwide have the inherited disorder, which robs the body of its ability to break down a fat and leads to buildups of lipid-filled cells in organs.

Seeking the change the way the disorder is treated, Genyzme said that its Phase III "ENGAGE" study hit its primary goal, reducing spleen size by 30% overall compared with placebo in previously untreated patients with type 1 Gaucher, the most common form of the disease. It met all secondary endpoints as well, showing such benefits as improvements in platelet and hemoglobin levels in patients on the drug. Further details of the study are expected at a meeting in February 2013, according to Genzyme.

"The efficacy and safety data from our ENGAGE trial are consistent with what were observed in our Phase 2 study, continuing to suggest that eliglustat tartrate is a potent, well tolerated oral compound that may become a meaningful option for patients and physicians," Genzyme CEO Dr. David Meeker said in a statement. "The development of eliglustat tartrate has been underway for more than a decade and is the largest clinical program ever focused on Gaucher disease, demonstrating our ongoing commitment to innovation on behalf of this community."

Genzyme is wrapping up a second late-stage study called "ENCORE" that compares the tablet option with its IV drug Cerezyme. In all the eliglustat tartrate program involves more than 370 patients, a relatively low number compared with other pharma R&D efforts but enough to make it the largest effort in Gaucher ever.

- here's Genzyme's release
- see Reuters' article