Amicus Therapeutics (NASDAQ:FOLD) shares plummeted Thursday, a day after the company and GlaxoSmithKline plc (GSK) said a late-stage study of a treatment for Fabry disease didn’t meet the primary goal.
Shares in Amicus retreated more than 45 per cent on the Nasdaq this afternoon, to $3.13.
The partners announced the 6-month primary treatment period results from the first phase 3 global study of the oral migalastat HCl monotherapy in males and females with Fabry disease.
The trial randomized a total of 67 patients to receive oral migalastat HCl 150 mg or placebo on an every-other-day (QOD) dosing schedule during a 6-month, double-blind primary treatment period.
Globotriaosylceramide (GL-3) is the lipid substrate that accumulates in tissues of patients with Fabry disease, most notably in the kidney. GL-3 clearance from the kidney interstitial capillaries has been used as a marker of treatment effect in Fabry disease.
The accumulation of GL-3 is believed to cause the various manifestations of Fabry disease, including pain, kidney failure, and increased risk of heart attack and stroke.
The companies said that 41 per cent in the migalastat HCl treatment group showed a 50 per cent or greater reduction in kidney interstitial capillary GL-3 after 6 months of study treatment versus 28 per cent in the placebo group. This difference did not achieve statistical significance, according to the pre-specified primary endpoint analysis.
"Consistent with our phase 2 experience, the 6-month results from Study 011 demonstrate notable trends in kidney interstitial capillary GL-3 reduction in favor of migalastat HCl monotherapy compared to placebo," said chairman and CEO of Amicus, John F. Crowley.
"We look forward to announcing additional 6-month results at the WORLD Symposium in February, including a presentation of important secondary and tertiary endpoints in this study. We also anticipate 12-month results from this study in the first half of 2013."
The company said that once it has the 12-month data, it intends to meet with the FDA to discuss a U.S. approval pathway. "We continue to believe that migalastat HCl may become an important treatment option as an oral monotherapy drug for both men and women with Fabry disease who have amenable mutations," said Crowley.
So far, no drug-related serious adverse events have been observed.
Amicus is in collaboration with GlaxoSmithKline (GSK) in developing the investigational pharmacological chaperone migalastat HCl for the treatment of Fabry disease. Amicus has commercial rights to all Fabry products in the US, and GSK has commercial rights to all of these products in the rest of world.