Amicus Therapeutics Says Added 6-Month Results from Phase 3 Fabry Monotherapy Study Presented at LDN World Symposium Did Not Meet Primary Endpoint

Amicus Therapeutics

, today announced additional 6-month (Stage 1) results from the first ongoing Phase 3 global registration study (Study 011) of investigational oral migalastat HCl monotherapy (150 mg, every-other-day) in males and females with Fabry disease who had genetic mutations identified as amenable to migalastat HCl in a cell-based assay. Stage 1 results were highlighted in an oral platform presentation^1 at the Lysosomal Disease Network WORLD Symposium (LDN WORLD) by Dr. Fatih Ezgu, Gazi University. Study 011 consists of a 6-month, double-blind period (Stage 1) when subjects received migalastat HCl 150 mg or placebo, a 6-month open label-follow up period (Stage 2) when all patients received migalastat HCl, and an ongoing 12-month open-label extension. Initial top-line Stage 1 results previously reported in December, 2012 for the primary endpoint in Stage 1 did not meet statistical significance. The pre-specified primary and secondary analyses of the primary endpoint numerically favored migalastat HCl over placebo. In the primary responder analysis, 13/32 (41%) in the migalastat HCl group versus 9/32 (28%) in the placebo group demonstrated a 50% or greater reduction in kidney interstitial capillary GL-3 from baseline to month 6 (p=0.3). Taken alone the secondary analysis of the absolute percent change in kidney interstitial capillary GL-3 from baseline to month 6 showed a median reduction of 41% in the migalastat HCl group versus a median reduction of 6% in the placebo group (p=0.093). Study 011 entry criteria, particularly elevated urine GL-3, were intended to enrich for patients with higher interstitial capillary GL-3, and more measurable disease burden. Although all patients had detectable interstitial capillary GL-3 at baseline, a number of patients had low levels of GL-3 at baseline, making it difficult to detect a significant difference in responders between the 2 treatment groups. Clearance of kidney interstitial capillary GL-3, a marker of treatment effect, is being measured by histology^2 in evaluable kidney biopsies from baseline to month 6 (Stage 1) as well as baseline to month 12 (Stage 2). Stage 2 results remain blinded at this time.