ULTRAGENYX PHARMACEUTICAL INC.
The data were presented in a late-breaker presentation at the
As of the cut-off date and following at least 6 months of treatment with setrusumab, the annualized fracture rate across all 24 patients in the Phase 2 portion of the study was reduced by 67%. In the 2 years prior to treatment with setrusumab all patients experienced at least 1 fracture. The median annualized fracture rate of 0.72 in the 2 years prior to treatment was reduced to 0.00 (n=24, p=0.042) during the mean treatment duration period of 9 months. Following initiation of treatment with setrusumab, 20 patients experienced no radiographic-confirmed fractures, and 4 patients experienced 7 radiographic-confirmed fractures in 5 separate events. These fractures exclude fractures of the fingers, toes, skull, and face consistent with the Phase 3 study design.
'I have not yet encountered a patient with a fragility fracture while on setrusumab, and this may result from setrusumab's effects on the skeleton, improving the rate of new bone formation and bone quality,' said
The reduction in annualized fracture rates was associated with a clinically meaningful increase in BMD. At the 6-month timepoint, treatment with setrusumab resulted in a mean increase in lumbar spine BMD from baseline of 13% at 20 mg/kg (n=11) and 16% at 40 mg/kg (n=8), which represents the same substantial mean improvement in Z-score of +0.85 for both dose groups at 6 months compared to a combined mean baseline Z-score of -1.68. The small apparent difference in BMD change from baseline is likely related to differences in patients assigned to the two treated groups. There was no statistically significant difference in BMD percent change or Z-score change from baseline between the 20 and 40 mg/kg dosing cohorts.
'These data provide compelling evidence that improved bone mineral density, resulting from this unique mechanism of action, reduced the risk of fractures and that treatment with setrusumab could allow patients with OI to lead much more active lives with fewer fractures,' said
As of the data cut-off, there were no treatment-related serious adverse events observed in the study. Reported adverse events were generally consistent with those observed in the ASTEROID study with infusion-related events and headache determined to be the most common adverse events related to the study drug. There have been no reported hypersensitivity reactions related to setrusumab. There were no notable safety-related differences observed between dosing groups or age groups.
The Phase 3 portion of the study is currently enrolling approximately 195 patients at 50 sites across 12 countries.
Analyst Day and Webcast Information
Ultragenyx will host an Analyst Day at
An archived version of the remarks will also be available through the Ultragenyx website.
The Setrusumab Phase 3 Program
The global, seamless Phase 2/3 Orbit study is evaluating the effect of setrusumab on clinical fracture rate in patients aged 5 to
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