In the four patients who received agalsidase beta at 0.5 mg/kg co-administered with migalastat HCl 150 mg, levels of active enzyme in plasma ranged from 2.0 to 4.2-fold higher than with ERT alone, as measured by total area under the curve (AUC). In skin biopsies from three patients, increases in levels of active enzyme in the skin ranged from 1.1 to 3.9-fold higher at day two, but no higher at day seven, following co-administration compared to ERT alone.
In the two patients who received agalsidase beta at 1.0 mg/kg co-administered with migalastat HCl 150 mg, levels of active enzyme in plasma were 1.6 and 2.2-fold higher than with ERT alone, as measured by total AUC. In skin biopsies, increases in levels of active enzyme in the skin were 1.6 and 2.1-fold higher at day two, and 1.2 and 1.7-fold higher at day seven, following co-administration compared to ERT alone.
The preliminary results do not sound impressive. My guess is that the assays used to determine AUC are noisy enough that you'd need a 10X increase to be confident that migalastat is having a genuine effect on stability and/or activity of the enzyme.
Maybe the 450 mg dose will be better, but when I hear 1.1 to 3.9-fold effects on enzyme levels, I think "within the error of the assay."