Another thing too is these drugs are priced by weight and as these therapies help patients living longer and offer stabilization/improvement they gain weight. BMRN has also done a nice job with Naglazyme charging higher prices perhaps it sets a precedent for the more rare LSD's getting even higher price (or just give BMRN credit they got a much higher price for Kuvan then I expected).
I heard the company say Morquio is on the scale of Aldurazyme in terms of size. I believe MPS-I is estimated to have 3000 patients worldwide (I think MPS VI has about 1100). Do you know if the Morquio number is in-the-ballpark? TIA