Open-label extension study following the Late-Onset Treatment Study (LOTS) of alglucosidase alfa - Van der Ploeg, A T; Barohn, R; Carlson, L; Charrow, J; Clemens, P R; Hopkin, R J; Kishnani, P S; Laforêt, P; Morgan, C; Nations, S; Pestronk, A; Plotkin, H; Rosenbloom, B E; Sims, K B; Tsao, E (Mol Genet Metab, 2012)