Effects of Adalimumab in Mucopolysaccharidosis Types I, II and VI

This is a randomized, pilot study consisting of a 32-week, crossover, double-blind, placebo-controlled treatment phase of subjects with Mucopolysaccharidosis (MPS) types I, II or VI treated with enzyme replacement therapy (ERT) and/or hematopoietic cell transplantation (HCT). Subjects will be treated with adalimumab (group 1) or placebo (group 2) for 16 weeks (i.e., 8 doses) then cross over to the other group for 16 weeks. Subjects will be treated with adalimumab (20 mg \[weight 15-\<30 kg\] or 40 mg \[weight ≥30 kg\] administered subcutaneously \[subQ\] every other week) or placebo for 16 weeks, then cross-over to the other group for 16 weeks. Laboratory evaluations and Children's Health Questionnaire - Parent Form 50 (CHQ-PF50) for subjects \<18 years of age or the Medical Outcomes Study Short Form-36 (SF-36) for subjects ≥18 years will be assessed at Week 16 and 32 to evaluate early treatment safety and efficacy. Safety will be assessed with laboratory evaluations at 4, 8, 20, and 24 weeks after treatment initiation, and with study visits at week 16 and 32, Physical function will be measured by the CHQ-PF50/SF-36, joint range of motion (ROM), 6-minute walk test (6MWT), and strength testing (hand-grip dynamometer) at baseline, 16, and 32 weeks. Joint inflammation will be measured by serum markers at baseline, 16, and 32 weeks. Anthropometric measurements will also be performed at Baseline and 16 and 32 weeks.