Pilot study of the safety and effect of adalimumab on pain, physical function, and musculoskeletal disease in mucopolysaccharidosis types I and II

Mucopolysaccharidosis I and II are lysosomal storage disorders that, despite treatment with hematopoietic cell transplantation (HCT) and/or enzyme replacement therapy (ERT), continue to cause significant skeletal abnormalities leading to pain, stiffness, physical dysfunction, and short stature. Tumor necrosis factor – alpha (TNF-α) is elevated in individuals with MPS I and II and associated with pain and physical dysfunction. Therefore, we evaluated the safety and effects of the TNF-α inhibitor adalimumab in patients with MPS I and II in a 32-week, randomized, double blind, placebo-controlled, crossover study of adalimumab at a dose of 20 mg (weight 15– 5° in seven of eight joints in Subject #1 and five of eight joints in Subject #2 (range 7.0° to 52.8°). There was no change in the PPQ, 6MWT, or hand dynamometer. Data from this small pilot study suggest that treatment with adalimumab is safe, tolerable, and may improve ROM, physical function, and possibly pain, in children with MPS I or II. However, additional clinical trials are needed before this therapy should be recommended as part of clinical care.