JIMD Reports, Volume 43

Erika F. Augustine, Christopher A. Beck, Heather R. Adams, Sara Defendorf, Amy Vierhile, Derek Timm, Jill M. Weimer, Jonathan W. Mink, Frederick J. Marshall, Augustine, Erika F., Beck, Christopher A., Adams, Heather R., Defendorf, Sara, Vierhile, Amy, Timm, Derek, Weimer, Jill M., Mink, Jonathan W., Marshall, Frederick J.

Mycophenolate, an immunosuppressant, is commonly used off-label for autoimmune neurological conditions. In CLN3 disease, a neurodegenerative disorder of childhood, preclinical and clinical data suggest secondary autoimmunity and inflammation throughout the central nervous system are key components of pathogenesis. We tested the short-term tolerability of mycophenolate in individuals with CLN3 disease, in preparation for possible long-term efficacy trials of this drug. We conducted a randomized, double-blind, placebo-controlled, crossover study of mycophenolate in 19 ambulatory individuals with CLN3 disease to determine the safety and tolerability of short-term administration (NCT01399047). The study included two 8-week treatment periods with a 4-week intervening washout. Mycophenolate was well tolerated. 89.5% of participants completed the mycophenolate arm, on the assigned study dose (95% CI: 66.9-98.7%), and there were no significant differences in tolerability rates between mycophenolate and placebo arms (10.5%; 95% CI: -3.3-24.3%, p = 0.21). All reported adverse events were mild in severity; the most common adverse events on mycophenolate were vomiting (31.6%; 95% CI: 12.6-56.6%), diarrhea (15.8%; 95% CI: 3.4-39.6%), and cough (15.8%; 95% CI: 3.4-39.6%). These did not occur at a significantly increased frequency above placebo. There were no definite effects on measured autoimmunity or clinical outcomes in the setting of short-term administration. Study of long-term exposure is needed to test the impact of mycophenolate on key clinical features and CLN3 disease trajectory.