Effects of early nonsteroidal oral immunomodulatory therapy in myasthenia gravis (P6.459)

Objective: To assess the steroid-sparing effect and treatment outcomes of nonsteroidal oral immunomodulatory therapy in myasthenia gravis (MG). Background: There is currently limited evidence to support the early initiation of nonsteroidal oral immunomodulators such as azathioprine or mycophenolate mofetil in MG. Several randomized trials demonstrated a reduction in the prednisone maintenance dose, while others found no significant difference in outcome. Optimal timing to start treatment is unclear. Design/Methods: We conducted a retrospective chart review of 61 MG patients who are on immunosuppression. The prednisone plus immunomodulator group (PIG) was compared to the prednisone only group (POG) using adjusted T and Z-tests. The time to reach prednisone nadir (defined as the lowest prednisone maintenance dose for at least 3 months) in relation to time of starting immunomodulators was analyzed using the Pearson correlation. Results: The PIG included more generalized than ocular MG patients compared to the POG (88.2% vs 33.3%, p=0.0001). The PIG also had a higher average MFGA clinical classification (2.12 vs 1.28, p=0.0110) and lower MRC sum score (18.2 vs 19.7, P=0.0427) at time of prednisone initiation. However, there was no significant difference in the prednisone nadir dose (7.92±8.21 mg vs 9.76±12.4 mg, p=0.9999) and use of monthly IVIG (3.7% vs 23.5%, p=0.3279) between the two groups. There is a trend towards higher prednisone dose reduction from maximal dose to nadir (73.3% vs 56.1%, p=0.2266) in the PIG, and slight improvement in outcome measures (decrease in MGFA by 0.654 vs 0.25, p=0.3427; increase in MRC sumscore by 1.33 vs 0.292, p=0.2084). Finally, there is a nearly significant correlation between time to start immunomodulatory therapy and time to achieve prednisone nadir (Pearson correlation 0.3543, p=0.0698). Conclusions: Timely initiation of a nonsteroidal immunomodulator may expedite achieving prednisone nadir in generalized MG. A prospective study is needed to assess this trend. Disclosure: Dr. Lu has nothing to disclose. Dr. Lucido has nothing to disclose. Dr. Scelsa has nothing to disclose. Dr. MacGowan has nothing to disclose.