Mycophenolate mofetil and methotrexate efficacy in dermatomyositis-BJD study

For both MMF (n = 13) and MTX (n = 11), there was no baseline difference in CDASI-A scores at treatment initiation. There was no significant difference in the degree of improvement on either medication, with a mean difference in daily CDASI-A change between MTX and MMF of -0.0028 ± 0.0024 (P = 0.24) using a mixed linear effects model. For MTX, the median percentage change in CDASI-A between the first and last study visit was -74%. For MMF, the median percentage change was -76%.

A decrease of 40% or greater in the CDASI-A score has previously been associated with a meaningful change in quality of life. When 'responders' were defined as having a ≥ 40% improvement in their CDASI-A score between the first and second observations, 27% of the patients taking MTX were responders while 54% of patients taking MMF were responders.

The range of time varied between the first and second visits, with 50% of patients having a second study visit within 150 days. By last follow-up, 55% of patients taking MTX were considered responders and 77% of patients taking MMF met the criteria to be considered responders. For the patients treated with MTX, the median follow-up for the second visit was 178 days and for the last visit was 776 days. For those treated with MMF, the median follow-up was similar – 147 days for the second visit and 787 days for the last visit. Six patients who received MMF had previously been treated with MTX and one patient who received MTX had previously been treated with MMF.

In conclusion there was no significant difference between the efficacy of MTX and MMF in DM. The study suggests that responders continue to improve over time while most non- responders show little improvement at first follow-up during the observation period. Thus both MMF or MTX may be added to treatment plans for patients with DM who have not responded to antimalarials.

Source- Grinnell, M., Keyes, E., Diaz, D., Vazquez, T., Feng, R. and Werth, V.P. (2022), Mycophenolate mofetil and methotrexate efficacy in dermatomyositis. Br J Dermatol, 187: 437-438. https://doi.org/10.1111/bjd.21235