Comparison of CD4 counts with mycophenolate mofetil versus methotrexate from the First-line Antimetabolites as Steroid-sparing Treatment (FAST) Uveitis Trial

Abstract

Purpose : Mycophenolate mofetil (MMF) can decrease CD4 counts by inhibiting an enzyme in GTP synthesis crucial for lymphocyte proliferation; however, it is unclear if MMF has a significant effect on CD4 counts that requires lab monitoring when treating uveitis for 6 months or longer. The FAST randomized control trial compared MMF and MTX as corticosteroid-sparing treatments for uveitis. We performed a sub-analysis to compare the change in CD4 counts between patients treated with MMF and MTX.

Methods : A subset of clinical sites obtained CD4 counts in the FAST Trial. Patients with CD4 counts at baseline, the primary endpoint (6-month visit or treatment failure (TF) before 6 months) and secondary endpoint (12-month visit or TF between 6-12 months) who did not change treatment (MMF or MTX) were included. Treatment was randomly allocated to either 1.5 g twice daily MMF or 25 mg weekly MTX. Change in CD4 count was measured from baseline to the primary/secondary endpoint and reported in cells/μL. The effect of treatment on change in CD4 count was analyzed using linear regression, adjusting for country, age, and sex.

Results : A total of 124 patients were included in the sub-analysis, with 62 patients per treatment arm. For patients on MMF, the mean baseline CD4 count was 1,020 cells/μL (95% CI: 785-1250) and the mean 6-month count was 1,040 cells/μL (95% CI: 870-1204) (Table 1). For patients on MTX, the mean baseline CD4 count was 960 cells/μL (95% CI: 796-1124) and mean 6-month count was 1,000 cells/μL (95% CI: 881-1125). There was no significant difference in the change in CD4 counts between MMF and MTX in the adjusted model at 6 months (-31.7 cells/μL for MMF compared to MTX; 95% CI: -358.2 to 294.8, P= 0.85). Of the 73 patients with a measurement at 12 months, there was no significant difference in the change in CD4 counts between MMF and MTX in the adjusted model at 12 months (-78.3 cells/μL for MMF compared to MTX; 95% CI: -468.0-311.3; P=0.69).

Conclusions : There was no significant difference between MMF and MTX when comparing the change in CD4 counts from baseline to 6 and 12 months, suggesting that MMF may not have a significant effect on CD4 counts when given orally as 1.5 g twice daily for up to one year.

This is a 2020 ARVO Annual Meeting abstract.