Hold Myophenolate or Not with COVID-19 Vaccination? Save

While the American College of Rheumatology (ACR) recommends holding mycophenolate (MMF) in rheumatic and musculoskeletal diseases (RMD) patients receiving COVID-19 vaccines, there is limited data on such an approach. A recent cohort study of RMD patients showed that holding MMF yielded higher antibody responses than continuing MMF.

Since post-vaccination antibody responses are blunted in autoimmune patients and in those treated with MMF, the ACR advisory task force has recommended withholding mycophenolate for 1 week after vaccination to enhance immunogenicity to the COVID-19 vaccine. In this case series, researchers compared antibody titer outcomes between 24 RMD patients in whom MMF was held against 171 patients who continued MMF during and after vaccination.

Observational data accrued betwen December 2020 and May 2021 looked at antibody titers to the spike protein (anti-receptor binding domain (RBD) 30 days post vaccination. of the SARS-CoV-2 spike protein. Most patients completed vaccination with the two-dose Pfizer/BioNTech or Moderna mRNA vaccines.

Post vaccination anti-RBD antibody levels were compared between the group that withheld mycophenolate (n=24) and those that continued mycophenolate (n=171):

RMD patients on MMF included systemic lupus erythematosus (25%) and myositis (20%). The median number of doses held was 20 (8–34). Nearly half (54%) withheld before vaccination, nine (38%) withheld both before and after vaccination, while two (8%) withheld after vaccination.

At a median of 32 (28–35) days after vaccination, the detectable anti-spike protein antibodies were seen in:

• MMF held - 22/24 (92%)
• MMF continued - 112/171  (65%)  (92% vs 65%, p=0.01).

Holding MMF resulted in a 5 fold greater chance of a positive antibody response (OR 5.8, 95% CI 1.3 to 25.5 p=0.02). Overall, median anti-RBD Ig titers in the withholding group were significantly higher than the group that continued therapy (125 vs 7 U/L, p=0.004).

There were 2 RMD flares in the perivaccination period.

This small case series did not evaluate the optimal duration of withholding therapy. Nonetheless, these findings support the practice of a a temporary hold in mycophenolate therapy to augment the humoral response to SARS-CoV-2 vaccination in RMD patients.