Continuing Use of tsDMARDs Decreases Antibody Response to COVID-19 Vaccination

Patients with immune-mediated inflammatory diseases (IMIDs) receiving disease-modifying antirheumatic drugs (DMARDs), except targeted synthetic DMARDs, and those without IMIDs were found to have similar levels of antibody response to SARS-CoV-2 vaccination, according to study findings published in RMD Open.

The RESCUE-2 study aimed to evaluate follow-up data from a multicenter, 3-arm, randomized clinical trial at 6 months after the first dose of the SARS-CoV-2 vaccine and 4 weeks after the third dose.

Patients with IMIDs were randomly assigned to withhold or continue using DMARDs during vaccination. Antibody responses were compared with a group of non-IMID control participants.

Protective antibody response levels from SARS-CoV-2 vaccination were defined as antibody titers at 7.0 U/mL or greater.

A total of 175 patients with IMIDs and 59 without IMIDs were included in the study, the withhold (n=82), continuation (n=99), and control cohorts were 73.2%, 66.3%, and 59.6% women, with mean ages of 55.4, 53.3, and 54.4 years, respectively; 82.5%, 84%, and 69%, respectively, were White.

In the IMID group, 34.8% received biologic DMARDs (bDMARDs), 33.2% received targeted synthetic DMARDs, and 32.0% received conventional synthetic DMARDs (csDMARDs). The most common IMIDs were rheumatoid arthritis (53.6%) and psoriatic arthritis (29.3%).

After the second dose, SARS-CoV-2 immunoglobulin G (IgG) antibodies were detected in 100% of control participants, 100% of patients in whom DMARDs were withheld, and 83.7% of patients in whom DMARDs were continued; and at 6 months, antibodies were detected among 79.2%, 87.5%, and 85.4% (P =.756), respectively. The median IgG SARS-CoV-2 antibody titers among the control participants, those in whom DMARDs were withheld, and those in whom DMARDs were continued were 7.3, 14.2, and 5.7 U/mL after the second dose and 2.3, 3.3, and 3.3 U/mL at 6 months (P =.344), respectively.

Antibody levels at 6 months were significantly lower among the patients who continued to receive DMARD therapy and the Pfizer vaccine compared with control participants or those in whom treatment was withheld (median, 3.1 vs 10.5 vs 12.0 U/mL; P =.001), respectively.

Stratified by type of DMARD, the researchers did not observe a difference in SARS-CoV-2 IgG antibody titers between those receiving csDMARDs (median, 5.8 U/mL; P =.798) and bDMARDs (median, 2.6 U/mL; P =.357) compared with control participants (median, 5.7 U/mL); however, the tsDMARD-recipients had lower levels (median, 2.1 U/mL; P =.010).

The time to reach antibody titers below levels of protection was 68.3 days for csDMARDs, 71.8 days for bDMARDs, and 64.0 days for tsDMARDs. Among the subset of patients who were vaccinated with the Pfizer vaccine, the time to reach levels below protection were 185.5, 137.5, and 116.0 days, respectively.

Significant predictors for maintaining levels of protection were tsDMARD vs csDMARD (odds ratio [OR], 0.38; P =.023), age (OR, 0.95; P =.000), and withholding DMARDs (OR, 2.89; P =.003).

The study may have been limited by the variable timing between doses and different types of vaccines included in the analysis.

The study authors concluded, “Six months after standard vaccination regimens, patients with IMID had protective levels of SARS-CoV-2 IgG [antibodies] similar to control [participants], except for those on tsDMARDs.”