Study: Ultralow-Dose Rituximab Effective in Pemphigus
Key Takeaways
Ultralow-dose rituximab (100 mg) effectively managed moderate-to-severe pemphigus with similar efficacy to standard dosing.
CD20+ B-cell depletion and remission rates were comparable across all regimens.
Ultralow-dose rituximab was associated with fewer adverse events and lower costs of treatment.
A new 52-week clinical trial found that ultralow-dose rituximab (ULRTX) achieved comparable efficacy, safety, and B-cell depletion to standard and low-dose regimens in patients with moderate-to-severe pemphigus vulgaris (PV) and pemphigus foliaceus (PF).
The prospective, open-label study, conducted at the Dermatology Hospital of Shandong First Medical University in China, included 52 patients with moderate (PDAI 15–45) or severe (PDAI >45) pemphigus. Participants were assigned to receive rituximab at ultralow (100mg), low (500mg), or standard (1000mg) doses on days 0 and 14, alongside corticosteroids tapered per disease severity. Supplementary rituximab was administered based on B-cell repopulation assessed at 26 weeks.
“All patients achieved disease control, and the median time to control was slightly longer for the ULRTX group (15.5 days) compared to LRTX (14.0 days) and SDRTX (13.0 days) (P = .02),” the authors noted. CD20+ B-cell depletion was universally achieved by week 2. While B-cell reconstitution occurred earlier in the ULRTX group, this did not impact clinical remission rates.
Complete remission (CR) was observed in 92.3% of patients in the ULRTX group, compared to 100% in both LRTX and SDRTX cohorts. There were no statistically significant differences in rates of CR off therapy (CROT), CR on minimal therapy (CRMT), cumulative glucocorticoid use, relapse rates, or PDAI score improvements across groups.
The researchers reported no significant differences in adverse events among the regimens, though ULRTX showed a favorable safety profile with fewer events. “ULRTX demonstrated cost advantages without compromising therapeutic outcomes,” they wrote, suggesting it may offer a more accessible treatment path in resource-limited settings.
Limitations of the study include its single-center, non-randomized design and relatively small sample size. Further multicenter trials with randomization are needed to validate these findings across broader populations.
“All regimens demonstrated comparable efficacy and B-cell depletion,” the authors concluded. “ULRTX, despite a marginally longer time to disease, had the lowest AEs and cost, supporting its utility in pemphigus management.”
Source: Cao S, Yang B, Wang Z, et al. J Am Acad Dermatol. 2025. doi: 10.1016/j.jaad.2025.05.1374