Maintenance treatment of pemphigus with rituximab in real life: A single-center study of 50 patients

Background

Following the RITUX 3 therapeutic trial, the French national diagnosis and care protocol (NDCP) for the treatment of pemphigus was updated in 2018. The updated protocol recommends initial treatment with rituximab (RTX) followed by maintenance therapy at 12 and 18 months, and potentially at 6 months where there are risk factors for early relapse. We evaluated these recommendations regarding the management of our own patients.

Patients and Methods

Our single-center retrospective study included all patients with pemphigus diagnosed between 01/2015 and 10/2020 and receiving at least one initial infusion of RTX. We collected the following data: type of pemphigus, severity, levels of anti-desmoglein 1 and 3 antibodies at diagnosis and between 2 and 6 months after initial RTX, presence or absence of maintenance therapy and modalities, time to first relapse and duration of associated systemic corticosteroid therapy ≥5 mg/day. Maintenance treatment modalities were as follows: no maintenance treatment, maintenance “on demand” (MT1) i.e. not performed at the rate imposed by the NDCP, and maintenance “according to NDCP” (MT2).

Results

Fifty patients were included (women 54%, median age 58 years, pemphigus vulgaris 68%, moderate to severe 68%). Initial RTX was combined with systemic corticosteroid therapy at 0.5 to 1 mg/kg in 74% of cases. Twenty-seven patients (54%) received no maintenance therapy, 13 were on an MT1 regimen (26%), and 10 were on an MT2 regimen (20%). Median follow-up was 42 months. At the last follow-up, 39 patients (78%) were in complete remission. A total of 25 patients (50%) relapsed: 18/27 (67%) patients without maintenance, 5/13 (38%) with MT1, and 2/10 (20%) with MT2 (p = 0.026). The probability of relapse over time was significantly lower in patients receiving maintenance therapy compared to those who receiving none (p = 0.022). The median time to relapse was 15 months in patients without maintenance, and 30 and 28 in those with maintenance (p = 0.27). The median duration of systemic corticosteroid therapy ≥ 5 mg/day in the no-maintenance group was 10 months, compared to 7 and 9 months respectively in MT1 and MT2 (p = 0.91).

Conclusion

Our study confirms the value of RTX maintenance therapy in pemphigus in real life.