Publication:

A prospective observational study on efficacy of serial low dose infusion of rituximab (500 mg) on patients of pemphigus

Background Rituximab (RTX) is a chimeric anti-CD20 monoclonal antibody being increasingly used in management of pemphigus. Various studies show a lack of any uniform treatment protocol. The objective of the study was to assess the effectiveness of RTX in patients of pemphigus receiving serial low doses of RTX (500 mg; maximum of 4 doses; 2 weeks apart).

Methods It was a prospective observational review of 40 pemphigus patients to assess the proportion of patients achieving complete remission after serially receiving low dose RTX, time and number of doses required to achieve complete remission (CR), proportion of patients who responded partially or didn’t respond or relapsed after achieving CR. Additionally, the study was done to find whether a correlation existed between age, gender, and site of lesion and RTX administration.

Results 40 pemphigus patients followed up for a mean duration (MD) of 174.15±95.67 days received 4 doses of RTX (500 mg) irrespective of the disease activity 0.30 (75%) attained CR on therapy with ≥3 doses of RTX 500 mg (MD= 76.39±34.45 days) and azathioprine 100 mg/day. No patients relapsed after 4 doses while 3 (7.5%) patients didn’t respond. Oral lesions and pemphigus vulgaris took more time for achieving CR.

Conclusion While we reinforce the idea of using more than 3 doses of RTX 500 mg in a view to achieve prolonged remission we promote considering usage of a more cost-effective drug like azathioprine for maintaining remission especially in a poor remote tertiary center in India with limited resources. Immunological assays were not performed limiting the study.