Belimumab (BLM), a soluble human monoclonal antibody which inhibits the stimulator factor of lymphocyte B (BLyS), is the only biologic drug approved for the treatment of system lupus erythematosus (SLE). It is recommended in patients with active SLE (excluding patients with severe renal compromise or compromise of the central nervous system), with positive antibodies and high grade disease activity despite standard treatment.

We now present the clinical experience of BLM use in a regional hospital servicing a population of 165,000 inhabitants.

Eleven patients with SLE who had received BLM at some time were included. One hundred per cent were female, with a mean age at lupus diagnosis of 31.6±9.7 years. Regarding clinical manifestations that presented during the course of the disease, joints were most commonly affected (100%), followed by cutaneous (81%), haematological (64%), renal (27%), pulmonary (9%) and cardiac (9%) manifestations. One hundred per cent of patients presented positivity for antinuclear antibodies, with 27% being positive for anti-DNA native antibodies, 45% for anti-SSA antibodies and 36% for anti-SSB antibodies. 45% of patients presented with positivity for antiphospholipid antibodies and over one third presented with hypocomplementemia.

Regarding treatments prior to the initiation of BLM, 100% of patients had received antimalarial drugs, over 80% methotrexate and 27% azathioprine. Twenty seven per cent had received anti-TNF drugs, 18% cyclophosphamide and 18% leflunomide. One of the patients had received treatment with tacrolimus and rituximab. The mean age of the patients at treatment initiation with BLM was 38.9±9.6 years. The main manifestations for which treatment was prescribed were joint symptoms followed by cutaneous symptoms. Over 60% of patients underwent an improvement of cutaneous and joint symptoms, with no resolution of lymphopenia being observed in our patients. In 4 of them (37%), treatment was suspended due to ineffectiveness after a median duration of 12.2±7.3 months. Particular mention is of one patient who developed a type IV lupus nephritis during treatment. Treatment was not definitively suspended due to side effects in any cases but was temporarily suspended in one patient (9%) due to a respiratory infection. With regard to concomitant treatments, in 3 of them (27%) treatment with BLM led to reduced doses of concomitant treatment (methotrexate, mycophenolate) and it was not possible to assess the possible corticoid sparing effect given the retrospective nature of the study.

There have been several reports of patient cohorts in U.S.A., Canada and Germany1–3 treated with BLM with favourable results on the reduction of activity, improvements in lab tests and steroid sparing. However, few data on clinical practice is available in Mexico. The OBSERVE4 study which included 64 patients with SLE, showed an improvement of ≥20%, ≥50%, ≥80% in 72%, 52% and 27% of cases, respectively. The BIOGEAS5 study which included 10 patients with SLE refractory to antimalarial drugs and at least one other immunosuppressant, where manifestations of BLM were mucocutaneous, reported a response rate to the drug of 80%, higher than that reported by our study and by the OBSERVE study.

To conclude, in clinical practice BLM has proven to be an alternative therapy to consider in patients with LES with cutaneous manifestations or joints refractory to standard immunosuppressants.