Belimumab

Human monoclonal IgG1λ antibody with a molecular weight of approximately 147 kDa. The antibody binds to the soluble human B-lymphocyte stimulator protein BLyS and shortens the lifespan of CD20+ B-lymphocytes and plasma cells. Thus Belimumab acts selectively immunosuppressive. Belimumab is approved for the treatment (add-on therapy) of adult patients with active, autoantibody-positive, systemic lupus erythematosus (SLE) who have not responded adequately to the standard therapy (e.g. with glucocorticoids, hydroxychloroquine, azathioprine and non-steroidal anti-inflammatory drugs) that has been carried out (and exhausted) to date and who show clear disease progression.

The terminal half-life of belimumab is about 19 days.

Elevated levels of BLyS have been found in patients with systemic lupus erythematosus and other autoimmune diseases. B cells play an important role in disease progression. Approved since 2011 for adults with active, autoantibody-positive systemic lupus erythematosus, and since 2019 also for adolescents and children aged 5 years and older.

SLE; the indication for this therapy must be given if the disease remains active despite standard treatment.

10 mg/kg i.v. on days 0, 14 and 28 and every four weeks thereafter. The infusion solution should be infused over a period of one hour.

Nausea, diarrhea, fever, infectious diseases, leukopenia, hypersensitivity reactions, depression, insomnia, pain in the extremities and infusion reactions. The toxicity of belimumab is not insignificant. In the studies involving 1,684 SLE patients, the death rate was higher with belimumab therapy than in the placebo arm. Furthermore, the risk of serious infections increased. A higher rate of oral herpes simplex infections compared to controls has been described (Wilms L et al. 2022).

Vaccination with live vaccines is strictly contraindicated during therapy.

Benlysta®

Belimumab has been approved since February 2012 as an add-on treatment for patients with the autoimmune disease "systemic lupus erythematosus" (SLE).

Note: The effect of belimumab cannot be considered outstanding. In one of the two pivotal studies the response rate was 43% compared to 34% in the control group. This results in a "number needed to treat" of 11 patients who need to be treated for 1 patient to have a relevant benefit.

The Institute for Quality and Efficiency in Health Care (IQWiG) has expressed doubts about the additional benefit of the drug.

1. Drug information (EMA, USA)
2. Dubey A K (2011) First targeted biological treatment for systemic lupus erythematosus. J Pharmacol Pharmacother 2: 317-319
3. Gläser N (2012) Belimumab Hautarzt 63: 253-255
4. Navarra SV (2011) Efficacy and safety of belimumab in patients with active systemic lupus erythematosus: a randomized, placebo-controlled, phase 3 trial. Lancet 377: 721-731
5. Thanou-Stavraki A (2011) An update on belimumab for the treatment of lupus. Biologics 5: 33-43

6. Wilms L et al. (2022) Infections with herpes simplex and varicella zoster virus. J Dtsch Dermatol Ges 20:1327-1353.

7. https://www.iqwig.de/projekte/a19-94.html