Siltuximab


Siltuximab is a chimeric monoclonal antibody. It binds to interleukin-6. Siltuximab has been investigated for the treatment of neoplastic diseases: metastatic renal cell cancer, prostate cancer, and Castleman's disease, among other types of cancer.
On April 23, 2014, siltuximab was FDA approved under the brand name of Sylvant for the treatment of patients with idiopathic multicentric Castleman’s disease who do not have human immunodeficiency virus or human herpesvirus-8.

Medical uses

Used for the treatment of idiopathic multicentric Castleman disease.

Clinical trials

Siltuximab has demonstrated significant efficacy and safety in patients with idiopathic multicentric Castleman disease. Treatment results with Siltuximab in B-cell non-Hodgkin's lymphoma are inferior to those obtained in multicentric Castleman disease. Siltuximab has also been evaluated in the treatment ovarian cancer, however the efficacy for this cancer is debatable. In addition, siltuximab has been evaluated for multiple myeloma, but there was an insignificant increase in response rates.

Side effects

Siltuximab may lower resistance to infections and should not be administered to patients with severe infections. Siltuximab should be discontinued in patients with severe infusion related reactions, anaphylaxis, severe allergic reactions or cytokine release syndromes. Live vaccines should not be administered to patients receiving siltuximab since IL-6 inhibition may interfere with normal immune response to new antigens.
Common
The following has been shown to occur in treatment of Multicentric Castleman's disease with siltuximab during a clinical trial :
Long term exposure
Siltuximab may increase CYP450 activity leading to increased metabolism of drugs that are CYP450 substrates. Co-administration of siltuximab and CYP450 substrates with narrow therapeutic index such as warfarin, ciclosporin or theophylline should be closely monitored.

Mechanism of action

Siltuximab is a chimeric monoclonal antibody that binds to interleukin-6, preventing binding to soluble and membrane bound interleukin-6 receptors. Siltuximab interferes with IL-6 mediated growth of B-lymphocytes and plasma cells, secretion of vascular endothelial growth factor and autoimmune phenomena.