Drug updated on 12/11/2024
| Dosage Form | Injection (intravenous; 100 mg, 400 mg) | 
| Drug Class | Interleukin-6 (IL-6) antagonists | 
|  Ongoing and  Completed Studies  | ClinicalTrials.gov | 
Indication
- Indicated for the treatment of patients with multicentric Castlemans disease (MCD) who are human immunodeficiency virus (HIV) negative and human herpesvirus-8 (HHV-8) negative.
 
Latest News

Summary
- This summary is based on the review of two systematic review(s)/meta-analysis(es). [1-2]
 - Siltuximab is effective in idiopathic multicentric Castleman disease (iMCD), although the response rate remains below 50%, indicating limited efficacy for a subset of patients. Additionally, siltuximab and other IL-6 inhibitors demonstrate beneficial effects in several inflammatory diseases, including rheumatoid arthritis, juvenile idiopathic arthritis, giant cell arteritis, Takayasu arteritis, adult-onset Still's disease, cytokine release syndrome, and systemic sclerosis-associated interstitial lung disease.
 - Comparative Effectiveness: Siltuximab has shown efficacy in iMCD, but alternatives like thalidomide have reported higher response rates in iMCD patients. In human herpesvirus-8 (HHV8)-associated MCD, a rituximab-based regimen with doxorubicin, zidovudine, and valganciclovir is the most effective treatment, whereas tocilizumab is particularly effective for advanced COVID-19 cases. Siltuximab demonstrates a safety profile comparable to other biological disease-modifying antirheumatic drugs (bDMARDs), although specific adverse effects for siltuximab were not detailed in the studies.
 - Tocilizumab is associated with increased risks of diverticulitis and lower gastrointestinal perforations, with inconsistent findings regarding infection risks compared to tumor necrosis factor (TNF)-inhibitors. Siltuximab is Food and Drug Administration (FDA)-approved for idiopathic multicentric Castleman disease (iMCD) but has a response rate of less than 50%, indicating the need for alternative or supplementary treatments in this population. In contrast, rituximab-based therapy combined with doxorubicin, zidovudine, and valganciclovir is considered most effective for human herpesvirus-8-associated MCD (HHV8-MCD), while tocilizumab has shown efficacy specifically in advanced COVID-19 cases.
 
Product Monograph / Prescribing Information
| Document Title | Year | Source | 
|---|---|---|
| Sylvant (siltuximab) Prescribing Information. | 2019 | EUSA Pharma (UK) Ltd, | 
Systematic Reviews / Meta-Analyses
| Document Title | Year | Source | 
|---|---|---|
| A systematic literature review informing the consensus statement on efficacy and safety of pharmacological treatment with interleukin-6 pathway inhibition with biological DMARDs in immune-mediated inflammatory diseases | 2022 | Rheumatic & Musculoskeletal Diseases Open | 
| Efficacy and safety of regimens used for the treatment of multicentric Castleman disease: A systematic review | 2022 | European Journal of Haematology | 

