Phase 2 study using oral thalidomide-cyclophosphamide-prednisone for idiopathic multicentric Castleman disease

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Idiopathic multicentric Castleman disease (iMCD) is a rare lymphoproliferative disorder with limited treatment options.
• Current anti-interleukin 6 (IL-6) therapy, siltuximab, is not universally available and is ineffective for many patients.
• Novel therapeutic strategies are critically needed for iMCD management.

Purpose of the Study:

• To evaluate the efficacy and safety of a thalidomide-cyclophosphamide-prednisone (TCP) regimen in newly diagnosed iMCD patients.
• To assess the TCP regimen as an alternative treatment for iMCD, particularly when IL-6 targeted therapy is not feasible.
• To investigate a treatment targeting pathways other than IL-6 signaling in iMCD.

Main Methods:

• A single-center, single-arm, phase 2 clinical trial was conducted.
• Twenty-five newly diagnosed iMCD patients received the TCP regimen for up to 2 years.
• The primary endpoint was durable tumor and symptomatic response for at least 24 weeks.

Main Results:

• 48% of patients achieved the primary endpoint with no relapse.
• Significant improvements were observed in symptom scores, IL-6 levels, hemoglobin, and inflammatory markers across all patients.
• The TCP regimen was generally well-tolerated, with manageable adverse events.

Conclusions:

• The thalidomide-cyclophosphamide-prednisone regimen demonstrates efficacy and safety in newly diagnosed iMCD patients.
• TCP offers a viable alternative treatment option for iMCD, especially in settings where siltuximab is unavailable.
• This study provides evidence for a non-IL-6 targeted approach in iMCD treatment.