Rituximab
Rituximab is the medication used to treat both non-Hodgkin's lymphoma and rheumatoid arthritis. This anti-CD20 monoclonal antibody was first FDA-approved in 1997 for non-Hodgkin's B-cell lymphoma and subsequently approved for refractory rheumatoid arthritis in 2007 1.
Clinical Context and Guideline Support
The 2021 American College of Rheumatology guideline specifically addresses rituximab's unique role in RA management, particularly for patients with specific comorbidities 2:
- For patients with a previous lymphoproliferative disorder (for which rituximab is an approved treatment) who have moderate-to-high RA disease activity, rituximab is conditionally recommended over other DMARDs 2
- The rationale is that rituximab would not be expected to increase the risk of recurrence or worsening of these lymphoproliferative disorders 2
Mechanism and Dual Indication
Rituximab targets CD20 antigen on B cells, leading to B-cell depletion 3. This mechanism makes it effective for:
- Non-Hodgkin's lymphoma: Particularly follicular lymphoma and diffuse large B-cell lymphoma 4
- Rheumatoid arthritis: By depleting pathogenic B cells involved in autoimmune inflammation 3
Safety Profile Differences
An important clinical consideration: infusion reactions occur less frequently when rituximab is used for RA compared to B-cell malignancies, likely because RA patients invariably receive concomitant steroids with rituximab infusions 5. This is not necessarily standard practice in lymphoma treatment 5.
Biosimilar Availability
CT-P10 (Truxima™) is an approved biosimilar of rituximab for all indications including both follicular lymphoma, diffuse large B-cell non-Hodgkin's lymphoma, and rheumatoid arthritis, providing an alternative option 4.