Comparing outcomes after adding two doses of rituximab to R-CHOP chemotherapy for aggressive B-cell lymphoma

This study investigated the safety and effectiveness of six versus eight doses of rituximab (Rituxan) in R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy for patients with aggressive B-cell lymphoma. This study concluded that adding two extra doses of rituximab to R-CHOP had similar outcomes in these patients.

For patients with aggressive B-cell lymphoma, R-CHOP chemotherapy is the current standard of first-line treatment. This type of treatment combines immunotherapy and chemotherapy to stimulate the immune system to attack and destroy cancer cells.

Conventional R-CHOP typically involves six doses of rituximab. Rituximab is a monoclonal antibody. This type of treatment helps the body’s immune system attack cancer cells, leading to cancer cell death. Whether increasing the number of doses of rituximab in R-CHOP leads to improved outcomes in patients with aggressive B-cell lymphoma remains under investigation.

This study involved 616 patients with aggressive B-cell lymphoma. 544 (88.3%) of patients had diffuse large B-cell lymphoma (DLBCL). The rest of patients had primary mediastinal B-cell lymphoma (PMBCL) or follicular lymphoma (FL). 335 patients received standard R-CHOP with 6 doses of rituximab. 281 received R-CHOP with 8 doses of rituximab. Patients were followed-up for an average of 52 months.

Overall, over 86% of patients responded to treatment in both groups. Over 53% of patients had a complete disappearance of all signs of cancer in both groups.

In patients with DLBCL, 2-year overall survival (patients still alive 2 years later; OS) was 88.9% (8 doses) versus 87.4% (6 doses). In patients with PMBCL, 2-year OS was 93.3% (8 doses) versus 100% (6 doses). In patients with FL, this rate was 100% in both groups.

In patients with DLBCL, 2-year progression-free survival (patients still alive 2 years later without tumor growth or spread; PFS) was 80.9% (8 doses) versus 77.5% (6 doses). In patients with PMBCL, 2-year PFS was 93.3% versus 100%. In patients with FL, this rate was 85.7% vs. 100%.

Side effects were similar in 6 or 8 doses of rituximab. Severe low red blood cell count, low white blood cell count, infection, and diarrhea were more common in patients older than age 60.

This study concluded that adding two extra doses of rituximab to R-CHOP resulted in similar outcomes in patients with aggressive B-cell lymphoma.

The number of patients with PMBCL or FL in this study was small. Also, only patients with chemosensitive (does respond to chemotherapy) disease were included. Further studies are needed to confirm these results.