Evaluating pembrolizumab plus R-CHOP chemotherapy for patients with untreated diffuse large B-cell lymphoma

This study evaluated the safety and effectiveness of pembrolizumab (Keytruda) plus R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy for patients with diffuse large B-cell lymphoma (DLBCL). This study concluded that pembrolizumab can be safely added to R-CHOP, with improved survival outcomes.

DLBCL is the most common type of non-Hodgkin's lymphoma. The most widely used treatment for this aggressive cancer is R-CHOP. This regimen is effective for many patients. However, some patients experience relapse (cancer comes back) or stop responding to treatment.

Cancer cells that have a molecule on their surface called PD-L1 are associated with poor outcomes. However, these cells may be sensitive to a type of targeted therapy called PD-L1 blockers. Pembrolizumab is one such treatment. Whether adding pembrolizumab to R-CHOP chemotherapy is safe and effective for patients with DLBCL is unclear.

This study had 38 patients with previously untreated DLBCL. 30 patients received pembrolizumab with R-CHOP chemotherapy. Patients were followed for an average of 25.5 months.

Overall, 90% of patients responded to treatment. 77% of patients had no signs of cancer after treatment. 13% of patients had tumor shrinkage.

84% of patients were still alive 2 years later, with 83% of patients alive without tumor growth or spread. Significantly more patients with a lower-risk disease were still alive 2 years later compared to patients who had higher risk disease (100% vs. 64%).

43% of patients reported serious side effects. The most common ones were low white blood cell count with fever (23%), infection (10%), and episodes of fainting (10%). Severely low white blood cell count (16 patients) and low white blood cell count with fever (7 patients) were also reported.

This study concluded that adding pembrolizumab to R-CHOP chemotherapy is a safe and effective first-line treatment for patients with DLBCL. The authors suggest that this regimen may have the potential to improve first-line therapy for these patients.

This study was very small and did not compare the study treatment to other therapies. More studies with larger numbers of patients are needed to confirm these results. This study received funding support from Merck, the manufacturer of pembrolizumab.