Pola-R-CHP Regimen for Frontline Therapy in Diffuse Large B Cell Lymphoma with High-Risk Factors

Background:

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of malignant tumors. Currently, the first-line R-CHOP chemotherapy regimen can cure approximately 60% of DLBCL patients, but about 40% still experience refractory or relapses. Further studies have found that patients with refractory or relapses often present with high-risk factors at initial diagnosis, such as high international prognostic index (IPI), extranodal involvement, double-expressor lymphoma (DEL), and double-hit lymphoma.

Aims:

This study aimed to evaluate the clinical efficacy and treatment tolerance of the Pola-R-CHP regimen for DLBCL patients with high-risk factors.

Methods:

We enrolled newly diagnosed DLBCL patients with high-risk factors who were treated with Pola-R-CHP as the first-line regimen at our hospital in China between April 2023 and May 2024. In this study, high-risk factors included an IPI >2, DEL, P53 protein overexpression (>50%), and extranodal involvement >2 at diagnosis. We collected clinical information, overall response rates, and adverse events for all patients. The Pola-R-CHP regimen included polatuzumab vedotin (1.8 mg/kg), rituximab (375 mg/m²), cyclophosphamide (750 mg/m²), liposomal doxorubicin (30 mg/m²) on day 1 of each cycle, and prednisone (100 mg orally, once daily) on days 1 through 5 of each of the first six cycles.

Results:

Forty-seven newly diagnosed DLBCL patients with high-risk factors were eventually enrolled, with a median age of 68 years (range 33-79). The male-to-female ratio was 1.1:1.0. Based on the Ann Arbor staging system, 78.7% of patients were classified as stage III/IV, and 61.7% had an IPI >2. Additionally, 48.9% of patients had at least three extranodal lesions, with the spleen, gastrointestinal tract, kidneys, adrenal glands, and bone marrow, being the most commonly involved organs. Furthermore, 66.0% of patients had B symptoms. White blood cell count, hemoglobin, and platelet count were nearly normal across all patients, while high levels of lactic dehydrogenase and β2 microglobulin were found in 63.8% and 61.7% of patients, respectively. According to the Hans algorithm, 76.6% of patients were in the non-GCB group, and the median Ki-67 value was 80% (range 60%-95%). Five patients were CD5 positive, and 48.9% were diagnosed with DEL. Among the cohort, 53.2% of patients exhibited expression greater than 50%. All patients completed at least three cycles of the Pola-R-CHP regimen. The overall response rate (ORR) was 93.6%, with a complete response rate (CRR) of 48.9% at the end of the third cycle. By the end of treatment, the ORR was 89.7%, and the CRR was 76.9%. The most common adverse events were hematologic toxicities, with 36.1% of patients experiencing grade 3/4 granulocytopenia after three cycles.

Conclusion: The Pola-R-CHP regimen showed high response rates and good tolerability in DLBCL patients with high-risk factors, proving it to be an effective therapeutic option.

No relevant conflicts of interest to declare.