Lung infections and clinical outcomes of diffuse large B-cell lymphoma treated with polatuzumab vedotin-based combination therapy

Abstract Background: Real-world clinical data on the polatuzumab vedotin-based regimen for the treatment of diffuse large B-cell lymphoma (DLBCL) remains limited, emphasizing the importance for clinical feedback data from medical institutions for the prevention of treatment-related toxicities in patients during the peri-chemotherapy period. Method: We retrospectively enrolled patients diagnosed with DLBCL who received a polatuzumab vedotin-based (Pola+X) regimen at Guangdong Provincial People's Hospital between March 2023 and June 2025. Clinical information was retrospectively collected from medical records. Safety and efficacy were assessed by investigators per CTCAE v5.0 and RECIST v1.1, respectively. The primary endpoint was the progression-free survival (PFS) and overall survival (OS) , and the secondary endpoints was the safety. Results: A total of 79 patients in our center recived Pola+X regimen. Median age was 57 years (range: 23-80), and 34 (43%) patients were female. 32 (41%) patients had double expression lymphoma. 31 (39%) patients were classified as germinal center B-cell-like (GCB) subtype. 40 (51%) patients had an International prognosis index (IPI) score of 0-2, and 53 (67%) patients had advanced stage diseases. 64 (81%) patients have completed Pola+R-CHP treatment, and the 1-year OS and 1-year PFS were 98% and 96%, respectively. All patients were divided into two groups: a prophylaxis group(Treated with Sulfamethoxazole) and a non-prophylaxis group. 32 (41%) patients did not receive prophylactic treatment for lung infections. Among them, six patients were diagnosed with Pneumocystis jirovecii pneumonia, and two patients with cytomegalovirus infection through pathogen detection. None of the 47 patients who received prophylactic treatment developed lung infections during the course of treatment. A 0% incidence of lung infection was observed. Conclusion: The Pola+R-CHP regimen is a highly effective option for DLBCL patients. The high incidence of Pneumocystis jirovecii infection during Pola+X regimen treatment highlights the critical importance of prophylactic use of Sulfamethoxazole throughout the peri-chemotherapy period.