Efficacy and safety of R-THP-COP therapy for elderly patients with untreated diffuse large B-cell lymphoma

R-CHOP therapy consisting of rituximab, cyclophosphamide, doxorubicin (DOX), vincristine and prednisolone is the standard regimen for newly diagnosed diffuse large B-cell lymphoma (DLBCL). Pirarubicin (THP) was identified as an anthracycline drug having fewer toxicities than DOX. Accordingly, elderly and unfit patients with DLBCL have often been treated with R-THP-COP using THP instead of DOX in our institution. Here we investigated the efficacy and safety of R-THP-COP therapy in elderly patients with untreated DLBCL. We retrospectively analyzed 45 patients with newly diagnosed DLBCL treated with R-THP-COP between 2017 and 2020 in Japanese Red Cross Kyoto Daiichi Hospital. Dose modifications were made according to physicians’ discretion. The median age was 81 years (range, 65 to 94). Twenty-seven (60.0%) patients were male; 21 (46.7%) had ECOG-PS 2 or higher; 33 (73.3%) had advanced-stage disease (stage 3 or 4); 11 (24.4%) had cardiac complications, such as arrhythmia, angina, and old myocardial infarction. According to the International Prognostic Index, 14 (31.1%) had high-intermediate risk and 21 (46.7%) had high-risk disease. Chemotherapy dose reduction during the first cycle was performed in 40 (88.9%) patients. The overall response rate was 84.4% (complete response 71.1%). The 2-year progression-free survival (PFS) and overall survival (OS) rates were 53.3% and 61.9%, respectively. The most common grade 3 to 4 toxicities observed were neutropenia (60.0%), thrombocytopenia (24.4%), and anemia (11.1%). One patient discontinued the treatment due to grade 4 hepatobiliary disorder. No serious cardiac adverse event was observed. Our results suggested that R-THP-COP therapy may be effective and feasible for elderly and unfit patients with newly diagnosed DLBCL.