Preliminary study on efficacy and safety of pixantrone in relapsed/refractory aggressive B-cell lymphomas: multicenter, retrospective cohort study by Polish Lymphoma Research Group (PLRG)

Background: Pixantrone (PIX) is an anthracycline derivative with reduced cardiotoxicity, registered in Poland for monotherapy in relapsed/refractory (R/R) aggressive B-cell non-Hodgkin lymphoma (B-NHL) in the third or fourth line of treatment. As R/R population is difficult to treat due to comorbidities including circulatory system pathologies we evaluate polish patients treated with PIX. This is the first real life study evaluating patients treated with PIX in Poland with emphasis on efficacy and cardiovascular toxicity.

Methods: The retrospective study assessing safety and effectiveness of PIX administered in patients with aggressive de novo or transformed B-NHL [according to the Revised European American Lymphoma (REAL) and World Health Organization (WHO) classifications], who relapsed or were refractory to two or three previous lines of chemotherapy regimens, including at least one standard anthracycline-based regimen. Patients who did not remain sensitive to anthracyclines were excluded from this study. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), complete response (CR) rate, overall response rate (ORR) and safety.

Results: The data of 17 patients were collected in 6 study sites. The median age was 72 (range: 58–82) years old with male predominance (65%). In observed group10 patients had diffuse large B-cell lymphoma (DLBCL), 6 mantle cell lymphoma (MCL) and 1 patient had Richter syndrome. Five subjects responded to PIX (CR 2 and partial response 3)—ORR was 29%. The median of PFS was 12.9 months [standard error (SE) 2.2; 95% confidence interval (CI): 8.5, 17.2]. The median of survival time was 22.6 months (SE 7.3; 95% CI: 8.3, 36.8). The PIX compliance was good, with incidental dose omission or delay. The main reason for discontinuation was disease progression.

Conclusions: Administration of PIX to patients with R/R aggressive B-NHL treated with multiple lines of chemotherapy containing maximal cumulative dose of anthracycline and with numerous concomitant diseases may be a potentially valuable therapeutic option but data from larger clinical studies will help in confirming PIX as an effective and safe option.