835P - A safe and effective immunochemotherapy with oral sobuzoxane and etoposide for untreated diffuse large B cell lymphoma patients aged 80 and over

Background

Very old patients usually have various comorbidities, poor performance status and poor frailty. Therefore, as patients get aged, they generally tend to be intolerable to intensive chemotherapy. In Japan, sobuzoxane, which is an oral anticancer drug that inhibits DNA topoisomerase II, was approved in 1994 and has been used for patients with lymphoma. Thus far, we have treated lymphoma patients with an attenuated chemotherapy, oral sobuzoxane and etoposide plus rituximab (R-PVP).

Methods

We retrospectively analysed 30 patients aged 80 and over who were newly diagnosed with diffuse large B-cell lymphoma (DLBCL) and initially treated with R-PVP therapy from 2008 to 2022.

Results

The median age of the patients was 84 years (range, 80-93). The median number of Charlson Comorbidity Index (CCI) was 4 (range, 2-11). Median four doses of both sobuzoxane 400 mg and etoposide 25 mg were orally administered every other day per cycle, and rituximab 375 mg/m² intravenously once. Patients received a median of six cycles of R-PVP at a four-week interval. With a median follow-up of 26.4 months (range, 5.4-72.9), median progression ‘free survival (PFS) and overall survival (OS) time was 13.9 and 32.0 months, with a 5-year PFS and OS rate of 24% (95% CI, 8-46%) and 28% (95% CI, 10-49%), respectively. The most frequent grade 3 or 4 adverse event was neutropaenia (53%). No deaths were documented due to the toxicities of the treatment. A multivariate logistic regression analysis revealed that serum LDH value of >=1.5x upper limit of normal was the only unfavourable variable for both PFS and OS in R-PVP therapy (PFS: hazard ratio (HR), 5.60; 95% CI, 1.64-19.11; p = 0.006; OS: HR, 4.83; 95% CI, 1.22-19.17; p = 0.025). In a cohort of 20 patients who underwent R-PVP and 25 R-miniCHOP over the past decade, using the Kaplan-Meier method, there were no statistical differences between the groups regarding PFS and OS (median PFS: R-PVP 9.3 months vs. R-miniCHOP 26.4 months, p = 0.307; median OS: R-PVP not reached (NR) vs. R-miniCHOP NR, p = 0.375).

Conclusions

Our findings may suggest that R-PVP therapy is one of safe and effective treatments for a subgroup of patients, i.e. those who have high CCI or low tumour burden, among untreated DLBCL patients aged over 80.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.