For patients with primary central nervous system lymphoma (PCNSL), adding rituximab to combination high-dose methotrexate and temozolomide significantly boosted the 5-year overall survival rate, according to a retrospective study.
The triplet combination could be a safe and effective first-line option for patients with PCNSL, particularly the frail and elderly, who may have issues with toxicity when receiving current standard care, reported lead author Cui Chen, MD, of Sun Yat-Sen University Cancer Center in Guangzhou, China, and his colleagues.
“An increasing number of studies and meta‐analyses have investigated the effect of rituximab in PCNSL, indicating that rituximab can robustly enhance the response rate and possibly improve survival,” the investigators wrote in Cancer Medicine. “However, data regarding the addition of rituximab to [methotrexate and temozolomide] for PCNSL are limited, and no study has directly compared the efficacy of [rituximab/high-dose methotrexate/temozolomide] to that of [high-dose methotrexate/temozolomide].”
The study involved 62 patients with untreated PCNSL who were diagnosed between 2005 and 2015. Out of the 62 patients, 32 received rituximab/high-dose methotrexate/temozolomide (RMT) and 30 received high-dose methotrexate/temozolomide (MT). Patients received up to eight cycles of therapy, with discontinuation upon disease progression or toxicity.
The results showed that patients treated with RMT had significantly better outcomes than those who received MT, first marked by objective response rates, which were 93.7% for RMT and 69.0% for MT.
Survival rates also showed the advantage of rituximab. For the RMT group, 2-year and 5-year progression-free survival rates were 81.3% and 53.3%, respectively, compared with 46.5% and 29.1% for patients receiving MT.
Most importantly, rituximab boosted overall survival to a significant and notable extent, with higher rates at 2 years (82.3% vs. 65.7%) and 5 years (82.3% vs. 50.0%).
Efficacy did not diminish safety, as no significant differences in toxicity were found between treatment types. The most common grade 3-4 toxicities were hematologic; most commonly, this entailed neutropenia, which occurred in about one-quarter of patients.
“Given its outstanding efficacy and favorable toxicity, we consider RMT to be a feasible and safe therapeutic approach as a first‐line treatment for PCNSL. Moreover, RMT is an ideal regimen for elderly patients and frail populations who may not tolerate [whole‐brain radiation therapy] or [autologous stem‐cell transplantation],” the researchers wrote.
The study was funded by the Natural Science Foundation of Guangdong Province. The researchers reported having no conflicts of interest.
SOURCE: Chen C et al. Cancer Med. 2019 Mar 1. doi: 10.1002/cam4.1906.