BACKGROUNDThe prognosis is poor for patients with relapsed or refractory non-Hodgkin's lymphoma (NHL). The main reason for poor prognosis is multidrug resistance (MDR), for which the main phenotype is overexpression of P-glycoprotein (P-gp). This study explored the efficacy of ligustrazine as a salvage agent in patients with relapsed or refractory NHL, and the relationship to P-gp expression.

METHODSSixty patients were randomized to a reversal agent group, receiving ligustrazine plus chemotherapy, and a control group, receiving chemotherapy alone. Flow cytometry was performed to evaluate P-gp expression.

RESULTSIn the 56 patients we were able to evaluate, there was no statistically significant difference in progression-free survival (PFS) in the two groups (P = 0.0651), but the reversal agent group had a higher overall response rate (ORR) than did the control group (P = 0.048). Forty-one of 56 patients had P-gp(+) tumor cells. Among these patients, six of eighteen patients in the reversal agent group and in the control group had complete remission or complete remission/unconfirmed (CR+CRu) reflecting a significant advantage in the reversal agent group (P = 0.048). Patients with P-gp(+) tumor cells in the reversal agent group had a higher overall response rate (ORR) than did the control group (11/18 vs. 6/23, P = 0.024). Kaplan-Meier Survival curve and log-rank test demonstrated that patients with P-gp(+) tumor cells in the reversal agent group had longer progression-free survival than did the control group (P = 0.0464). A small number of patients who received ligustrazine had a decrease in blood pressure.

CONCLUSIONLigustrazine as a salvage agent in combination with chemotherapy can elevate response rate, prolong PFS with manageable toxicity, and correlate with P-gp expression in relapsed or refractory NHL.