Number Needed to Treat (NNT) Comparing Axicabtagene Ciloleucel and Best Supportive Care for Third Line Diffuse Large B-Cell Lymphoma in Brazil

OBJECTIVES: In this study we assessed the relative benefit in overall survival of axicabtagene ciloleucel (axi-cel) versus best supportive care (BSC) in the treatment of adult patients with relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL), after two or more lines of systemic therapy, using the number needed to treat (NNT) for one additional survivor.

METHODS: We used two different NNT calculation methods to compare axi-cel and BSC in R/R LBCL. Absolute risk reduction (ARR) and restricted mean survival time (RMST) values for overall survival (OS) at 12, 24 and 32 months (time from onset of salvage therapy) follow-up were extracted from a published propensity score matching study comparing axi-cel to BSC based on clinical outcomes reported in the ZUMA-1 clinical trial (NCT02348216) and the SCHOLAR-1 retrospective cohort study. The NNTs were then calculated in two ways: first, using the inverse of the absolute risk reduction (NNT_ARR) and then using a restricted mean survival time approach (NNT_RMST) to capture the profile of the treatment effect over time.

RESULTS: Axi-cel was associated with an incremental RMST of 4.28 months (NNT_RMST = 1.53; 95% IC 1.26 to 1.91) compared to BSC at 12 months, incremental RMST of 9.01 months (NNT_RMST = 1.02; 95% IC 0.80 to 1.37) at 24 months, and an incremental 11.59 months (NNT_RMST = 0.93; 95% IC 0.70 to 1.29) at 32 months. Calculations for NNT_ARR were 2.22, 2.94 and 5.10 at 12, 24 and 32 months, respectively.

CONCLUSIONS: Our results demonstrated a low NNT_RMST for axi-cel compared to BSC indicating the potential to prevent an extra death for every DLBCL patient treated with axi-cel. Our findings may be useful for decision making in treatment allocation for R/R LBCL.