Dinutuximab beta versus historical controls in the treatment of relapsed neuroblastoma: unadjusted and adjusted indirect comparisons

Objective: Dinutuximab beta (dB) immunotherapy is used as maintenance treatment for relapsed/refractory neuroblastoma (NBL); however, comparative studies directly comparing dB with no dB therapy in this setting are lacking. This study aimed to indirectly compare dB (with or without interleukin-2) with no immunotherapy in patients with relapsed NBL. Methods: Three studies of dB (APN311-202, APN311-304, and APN311-303) with individual patient data, along with two historical control cohorts (INBR and R1) were included. Both unadjusted (naïve) and population-adjusted comparisons of overall survival (OS) were performed, with adjustment conducted using inverse probability or odds weighting. Harmonized inclusion criteria were applied across all study populations. The adjusted comparison used the propensity score reweighting to balance the cohorts based on key baseline prognostic factors. Results: The base-case unadjusted indirect comparison revealed that dB (with or without IL-2) significantly prolonged OS compared to historical controls not treated with dB (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.31- 0.79; p