Table 5. Summary of studies done to evaluate the efficacy of DFMO in high-risk neuroblastoma.

EFS: event-free survival; PFS: progression-free survival; OS: overall survival

Study	Group	Year	EFS	PFS	OS
A phase I trial of DFMO targeting polyamine addiction in patients with relapsed/refractory neuroblastoma (NCT01059071) [36]	Sholler et al.	2015		Median PFS: 80.5 days
Maintenance DFMO increases survival in high-risk neuroblastoma (phase II) (NCT01586260, NCT02395666) [37]	Sholler et al.	2018	Stratum 1: 2-year EFS 84%; stratum 2: 2-year EFS 54%		Stratum 1: 2-year OS 97%; stratum 2: 2-year OS: 84%
A subset analysis of a phase II trial evaluating the use of DFMO as maintenance therapy for high-risk neuroblastoma (stratum 1 from phase II vs. no maintenance DFMO) (NMTRC003/003b) [53]	Lewis et al.	2020	5-year EFS: 85.2%		5-year OS: 95.1%
A pilot study of genomic-guided induction therapy followed by immunotherapy with difluoromethylornithine maintenance for high-risk neuroblastoma (NCT02559778) [54]	Kraveka et al.	2022	Yet to reach 2-year or 5-year endpoint		Yet to reach 2-year or 5-year endpoint