Predictors of response, progression-free survival, and overall survival using NANT Response Criteria (v1.0) in relapsed and refractory high-risk neuroblastoma.

PurposeThe New Approaches to Neuroblastoma Therapy Response Criteria (NANTRC) were developed to optimize response assessment in patients with recurrent/refractory neuroblastoma. Response predictors and associations of the NANTRC version 1.0 (NANTRCv1.0) and prognostic factors with outcome were analyzed. MethodsA retrospective analysis was performed of patients with recurrent/refractory neuroblastoma enrolled from 2000 to 2009 on 13 NANT Phase 1/2 trials. NANTRC overall response integrated CT/MRI (Response Evaluation Criteria in Solid Tumors [RECIST]), metaiodobenzylguanidine (MIBG; Curie scoring), and percent bone marrow (BM) tumor (morphology). ResultsFourteen (6.9%) complete response (CR) and 14 (6.9%) partial response (PR) occurred among 203 patients evaluable for response. Five-year progression-free survival (PFS) was 16 3%; overall survival (OS) was 27 +/- 3%. Disease sites at enrollment included MIBG-avid lesions (100% MIBG trials; 84% non-MIBG trials), measurable CT/MRI lesions (48%), and BM (49%). By multivariable analysis, Curie score of 0 (P<0.001), lower Curie score (P=0.003), no measurable CT/MRI lesions (P=0.044), and treatment on peripheral blood stem cell (PBSC) supported trials (P=0.005) were associated with achieving CR/PR. Overall response of stable disease (SD) or better was associated with better OS (P<0.001). In multivariable analysis, MYCN amplification (P=0.037) was associated with worse PFS; measurable CT/MRI lesions (P=0.041) were associated with worse OS; prior progressive disease (PD; P<0.001/P<0.001), Curie score1 (P<0.001; P=0.001), higher Curie score (P=0.048/0.037), and treatment on non-PBSC trials (P=<0.001/0.003) were associated with worse PFS and OS. ConclusionsNANTRCv1.0 response of at least SD is associated with better OS in patients with recurrent/refractory neuroblastoma. Patient and tumor characteristics may predict response and outcome. Identifying these variables can optimize Phase 1/2 trial design to select novel agents for further testing.