Background: ASCT improves event-free survival (EFS) for HR-NB. Pilot studies suggest that intensification of myeloablative therapy using tandem ASCT further improves outcome for HR-NB. We conducted a multicenter RCT comparing tandem vs. single consolidation in patients with HR-NB.
Methods: Between 11/2007 and 2/2012, 652 eligible patients (pts) with newly diagnosed HR-NB received induction therapy: 6 cycles of chemotherapy including initial 2 cycles of dose-intensive cyclophosphamide/topotecan followed by PBSC collection. Randomization occurred at end induction to single ASCT with carboplatin-etoposide-melphalan (CEM) or tandem ASCT with thiotepa–cyclophosphamide ASCT followed by a modified CEM (TC:CEM). HR pts with non-MYCN amplified Stage 3 (age>18mos) or Stage 4 (age 12-18 mos) tumors were non-randomly assigned to single ASCT (CEM). EFS and overall survival (OS) were analyzed as intent-to-treat.
Results: Median age at study entry was 3.1 yrs, 88% (n=574 pts) had Stage 4 disease and 38.2% (n=249 tumors) had MYCN amplification. A total of 355 pts were randomized (CEM n=179 pts; TC:CEM n=176 pts) and 27 patients were non-randomly assigned to CEM. Of randomized pts, 249 patients received post-consolidation immunotherapy on COG trials. Treatment-related mortality was 2.6% (Induction n=7 [1%]; Consolidation n=10 [2.8%; n=8 CEM, n=2 TC:CEM]). Rates of severe mucosal, infectious or liver toxicities were similar between arms. 3-year EFS and OS from diagnosis were 51.1±2.0% and 68.2±1.9%, respectively. EFS and OS for randomized cohort are noted in the Table.
Cohorts |
N |
3-yr EFS +/- SE (%) |
2-sided p-value |
3-yr OS +/- SE (%) |
2-sided p-value |
CEM |
179 |
48.8 ± 4.0 |
|
69.0 ± 3.6 |
|
TC:CEM |
176 |
61.8 ± 4.1 |
0.0082 |
73.8 ± 3.7 |
0.2563 |
Immunotherapy |
|
|
|
|
|
CEM |
129 |
55.4 ± 4.6 |
|
75.7 ± 3.9 |
|
TC:CEM |
120 |
73.7 ± 4.4 |
0.0009 |
86.3 ± 3.4 |
0.0158 |
Conclusions: Tandem myeloablative consolidation therapy improves survival probability in patients with high-risk neuroblastoma, especially in the setting in post-consolidative immunotherapy.