Randomized Trial of Two Induction Therapy Regimens for High-Risk Neuroblastoma: HR-NBL1.5 International Society of Pediatric Oncology European Neuroblastoma Group Study

PURPOSE Induction therapy is a critical component of the therapy of high-risk neuroblastoma. We aimed to assess if the Memorial Sloan Kettering Cancer Center (MSKCC) N5 induction regimen (MSKCC-N5) would improve metastatic complete response (mCR) rate and 3-year event-free survival (EFS) compared with rapid COJEC (rCOJEC; cisplatin [C], vincristine [O], carboplatin [J], etoposide [E], and cyclophosphamide [C]). PATIENTS AND METHODS Patients (age 1-20 years) with stage 4 neuroblastoma or stage 4/4s aged < 1 year with MYCN amplification were eligible for random assignment to rCOJEC or MSKCC-N5. Random assignment was stratified according to national group and metastatic sites. Following induction, therapy comprised primary tumor resection, high-dose busulfan and melphalan, radiotherapy to the primary tumor site, and isotretinoin with ch14.18/CHO (dinutuximab beta) antibody with or without interleukin-2 immunotherapy. The primary end points were mCR rate and 3-year EFS. RESULTS A total of six hundred thirty patients were randomly assigned to receive rCOJEC (n = 313) or MSKCC-N5 (n = 317). Median age at diagnosis was 3.2 years (range, 1 month to 20 years), and 16 were younger than 1 year of age with MYCN amplification. mCR rate following rCOJEC induction (32%, 86/272 evaluable patients) was not significantly different from 35% (99/281) with MSKCC-N5 (P = .368), and 3-year EFS was 44% +/- 3% for rCOJEC compared with 47% +/- 3% for MSKCC-N5 (P = .527). Three-year overall survival was 60% +/- 3% for rCOJEC compared with 65% +/- 3% for MSKCC-N5 (P = .379). Toxic death rates with both regimens were 1%. However, nonhematologic CTC grade 3 and 4 toxicities were higher with MSKCC-N5: 68% (193/283) versus 48% (129/268) (P < .001); infection 35% versus 25% (P = .011); stomatitis 25% versus 3% (P < .001); nausea and vomiting 17% versus 7% (P < .001); and diarrhea 7% versus 3% (P = .011). CONCLUSION No difference in outcome was observed between rCOJEC and MSKCC-N5; however, acute toxicity was less with rCOJEC, and therefore rCOJEC is the preferred induction regimen for International Society of Pediatric Oncology European Neuroblastoma Group.