Aim
After the first important results of the antiGD2/SP02 combination immunotherapy (Alice Yu, NEJM, 2010), this trial investigated the potential and tolerance of ch14.18/CHO monoclonal antibody immunotherapy(IT)± subcutaneous interleukin 2(scIL2) in high-risk neuroblastoma (HRNBL1) front-line patients (pts).
Methods
Between 2009-2011,the HR-NBL1/SIOPEN Phase III trial (APN311-302)(EudraCT:2006-001489-17) randomized 406pts (all stage 4 but if <1yr only with MycN amplification (MNA) and MNA stages 2&3 all ages up to 21yrs). Pts were randomised for IT(R2) at start of maintenance. Eligibility included a COJEC induction ± 2TVD; enrolment on the HDC randomisation (R1, BUMEL vs CEM) with R1response criteria. Local treatments aimed at gross surgical resection and radiotherapy (21Gy). Pts receiver either 100mg/m² ch14.18/CHO (d8-12) as 5 daily 8-hour short-term infusion (STI) alone (STIA) or combined with 6x106IU/m2 scIL2 (d1-5;8-12) (STIB) for a total of 5 IT cycles; both had 6 cyles of oral 13-cis-RA (160mg/m2,d19-32). The median age at diagnosis was 3yrs(1month-19yrs) and the median observation time 3.1yrs. Outcomes are reported as 3-yrs event free/overall survival rates (EFS/OS).
Results
The EFS/OS for pts treated with ch14.18/CHO with and without scIL2 was 0.60±0.04/0.66±0.04(206pts) and 0.57±0.04/0.65±0.04/(200pts)(NS). The EFS for CR-pts (or VGPR/PRpts) on STIA was 0.68±0.05 (0.46±0.06) and with STIB 0.65±0.05 (0.53±0.06) indicating no benefit for scIL2. Early termination of IT occurred in 18% in STIA but in 44% in STIB (36% toxicity-related, 8% progressions). A Lansky performance status of ≤30% was found 17% STIA-pts but in of 39% STIB-pts (p<0.001). CTC-grade 3&4 allergic reactions was observed in 9% and 20% of STIA-pts and STIB-pts (<0.001). Incidence of capillary leak and CTC-grade 3&4 fever significantly lower without scIL2 STIA (1% and 14%) vs. STIB (9% and 40%).
Conclusion The EFS/OS rates at 3yrs show a clear improvement to previous SIOPEN experience. A markedly reduced toxicity without IL2 and equivalent outcome suggest a ch14.18/CHO only approach.