Caution: IL-2 added to anti-GD2 therapy

Interleukin-2 was part of the original anti-GD2 immunotherapy package for high-risk neuroblastoma, and this caution pairing records why it has been dropped. In the R2 randomised comparison of the SIOPEN HR-NBL1 trial, adding subcutaneous IL-2 to dinutuximab beta produced no meaningful improvement in event-free survival but far more severe toxicity. The rationale is that IL-2 expands regulatory T cells and causes capillary leak, whereas the NK-cell-mediated antibody-dependent cytotoxicity that the anti-GD2 antibody relies on is sufficiently supported by GM-CSF. European protocols omit IL-2 and the Children's Oncology Group has since removed it as well in ANBL1531, so the combination now stands as a warning example within the broader cytokine therapy record.