Neuroblastoma patients with high-affinity FCGR2A, -3A and stimulatory KIR 2DS2 treated by long-term infusion of anti-GD₂ antibody ch14.18/CHO show higher ADCC levels and improved event-free survival

Abstract

Polymorphisms in Fc-gamma-receptor (FCGR) genes as well as killer cell immunoglobulin-like receptor (KIR) and KIR ligand (KIRL) repertoires may influence antitumor effects of monoclonal antibodies (mAb). Here, we systematically analyzed high-and low-affinity FCGR2A and -3A genotypes as well as stimulating and inhibitory KIR/KIRL combinations in 53 neuroblastoma (NB) patients treated by long-term infusion (LTI) of anti-GD 2 IgG1 Ab ch14.18/CHO using validated real-time PCR methods.Patients with high-affinity FCGR2A and -3A genotypes showed a higher level of Ab-dependent cellmediated cytotoxicity (ADCC) on day 8 after the start of ch14.18/CHO and superior event-free survival (EFS) compared to patients with low FCGR genotypes. Similar observations were made for patients with stimulatory KIR/KIRL haplotype B (combination of KIR genes including activating receptor genes) compared to inhibitory haplotype A (a fixed set of genes encoding for inhibitory receptors, except 2DS4) and stronger effects were found in patients when haplotype B and high-affinity FCGRs were combined. Surprisingly, independent analysis of KIRs showed a major role of activating KIR 2DS2 for high ADCC levels and prolongation of EFS. The greatest effect was observed in 2DS2-positive patients that also had highaffinity FCGR2A and -3A genotypes.In summary, the presence of the activating KIR 2DS2 has a major effect on ADCC levels and survival in NB patients treated by LTI of ch14.18/CHO and may therefore be a useful biomarker in combination with FCGR polymorphisms for Ab-based immunotherapies.

Low CD4⁺/CD25⁺/CD127⁻ regulatory T cell- and high INF-γ levels are associated with improved survival of neuroblastoma patients treated with long-term infusion of ch14.18/CHO combined with interleukin-2

“…Indeed, high-risk NB patients with high-affinity polymorphisms of FCGR 2A and −3A that are expressed on neutrophils and cytotoxic NK cells, showed an increased ADCC and an improved EFS when treated with ch14.18/CHO in combination with IL-2 compared to those with low-affinity polymorphisms. 11 The rationale to combine the immune-stimulating cytokine IL-2 with anti-GD 2 Ab was based on preclinical data showing an IL-2-dependent increase of Ab-mediated effector functions. 12 A prospective randomized phase 3 trial was conducted to assess the role of IL-2 in GD 2 -directed immunotherapies.…”

Peptide:MHC dependent activation of natural killer cells through KIR2DS2 generates anti-tumor responses

“…Consistent with this enhanced functionality, in a clinical trial of an anti-GD2 antibody in neuroblastoma, KIR2DS2-positive patients had improved survival compared to KIR2DS2negative patients (29). Taken together these studies suggest that KIR2DS2 has potential as a target for anti-cancer therapies.…”

“…Additionally, KIR2DS2+ NK cells appear to have a greater potential to mediate ADCC in vitro and in vivo (28,29). Thus, the utility of targeting KIR2DS2 in cancer immunotherapy may extend to combination with antibody based therapeutics.…”

The challenge of defining “ultra‐high‐risk” neuroblastoma

“…These include both clinical and biological factors examined at diagnosis and following response to therapy (e.g., end of induction). Factors may be simply “prognostic” (associated with outcome regardless of type of treatment), e.g., age at diagnosis, or “predictive” (predict outcome with a particular therapy), e.g., the potential for Fc‐gamma‐receptor polymorphisms to predict response to anti‐GD2 immunotherapy, or both prognostic and predictive. At diagnosis, risk substratification factors include simple clinical characteristics such as patient age, serum lactate dehydrogenase (LDH), serum ferritin, histopathology and pattern, and extent of metastatic disease .…”

“…These include both clinical and biological factors examined at diagnosis and following response to therapy (e.g., end of induction). Factors may be simply "prognostic" (associated with outcome regardless of type of treatment), e.g., age at diagnosis, or "predictive" (predict outcome with a particular therapy), e.g., the potential for Fc-gamma-receptor polymorphisms to predict response to anti-GD2 immunotherapy, 22 scores, is useful for response evaluation 3 and prognostication. 17 Quantification of tumor-derived mRNA in blood and bone marrow at diagnosis (and during therapy) has been shown to correlate with outcome in patients with HR-NBL.…”