Irene Y. Cheung

Anti-G(D2) antibody treatment of minimal residual stage 4 neuroblastoma diagnosed at more than 1 year of age.

PURPOSE To eradicate minimal residual disease with anti-G(D2) monoclonal antibody 3F8 in stage 4 neuroblastoma (NB) diagnosed at more than 1 year of age. PATIENTS AND METHODS Thirty-four patients were treated with 3F8 at the end of chemotherapy. Most had either bone marrow (n=31) or distant bony metastases (n=29). Thirteen patients were treated at second or subsequent remission (group I) and 12 patients in this group had a history of progressive/persistent disease after bone marrow transplantation (BMT); 21 patients were treated in first remission following N6 chemotherapy (group II). RESULTS Before 3F8 treatment, 23 patients were in complete remission CR, eight in very good partial remission (VGPR), one in partial remission (PR), and two had microscopic foci in marrow. Twenty-five had evidence of NB by at least one measurement of occult/minimal tumor (iodine 131[(131)I]-3F8 imaging, marrow immunocytology, or marrow reverse-transcriptase polymerase chain reaction [RT-PCR]). Acute self-limited toxicities of 3F8 treatment were severe pain, fever, urticaria, and reversible decreases in blood counts and serum complement levels. There was evidence of response by immunocytology (six of nine), by GAGE RT-PCR (seven of 12), and by (131)I-3F8 scans (six of six). Fourteen patients are alive and 13 (age 1.8 to 7.4 years at diagnosis) are progression-free (40 to 130 months from the initiation of 3F8 treatment) without further systemic therapy, none with late neurologic complications. A transient anti-mouse response or the completion of four 3F8 cycles was associated with significantly better survival. CONCLUSION Despite high-risk nature of stage 4 NB, long-term remission without autologous (A)BMT can be achieved with 3F8 treatment. Its side effects were short-lived and manageable. The potential benefits of 3F8 in consolidating remission warrant further investigations.

Murine Anti-GD2 Monoclonal Antibody 3F8 Combined With Granulocyte-Macrophage Colony-Stimulating Factor and 13-Cis-Retinoic Acid in High-Risk Patients With Stage 4 Neuroblastoma in First Remission

PURPOSE Anti-GD2 monoclonal antibody (MoAb) combined with granulocyte-macrophage colony-stimulating factor (GM-CSF) has shown efficacy against neuroblastoma (NB). Prognostic variables that could influence clinical outcome were explored. PATIENTS AND METHODS One hundred sixty-nine children diagnosed with stage 4 NB (1988 to 2008) were enrolled onto consecutive anti-GD2 murine MoAb 3F8 ± GM-CSF ± 13-cis-retinoic acid (CRA) protocols after achieving first remission (complete remission/very good partial remission). Patients enrolled in regimen A (n = 43 high-risk [HR] patients) received 3F8 alone; regimen B (n = 41 HR patients), 3F8 + intravenous GM-CSF + CRA, after stem-cell transplantation (SCT); and regimen C (n = 85), 3F8 + subcutaneous GM-CSF + CRA, 46 of 85 after SCT, whereas 28 of 85 required additional induction therapy and were deemed ultra high risk (UHR). Marrow minimal residual disease (MRD) was measured by quantitative reverse transcription polymerase chain reaction. Survival probability was calculated by the Kaplan-Meier method, and prognostic variables were analyzed by multivariate Cox regression model. RESULTS At 5 years from the start of immunotherapy, progression-free survival (PFS) improved from 44% for HR patients receiving regimen A to 56% and 62% for those receiving regimens B and C, respectively. Overall survival (OS) was 49%, 61%, and 81%, respectively. PFS and OS of UHR patients were 36% and 75%, respectively. Relapse was mostly at isolated sites. Independent adverse prognostic factors included UHR (PFS) and post-cycle two MRD (PFS and OS), whereas the prognostic factors for improved outcome were missing killer immunoglobulin-like receptor ligand (PFS and OS), human antimouse antibody response (OS), and regimen C (OS). CONCLUSION Retrospective analysis of consecutive trials from a single center demonstrated that MoAb 3F8 + GM-CSF + CRA is effective against chemotherapy-resistant marrow MRD. Its positive impact on long-term survival can only be confirmed definitively by randomized studies.

N7: a novel multi-modality therapy of high risk neuroblastoma (NB) in children diagnosed over 1 year of age.

BACKGROUND The N7 protocol for poor-risk neuroblastoma uses dose-intensive chemotherapy (as in N6 protocol [Kushner et al.: J Clin Oncol 12:2607-2613, 1994] but with lower dosing of vincristine) for induction, surgical resection and 2100 cGy hyperfractionated radiotherapy for local control, and for consolidation, targeted radioimmunotherapy with 131I-labeled anti-GD2 3F8 monoclonal antibody and immunotherapy with unlabeled/unmodified 3F8 (400 mg/m2). PROCEDURE The chemotherapy consists of: cyclophosphamide 70 mg/kg/d x 2 and a 72-hr infusion of doxorubicin 75 mg/m2 plus vincristine 2 mg/m2, for courses 1, 2, 4, and 6; and cisplatin 50 mg/m2/d x 4 and etoposide 200 mg/m2/d x 3, for courses 3, 5, and 7. 131I-3F8 is dosed at 20 mCi/kg, which is myeloablative and therefore necessitates stem-cell support. RESULTS Of the first 24 consecutive previously untreated patients more than 1 year old at diagnosis, 22 were stage 4 and two were unresectable stage 3 with MYCN amplification. Chemotherapy achieved CR/VGPR in 21 of 24 patients. Twenty patients to date have completed treatment with 131I-3F8, and 15 patients have completed all treatment. With a median follow-up of 19 months, 18 of 24 patients remain progression-free. CONCLUSIONS Major toxicities were grade 4 myelosuppression and mucositis during chemotherapy, and self-limited pain and urticaria during antibody treatment. Late effects include hearing deficits and hypothyroidism.

FCGR2A Polymorphism Is Correlated With Clinical Outcome After Immunotherapy of Neuroblastoma With Anti-GD2 Antibody and Granulocyte Macrophage Colony-Stimulating Factor

PURPOSE Anti-GD2 murine IgG3 antibody 3F8 kills neuroblastoma cells by antibody-dependent cell-mediated cytotoxicity (ADCC). Granulocyte macrophage colony-stimulating factor (GM-CSF) enhances phagocyte-mediated ADCC. The differential affinity of the human FCGR polymorphic alleles for 3F8 may influence the effectiveness of antibody immunotherapy. PATIENTS AND METHODS The entire cohort of high risk neuroblastoma patients (N = 136) treated on protocol using 3F8 and GM-CSF were the subjects of this analysis. Tumor response was measured by standard clinical tools plus sensitive molecular monitoring using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Polymorphic alleles of FCGR2A and FCGR3A were determined by PCR plus direct sequencing using genomic DNA samples obtained from marrow or blood of patients. RESULTS FCGR2A (R/R) genotype correlated with progression-free survival for the entire cohort (P = .049) and for the subset of patients with no history of prior relapse (P = .023). FCGR2A (R/R) also correlated with marrow remission 2.5 months after treatment initiation: by histology (P = .021 and P = .036, for the entire cohort and the subset, respectively) and by qRT-PCR (P = .052 and P = .033, respectively). CONCLUSION The favorable outcome associated with FCGR2A (R/R) genotype is consistent with the proposed role of FCGR2A and phagocyte-mediated ADCC in 3F8 plus GM-CSF immunotherapy.

KIR and HLA Genotypes Are Associated with Disease Progression and Survival following Autologous Hematopoietic Stem Cell Transplantation for High-Risk Neuroblastoma

Purpose: NK cells exhibit cytotoxicity against neuroblastoma. Gene polymorphisms governing NK cell function, therefore, may influence prognosis. Two highly polymorphic genetic loci instrumental in determining NK cell responses encode the NK cell killer immunoglobulin-like receptors (KIR) and their class I human leukocyte antigen (HLA) ligands. We hypothesized that patients with a “missing ligand” KIR-HLA compound genotype may uniquely benefit from autologous hematopoietic stem cell transplantation (HSCT). Experimental Design: One hundred sixty-nine patients treated with autologous HSCT for stage IV neuroblastoma underwent KIR and HLA genotyping. Patients were segregated according to the presence or absence of HLA ligands for autologous inhibitory KIR. Univariate and multivariate analyses were done for overall and progression-free survival. Results: Sixty-four percent of patients lacked one or more HLA ligands for inhibitory KIR. Patients lacking a HLA ligand had a 46% lower risk of death [hazard ratio, 0.54; 95% confidence interval (95% CI), 0.35-0.85; P = 0.007] and a 34% lower risk of progression (hazard ratio, 0.66; 95% CI, 0.44-1.0; P = 0.047) at 3 years compared with patients who possessed all ligands for his/her inhibitory KIR. Among all KIR-HLA combinations, 16 patients lacking the HLA-C1 ligand for KIR2DL2/KIR2DL3 experienced the highest 3-year survival rate of 81% (95% CI, 64-100). Survival was more strongly associated with “missing ligand” than with tumor MYCN gene amplification. Conclusion: KIR-HLA immunogenetics represents a novel prognostic marker for patients undergoing autologous HSCT for high-risk neuroblastoma. (Clin Cancer Res 2009;15(23):7330–4)

Detection of metastatic neuroblastoma in bone marrow: when is routine marrow histology insensitive?

PURPOSE To measure the sensitivity of histologic examination in detecting metastatic solid tumor in bone marrow. PATIENTS AND METHODS A total of 145 patients with stage 4 neuroblastoma underwent 840 marrow examinations, each consisting of six sites (four aspirates and two biopsies), from October 1990 to June 1996 at Memorial Sloan-Kettering Cancer Center. Metastasis was detected by either histology (aspirate by Wright-Giemse and biopsy by Hematoxylin-Eosin stains) or immunostaining of aspirates using anti-G(D2) monoclonal antibodies. RESULTS The absence of tumor by histology at a single marrow site was a poor guarantee of the absence of disease. The number of false-negative sites increased as the percent of G(D2)-positive tumor cells in the marrow decreased: zero of six if tumor cell count was > or = 1%, and approximately six of six sites if < or = 0.003%. Sensitivity was comparable between marrow aspirate and biopsy. A lower bound (LB) for the probability of false-negative histology was calculated from the (1) discordance among the six marrow samplings and (2) comparison with immunofluorescence. When disease was extensive (eg, at diagnosis), the LB was 0.13 and 0.3, respectively. After treatment, it increased to 0.37 and 0.8. Examining multiple marrow sites can decrease the LB to 0.15. However, at least three sites have to be negative at relapse, six at diagnosis, and more than 50 during treatment or off-therapy follow-up. The marginal decrease in the LB by additional samplings rapidly diminished to less than 0.05 after two sites. CONCLUSION Except at diagnosis and relapse when gross disease is present, marrow sampling by histology has limited sensitivity. Current practice grossly underestimates the true prevalence of marrow disease.

Humanizing murine IgG3 anti-GD2 antibody m3F8 substantially improves antibody-dependent cell-mediated cytotoxicity while retaining targeting in vivo

Murine IgG3 anti-GD2 antibody m3F8 has shown anti-neuroblastoma activity in Phase I/II studies, where antibody-dependent cell-mediated cytotoxicity (ADCC) played a key role. Humanization of m3F8 should circumvent human anti-mouse antibody (HAMA) response and enhance its ADCC properties to reduce dosing and pain side effect. Chimeric 3F8 (ch3F8) and humanized 3F8 (hu3F8-IgG1 and hu3F8-IgG4) were produced and purified by protein A affinity chromatography. In vitro comparison was made with m3F8 and other anti-GD2 antibodies in binding, cytotoxicity, and cross-reactivity assays. In GD2 binding studies by SPR, ch3F8 and hu3F8 maintained KD comparable to m3F8. Unlike other anti-GD2 antibodies, m3F8, ch3F8 and hu3F8 had substantially slower koff.. Similar to m3F8, both ch3F8 and hu3F8 inhibited tumor cell growth in vitro, while cross-reactivity with other gangliosides was comparable to that of m3F8. Both peripheral blood mononuclear cell (PBMC)-ADCC and polymorphonuclear leukocytes (PMN)-ADCC of ch3F8 and hu3F8-IgG1 were more potent than m3F8. This superiority was consistently observed in ADCC assays, irrespective of donors or NK-92MI-transfected human CD16 or CD32, whereas complement mediated cytotoxicity (CMC) was reduced. As expected, hu3F8-IgG4 had near absent PBMC-ADCC and CMC. Hu3F8 and m3F8 had similar tumor-to-non tumor ratios in biodistribution studies. Anti-tumor effect against neuroblastoma xenografts was better with hu3F8-IgG1 than m3F8. In conclusion, humanizing m3F8 produced next generation anti-GD2 antibodies with substantially more potent ADCC in vitro and anti-tumor activity in vivo. By leveraging ADCC over CMC, they may be clinically more effective, while minimizing pain and HAMA side effects. A Phase I trial using hu3F8-IgG1 is ongoing.

Quantitation of GD2 Synthase mRNA by Real-Time Reverse Transcriptase Polymerase Chain Reaction: Clinical Utility in Evaluating Adjuvant Therapy in Neuroblastoma

PURPOSE Minimal residual disease (MRD) is one of the final hurdles to cancer cure. Because therapy (myeloablation, immunotherapy, or differentiation) for MRD is applied at the time of clinical remission, objective surrogate markers are needed to gauge treatment efficacy. PATIENTS AND METHODS Using quantitative reverse transcriptase polymerase chain reaction (RT-PCR) of GD2 synthase (beta1,4-N-acetylgalactosaminyltransferase, EC 2.4.1.92) mRNA, we evaluated MRD response to anti-GD2 monoclonal antibody 3F8 adjuvant therapy, namely, one cycle of radioimmunotherapy using iodine-131 ((131)I)-3F8 plus one cycle of unlabeled 3F8 in 45 stage 4 neuroblastoma patients (newly diagnosed or without prior relapse) on the N7 protocol at Memorial Sloan-Kettering Cancer Center. The prognostic effect of MRD in their bone marrows before and after this phase of adjuvant therapy on progression-free survival (PFS) and overall survival (OS) was also analyzed. RESULTS Before 3F8 treatment, 24 of 45 patients were in complete remission (CR), 12 were in very good partial remission (VGPR), and nine were in partial remission (PR), according to criteria from International Neuroblastoma Staging System plus (131)I-3F8 scan; 71% had detectable tumor cells in marrow by real-time RT-PCR. Of the 32 positive patients, 20 became negative after therapy, with a 63% efficacy. When patients were stratified by CR/VGPR versus PR, GD2 synthase positivity was prognostic when detected before 3F8-targeted therapy (PFS, P =.045 and OS, P =.010). Persistent marker positivity was also predictive of PFS (P =.035) and OS (P =.027). Patients who succumbed to the disease had transcript levels four times higher than those who remain alive. CONCLUSION GD2 synthase mRNA is a useful surrogate marker for evaluating adjuvant treatment efficacy in neuroblastoma with prognostic potential.

Exploiting Gene Expression Profiling to Identify Novel Minimal Residual Disease Markers of Neuroblastoma

Purpose: Minimal residual disease (MRD) presents a significant hurdle to curing metastatic neuroblastoma. Biological therapies directed against MRD can improve outcome. Evaluating treatment efficacy requires MRD measurement, which serves as surrogate endpoint. Because of tumor heterogeneity, no single marker will likely be adequate. Genome-wide expression profiling can uncover potential MRD markers differentially expressed in tumors over normal marrow/blood. Experimental Design: Gene expression array was carried out on 48 stage 4 tumors and 9 remission marrows using the Affymetrix U95 gene chip. Thirty-four genes with a tumor-to-marrow expression ratio higher than tyrosine hydroxylase were identified. Quantitative reverse transcription-PCR was done on all 34 genes to study the dynamic range of tumor cell detection and the expression of these genes in normal marrow/blood samples and in stage 4 neuroblastoma tumors. Top ranking markers were then tested for prognostic significance in the marrows of stage 4 patients collected from the same treatment protocol after two cycles of immunotherapy. Results: Based on sensitivity assays, 8 top-ranking markers were identified: CCND1, CRMP1, DDC, GABRB3, ISL1, KIF1A, PHOX2B, and TACC2. They were abundantly expressed in stage IV neuroblastoma tumors (n = 20) and had low to no detection in normal marrow/blood samples (n = 20). Moreover, expression of CCND1, DDC, GABRB3, ISL1, KIF1A, and PHOX2B in 116 marrows sampled after two treatment cycles was highly prognostic of progression-free and overall survival (P < 0.001). Conclusions: Marker discovery based on differential gene expression profiling, stringent sensitivity and specificity assays, and well-annotated patient samples can rapidly prioritize and identify potential MRD markers of neuroblastoma.

Novel Markers of Subclinical Disease for Ewing Family Tumors from Gene Expression Profiling

Purpose: Targeting subclinical disease in the bone marrow is particularly relevant in metastatic Ewing family tumors (EFT) where cure is difficult. Genome-wide expression arrays can uncover novel genes differentially expressed in tumors over normal marrow/blood, which may have potentials as markers of subclinical disease. Experimental Design: Gene expression array data were obtained on 28 EFT tumors using the Affymetrix U133 gene chip and compared with 10 normal blood samples. Ten genes with high tumor to blood ratios were identified. Quantitative reverse transcription-PCR was done to study (a) the dynamic range of detection of rare tumor cells, (b) the gene expression in normal blood/marrow samples, (c) the gene expression among EFT tumors, and (d) the detection and prognostic impact of marker positivity in histology-negative diagnostic marrows of EFT patients. Results: Five of 10 genes (i.e., six-transmembrane epithelial antigen of the prostate 1 [STEAP1], cyclin D1 [CCND1], NKX2-2 transcription factor [NKX2-2], plakophilin 1 [PKP1], and transmembrane protein 47 [TMEM47]) were chosen for further analyses based on their steep linear dynamic range in detecting tumor cells seeded in normal mononuclear cells and on their homogeneous expression among EFT tumors. Prognostic effect was evaluated in 35 histology-negative diagnostic marrows. Marker negativity of STEAP1, CCND1, or NKX2-2, as well as three markers in combination, was strongly correlated with patient survival as well as survival without new metastases. Conclusions: This gene expression array-based approach identified novel markers that may be informative at diagnosis for risk group assessment. Their clinical utility needs to be tested in large patient cohorts.