Safety and efficacy of tandem 131I-metaiodobenzylguanidine infusions in relapsed/refractory neuroblastoma

BACKGROUND

Targeted radiotherapy with (131) I-Metaiodobenzylguanidine ((131) I-MIBG) is safe and effective therapy for patients with relapsed neuroblastoma, but anti-tumor activity is sometimes transient. The goal of this study was to determine the safety and efficacy of early (<100 days) second (131) I-MIBG treatment following an effective initial treatment.

PROCEDURES

After an initial infusion of 18 mCi/kg (131) I-MIBG, patients with tumor response or stable disease (SD), and available hematopoietic stem cell product, were eligible for additional (131) I-MIBG therapy. Residual thrombocytopenia did not preclude patients from receiving additional treatment. Subsequent treatment was administered a minimum of 6 weeks and maximum 100 days from initial infusion, and subjects could receive subsequent therapy if the same criteria were met.

RESULTS

Seventy-six heavily pretreated patients (median 4 prior chemotherapy regimens, range 1-8) with relapsed neuroblastoma were treated with (131) I-MIBG. Response rate to the first infusion was 30%, with 49% showing SD. Response rate among the 41 patients receiving a subsequent second infusion was 29%. After two treatments, 39% of patients experienced a reduction in overall disease burden. Four of five complete responses (CRs) to the initial infusion were maintained, despite all five having disease readily apparent on immediate post-second treatment (131) I-MIBG scanning. Hematologic toxicity was managed with early PBSC support after the second therapy (median: 15 days).

CONCLUSIONS

Early second (131) I-MIBG safely reduces disease burden in patients with relapsed neuroblastoma. Patients with CR by conventional (123) I-MIBG scintigraphy may have substantial disease burden apparent on high-dose (131) I-MIBG scintigraphy, supporting consolidation with subsequent (131) I-MIBG therapy in cases of apparent complete remission. Pediatr Blood Cancer 2011; 57: 1124-1129. © 2011 Wiley Periodicals, Inc.

Serial Profiling of Circulating Tumor DNA Identifies Dynamic Evolution of Clinically Actionable Genomic Alterations in High-Risk Neuroblastoma

Neuroblastoma evolution, heterogeneity, and resistance remain inadequately defined, suggesting a role for circulating tumor DNA (ctDNA) sequencing. To define the utility of ctDNA profiling in neuroblastoma, 167 blood samples from 48 high-risk patients were evaluated for ctDNA using comprehensive genomic profiling. At least one pathogenic genomic alteration was identified in 56% of samples and 73% of evaluable patients, including clinically actionable ALK and RAS-MAPK pathway variants. Fifteen patients received ALK inhibition (ALKi), and ctDNA data revealed dynamic genomic evolution under ALKi therapeutic pressure. Serial ctDNA profiling detected disease evolution in 15 of 16 patients with a recurrently identified variant-in some cases confirming disease progression prior to standard surveillance methods. Finally, ctDNA-defined ERRFI1 loss-of-function variants were validated in neuroblastoma cellular models, with the mutant proteins exhibiting loss of wild-type ERRFI1's tumor-suppressive functions. Taken together, ctDNA is prevalent in children with high-risk neuroblastoma and should be followed throughout neuroblastoma treatment.

SIGNIFICANCE

ctDNA is prevalent in children with neuroblastoma. Serial ctDNA profiling in patients with neuroblastoma improves the detection of potentially clinically actionable and functionally relevant variants in cancer driver genes and delineates dynamic tumor evolution and disease progression beyond that of standard tumor sequencing and clinical surveillance practices. See related commentary by Deubzer et al., p. 2727. This article is highlighted in the In This Issue feature, p. 2711.

Dinutuximab

Therapy combining dinutuximab with granulocyte macrophage colony stimulating factor, interleukin 2, and isotretinoin has significant side effects; however, these complications are generally predictable and can be managed proactively.

Phase I trial of temsirolimus (TEM), irinotecan (IRN), and temozolomide (TMZ) in children with refractory solid tumors: A Children's Oncology Group study

9540

Background: Inhibitors of mTOR have demonstrated activity in preclinical pediatric solid tumor models. A phase I trial to define the dose limiting toxicities (DLTs) associated with the mTOR inhibitor TEM in combination with IRN and TMZ was conducted in patients (pts) with refractory solid tumors. Methods: Escalating doses of TEM were administered intravenously on days (d) 1 and 8 of a 21-d cycle for a maximum of 1 year (y). IRN (50 mg/m2/dose) was administered orally on d1-5. TMZ (100 mg/m2/dose) was administered orally on d1-5. When the maximum planned dose of TEM was reached (35 mg/m2/dose), IRN was escalated stepwise from 50 to 90 mg/m2/dose. Pts were enrolled on 6 dose levels using the rolling-six design. Results: 46 eligible pts (30 male, median age 11y, range 1 – 21) were enrolled; 37 were fully evaluable for toxicity [neuroblastoma (9), osteosarcoma (4), Ewing sarcoma (3), rhabdomyosarcoma (3), CNS (10) or other (8) tumors]. 173 cycles, median 2 (range 1 – 17) have been delivered. Dose-limiting hyperlipidemia was observed during cycle 1 in 2 pts at dose level 3 (TEM 25 mg/m2, IRN 50 mg/m2, TMZ 100 mg/m2); both pts were on chronic corticosteroids. The protocol was amended to preclude chronic systemic steroid use and modify hyperlipidemia management. Dose-limiting hyperlipidemia was not observed in subsequent pts. Cycle 1 DLT (elevated GGT) was observed in 1 pt treated with TEM 35 mg/m2, IRN 65 mg/m2, TMZ 100 mg/m2. DLT has not been observed in 4 of the first 6 pts treated at the highest planned dose level (TEM 35 mg/m2, IRN 90 mg/m2, TMZ 100 mg/m2). Additional ≥Grade 3 regimen-related toxicities occurring in >1 evaluable pt include neutropenia (12), lymphopenia (10), leukopenia (6), thrombocytopenia (4), anemia (2), nausea or vomiting (5), hypokalemia (4), hypophosphatemia (2), diarrhea (2), elevated transaminases (2), and infection (2). 1 pt had a Grade 3 allergic reaction to TEM. 1 pt had a confirmed partial response and 4 have remained on protocol therapy for ≥1 year. Conclusions: The combination of TEM (35 mg/m2/dose) d 1 and 8, IRN (90 mg/m2/dose) d 1-5, and TMZ (100 mg/m2/dose) d 1-5 of a 21-d cycle appears to be well tolerated in children with refractory solid tumors.

Abstract 3105: Serial profiling of ctDNA identifies clinically actionable genomic evolution in high-risk neuroblastoma

Background: Analysis of circulating tumor DNA (ctDNA) provides a noninvasive method to profile tumor-associated genomic aberrations, heterogeneity and evolution.

Methods: Peripheral blood from 5 newly diagnosed and 33 relapsed high-risk neuroblastoma patients was serially profiled for ctDNA (n=1-7 samples/patient; total n=122 samples) with the FoundationACT assay that utilizes hybrid capture-based genomic profiling of 62 genes. Samples were sequenced to a median unique coverage depth of at least 3168x and variants were evaluated and compared with temporally-matched tumor sequencing and imaging evaluations.

Results: Ninety-three percent (114/122) of peripheral blood samples yielded suitable cell-free DNA for sequencing. ctDNA was detected in 68% (78/114) of samples (maximum somatic allele frequency [MSAF] &gt;0; median MSAF=0.53%; range MSAF 0-79%). At least 1 pathogenic genomic alteration (genomic short-variant or amplification) was found in 54% (61/114) of samples (range 1-6 alterations). Fifty-four percent (13/24) of detected ctDNA genomic-short variants were not present in temporally matched tumor samples at diagnosis or relapse (collected within 3 months of each other; n=23 patients), including pathogenic variants in ALK, TP53, TERT, NF1, FLT3, PTPN11, and PIK3CA. There was 100% concordance between the detection of MYCN (6/6) and ALK (3/3) amplification in paired ctDNA/tissue samples. For example, a newly diagnosed patient with stage 4 neuroblastoma had MYCN amplification noted on both tumor and ctDNA sequencing, however had 3 separate ALKmutations (R1275Q, F1245L, and F1174L) uniquely identified in ctDNA. Twenty-eight patients had multiple ctDNA samples sequenced (range 2-7 samples) and 50% (14/28) had alterations emerge or regress across serial samples. For example, pathogenic variants in ALK, BRCA2, NRAS, PTEN, TP53, CDKN2A, PTPN11, ABL1,CDH1, MET, ERRFl1 and ERBB2 appeared in subsequent ctDNA sequencing that were not present in the initial ctDNA or tumor sequencing. Overall, serial ctDNA profiling identified additional pathogenic variants in driver cancer genes beyond that derived from tumor sequencing in 45% (17/38) of cases, including identifying targetable ALK-RAS-MAPK pathway alterations uniquely in ctDNA in 21% (8/38) of cases. For the 18 patients that had 3 or more ctDNA samples, 33% (6/18) developed ctDNA unique ALK-RAS-MAPK pathway mutations during therapy. Finally, in most cases ctDNA profiling was complementary to standard imaging surveillance, however in 3 cases rising ctDNA allele frequencies occurred prior to clinical or imaging signs of disease relapse; additional correlation of ctDNA data and disease evaluations is ongoing.

Conclusions: Sequencing of ctDNA from neuroblastoma patients identified clinically actionable tumor-associated genetic aberrations emerging under the selective pressure of standard and targeted therapies.

Citation Format: Kristopher R. Bosse, Samantha Buongervino, Maria Lane, Adam Hyman, Maria Gemino-borromeo, Jennifer Saggio, Alana Fitzsimmons, Brady Forcier, Anne Murphy, John Wick, Matthew Cooke, Jennifer Webster, Russell Madison, Alley Welsh, Vincent A. Miller, Siraj M. Ali, John M. Maris, Yael P. Mosse. Serial profiling of ctDNA identifies clinically actionable genomic evolution in high-risk neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3105.