Irinotecan Plus Temozolomide for Relapsed or Refractory Neuroblastoma

Irinotecan and temozolomide in combination with dasatinib and rapamycin versus irinotecan and temozolomide for patients with relapsed or refractory neuroblastoma (RIST-rNB-2011): a multicentre, open-label, randomised, controlled, phase 2 trial

BACKGROUND

Neuroblastoma is the most common extracranial solid tumour in children. Relapsed or refractory neuroblastoma is associated with a poor outcome. We assessed the combination of irinotecan-temozolomide and dasatinib-rapamycin (RIST) in patients with relapsed or refractory neuroblastoma.

METHODS

The multicentre, open-label, randomised, controlled, phase 2, RIST-rNB-2011 trial recruited from 40 paediatric oncology centres in Germany and Austria. Patients aged 1-25 years with high-risk relapsed (defined as recurrence of all stage IV and MYCN amplification stages, after response to treatment) or refractory (progressive disease during primary treatment) neuroblastoma, with Lansky and Karnofsky performance status at least 50%, were assigned (1:1) to RIST (RIST group) or irinotecan-temozolomide (control group) by block randomisation, stratified by MYCN status. We compared RIST (oral rapamycin [loading 3 mg/m2 on day 1, maintenance 1 mg/m2 on days 2-4] and oral dasatinib [2 mg/kg per day] for 4 days with 3 days off, followed by intravenous irinotecan [50 mg/m2 per day] and oral temozolomide [150 mg/m2 per day] for 5 days with 2 days off; one course each of rapamycin-dasatinib and irinotecan-temozolomide for four cycles over 8 weeks, then two courses of rapamycin-dasatinib followed by one course of irinotecan-temozolomide for 12 weeks) with irinotecan-temozolomide alone (with identical dosing as experimental group). The primary endpoint of progression-free survival was analysed in all eligible patients who received at least one course of therapy. The safety population consisted of all patients who received at least one course of therapy and had at least one post-baseline safety assessment. This trial is registered at ClinicalTrials.gov, NCT01467986, and is closed to accrual.

FINDINGS

Between Aug 26, 2013, and Sept 21, 2020, 129 patients were randomly assigned to the RIST group (n=63) or control group (n=66). Median age was 5·4 years (IQR 3·7-8·1). 124 patients (78 [63%] male and 46 [37%] female) were included in the efficacy analysis. At a median follow-up of 72 months (IQR 31-88), the median progression-free survival was 11 months (95% CI 7-17) in the RIST group and 5 months (2-8) in the control group (hazard ratio 0·62, one-sided 90% CI 0·81; p=0·019). Median progression-free survival in patients with amplified MYCN (n=48) was 6 months (95% CI 4-24) in the RIST group versus 2 months (2-5) in the control group (HR 0·45 [95% CI 0·24-0·84], p=0·012); median progression-free survival in patients without amplified MYCN (n=76) was 14 months (95% CI 9-7) in the RIST group versus 8 months (4-15) in the control group (HR 0·84 [95% CI 0·51-1·38], p=0·49). The most common grade 3 or worse adverse events were neutropenia (54 [81%] of 67 patients given RIST vs 49 [82%] of 60 patients given control), thrombocytopenia (45 [67%] vs 41 [68%]), and anaemia (39 [58%] vs 38 [63%]). Nine serious treatment-related adverse events were reported (five patients given control and four patients given RIST). There were no treatment-related deaths in the control group and one in the RIST group (multiorgan failure).

INTERPRETATION

RIST-rNB-2011 demonstrated that targeting of MYCN-amplified relapsed or refractory neuroblastoma with a pathway-directed metronomic combination of a multkinase inhibitor and an mTOR inhibitor can improve progression-free survival and overall survival. This exclusive efficacy in MYCN-amplified, relapsed neuroblastoma warrants further investigation in the first-line setting.

FUNDING

Deutsche Krebshilfe.

Stage 4N neuroblastoma before and during the era of anti-GD2 immunotherapy

Patients with stage 4N neuroblastoma (distant metastases limited to lymph nodes) stand out as virtually the only survivors of high-risk neuroblastoma (HR-NB) before myeloablative therapy (MAT) and immunotherapy with anti-GD2 monoclonal antibodies (mAbs) became standard. Because no report presents more recent results with 4N, we analyzed our large 4N experience. All 51 pediatric 4N patients (<18 years old) diagnosed 1985 to 2021 were reviewed. HR-NB included MYCN-nonamplified 4N diagnosed at age ≥18 months and MYCN-amplified 4N. Among 34 MYCN-nonamplified high-risk patients, 20 are relapse-free 1.5+ to 37.5+ (median 12.5+) years post-diagnosis, including 13 without prior MAT and 5 treated with little (1 cycle; n = 2) or no mAb (n = 3), while 14 patients (7 post-MAT, 8 post-mAbs) relapsed (all soft tissue). Of 15 MYCN-amplified 4N patients, 7 are relapse-free 2.1+ to 26.4+ (median 11.6+) years from the start of chemotherapy (all received mAbs; 3 underwent MAT) and 4 are in second remission 4.2+ to 21.8+ years postrelapse (all soft tissue). Statistical analyses showed no significant association of survival with either MAT or mAbs for MYCN-nonamplified HR-NB; small numbers prevented these analyses for MYCN-amplified patients. The two patients with intermediate-risk 4N (14-months-old) are relapse-free 7+ years postresection of primary tumors; distant disease spontaneously regressed. The natural history of 4N is marked by NB confined to soft tissue without early relapse in bones or bone marrow, where mAbs have proven efficacy. These findings plus curability without MAT, as seen elsewhere and at our center, support consideration of treatment reduction for MYCN-nonamplified 4N.

Early Salvage Chemo-Immunotherapy with Irinotecan, Temozolomide and Naxitamab Plus GM-CSF (HITS) for Patients with Primary Refractory High-Risk Neuroblastoma Provide the Best Chance for Long-Term Outcomes

Patients with high-risk neuroblastoma (HR-NB) who are unable to achieve a complete response (CR) to induction therapy have worse outcomes. We investigated the combination of humanized anti-GD2 mAb naxitamab (Hu3F8), irinotecan (I), temozolomide (T), and sargramostim (GM-CSF)-HITS-against primary resistant HR-NB. Eligibility criteria included having a measurable chemo-resistant disease at the end of induction (EOI) treatment. Patients were excluded if they had progressive disease (PD) during induction. Prior anti-GD2 mAb and/or I/T therapy was permitted. Each cycle, administered four weeks apart, comprised Irinotecan 50 mg/m2/day intravenously (IV) plus Temozolomide 150 mg/m2/day orally (days 1-5); naxitamab 2.25 mg/kg/day IV on days 2, 4, 8 and 10, (total 9 mg/kg or 270 mg/m2 per cycle), and GM-CSF 250 mg/m2/day subcutaneously was used (days 6-10). Toxicity was measured using CTCAE v4.0 and responses through the modified International Neuroblastoma Response Criteria (INRC). Thirty-four patients (median age at treatment initiation, 4.9 years) received 164 (median 4; 1-12) HITS cycles. Toxicities included myelosuppression and diarrhea, which was expected with I/T, and pain and hypertension, expected with naxitamab. Grade ≥3-related toxicities occurred in 29 (85%) of the 34 patients; treatment was outpatient. The best responses were CR = 29% (n = 10); PR = 3% (n = 1); SD = 53% (n = 18); PD = 5% (n = 5). For cohort 1 (early treatment), the best responses were CR = 47% (n = 8) and SD = 53% (n = 9). In cohort 2 (late treatment), the best responses were CR = 12% (n = 2); PR = 6% (n = 1); SD = 53% (n = 9); and PD = 29% (n = 5). Cohort 1 had a 3-year OS of 84.8% and EFS 54.4%, which are statistically significant improvements (EFS p = 0.0041 and OS p = 0.0037) compared to cohort 2. In conclusion, naxitamab-based chemo-immunotherapy is effective against primary chemo-resistant HR-NB, increasing long-term outcomes when administered early during the course of treatment.

Pediatric DDR inhibitor combinations: Are WEE1 there yet?

A phase 2 study of the WEE1 inhibitor adavosertib in combination with irinotecan in children demonstrates an intriguing positive signal of efficacy in neuroblastoma, a pediatric tumor characterized by replication stress. Further pediatric development of adavosertib and related compounds targeting DNA damage response will be challenged by appropriate patient selection, fit‐for‐filing trial design, and ongoing access to agents, likely to be predicated on success in adult malignancy.

Clinical outcomes of pediatric patients receiving multimodality treatment of second central nervous system relapse of neuroblastoma

BACKGROUND

In high-risk neuroblastoma, multimodality therapy including craniospinal irradiation (CSI) is effective for central nervous system (CNS) relapse. Management of post-CSI CNS relapse is not clearly defined.

PROCEDURE

Pediatric patients with neuroblastoma treated with CSI between 2000 and 2019 were identified. Treatment of initial CNS disease (e.g., CSI, intraventricular compartmental radioimmunotherapy [cRIT] with ¹³¹ I-monoclonal antibodies targeting GD2 or B7H3) and management of post-CSI CNS relapse ("second CNS relapse") were characterized. Cox proportional hazards models to evaluate factors associated with third CNS relapse and overall survival (OS) were used.

RESULTS

Of 128 patients (65% male, median age 4 years), 19 (15%) received CSI with protons and 115 (90%) had a boost. Most (103, 81%) received cRIT, associated with improved OS (hazard ratio [HR] 0.3, 95% confidence interval [CI]: 0.1-0.5, p < .001). Forty (31%) developed a second CNS relapse, associated with worse OS (1-year OS 32.5%, 95% CI: 19-47; HR 3.8; 95% CI: 2.4-6.0, p < .001), and more likely if the leptomeninges were initially involved (HR 2.5, 95% CI: 1.3-4.9, p = .006). Median time to second CNS relapse was 6.8 months and 51% occurred outside the CSI boost field. Twenty-five (63%) patients underwent reirradiation, most peri-operatively (18, 45%) with focal hypofractionation. Eight (20%) patients with second CNS relapse received cRIT, associated with improved OS (HR 0.1; 95% CI: 0.1-0.4, p < .001).

CONCLUSIONS

CNS relapse after CSI for neuroblastoma portends a poor prognosis. Surgery with hypofractionated radiotherapy was the most common treatment. Acknowledging the potential for selection bias, receipt of cRIT both at first and second CNS relapse was associated with improved survival. This finding necessitates further investigation.

A phase I trial of metformin in combination with vincristine, irinotecan, and temozolomide in children with relapsed or refractory solid and central nervous system tumors: A report from the national pediatric cancer foundation

BACKGROUND

Patients with relapsed and refractory solid and central nervous system (CNS) tumors have poor outcomes and need novel therapeutic options. Vincristine, irinotecan, and temozolomide (VIT) is a common chemotherapy regimen in relapsed pediatric tumors with an established toxicity profile. Metformin shows preclinical anti-cancer activity through multiple pathways.

METHODS

The objective of this Phase I trial was to establish the maximum tolerated dose (MTD) and recommended Phase II dose (RP2D) of metformin in combination with VIT in children with relapsed and refractory solid and CNS tumors. A 3 + 3 design was used to test the addition of metformin at five dose levels (666, 999, 1333, 1666, and 2000 mg/m² /day). Therapy toxicity, pharmacokinetics, and radiologic response to treatment were evaluated.

RESULTS

Twenty-six patients (median age 13 years, range 2-18 years) were enrolled with 22 evaluable for toxicity. The most common diagnoses were Ewing sarcoma (n = 8), rhabdomyosarcoma (n = 3) and atypical teratoid/rhabdoid tumor (n = 3). The MTD was exceeded at Dose Level 5 due to two dose-limiting toxicities; both were Grade 3 diarrhea requiring prolonged hospitalization and intravenous fluids. The MTD was not determined due to study closure with less than six patients enrolled at Dose Level 4. Frequently observed toxicities were gastrointestinal (most notably diarrhea) and hematologic. Amongst 16 patients evaluable for best overall response, there was one complete response (Ewing sarcoma), three partial responses (Ewing sarcoma, glioblastoma multiforme, and alveolar rhabdomyosarcoma), and five patients with stable disease.

CONCLUSIONS

The MTD of VIT with metformin was not determined due to premature study closure. We recommend an RP2D of Dose Level 4, 1666 mg/m² /day. Radiographic responses were seen in multiple tumor types. Further evaluation for efficacy could be investigated in a Phase II trial.

Dinutuximab beta plus conventional chemotherapy for relapsed/refractory high-risk neuroblastoma: A single-center experience

Background

Relapsed/refractory high-risk neuroblastoma has a dismal prognosis. Anti-GD2-mediated chemo-immunotherapy has a notable anti-tumor activity in patients with relapsed/refractory high-risk neuroblastoma. The purpose of this study was to analyze the efficacy and safety of the combination of immunotherapy with dinutuximab beta (DB) and chemotherapy in patients with relapsed/refractory high-risk neuroblastoma.

Methods

All patients received the Turkish Pediatric Oncology Group NB 2009 national protocol for HR-NB treatment at the time of diagnosis. Salvage treatments were administered after progression or relapse. The patients who could not achieve remission in primary or metastatic sites were included in the study. The most common chemotherapy scheme was irinotecan and temozolomide. DB was administered intravenously for 10 days through continuous infusion with 10 mg/m² per day. The patients received 2 to 14 successive cycles with duration of 28 days each. Disease assessment was performed after cycles 2, 4, and 6 and every 2 to 3 cycles thereafter.

Results

Between January 2020 and March 2022, nineteen patients received a total of 125 cycles of DB and chemotherapy. Objective responses were achieved in 12/19 (63%) patients, including complete remission in 6/19 and partial response in 6/19. Stable disease was observed in two patients. The remaining five patients developed bone/bone marrow and soft tissue progression after 2-4 cycles of treatment. The most common Grade ≥3 toxicities were leukopenia, thrombocytopenia, hypertransaminasemia, fever, rash/itching and capillary leak syndrome, respectively.

Conclusion

Our study results suggest that DB-based chemo-immunotherapy seems to be suitable with encouraging response rates in patients with relapsed/refractory high-risk neuroblastoma.

Early-phase clinical trial eligibility and response evaluation criteria for refractory, relapsed, or progressive neuroblastoma: A consensus statement from the National Cancer Institute Clinical Trials Planning Meeting

BACKGROUND

International standardized criteria for eligibility, evaluable disease sites, and disease response assessment in patients with refractory, progressive, or relapsed high-risk neuroblastoma enrolled in early-phase clinical trials are lacking.

METHODS

A National Cancer Institute-sponsored Clinical Trials Planning Meeting was convened to develop an international consensus to refine the tumor site eligibility criteria and evaluation of disease response for early-phase clinical trials in children with high-risk neuroblastoma.

RESULTS

Standardized data collection of patient and disease characteristics (including specified genomic data), eligibility criteria, a definition of evaluable disease, and response evaluations for primary and metastatic sites of disease were developed. Eligibility included two distinct patient groups: progressive disease and refractory disease. The refractory disease group was subdivided into responding persistent disease and stable persistent disease to better capture the clinical heterogeneity of refractory neuroblastoma. Requirements for defining disease evaluable for a response assessment were provided; they included requirements for biopsy to confirm viable neuroblastoma and/or ganglioneuroblastoma in those patients with soft tissue or bone disease not avid for iodine-123 meta-iodobenzylguanidine. Standardized evaluations for response components and time intervals for response evaluations were established.

CONCLUSIONS

The use of international consensus eligibility, evaluability, and response criteria for early-phase clinical studies will facilitate the collection of comparable data across international trials and promote more rapid identification of effective treatment regimens for high-risk neuroblastoma.

Advancing therapy for neuroblastoma

Neuroblastomas are tumours of sympathetic origin, with a heterogeneous clinical course ranging from localized or spontaneously regressing to widely metastatic disease. Neuroblastomas recapitulate many of the features of sympathoadrenal development, which have been directly targeted to improve the survival outcomes in patients with high-risk disease. Over the past few decades, improvements in the 5-year survival of patients with metastatic neuroblastomas, from <20% to >50%, have resulted from clinical trials incorporating high-dose chemotherapy with autologous stem cell transplantation, differentiating agents and immunotherapy with anti-GD2 monoclonal antibodies. The next generation of trials are designed to improve the initial response rates in patients with high-risk neuroblastomas via the addition of immunotherapies, targeted therapies (such as ALK inhibitors) and radiopharmaceuticals to standard induction regimens. Other trials are focused on testing precision medicine strategies for patients with relapsed and/or refractory disease, enhancing the antitumour immune response and improving the effectiveness of maintenance regimens, in order to prolong disease remission. In this Review, we describe advances in delineating the pathogenesis of neuroblastoma and in identifying the drivers of high-risk disease. We then discuss how this knowledge has informed improvements in risk stratification, risk-adapted therapy and the development of novel therapies.

Vincristine, Irinotecan, and Temozolomide in Patients With Relapsed/Refractory Neuroblastoma

Purpose

The combination of irinotecan, temozolomide and vincristine has been proposed as an effective salvage regimen for some pediatric malignancies. Thus, we sought to evaluate this combination for patients with relapsed and refractory neuroblastoma (NB).

Patients and Methods

In this retrospective study, forty-six patients with relapsed or refractory NB were treated with the combination of vincristine (1.5 mg/m² i.v. day 1), irinotecan (50 mg/m²/day i.v. days 1–5) and temozolomide (100 mg/m²/day p.o. days 1–5) (VIT) during the period 2011–2019. All toxicities were documented.

Results

A total of 251 cycles (median 6 cycles/patient) were administered. A complete response (CR) was achieved in 5 patients, partial response (PR) in 27 patients, stable disease (SD) in 8 patients, and progression disease (PD) in 6 patients, with an overall objective response rate (CR+PR) of 69.6%. Eighteen patients developed diarrhea with Grade 3 or less. Grade 1-2 hematologic toxicity occurred in 10 patients. Grade 3-4 hematologic toxicity developed in 32 patients. VIT was an effective regimen for different metastatic sites. UGT1A*28 genotyping performed in 7 patients revealed wild type. Diarrhea occurred in 4 of them.

Conclusion

The shorter, 5-day VIT regimen is an active and well-tolerated salvage regimen in relapse/refractory NB.

Combination chemotherapy consisting of irinotecan, etoposide, and carboplatin for refractory or relapsed neuroblastoma

BACKGROUND

Patients with primary refractory and relapsed neuroblastoma have a poor prognosis since safe and effective chemotherapies for these patients are currently limited. The development of new chemotherapy regimens for these patients is imperative to improve survival outcomes.

METHODS

We retrospectively analyzed 40 patients with refractory (n = 36) or relapsed (n = 4) neuroblastoma who received irinotecan, etoposide, and carboplatin (IREC) as a second-line treatment. We evaluated their therapeutic response and the toxicity of IREC. We also assessed the impact of UGT1A1 gene polymorphisms, which are involved in irinotecan metabolism, on outcomes and toxicity.

RESULTS

A total of 112 cycles of IREC were administered to 40 patients with a median of 2 cycles per patient (range, 1-9). Six (15%) patients (UGT1A1 wild-type [n = 2] and heterozygous [n = 4]) showed objective responses, including partial response (n = 1), tumor shrinkage (n = 4), and improved findings on their MIBG scan (n = 1). Grade 4 neutropenia, grade 4 leukopenia, and grades 3-4 gastrointestinal toxicity were observed in 110 (98%), 88 (79%), and 3 (3%) cycles, respectively. There was no IREC-related mortality. Patients with UGT1A1 polymorphisms showed a higher frequency of grade 4 leukopenia, but these patients did not have increased treatment-related mortality or non-hematologic toxicity.

CONCLUSIONS

IREC showed an objective response rate of 15% including 1 case with partial response. IREC was well tolerated regardless of UGT1A1 genotype. This study suggests that IREC is a promising second-line chemotherapy for refractory or relapsed neuroblastoma.

High-Risk Neuroblastoma: Poor Outcomes Despite Aggressive Multimodal Therapy

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Neuroblastoma (NBL) is a highly malignant embryonal tumor that originates from the primordial neural crest cells. NBL is the most common tumor in infants and the most common extracranial solid tumor in children. The tumor is more commonly diagnosed in children of 1-4 years of age. NBL is characterized by enigmatic clinical behavior that ranges from spontaneous regression to an aggressive clinical course leading to frequent relapses and death. Based on the likelihood of progression and relapse, the International Neuroblastoma Risk Group classification system categorized NBL into very low risk, low risk, intermediate risk, and high risk (HR) groups. HR NBL is defined based on the patient's age (> 18 months), disease metastasis, tumor histology, and MYCN gene amplification. HR NBL is diagnosed in nearly 40% of patients, mainly those > 18 months of age, and is associated with aggressive clinical behavior. Treatment strategies involve the use of intensive chemotherapy (CTR), surgical resection, high dose CTR with hematopoietic stem cell support, radiotherapy, biotherapy, and immunotherapy with Anti-ganglioside 2 monoclonal antibodies. Although HR NBL is now better characterized and aggressive multimodal therapy is applied, the outcomes of treatment are still poor, with overall survival and event-free survival of approximately 40% and 30% at 3-years, respectively. The short and long-term side effects of therapy are tremendous. HR NBL carries a high mortality rate accounting for nearly 15% of pediatric cancer deaths. However, most mortalities are attributed to the high frequency of disease relapse (50%) and disease reactiveness to therapy (20%). Newer treatment strategies are therefore urgently needed. Recent discoveries in the field of biology and molecular genetics of NBL have led to the identification of several targets that can improve the treatment results. In this review, we discuss the different aspects of the epidemiology, biology, clinical presentations, diagnosis, and treatment of HR NBL, in addition to the recent developments in the management of the disease.

Irinotecan Plus Doxorubicin Hydrochloride Liposomes for Relapsed or Refractory Wilms Tumor

Purpose

The prognosis of relapsed or refractory pediatric Wilms tumor (WT) is dismal, and new salvage therapies are needed. This study aimed to evaluate the efficacy of the combination of irinotecan and a doxorubicin hydrochloride liposome regimen for relapsed or refractory pediatric WT.

Patients and Methods

The present study enrolled relapsed or refractory pediatric WT patients who were treated with the AI regimen (doxorubicin hydrochloride liposomes 40 mg/m² per day, day 1, and irinotecan 50 mg/m² per day with 90-min infusion, days 1–5; this regimen was repeated every 3 weeks) at Sun Yat-sen University Cancer Center from July 2018 to September 2020. The response was defined as the best-observed response after at least two cycles according to the Response Evaluation Criteria of Solid Tumors (RECIST 1.1), and toxicity was evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE 4.03).

Results

A total of 16 patients (male:female, 8:8) with a median age of 4.2 years (0.5–11 years) with relapsed or refractory disease were enrolled in this study, including 14 patients with relapsed disease and two patients with refractory disease. These patients received 1–8 courses (median, 3 courses) of the AI regimen. Fourteen patients were assessable for response: two with complete response (CR), five with partial response (PR), two with stable disease (SD), and five with progressive disease (PD). The objective response rate was 50% (two CR, five PR), and the disease control rate was 64% (two CR, five PR, and two SD). Seven out of 14 patients (50%) were alive at the last follow-up, ranging from 2.6 to 32.4 months. The median progression-free survival and median overall survival were 3.5 months (range 0.5–12 months) and 8 months (range 1–28 months), respectively. Sixteen patients were assessable for toxicity, with the most common grade 3 or 4 adverse events being alopecia (62%), leukopenia (40%), abdominal pain (38%), diarrhea (23%), and mucositis (16%), etc. No fatal adverse events have been observed, and modest adverse effects can be administered.

Conclusion

Irinotecan and doxorubicin hydrochloride liposome regimens have positive efficacy on relapsed or refractory pediatric WT with well-tolerated toxicity. A prospective clinical trial is warranted.

An overview of current results with the vincristine-irinotecan-temozolomide combination with or without bevacizumab in pediatric, adolescence and adult solid tumors

Malignant tumors in young patients present a significant therapeutic challenge for physicians, partially due to their rarity and a relative lack of data, at least compared to adult tumors. As a result, there is an urgent need to explore new possible therapeutic regimens, either by introducing novel agents or by exploring combinations of existing agents. Vincristine, Temozolomide and Irinotecan are chemotherapeutic drugs which have emerged over the last six decades as monotherapy or as part of therapeutic regimens in various solid tumors. Combining these agents can yield strong synergistic effects, as suggested by preclinical data and results from clinical trials. Furthermore, adding novel molecules, such as anti-VEGF factor Bevacizumab to the aforementioned regimens, has shown efficacy in a limited number of trials, which are thoroughly analyzed throughout this review. Data presented throughout this paper suggest that VIT(b) regimen should be further explored in solid tumors in pediatric and adolescent patients.

Randomized Phase II Trial of Vincristine-Irinotecan With or Without Temozolomide, in Children and Adults With Relapsed or Refractory Rhabdomyosarcoma: A European Paediatric Soft tissue Sarcoma Study Group and Innovative Therapies for Children With Cancer Trial

PURPOSE

The VIT-0910 trial was conducted to evaluate efficacy and safety of the vincristine-irinotecan combination with and without temozolomide (VIT and VI, respectively) in relapsed or refractory rhabdomyosarcoma (RMS).

METHODS

In this randomized European phase II trial, patients age 0.5-50 years received 21-day cycles combining vincristine (1.5 mg/m² once a day on day 1 and day 8) and irinotecan (50 mg/m² once a day from day 1 to day 5) with and without temozolomide (125 mg/m² once a day from day 1 to day 5 and 150 mg/m² once a day from cycle 2), until progression or unacceptable toxicity. The primary end point was objective response rate after two cycles. Secondary end points included best response, progression-free survival, overall survival, and adverse events. A Simon 2-stage design was initially planned to separately analyze 40 patients/arm. After amendment, the trial sample size was increased to 120 and a comparison between arms, adjusted for confounding factors, was added to the statistical plan (ClinicalTrials.gov, NCT01355445).

RESULTS

Overall, 120 patients (60 per arm) were recruited in 37 European centers. The median age was 11 years (range, 0.75-45); 89% of patients had a relapsed RMS. The objective response rate was 44% (24 of 55 evaluable patients) for VIT versus 31% (18 of 58) for VI (adjusted odds ratio, 0.50; 95% CI, 0.22 to 1.12; P = .09). The VIT arm achieved significantly better overall survival (adjusted hazard ratio, 0.55; 95% CI, 0.35 to 0.84; P = .006) compared with VI, with consistent progression-free survival results (adj-hazard ratio, 0.68; 95% CI, 0.46 to 1.01; P = .059). Overall, patients experienced adverse events ≥ grade 3 more frequently with VIT than VI (98% v 78%, respectively; P = .009), including a significant excess of hematologic toxicity (81% v 61%; P = .025).

CONCLUSION

The addition of temozolomide to VI improved chemotherapy efficacy for patients with relapsed RMS, with manageable increase in toxicity. VIT is considered the new standard treatment in these patients in the European paediatric Soft Tissue Sarcoma Group and will be the control arm in the next randomized trial.

Temozolomide with irinotecan versus temozolomide, irinotecan plus bevacizumab for recurrent medulloblastoma of childhood: Report of a COG randomized Phase II screening trial

BACKGROUND

Approximately 30% of children with medulloblastoma (MB) experience recurrence, which is usually incurable. This study compared the overall survival (OS) of patients receiving temozolomide (TMZ) and irinotecan with that of patients receiving TMZ, irinotecan, and bevacizumab for recurrent MB/central nervous system (CNS) primitive neuroectodermal tumor (PNET).

METHODS

Patients with relapsed/refractory MB or CNS PNET were randomly assigned to receive TMZ (150 mg/m² /day PO on days 1-5) and irinotecan (50 mg/m² /day IV on days 1-5) with or without bevacizumab (10 mg/kg IV on days 1 and 15).

RESULTS

One hundred five patients were eligible and treated on study. Median OS was 13 months in the standard arm and 19 months with the addition of bevacizumab; median event-free survival (EFS) was 6 months in the standard arm and 9 months with the addition of bevacizumab. The hazard ratio for death from the stratified relative-risk regression model is 0.63. Overall, 23 patients completed 12 courses of planned protocol therapy, 23% (12/52) in the experimental arm with bevacizumab versus 21% (11/53) in the standard arm. Toxicity profiles were comparable in both treatment arms. The estimate of the incidence of feasibility events associated with the bevacizumab arm is three of 52 (5.8%) (95% CI 1.2-16%). Events included myelosuppression, electrolyte abnormalities, diarrhea, and elevated transaminases. One intracranial hemorrhage event was observed in each arm.

CONCLUSION

The addition of bevacizumab to TMZ/irinotecan significantly reduced the risk of death in children with recurrent MB. The combination was relatively well tolerated in this heavily pretreated cohort. The three-drug regimen demonstrated a sufficient risk reduction to warrant further investigation.

GD2-directed bispecific trifunctional antibody outperforms dinutuximab beta in a murine model for aggressive metastasized neuroblastoma

Background

Neuroblastoma is the most common extracranial solid tumor of childhood. Patients with high-risk disease undergo extremely aggressive therapy and nonetheless have cure rates below 50%. Treatment with the ch14.18 monoclonal antibody (dinutuximab beta), directed against the GD2 disialoganglioside, improved 5-year event-free survival in high-risk patients when administered in postconsolidation therapy and was recently implemented in standard therapy. Relapse still occurred in 57% of these patients, necessitating new therapeutic options. Bispecific trifunctional antibodies (trAbs) are IgG-like molecules directed against T cells and cancer surface antigens, redirecting T cells (via their CD3 specificity) and accessory immune cells (via their functioning Fc-fragment) toward tumor cells. We sought proof-of-concept for GD2/CD3-directed trAb efficacy against neuroblastoma.

Methods

We used two GD2-specific trAbs differing only in their CD3-binding specificity: EKTOMUN (GD2/human CD3) and SUREK (GD2/mouse Cd3). This allowed trAb evaluation in human and murine experimental settings. Tumor-blind trAb and the ch14.18 antibody were used as controls. A coculture model of human peripheral blood mononuclear cells (PBMCs) and neuroblastoma cell lines was established to evaluate trAb antitumor efficacy by assessing expression of T-cell surface markers for activation, proinflammatory cytokine release and cytotoxicity assays. Characteristics of tumor-infiltrating T cells and response of neuroblastoma metastases to SUREK treatment were investigated in a syngeneic immunocompetent neuroblastoma mouse model mimicking minimal residual disease.

Results

We show that EKTOMUN treatment caused effector cell activation and release of proinflammatory cytokines in coculture with neuroblastoma cell lines. Furthermore, EKTOMUN mediated GD2-dependent cytotoxic effects in human neuroblastoma cell lines in coculture with PBMCs, irrespective of the level of target antigen expression. This effect was dependent on the presence of accessory immune cells. Treatment with SUREK reduced the intratumor Cd4/Cd8 ratio and activated tumor infiltrating T cells in vivo. In a minimal residual disease model for neuroblastoma, we demonstrated that single-agent treatment with SUREK strongly reduced or eliminated neuroblastoma metastases in vivo. SUREK as well as EKTOMUN demonstrated superior tumor control compared with the anti-GD2 antibody, ch14.18.

Conclusions

Here we provide proof-of-concept for EKTOMUN preclinical efficacy against neuroblastoma, presenting this bispecific trAb as a promising new agent to fight neuroblastoma.

Nanoliposomal Irinotecan and Metronomic Temozolomide for Patients With Recurrent Glioblastoma: BrUOG329, A Phase I Brown University Oncology Research Group Trial

BACKGROUND

Liposomal formulations may improve the solubility and bioavailability of drugs potentially increasing their ability to cross the blood-brain barrier. We performed a phase I study to determine the maximum tolerated dose and preliminary efficacy of pegylated nanoliposomal irinotecan (nal-IRI)+metronomic temozolomide (TMZ) in patients with recurrent glioblastoma.

PATIENTS AND METHODS

Patients with glioblastoma who progressed after at least 1 line of therapy were eligible. All patients received TMZ 50 mg/m2/d until disease progression. Three dose levels of nal-IRI were planned, 50, 70, and 80 mg/m2, intravenously every 2 weeks. Patients were accrued in a 3+3 design. The study included a preliminary assessment after the first 13 evaluable patients. The trial would be terminated early if 0 or 1 responses were observed in these patients.

RESULTS

Twelve patients were treated over 2 dose levels (nal-IRI 50 and 70 mg/m2). At dose level 2, nal-IRI 70 mg/m2, 2 of 3 patients developed dose-limiting toxicities including 1 patient who developed grade 4 neutropenia and grade 3 diarrhea and anorexia and 1 patient with grade 3 diarrhea, hypokalemia fatigue, and anorexia. Accrual to dose level 1 was expanded to 9 patients. The Drug Safety Monitoring Board (DSMB) reviewed the data of the initial 12 patients-there were 0/12 responses (0%) and the median progression-free survival was 2 months and accrual was halted.

CONCLUSIONS

The maximum tolerated dose of nal-IRI was 50 mg/m2 every 2 weeks with TMZ 50 mg/m2/d. The dose-limiting toxicities were diarrhea and neutropenia. No activity was seen at interim analysis and the study was terminated.

Immunotherapeutic Strategies for Neuroblastoma: Present, Past and Future

Neuroblastoma is the most common extracranial pediatric solid tumor with a heterogeneous clinical course, ranging from spontaneous regression to metastatic disease and death, irrespective of intensive chemotherapeutic regimen. On the basis of several parameters, children affected by neuroblastoma are stratified into low, intermediate and high risk. At present, more than 50% of high-risk patients with metastatic spread display an overall poor long-term outcome also complicated by devastating long-term morbidities. Thus, novel and more effective therapies are desperately needed to improve lifespan of high-risk patients. In this regard, adoptive cell therapy holds great promise and several clinical trials are ongoing, demonstrating safety and tolerability, with no toxicities. Starting from the immunological and clinical features of neuroblastoma, we here discuss the immunotherapeutic approaches currently adopted for high-risk patients and different innovative therapeutic strategies currently under investigation. The latter are based on the infusion of natural killer (NK) cells, as support of consolidation therapy in addition to standard treatments, or chimeric antigen receptor (CAR) T cells directed against neuroblastoma associated antigens (e.g., disialoganglioside GD2). Finally, future perspectives of adoptive cell therapies represented by γδ T lymphocyes and CAR NK cells are envisaged.

Phase II study of temozolomide and topotecan (TOTEM) in children with relapsed or refractory extracranial and central nervous system tumors including medulloblastoma with post hoc Bayesian analysis: A European ITCC study

AIM

To assess objective response after two cycles of temozolomide and topotecan (TOTEM) in children with refractory or relapsed miscellaneous extracranial solid and central nervous system (CNS) tumors, including medulloblastoma and primitive neuroectodermal tumors (PNET).

PROCEDURE

Multicenter, nonrandomized, phase 2 basket trial including children with solid tumors, completed by a one-stage design confirmatory cohort for medulloblastoma, and an exploratory cohort for PNET. Main eligibility criteria were refractory/relapsed measurable disease and no more than two prior treatment lines. Temozolomide was administered orally at 150 mg/m² /day followed by topotecan at 0.75 mg/m² /day intravenously for five consecutive days every 28 days. Tumor response was assessed every two cycles according to WHO criteria and reviewed independently.

RESULTS

Thirty-two patients were enrolled and treated in the miscellaneous solid tumor and 33 in the CNS strata; 20 patients with medulloblastoma and six with PNET were included in the expansion cohorts. The median age at inclusion was 10.0 years (range, 0.9-20.9). In the basket cohorts, confirmed complete and partial responses were observed in one glioma, four medulloblastoma, and one PNET, leading to the extension. The overall objective response rate (ORR) in medulloblastoma was 28% (95% CI, 12.7-47.2) with 1/29 complete and 7/29 partial responses, those for PNET 10% (95% CI, 0.3-44.5). Post hoc Bayesian analysis estimates that the true ORR in medulloblastoma is probably between 20% and 30% and below 20% in PNET. The most common treatment-related toxicities of the combination therapy were hematologic.

CONCLUSIONS

Temozolomide-topotecan results in significant ORR in children with recurrent and refractory medulloblastoma with a favorable toxicity profile.

Feasibility and Safety of Treosulfan, Melphalan, and Thiotepa-Based Megachemotherapy with Autologous or Allogeneic Stem Cell Transplantation in Heavily Pretreated Children with Relapsed or Refractory Neuroblastoma

The prognosis of resistant or relapsing children with neuroblastoma remains very poor, and the search for new therapies is ongoing. In this analysis, we assessed the toxicity of a treosulfan, melphalan, and thiotepa (TMT) regimen in 17 children with recurrent or refractory neuroblastoma who underwent stem cell transplantation (SCT). For allogeneic SCT, fludarabine and antithymocyte globulin were added. The stem cell source was autologous in 8 patients, haploidentical in 8 patients, and a matched unrelated donor in 1 patient. The reported nonhematologic toxicities included grade 3 mucositis, grade 1 to 3 hypertransaminasemia, and in 3 patients, veno-occlusive disease. No neurologic, cardiac, or dermatologic toxicities were observed. The probability of overall survival (OS) in patients with primary resistance was superior to that in patients with relapsed disease (100% versus 22.6%; P = .046). Post-transplantation dinutuximab beta immunotherapy was associated with superior 5-year OS (66.7% versus 11.4%; P = .0007). The use of an allogeneic donor, previous autologous SCT with busulfan and melphalan, and pretreatment with high-dose metaiodobenzylguanidine therapy demonstrated no effect on outcomes. In 4 patients, TMT megatherapy alone was enough to achieve complete remission. The TMT conditioning regimen was well tolerated in heavily pretreated patients with neuroblastoma. The manageable toxicity and addition of new anticancer drugs with optional post-SCT immunotherapy or chemotherapy support further trials with the TMT regimen in patients with neuroblastoma.

Registration-directed phase 1/2 trial of irinotecan for pediatric solid tumors

BACKGROUND

Although irinotecan hydrochloride (IRI) is a promising chemotherapeutic agent for pediatric solid tumors, its indications had been off-label in the USA, EU and Japan. Therefore, we conducted a phase 1/2 trial of IRI monotherapy in a registration-directed setting.

METHODS

Children aged 2-18 years with solid tumors who were either refractory to or relapsed after standard chemotherapy were enrolled. Phase 1 was a conventional dose escalation study to determine the dose-limiting toxicity (DLT) and the recommended dose. IRI was given i.v. on days 1, 2, 3 and 8, 9, 10 in up to eight, 21 day cycles.

RESULTS

The starting dose (40 mg/m² /day) was determined to be the recommended dose because the next higher dose level (45 mg/m² /day) resulted in two cases of DLT. Seventeen children (11 in phase 1 and six in phase 2) with a refractory solid tumor received IRI. Of the 12 patients treated with 40 mg/m² /day, seven (58.3%) achieved a stable disease condition for >8 weeks.

CONCLUSIONS

The RD of IRI in this treatment schedule was 40 mg/m² /day. IRI did not cause tumor shrinkage but might help to stabilize refractory pediatric solid tumors. Based on the accumulating evidence from international studies of the efficacy of IRI against refractory pediatric solid tumors, the Japanese regulatory authority approved its use for this indication in 2011.

A systematic review of re-induction chemotherapy for children with relapsed high-risk neuroblastoma

BACKGROUND

Despite aggressive multimodal therapy, >50% of children with high-risk neuroblastoma (HRNB) relapse. Survival after relapse is rare, and no consensus currently exists on the most effective therapy.

OBJECTIVE

To conduct a systematic review of the literature on effectiveness of re-induction chemotherapy in children with relapsed HRNB.

METHODS

Database searches were performed to identify studies looking at response to 1st line chemotherapy for children >12 months at diagnosis with first relapse of HRNB. Studies not reporting separate outcomes for HRNB patients or of refractory patients only were excluded. Two independent reviewers extracted the data and assessed study quality using a modified Newcastle-Ottawa tool.

RESULTS

Nine studies were identified fitting the inclusion criteria. All except one were single arm cohorts, and two were retrospective database reviews from single centres. One was a multicentre randomised controlled trial. All used a version of the validated International Neuroblastoma Response Criteria with 8 recording best ever response and 1 at a specified time, and 5 had central review. The proportion of relapsed patients varied from 24 to 100% with 30-93% receiving upfront myeloablative therapy. The response rate varied from 6 to 64%; however, because of heterogeneity, studies were not directly comparable, and no single treatment emerged as the most effective re-induction therapy.

CONCLUSIONS

To date, there is no clear superior re-induction therapy for 1st relapse of HRNB. Randomised controlled trials with separate arms for relapsed versus refractory disease are needed to determine optimal re-induction chemotherapy to act as a backbone for testing newer targeted agents.

Phase II Trial of Alisertib in Combination with Irinotecan and Temozolomide for Patients with Relapsed or Refractory Neuroblastoma

PURPOSE

In phase I testing, alisertib tablets with irinotecan and temozolomide showed significant antitumor activity in patients with neuroblastoma. This study sought to confirm activity of this regimen; evaluate an alisertib oral solution; and evaluate biomarkers of clinical outcomes.

PATIENTS AND METHODS

We conducted a two-stage phase II trial of alisertib tablets (60 mg/m2/dose × 7 days), irinotecan (50 mg/m2/dose i.v. × 5 days), and temozolomide (100 mg/m2/dose orally × 5 days) in patients with relapsed or refractory neuroblastoma. The primary endpoint was best objective response. A separate cohort was treated with alisertib at 45 mg/m2 using oral solution instead of tablets. Exploratory analyses sought to identify predictors of toxicity, response, and progression-free survival (PFS) using pooled data from phase I, phase II, and oral solution cohorts.

RESULTS

Twenty and 12 eligible patients were treated in the phase II and oral solution cohorts, respectively. Hematologic toxicities were the most common adverse events. In phase II, partial responses were observed in 19 evaluable patients (21%). The estimated PFS at 1 year was 34%. In the oral solution cohort, 3 patients (25%) had first cycle dose-limiting toxicity (DLT). Alisertib oral solution at 45 mg/m2 had significantly higher median C max and exposure compared with tablets at 60 mg/m2. Higher alisertib trough concentration was associated with first cycle DLT, whereas MYCN amplification was associated with inferior PFS.

CONCLUSIONS

This combination shows antitumor activity, particularly in patients with MYCN nonamplified tumors. Data on an alisertib oral solution expand the population able to be treated with this agent.

Managing local-regional failure in children with high-risk neuroblastoma: A single institution experience

BACKGROUND

Intensification of systemic therapy for high-risk neuroblastoma (HRNB) has resulted in improved local control and overall survival (OS) leaving potential for de-escalation of primary site radiotherapy. The utility of primary site de-escalation should be evaluated in the context of potential for successful local-regional salvage. We evaluated salvage strategies and outcomes in patients with HRNB with local-regional recurrence as a component of first failure.

METHODS

Twenty of 89 patients with HRNB experienced local-regional recurrence as a component of first relapse after chemotherapy, radiotherapy, surgery, and stem cell transplant from 1997 to 2013. We reviewed salvage therapy strategies and disease control, and report on the impact of local therapy as salvage for local-regional relapse.

RESULTS

Six of 20 patients with local-regional failure (LRF) were alive after a median follow-up of 13 years (range, 0.9-25.2 years). Median OS was 4.6 years (95% CI, 0.6 to not reached) versus 0.6 years (95% CI, 0.05-2.6) after LRF with and without distant failure, respectively (P = 0.03). OS in patients receiving salvage radiotherapy was comparable to those receiving initial adjuvant but no salvage radiotherapy. Time to first failure and death was significantly impacted by the intensity of frontline systemic therapy (P = 0.03). Salvage radiotherapy reduced the hazard for subsequent LRF (hazard ratio 0.3, 95% CI 0.1-0.9, P = 0.04) but not OS (P = 0.07).

CONCLUSIONS

Our study highlights the potential of local control strategies at first failure in patients with LRF when primary site radiotherapy was initially omitted, and delineates potential selection factors which may further improve the therapeutic ratio.

Novel Therapies for Relapsed and Refractory Neuroblastoma

While recent increases in our understanding of the biology of neuroblastoma have allowed for more precise risk stratification and improved outcomes for many patients, children with high-risk neuroblastoma continue to suffer from frequent disease relapse, and despite recent advances in our understanding of neuroblastoma pathogenesis, the outcomes for children with relapsed neuroblastoma remain poor. These children with relapsed neuroblastoma, therefore, continue to need novel treatment strategies based on a better understanding of neuroblastoma biology to improve outcomes. The discovery of new tumor targets and the development of novel antibody- and cell-mediated immunotherapy agents have led to a large number of clinical trials for children with relapsed neuroblastoma, and additional clinical trials using molecular and genetic tumor profiling to target tumor-specific aberrations are ongoing. Combinations of these new therapeutic modalities with current treatment regimens will likely be needed to improve the outcomes of children with relapsed and refractory neuroblastoma.

Autophagy modulates temozolomide-induced cell death in alveolar Rhabdomyosarcoma cells

Rhabdomyosarcoma (RMS) is a muscle-derived tumor. In both pre-clinical and clinical studies Temozolomide (TMZ) has been recently tested against RMS; however, the precise mechanism of action of TMZ in RMS remains unclear. Here we demonstrate that TMZ decreases the cell viability of the RH30 RMS and C2C12 cell line, where cells display evidence of mitochondrial outer membrane permeability. Interestingly, the C2C12 mouse myoblast line was relatively more resistant to TMZ-induced apoptosis. Moreover, we observed that TMZ activated biochemical and morphological markers of autophagy in both cell lines. Autophagy inhibition in both RH30 and C2C12 cells significantly increased TMZ-induced cell death. In RH30 cells, TMZ increased Mcl-1 and Bax protein expression compared to corresponding time match controls while in C2C12 Mcl-1, Bcl-2, Bcl-XL, and Bax protein expression were not changed. Baf-A1 co-treatment with TMZ significantly decrease Mcl-1 expression compared to TMZ while increase Bax expression in C2C12 cells (Bcl2 and Bcl-XL do not significantly change in Baf-A1/TMZ co-treatment). Using a three-dimensional (3D) C2C12 and RH30 culture model we demonstrated that TMZ is significantly more toxic in RH30 cells (live/dead assay). Additionally, we have observed in our 3D culture model that TMZ induced both apoptosis (cleavage of PARP) and autophagy (LC3-puncta and localization of LC3/p62). Therefore, our data demonstrate that TMZ induces simultaneous autophagy and apoptosis in both RH30 and C2C12 cells in 2D and 3D culture model, where RH30 cells are more sensitive to TMZ-induced death. Furthermore, autophagy serves to protect RH30 cells from TMZ-induced death.

The addition of cixutumumab or temozolomide to intensive multiagent chemotherapy is feasible but does not improve outcome for patients with metastatic rhabdomyosarcoma: A report from the Children's Oncology Group

BACKGROUND

The outcome for patients with metastatic rhabdomyosarcoma (RMS) remains poor. A previous Children's Oncology Group (COG) study (ARST0431) for patients with metastatic RMS produced no improvement in outcome using multiple cytotoxic agents in a dose-intensive manner. The authors report results from the subsequent COG study (ARST08P1), which evaluated the feasibility and efficacy of adding cixutumumab (insulin-like growth factor-1 monoclonal antibody) or temozolomide to the ARST0431 intensive chemotherapy backbone.

METHODS

Two nonrandomized pilot studies were conducted in patients with metastatic RMS, initially to determine feasibility, and both pilots were expanded to assess efficacy. All patients received 54 weeks of chemotherapy, including vincristine/irinotecan, interval-compressed vincristine/doxorubicin/cyclophosphamide alternating with ifosfamide/etoposide, and vincristine/dactinomycin/cyclophosphamide. In pilot 1, patients received intravenous cixutumumab (3, 6, or 9 mg/kg) once weekly throughout therapy. In pilot 2, patients received oral temozolomide (100 mg/m² ) daily for 5 days with irinotecan. All patients received radiation to the primary tumor and to metastatic sites.

RESULTS

One hundred sixty-eight eligible patients were enrolled (97 on pilot 1 and 71 on pilot 2). Most patients were aged ≥10 years (73%), with alveolar histology (70%), and had bone and/or bone marrow metastases (59%). Toxicities observed in each pilot were similar to those reported on ARST0431. With a median follow-up of 2.9 years, the 3-year event-free survival rate was 16% (95% confidence interval, 7%-25%) with cixutumumab and 18% (95% confidence interval, 2%-35%) with temozolomide.

CONCLUSIONS

The addition of cixutumumab or temozolomide to intensive multiagent chemotherapy for metastatic RMS was safe and feasible. Neither agent improved outcome compared with the same chemotherapy that was used on ARST0431.

Vincristine, irinotecan, and temozolomide treatment for refractory/relapsed pediatric solid tumors: A single center experience

BACKGROUND

Although the survival of pediatric cancer has increased dramatically in the last decades, the survival of refractory, relapsed, and metastatic cases is still dismal. The combination of irinotecan and temozolomide has shown activity against refractory/relapsed pediatric solid tumors.

METHOD

Thirty-four children with refractory/relapsed solid tumors who had previously been heavily pretreated and who were given vincristine, irinotecan, and temozolomide as third- or further line chemotherapy during 2004-2015 were evaluated.

RESULTS

Patients were diagnosed with Ewing sarcoma (n = 15), rhabdomyosarcoma (n = 8), neuroblastoma (n = 8), osteosarcoma (n = 2), and Wilms' tumor (n = 1). Thirty patients presented with disease progression on therapy and the other four presented with relapsing. A total of 141 cycles were administered. Radiotherapy was used in 17 patients and surgery in 4 as local therapy. Among all patients, 6 had complete response, 3 had partial response, 14 had stable disease, and 11 had progressive disease. The objective response was 26.4% (complete response + partial response) and median survival duration was six months. The first and second year overall survival rates were 22.3% and 16.8%. The objective response in Ewing sarcoma patients was 40%. Diarrhea was the most common toxicity and 14 (10%) courses were associated with grade 3-4 diarrhea.

CONCLUSIONS

In heavily pretreated patients with refractory/relapsed solid tumors, the vincristine, irinotecan, and temozolomide regimen seemed promising in Ewing sarcoma patients and was well tolerated.

Neuroblastoma: clinical and biological approach to risk stratification and treatment

Neuroblastoma is the most common extra-cranial solid tumor of childhood and the most common in the first year of life. It is a unique malignancy in that infants often present with either localized or metastatic disease that can spontaneously regress without intervention while older children can succumb to the disease after months to years of arduous therapy. Given this wide range of outcomes, the International Neuroblastoma Risk Group was created to stratify patients based on presenting characteristics and tumor biology in order to guide intensity of treatment strategies. The goal has been to decrease therapy for low-risk patients to avoid long-term complications while augmenting and targeting therapies for high-risk patients to improve overall survival. The international risk stratification depends on age, stage, histology, MYCN gene amplification status, tumor cell ploidy and segmental chromosomal abnormalities. Treatment for asymptomatic low-risk patients with an estimated survival of > 98% is often observation or surgical resection alone, whereas intermediate-risk patients with an estimated survival of > 90% require moderate doses of response-adjusted chemotherapy along with resection. High-risk patients undergo multiple cycles of combination chemotherapy before surgery, followed by consolidation with myeloablative autologous hematopoietic stem cell transplantation and local radiation and finally immunotherapy with differentiation therapy as maintenance phase. With this approach, outcome for patients with neuroblastoma has improved, as the field continues to expand efforts in more targeted therapies for high-risk patients.

Investigational drugs in phase II clinical trials for the treatment of neuroblastoma

INTRODUCTION

Neuroblastoma (NB) is an embryonal tumor originating from undifferentiated neural crest cell, highly heterogeneous ranging from spontaneous regression to progression despite multimodal treatments. Approximately, 20% of patients are refractory to frontline therapy and 50% will relapse/progress after an initial response. The overall five year survival for high-risk neuroblastoma ranges from 35-45%. Despite enhanced understanding of NB biology and the addition of myeloablative chemotherapy, isotretinoin and immunotherapy, survival for high risk NB remains less than 50%. Areas covered: This review summarizes and gives a critical overview of phase II trials investigating therapies for relapsed-refractory and high risk neuroblastoma. Expert opinion: Several novel molecules have been developed and are currently under investigation for the treatment of NB. The trend of novel targeted agents is one towards individualized, tailored therapy, based on the molecular and biological differences that characterize tumors that seem similar based solely on histological analysis. The task of developing new molecules is particularly difficult for NB, given the recurrent development of new patterns of drug resistance. However, even if current research is focused towards identifying the best treatments for each children and young adult with a NB defined disease, a deeper knowledge of the molecular biology and genetics is needed.

MYCN-amplified stage 2/3 neuroblastoma: excellent survival in the era of anti-GD2 immunotherapy

High-risk neuroblastoma (HR-NB) includes MYCN-amplified stage 2/3, but reports covering anti-G_D2 immunotherapy, which recently became standard for HR-NB, do not provide details on this subset. We now report on all 20 MYCN-amplified stage 2/3 patients who received induction chemotherapy at our center during the era of consolidation with anti-G_D2 antibody 3F8/ granulocyte-macrophage colony-stimulating factor (GM-CSF) (2000-2015). Early in this period, consolidation included autologous stem-cell transplantation (ASCT). Event-free survival (EFS) and overall survival (OS) were estimated using Kaplan-Meier analyses. With induction, 19/20 (95%) patients achieved complete/very good partial remission (CR/VGPR) but one had progressive disease with early death. One responder did not receive consolidation and died of relapse. Five-year post-diagnosis EFS/OS rates for all 20 patients were 72%/84%. The 18 CR/VGPR patients who received consolidation had EFS/OS 81%/94% at five years from starting 3F8/GM-CSF: 4/4 ASCT patients remained relapse-free, while 11/14 non-ASCT patients remained relapse-free and two of the three relapsed patients achieved 2^nd CR (consolidated by retreatment with 3F8/GM-CSF) and remained in 2^nd CR at 36+ and 95+ months post-relapse. The 14 non-ASCT patients had EFS/OS 73.5%/93% at five years from starting 3F8/GM-CSF. This subset appears to have a good prognosis with contemporary multi-modality therapy, possibly even without ASCT.

Combination of bevacizumab, irinotecan, and temozolomide for refractory or relapsed neuroblastoma: Results of a phase II study

BACKGROUND

The rationale for studying the combination of bevacizumab, irinotecan, and temozolomide (BIT) in neuroblastoma (NB) is based on the following: (i) vascular endothelial growth factor (VEGF) expression is associated with an aggressive phenotype, (ii) anti-VEGF antibody bevacizumab enhances irinotecan-mediated suppression of NB xenografts, (iii) bevacizumab safety has been established in pediatric phase I studies, and (iv) irinotecan + temozolomide (IT) is a standard salvage chemotherapy.

PROCEDURE

We conducted a phase II study of BIT in patients with measurable/evaluable refractory or relapsed high-risk NB (www.clinicaltrials.gov, NCT01114555). Each cycle consisted of bevacizumab (15 mg/kg intravenously [IV]) on days 1 and 15 plus irinotecan (50 mg/m2 /day IV) and temozolomide (150 mg/m2 /day orally) on days 4-8. Patients could have previously received, but not relapsed on, IT. An early stopping rule mandated continuing therapy only if more than five patients of 27 evaluable patients achieved partial response (PR) or complete response (CR) after four cycles.

RESULTS

Thirty-three heavily pretreated patients (nine primary refractory; 24 relapsed) received one to eight cycles of BIT. Toxicities were expected and transient. Grade 4 toxicities were neutropenia (30%) and thrombocytopenia (24%). Grade 3 toxicities included hepatic transaminitis (15%), proteinuria (9%), and diarrhea (3%). Overall responses were as follows: three CR (all in prior IT-treated patients), 18 no response, and 12 progressive disease. Only one of 23 patients assessable for the early stopping rule regarding efficacy achieved PR/CR, so patient accrual was discontinued. Median progression-free survival and overall survival was 7.7 ± 1.7 and 31.5 ± 5.6 months, respectively; all patients continued anti-NB therapy post-BIT.

CONCLUSIONS

BIT was well tolerated, but the addition of bevacizumab did not improve response rates in resistant NB compared to historical data for IT.

Irinotecan-temozolomide with temsirolimus or dinutuximab in children with refractory or relapsed neuroblastoma (COG ANBL1221): an open-label, randomised, phase 2 trial

BACKGROUND

Outcomes for children with relapsed and refractory neuroblastoma are dismal. The combination of irinotecan and temozolomide has activity in these patients, and its acceptable toxicity profile makes it an excellent backbone for study of new agents. We aimed to test the addition of temsirolimus or dinutuximab to irinotecan-temozolomide in patients with relapsed or refractory neuroblastoma.

METHODS

For this open-label, randomised, phase 2 selection design trial of the Children's Oncology Group (COG; ANBL1221), patients had to have histological verification of neuroblastoma or ganglioneuroblastoma at diagnosis or have tumour cells in bone marrow with increased urinary catecholamine concentrations at diagnosis. Patients of any age were eligible at first designation of relapse or progression, or first designation of refractory disease, provided organ function requirements were met. Patients previously treated for refractory or relapsed disease were ineligible. Computer-based randomisation with sequence generation defined by permuted block randomisation (block size two) was used to randomly assign patients (1:1) to irinotecan and temozolomide plus either temsirolimus or dinutuximab, stratified by disease category, previous exposure to anti-GD2 antibody therapy, and tumour MYCN amplification status. Patients in both groups received oral temozolomide (100 mg/m² per dose) and intravenous irinotecan (50 mg/m² per dose) on days 1-5 of 21-day cycles. Patients in the temsirolimus group also received intravenous temsirolimus (35 mg/m² per dose) on days 1 and 8, whereas those in the dinutuximab group received intravenous dinutuximab (17·5 mg/m² per day or 25 mg/m² per day) on days 2-5 plus granulocyte macrophage colony-stimulating factor (250 μg/m² per dose) subcutaneously on days 6-12. Patients were given up to a maximum of 17 cycles of treatment. The primary endpoint was the proportion of patients achieving an objective (complete or partial) response by central review after six cycles of treatment, analysed by intention to treat. Patients, families, and those administering treatment were aware of group assignment. This study is registered with ClinicalTrials.gov, number NCT01767194, and follow-up of the initial cohort is ongoing.

FINDINGS

Between Feb 22, 2013, and March 23, 2015, 36 patients from 27 COG member institutions were enrolled on this groupwide study. One patient was ineligible (alanine aminotransferase concentration was above the required range). Of the remaining 35 patients, 18 were randomly assigned to irinotecan-temozolomide-temsirolimus and 17 to irinotecan-temozolomide-dinutuximab. Median follow-up was 1·26 years (IQR 0·68-1·61) among all eligible participants. Of the 18 patients assigned to irinotecan-temozolomide-temsirolimus, one patient (6%; 95% CI 0·0-16·1) achieved a partial response. Of the 17 patients assigned to irinotecan-temozolomide-dinutuximab, nine (53%; 95% CI 29·2-76·7) had objective responses, including four partial responses and five complete responses. The most common grade 3 or worse adverse events in the temsirolimus group were neutropenia (eight [44%] of 18 patients), anaemia (six [33%]), thrombocytopenia (five [28%]), increased alanine aminotransferase (five [28%]), and hypokalaemia (four [22%]). One of the 17 patients assigned to the dinutuximab group refused treatment after randomisation; the most common grade 3 or worse adverse events in the remaining 16 patients evaluable for safety were pain (seven [44%] of 16), hypokalaemia (six [38%]), neutropenia (four [25%]), thrombocytopenia (four [25%]), anaemia (four [25%]), fever and infection (four [25%]), and hypoxia (four [25%]); one patient had grade 4 hypoxia related to therapy that met protocol-defined criteria for unacceptable toxicity. No deaths attributed to protocol therapy occurred.

INTERPRETATION

Irinotecan-temozolomide-dinutuximab met protocol-defined criteria for selection as the combination meriting further study whereas irinotecan-temozolomide-temsirolimus did not. Irinotecan-temozolomide-dinutuximab shows notable anti-tumour activity in patients with relapsed or refractory neuroblastoma. Further evaluation of biomarkers in a larger cohort of patients might identify those most likely to respond to this chemoimmunotherapeutic regimen.

FUNDING

National Cancer Institute.

Overview and recent advances in the treatment of neuroblastoma

INTRODUCTION

Children with neuroblastoma have widely divergent outcomes, ranging from cure in >90% of patients with low risk disease to <50% for those with high risk disease. Recent research has shed light on the biology of neuroblastoma, allowing for more accurate risk stratification and treatment reduction in many cases, although newer treatment strategies for children with high-risk and relapsed neuroblastoma are needed to improve outcomes. Areas covered: Neuroblastoma epidemiology, diagnosis, risk stratification, and recent advances in treatment of both newly diagnosed and relapsed neuroblastoma. Expert commentary: The identification of newer tumor targets and of novel cell-mediated immunotherapy agents may lead to novel therapeutic approaches, and clinical trials for regimens designed to target individual genetic aberrations in tumors are underway. A combination of therapeutic modalities will likely be required to improve survival and cure rates for patients with high-risk neuroblastoma.

Clinical research on rare diseases of children: neuroblastoma

PURPOSE

Early access to new treatment options should not preclude accurate research planning, especially for rare diseases and fragile populations. Taking neuroblastoma as a model case, we analyzed the rationale supporting the search for future therapeutic strategies in the light of preclinical and clinical evidence.

METHODS

We reviewed ongoing randomized trials of pharmacological interventions for the treatment of neuroblastoma retrieved by searching ClinicalTrials.gov and the European Union Clinical Trials Registry (last update March 2016).

RESULTS

Our search identified four randomized clinical trial reports. We found poor evidence from preclinical and early clinical research supporting their rationale. Their methodology was questionable too.

CONCLUSIONS

The urgency to cover unmet needs in difficult clinical settings like rare diseases, particularly those involving fragile populations, cannot justify disorderly research approaches. Under these circumstances, clinical questions should be properly identified and addressed to protect patients and avoid wasteful research.

Neuroblastoma

Neuroblastoma is the most common extracranial solid tumour occurring in childhood and has a diverse clinical presentation and course depending on the tumour biology. Unique features of these neuroendocrine tumours are the early age of onset, the high frequency of metastatic disease at diagnosis and the tendency for spontaneous regression of tumours in infancy. The most malignant tumours have amplification of the MYCN oncogene (encoding a transcription factor), which is usually associated with poor survival, even in localized disease. Although transgenic mouse models have shown that MYCN overexpression can be a tumour-initiating factor, many other cooperating genes and tumour suppressor genes are still under investigation and might also have a role in tumour development. Segmental chromosome alterations are frequent in neuroblastoma and are associated with worse outcome. The rare familial neuroblastomas are usually associated with germline mutations in ALK, which is mutated in 10-15% of primary tumours, and provides a potential therapeutic target. Risk-stratified therapy has facilitated the reduction of therapy for children with low-risk and intermediate-risk disease. Advances in therapy for patients with high-risk disease include intensive induction chemotherapy and myeloablative chemotherapy, followed by the treatment of minimal residual disease using differentiation therapy and immunotherapy; these have improved 5-year overall survival to 50%. Currently, new approaches targeting the noradrenaline transporter, genetic pathways and the tumour microenvironment hold promise for further improvements in survival and long-term quality of life.

Lack of survival advantage with autologous stem-cell transplantation in high-risk neuroblastoma consolidated by anti-GD2 immunotherapy and isotretinoin

Since 2003, high-risk neuroblastoma (HR-NB) patients at our center received anti-G_D2 antibody 3F8/GM-CSF + isotretinoin – but not myeloablative therapy with autologous stem-cell transplantation (ASCT). Post-ASCT patients referred from elsewhere also received 3F8/GM-CSF + isotretinoin. We therefore accrued a study population of two groups treated during the same period and whose consolidative therapy, aside from ASCT, was identical. We analyzed patients enrolled in 1st complete/very good partial remission (CR/VGPR). Their event-free survival (EFS) and overall survival (OS) were calculated from study entry. Large study size allowed robust statistical analyses of key prognosticators including MYCN amplification, minimal residual disease (MRD), FCGR2A polymorphisms, and killer immunoglobulin-like receptor genotypes of natural killer cells. The 170 study patients included 60 enrolled following ASCT and 110 following conventional chemotherapy. The two cohorts had similar clinical and biological features. Five-year rates for ASCT and non-ASCT patients were, respectively: EFS 65% vs. 51% (p = .128), and OS 76% vs. 75% (p = .975). In multivariate analysis, ASCT was not prognostic and only MRD-negativity after two cycles of 3F8/GM-CSF correlated with significantly improved EFS and OS. Although a trend towards better EFS is seen with ASCT, OS is near identical. Cure rates may be similar, as close surveillance detects localized relapse and effective salvage treatments are applied. ASCT may not be needed to improve outcome when anti-G_D2 immunotherapy is used for consolidation after dose-intensive conventional chemotherapy.

Patient-derived mouse xenografts from pediatric liver cancer predict tumor recurrence and advise clinical management

Identification of new treatments for relapsing pediatric cancer is an unmet clinical need and a societal challenge. Liver cancer occurrence in infancy, 1.5 for million children per year, falls far below the threshold of interest for dedicated drug development programs, and this disease is so rare that it is very difficult to gather enough children into a phase II clinical trial. Here, we present the establishment of an unprecedented preclinical platform of 24 pediatric liver cancer patient-derived xenografts (PLC-PDXs) from 20 hepatoblastomas (HBs), 1 transitional liver cell tumor (TCLT), 1 hepatocellular carcinoma, and 2 malignant rhabdoid tumors. Cytogenetic array and mutational analysis of the parental tumors and the corresponding PLC-PDXs show high conservation of the molecular features of the parental tumors. The histology of PLC-PDXs is strikingly similar to that observed in primary tumors and recapitulates the heterogeneity of recurrent disease observed in the clinic. Tumor growth in the mouse is strongly associated with elevated circulating alpha-fetoprotein (AFP), low rate of necrosis/fibrosis after treatment, and gain of chromosome 20, all indicators of resistance to chemotherapy and poor outcome. Accordingly, the ability of a tumor to generate PLC-PDX is predictive of poor prognosis. Exposure of PLC-PDXs to standards of care or therapeutic options already in use for other pediatric malignancies revealed unique response profiles in these models. Among these, the irinotecan/temozolomide combination induced strong tumor regression in the TCLT and in a model derived from an AFP-negative relapsing HB.

CONCLUSION

These results provide evidence that PLC-PDX preclinical platform can strongly contribute to accelerate the identification and diversification of anticancer treatment for aggressive subtypes of pediatric liver cancer. (Hepatology 2016;64:1121-1135).

Initial Experience With Gallium-68 DOTA-Octreotate PET/CT and Peptide Receptor Radionuclide Therapy for Pediatric Patients With Refractory Metastatic Neuroblastoma

RATIONALE

Pediatric patients with refractory neuroblastoma have limited therapeutic options. Neuroblastoma may express somatostatin receptors (SSTRs) allowing imaging with 68Ga-DOTA-Octreotate (GaTATE) positron emission tomography/computed tomography (PET/CT) and peptide receptor radionuclide therapy (PRRT). We reviewed our experience with this theranostic combination.

MATERIALS AND METHODS

GaTATE studies (8 patients; 2 to 9 years old) were reviewed and compared with 123I-MIBG or posttreatment 131I-MIBG studies. Immunohistochemistry (IHC) for SSTR subtype 2 was performed in 5 patients. Four patients received PRRT.

RESULTS

GaTATE PET showed additional disease in 38% (3/8 patients), and upstaged 1 patient by detecting marrow involvement. IHC detected SSTR 2 in all patients assessed. Six patients were deemed suitable for PRRT on imaging. Four patients received 17 cycles of palliative PRRT (10 111In-DOTATATE; 5 177Lu-DOTATATE; 1 combined 111In and 177Lu-DOTATATE; 1 combined 177Lu and 90Y-DOTATATE) with no significant toxicity attributed to PRRT. All had objective responses. Two survivors are now 40 and 56 months from PRRT commencement.

CONCLUSIONS

GaTATE PET was positive in a high proportion of patients with refractory neuroblastoma, correlating with SSTR 2 on IHC, with additional disease identified compared with MIBG imaging. PRRT seems safe, feasible, with responses observed in patients with progression despite multimodality treatment. These data support ongoing clinical trials in such patients.

Trametinib-induced Left Ventricular Dysfunction in a Child With Relapsed Neuroblastoma

The MEK inhibitor trametinib is globally approved for metastatic melanoma harboring BRAF mutations. There are no reports thus far on its use in children. Exome sequencing on a relapsed tumor sample from an 11-year-old male with progressive, multiply relapsed stage 4 neuroblastoma revealed NRASQ61K mutation. After demonstration of normal cardiac function, he was started on oral trametinib. On day 13 of treatment, echocardiogram showed moderate left ventricular dysfunction. Trametinib was discontinued on day 15 and oral lisinopril was started. Left ventricular function recovered to baseline 37 days after discontinuing trametinib. However, neuroblastoma showed further progression.

Primary Multiple Pulmonary Primitive Neuroectodermal Tumor: Case Report and Literature Review

Primitive neuroectodermal tumors (PNETs) arising directly from the lung are extremely rare but particularly aggressive neoplasms. Although thoracic PNET usually develops on the chest wall, there have been reports of primary Ewing sarcoma/PNET of the lung.We present the case of a 16-year-old male with PNET diagnosed following histologic and immunohistochemical examination of a video-assisted thoracic surgical biopsy. As typically occurring for these tumors, the diagnosis was initially delayed in our patient and prognosis was poor despite aggressive surgical resection and postoperative chemotherapy. We attempted to explore the use of targeted pharmacotherapy through high-throughput sequencing in this case. We found that this treatment using Avastin and Cetuximab could provide a new therapeutic direction for PNET.PNENTs arising from the lung parenchyma without pleural or chest wall involvement are extremely rare. Although uncommon, if the pathological features are similar to Ewing sarcoma, PNENTs should be kept in mind, and the target therapy may be a potent treatment for this disease.

Prolonged progression-free survival after consolidating second or later remissions of neuroblastoma with Anti-GD2 immunotherapy and isotretinoin: a prospective Phase II study

Relapse of high-risk neuroblastoma (HR-NB) is deemed invariably fatal yet increasing numbers of HR-NB patients achieve a second complete/very good partial remission (CR/VGPR), hence the urgency to find a successful consolidative therapy. Identifying efficacy in patients without assessable disease, however, is problematic. We report the first study providing outcome data for this group of patients with poor prognosis. To prevent another relapse, HR-NB patients in second or later CR/VGPR received the anti-G_D2 murine antibody 3F8 plus granulocyte-macrophage colony-stimulating factor plus isotretinoin in a Phase II trial. Upon meeting the target aim for progression-free survival (PFS) in the initial cohort of 33 patients, the trial was amended to allow patients who developed human anti-mouse antibody (HAMA) to receive rituximab to ablate HAMA with or without low-dose maintenance chemotherapy until immunotherapy could resume. For the total of 101 study patients, 5-year PFS and overall survival (OS) rates were 33% ± 5% and 48% ± 5%, respectively. Among the 33 long-term progression-free survivors, 19 had MYCN amplification, 19 had previously received anti-G_D2 immunotherapy plus isotretinoin (as first-line therapy), and 15 never received maintenance chemotherapy. In a multivariate analysis of prognostic factors, only absence of minimal residual disease in bone marrow after 2 cycles of immunotherapy and before initiation of isotretinoin or anti-HAMA therapy was significantly favorable for both PFS and OS. Therefore, long-term PFS is possible for HR-NB patients who achieve at least a second CR/VGPR and receive consolidation that includes anti-G_D2 immunotherapy plus isotretinoin, even if the patients received these biological treatments before relapse. Results from this prospective study will aid in the development of future Phase II studies for this growing ultra high-risk patient population.

Additional Therapies to Improve Metastatic Response to Induction Therapy in Children With High-risk Neuroblastoma

Children with high-risk neuroblastoma who fail to achieve adequate metastatic response after induction chemotherapy have dismal outcome and new therapeutic strategies are needed. However, timing of introduction of novel agents still remains under discussion. Given an increase in number of phase I-II studies of molecularly targeted drugs in neuroblastoma, it is crucial to determine, as early as possible, which patients may be suitable candidates for new therapeutic strategies. This single-center retrospective analysis of patients with high-risk neuroblastoma showed that the addition of conventional chemotherapy improved the quality of metastatic response only for the group of patients with partial response. It is therefore proposed to develop stratification criteria for those patients very unlikely to benefit from a plethora of additional lines of treatment, but might benefit from introduction of novel agents.

Vincristine and irinotecan in children with relapsed hepatoblastoma: a single-institution experience

PURPOSE

This study was to determine the efficacy of vincristine and irinotecan in children with relapsed hepatoblastoma (HB).

METHODS

A total of 10 patients with relapsed HB were enrolled. Three patients were excluded. Patients received irinotecan 50 mg/m(2)/day, day 1-5 and vincristine 1.5 mg/m(2)/day, day 1, repeated every 3 weeks. The maximum cycles were eight. Reevaluation of tumor was performed every two cycles. The primary outcome was the rate of complete resection. Secondary outcomes were event-free survival (EFS) and overall survival (OS).

RESULTS

Of the seven patients assessable for response, one patient with normal AFP level showed a progressive disease and withdrew. He finally died 6 months later. Four had PR, all of them underwent a second surgery and achieved complete resection. Two patients had SD, one patient relapsed 6 months after orthotopic liver transplantation and died, the other one undergoing surgery had micro margin positive, he relapsed again but alive. The rate of complete resection was 71.4% (including orthotopic liver transplantation). The 2-year EFS and OS for the whole group were 57.1% (95% CI, 12.7% to 34.2%) and 71.4% (95% CI, 16.39% to 37.4%), respectively.

CONCLUSIONS

The combination of irinotecan and vincristine has a significant antitumor activity and acceptable toxicity in children with relapsed HB.

Phase 1 evaluation of EZN-2208, a polyethylene glycol conjugate of SN38, in children adolescents and young adults with relapsed or refractory solid tumors

BACKGROUND

EZN-2208 is a water-soluble PEGylated conjugate of the topoisomerase inhibitor SN38, the active metabolite of irinotecan. Compared to irinotecan, EZN-2208 has a prolonged half-life permitting extended exposure to SN38. EZN-2208 has demonstrated clinical tolerability and antitumor activity in adults with advanced solid tumors. This Phase 1 study evaluated the safety, pharmacokinetics, and preliminary antitumor activity of EZN-2208 in children with relapsed or refractory solid tumors.

PROCEDURE

EZN-2208 was administered as a 1-hour intravenous infusion once every 21 days at five dose levels (12-30 mg/m(2) ). Filgrastim or pegfilgrastim was administered 24-48 hours after treatment with EZN-2208. The rolling-six design was used for dose determination.

RESULTS

Thirty eligible patients (15 females; median [range] age 11.5 years [2-21 years]) were treated with EZN-2208. Dose-limiting diarrhea occurred in one patient receiving 16 mg/m(2) and dose-limiting dehydration was seen in one patient receiving 24 mg/m(2) . At dose levels above 16 mg/m(2) , Grade ≥3 myelosuppression was demonstrated in the majority of patients. Additional adverse events included nausea, vomiting, and fatigue. The maximum tolerated dose was identified as 24 mg/m(2) due to dose-limiting thrombocytopenia in two patients receiving 30 mg/m(2) . Two of nine patients with neuroblastoma who were evaluable for response had partial responses. Five patients (four with neuroblastoma) remained on study for ≥8 cycles.

CONCLUSIONS

EZN-2208 was generally well-tolerated and was associated with clinical benefit in patients with neuroblastoma.

Molecular profiling of childhood cancer: Biomarkers and novel therapies

BACKGROUND

Technological advances including high-throughput sequencing have identified numerous tumor-specific genetic changes in pediatric and adolescent cancers that can be exploited as targets for novel therapies.

SCOPE OF REVIEW

This review provides a detailed overview of recent advances in the application of target-specific therapies for childhood cancers, either as single agents or in combination with other therapies. The review summarizes preclinical evidence on which clinical trials are based, early phase clinical trial results, and the incorporation of predictive biomarkers into clinical practice, according to cancer type.

MAJOR CONCLUSIONS

There is growing evidence that molecularly targeted therapies can valuably add to the arsenal available for treating childhood cancers, particularly when used in combination with other therapies. Nonetheless the introduction of molecularly targeted agents into practice remains challenging, due to the use of unselected populations in some clinical trials, inadequate methods to evaluate efficacy, and the need for improved preclinical models to both evaluate dosing and safety of combination therapies.

GENERAL SIGNIFICANCE

The increasing recognition of the heterogeneity of molecular causes of cancer favors the continued development of molecularly targeted agents, and their transfer to pediatric and adolescent populations.