Peter C. Adamson

Better therapies for childhood cancer remain an unmet need to improve the dismal prognosis of certain malignancies and to reduce the burden of toxicity. Rescuing discontinued or shelved drugs for children, adolescents, and young adults is a strategy to identify new uses for approved or investigational medicines outside the scope of their original medical indication. Our proposed multistakeholder consensus focuses on the development of innovative, patent-protected targeted agents, sourced from previously shelved or discontinued programs that have the potential to provide significant benefit to underserved patient populations, with unmet medical needs. There are several challenges to continuing/rescuing drugs for pediatric oncology development, which include the lack of information for decision making, corporate strategy considerations underlying the decision to invest in pediatric development, and the contracting and technology transfer complexities required to enable divestment and subsequent development. The multistakeholder approach for drug development has the advantage of conveying a consensus among academia, patient advocates, and importantly industry itself. We propose three areas of action to facilitate rescuing potentially beneficial drugs for children and adolescents with cancer: (i) initiatives to provide information to companies considering developing these drugs and a standards framework; (ii) incentives both in Europe and in the United States to encourage companies to develop pediatric-only drugs, with the reform of the EU Pharmaceutical Legislation posing an important opportunity; and (iii) communication of the issues to all stakeholders. Ultimately, this will benefit children and adolescents with cancer.

Ethosuximide was identified as the optimal option for new‐onset childhood absence epilepsy (CAE) in a randomized, two‐phase dose escalation comparative effectiveness trial of ethosuximide, lamotrigine, and valproic acid. However, 47% of ethosuximide initial monotherapy participants experienced short‐term treatment failure. This study aimed to characterize the initial monotherapy ethosuximide exposure‐response relationship and to propose model‐informed precision dosing guidance. Dose titration occurred over a 16–20‐week period until patients experienced seizure freedom or intolerable side effects. Subjects with initial monotherapy failure were randomized to one of the other two medications and dose escalation was repeated. A population pharmacokinetic model was created using plasma concentration data (n = 1,320), collected at 4‐week intervals from 211 unique participants during both the initial and second monotherapy phases. A logistic regression analysis was performed on the initial monotherapy cohort (n = 103) with complete exposure‐response data. Eighty‐four participants achieved seizure freedom with a wide range of ethosuximide area under the curves (AUC) ranging from 420 to 2,420 μg·h/mL. AUC exposure estimates for achieving a 50% and 75% probability of seizure freedom were 1,027 and 1,489 μg·h/mL, respectively, whereas the corresponding cumulative frequency of intolerable adverse events was 11% and 16%. Monte Carlo Simulation indicated a daily dose of 40 and 55 mg/kg to achieve 50% and 75% probability of seizure freedom in the overall population, respectively. We identified the need for adjusted mg/kg dosing in different body weight cohorts. This ethosuximide proposed model‐informed precision dosing guidance to achieve seizure freedom carries promise to optimize initial monotherapy success for patients with CAE.

Purpose:Anaplastic lymphoma kinase (ALK) aberrations are a promising target for patients with neuroblastoma. We assessed the activity of first-generation ALK inhibitor crizotinib in patients with no known curative treatments and whose tumors harbored an activating ALK alteration.Patients and Methods:Twenty patients with relapsed/refractory ALK-positive neuroblastoma received crizotinib at the recommended phase II dose of 280 mg/m2/dose. A Simon two-stage design was used to evaluate the antitumor activity of crizotinib monotherapy. Response evaluation occurred after cycles 1, 3, 5, 7, and then every 3 cycles. Correlation of ALK status and response was a secondary aim of the study.Results:The objective response rate for patients with neuroblastoma was 15% [95% confidence interval (CI): 3.3%–34.3%]: two with partial responses and 1 with a complete response. All three patients had a somatic ALK Arg1275Gln mutation, the most common ALK hotspot mutation observed in neuroblastoma and the only mutation predicted to be sensitive to ALK inhibition with crizotinib. Two patients had prolonged stable disease (10 and 13 cycles, respectively); both harbored an ALK Arg1275Gln mutation. Three patients with ALK Phe1174Leu mutations progressed during cycle 1 of therapy, and one patient with an ALK Phe1174Val received three cycles before disease progression. The two patients with ALK amplification had no response. The most common adverse event was a decrease in neutrophil count.Conclusions:Despite limited activity seen in this trial, we conclude that this is more likely due to an inability to reach the higher concentrations of crizotinib needed to overcome the competing ATP affinity.See related commentary by Schulte and Eggert, p. 3507

Purpose:Anaplastic lymphoma kinase (ALK) aberrations are a promising target for patients with neuroblastoma. We assessed the activity of first-generation ALK inhibitor crizotinib in patients with no known curative treatments and whose tumors harbored an activating ALK alteration.Patients and Methods:Twenty patients with relapsed/refractory ALK-positive neuroblastoma received crizotinib at the recommended phase II dose of 280 mg/m2/dose. A Simon two-stage design was used to evaluate the antitumor activity of crizotinib monotherapy. Response evaluation occurred after cycles 1, 3, 5, 7, and then every 3 cycles. Correlation of ALK status and response was a secondary aim of the study.Results:The objective response rate for patients with neuroblastoma was 15% [95% confidence interval (CI): 3.3%–34.3%]: two with partial responses and 1 with a complete response. All three patients had a somatic ALK Arg1275Gln mutation, the most common ALK hotspot mutation observed in neuroblastoma and the only mutation predicted to be sensitive to ALK inhibition with crizotinib. Two patients had prolonged stable disease (10 and 13 cycles, respectively); both harbored an ALK Arg1275Gln mutation. Three patients with ALK Phe1174Leu mutations progressed during cycle 1 of therapy, and one patient with an ALK Phe1174Val received three cycles before disease progression. The two patients with ALK amplification had no response. The most common adverse event was a decrease in neutrophil count.Conclusions:Despite limited activity seen in this trial, we conclude that this is more likely due to an inability to reach the higher concentrations of crizotinib needed to overcome the competing ATP affinity.See related commentary by Schulte and Eggert, p. 3507

Patients deserve not only full access to their medical information but timely interpretation and guidance from their personal physician.

PURPOSE: A dose-adjusted etoposide, doxorubicin, and cyclophosphamide with vincristine and prednisone plus rituximab (DA-EPOCH-R) regimen has been shown to deliver excellent survival for adults with primary mediastinal large B-cell lymphoma (PMLBL) without the use of radiotherapy. No international prospective evaluation of this regimen has previously been reported in children and adolescents. PATIENTS AND METHODS: We conducted an international single-arm phase II trial involving patients younger than age 18 years with PMLBL who were to receive six courses of DA-EPOCH-R. The primary end point was event-free survival (EFS). Overall survival and toxicity were also assessed. This trial was registered (ClinicalTrials.gov identifier: NCT01516567 ). RESULTS: Analyses were based on 46 patients. The median age was 15.4 years (interquartile range: 14-16 years). The median follow-up was 59.0 months (interquartile range: 52.6-69.2 months). Fourteen events were observed (eight relapses or progressions (including three parenchymal CNS relapses), four residual lymphoma, and two second malignancies). The 4-year EFS was 69.6% (95% CI, 55.2 to 80.9), which did not differ from the rate observed historically ( P = .59). Seven deaths occurred (six disease-related and one second malignancy). The overall survival was 84.8% (95% CI, 71.8 to 92.4). Twenty-two patients (48%) reached dose levels ≥ 4. Nonhematologic adverse events grade ≥ 3 or cardiac adverse events grade ≥ 2 occurred in 47 of 276 (17%) courses and 30 of 46 patients (65%). CONCLUSION: DA-EPOCH-R did not improve the EFS compared with a historical control in this first prospective multisite international study of children and adolescents with PMLBL. Further studies are required to determine the optimum therapy for children and adolescents with this lymphoma.