First phase 1 clinical study of olaparib in pediatric patients with refractory solid tumors.

BACKGROUND: The survival of patients with high-risk, refractory, relapsed, or metastatic solid tumors remains dismal. A poly(ADP-ribose) polymerase (PARP) inhibitor could be effective for the treatment of pediatric solid tumors with defective homologous recombination. METHODS: This open-label, multicenter phase 1 clinical trial evaluated the safety, tolerability, and efficacy of olaparib, a PARP inhibitor, in pediatric patients with refractory solid tumors to recommend a dose for Phase 2 trials. Olaparib (62.5, 125, and 187.5 mg/m2 twice daily) was administered orally every day (1 cycle = 28 days) using a standard 3 + 3 dose-escalation design. Patients aged 3-18 years with recurrent pediatric solid tumors were eligible. Pharmacokinetic and pharmacodynamic analyses were performed. RESULTS: Fifteen patients were enrolled and received olaparib monotherapy, which was well tolerated. The recommended phase 2 dose for daily administration was 187.5 mg/m2 twice daily. Pharmacokinetics were dose proportional. The area under the concentration-time curve from 0 to 12 h and the peak plasma concentration for 187.5 mg/m2 twice daily in children were comparable to previous data obtained in a 200-mg, twice-daily cohort and lower than those in the 300-mg twice-daily cohort in adults. Pharmacodynamic studies demonstrated substantial inhibition of PARP activity. Two partial responses were observed in patients with Wilms tumor and neuroblastoma. CONCLUSIONS: This report is the first clinical trial to describe the use of a PARP inhibitor as monotherapy in children. Olaparib was well tolerated, with preliminary antitumor responses observed in DNA damage response-defective pediatric tumors. LAY SUMMARY: This Phase 1 trial evaluated the efficacy and safety of olaparib in patients with refractory childhood solid tumors. Olaparib was well tolerated, achieving objective response in 2/15 patients. The DNA damage response was attenuated in nearly one-half of advanced neuroblastoma patients, demonstrating the utility of the PARP inhibitor. The results support further investigation of olaparib as a new treatment for DNA damage-response or repair-defective pediatric cancers.

PAX3/7-FOXO1 fusion-negative alveolar rhabdomyosarcoma in Schuurs-Hoeijmakers syndrome.

PAX3/7-FOXO1 fusion-negative alveolar rhabdomyosarcoma (ARMS) developed in a patient presenting with intellectual disability and dysmorphic facial features. Whole exome sequencing analysis of a germline sample identified a PACS1 c.607 C>T de novo variant and the patient was diagnosed with Schuurs-Hoeijmakers syndrome (SHS). SHS is a rare disease characterized by intellectual disability and dysmorphic facial features, among various physical abnormalities, due to PACS1 c.607 C>T de novo variant. Due to the rarity of the SHS, diagnosis based on phenotypic information is difficult. To date, there have been no previous reports describing malignancy associated with SHS. Comprehensive somatic mutation analysis revealed a unique pattern of genetic alterations in the PAX3/7-FOXO1 fusion-negative ARMS tumor, including mutations in the oncogene, HRAS; MYOD1, a molecule essential for muscle differentiation; and KMT2C and TET1, genes encoding factors involved in epigenetic regulation. Although the role of PACS1 in tumorigenesis is unclear, it is reported to function in apoptosis regulation. Our case suggests that PACS1 could have a novel role in oncogenesis.

Feasibility of dose-dense cisplatin-based chemotherapy in Japanese children with high-risk hepatoblastoma: Analysis of the JPLT3-H pilot study.

BACKGROUND: The SIOPEL-4 study has demonstrated that dose-dense cisplatin-based chemotherapy dramatically improves outcome in children with high-risk hepatoblastoma in western countries. However, the feasibility and safety of this regimen have not been clarified in Japanese patients. METHODS: A pilot study, JPLT3-H, was designed to evaluate the safety profile of the SIOPEL-4 regimen in Japanese children with newly diagnosed hepatoblastoma with either metastatic disease or low alpha-fetoprotein. RESULTS: A total of 15 patients (three female) were enrolled. Median age was 2 years (range, 0-14). Three patients were PRETEXT II (where PRETEXT is PRETreatment EXTent of disease), six PRETEXT III, and six PRETEXT IV. All patients had lung metastasis, none had low alpha-fetoprotein. Eight patients completed the prescribed treatment, and seven patients discontinued therapy prematurely, four due to progressive disease and three due to causes other than severe toxicity. Grade 4 neutropenia was documented in most patients in preoperative cycles A1-3 (11/15 in A1, 9/11 in A2, and 7/11 in A3) and in all considering all cycles. Grade 3-4 thrombocytopenia and grade 3 anemia were also frequently observed. Patients experienced several episodes of grade 3 febrile neutropenia, but none had grade 4 febrile neutropenia or severe infections. One patient had grade 3 heart failure only in the first cycle. Other grade 3 or 4 toxicities were hypomagnesemia, anorexia, nausea, mucositis, liver enzyme elevation, fever, infection, and fatigue. There were no unexpected severe toxicities. CONCLUSION: The toxicity profile of JPLT3-H was comparable to that of SIOPEL-4. Dose-dense cisplatin-based chemotherapy may be feasible among Japanese patients with high-risk hepatoblastoma.

Phase I clinical study of oral olaparib in pediatric patients with refractory solid tumors: study protocol.

BACKGROUND: There is no established standard chemotherapy for recurrent pediatric solid tumors such as neuroblastoma and sarcoma. Since some of these tumor cells show dysfunctions in homologous recombination repair, the goal is to conduct a phase I study of olaparib, a poly(ADP-ribose) polymerase inhibitor. In this clinical trial, the aims are to evaluate the safety, tolerability, and efficacy of olaparib in pediatric patients with refractory solid tumors and to recommend a dose for phase II trials. METHODS: In this open-label, multicenter study, olaparib tablets (62.5, 125, and 187.5 mg/m2 b.i.d.) will be administered orally in a standard 3 + 3 dose escalation design. Patients aged 3 to 18 years with recurrent pediatric solid tumors are eligible. Pharmacokinetic and pharmacodynamic analyses will also be performed. DISCUSSION: This study aims to extend the indications for olaparib by assessing its safety and efficacy in pediatric refractory solid tumor patients. TRIAL REGISTRATION: UMIN-CTR ( UMIN000025521 ); Registered on January 4, 2017.

Outcome and Late Complications of Hepatoblastomas Treated Using the Japanese Study Group for Pediatric Liver Tumor 2 Protocol.

PURPOSE: We report here the outcomes and late effects of the Japanese Study Group for Pediatric Liver Tumors (JPLT)-2 protocol, on the basis of cisplatin-tetrahydropyranyl-adriamycin (CITA) with risk stratification according to the pretreatment extent of disease (PRETEXT) classification for hepatoblastoma (HB). PATIENTS AND METHODS: From 1999 to 2012, 361 patients with untreated HB were enrolled. PRETEXT I/II patients were treated with up-front resection, followed by low-dose CITA (stratum 1) or received low-dose CITA, followed by surgery and postoperative chemotherapy (stratum 2). In the remaining patients, after 2 cycles of CITA, responders received the CITA regimen before resection (stratum 3), and nonresponders were switched to ifosfamide, pirarubicin, etoposide, and carboplatin (ITEC; stratum 4). Intensified chemotherapeutic regimens with autologous hematopoietic stem-cell transplantation (SCT) after resection were an optional treatment for patients with refractory/metastatic disease. RESULTS: The 5-year event-free and overall survival rates of HB patients were 74.2% and 89.9%, respectively, for stratum 1, 84.8% and 90.8%%, respectively, for stratum 2, 71.6% and 85.9%%, respectively, for stratum 3, and 59.1% and 67.3%%, respectively, for stratum 4. The outcomes for CITA responders were significantly better than those for nonresponders, whose outcomes remained poor despite salvage therapy with a second-line ITEC regimen or SCT. The late effects, ototoxicity, cardiotoxicity, and delayed growth, occurred in 61, 18, and 47 patients, respectively. Thirteen secondary malignant neoplasms (SMNs), including 10 leukemia, occurred, correlating with higher exposure to pirarubicin and younger age at diagnosis. CONCLUSION: The JPLT-2 protocol achieved up-front resectability in PRETEXT I/II patients with no annotation factors, and satisfactory survival in patients who were CITA responders in the remaining patients. However, outcomes for CITA nonresponders were unsatisfactory, despite therapy intensification with ITEC regimens and SCT. JPLT-2 had a relatively low incidence of cardiotoxicity but high rates of SMNs.

Atypical SIFD with novel TRNT1 mutations: a case study on the pathogenesis of B-cell deficiency.

Mutation in the gene encoding tRNA nucleotidyl transferase, CCA-adding 1 (TRNT1), an enzyme essential for the synthesis of the 3'-terminal CCA sequence in tRNA molecules, results in a disorder that features sideroblastic anemia, B-cell immunodeficiency, periodic fever, and developmental delay. Mutations in TRNT1 are also linked to phenotypes including retinitis pigmentosa, cataracts, and cardiomyopathy. To date, it has remained unclear how defective TRNT1 is linked to B-cell deficiency. Here we report the case of a 12-year-old boy without sideroblastic anemia who harbors novel compound heterozygous mutations in TRNT1. Immunophenotypic analysis revealed severely decreased levels of B cells and follicular helper T cells. In the bone marrow, B-cell maturation stopped at the CD19+CD10+CD20+/- pre-B-cell stage. Severe combined immunodeficiency mice transplanted with bone marrow hematopoietic stem cells from the patient showed largely normal B-cell engraftment and differentiation in the bone marrow and periphery at 24 weeks post-transplantation, comparable to those in mouse transplanted with healthy hematopoietic stem cells. Biochemical analysis revealed augmented endoplasmic reticulum (ER) stress response in activated T cells. Peripheral B-cell deficiency of TRNT1 deficiency may be associated with augmented ER stress in immature B cells in the bone marrow.

Neoplastic endocrine differentiation of pancreatic ductal adenocarcinoma in a metastatic lymph node: report of a case.

The occurrence of non-neoplastic, scattered endocrine cells in pancreatic ductal adenocarcinoma (DAC) is thought to be a general phenomenon. Conversely, neoplastic endocrine differentiation (NED) of pancreatic DAC is extremely unusual. We report a case of NED in a metastatic lymph node from pancreatic DAC. This case is distinct because the main tumor of the pancreas was composed purely of DAC without endocrine differentiation, and the NED was found in only one of four metastatic peripancreatic lymph nodes. To our knowledge, no other such case has ever been reported. The patient was a 61-year-old woman who underwent pylorus-preserving pancreaticoduodenectomy for pancreatic head cancer. Some authors reported that pancreatic DAC with endocrine differentiation was associated with a better prognosis than DAC without endocrine differentiation. However, more cases must be studied to investigate the impact of NED of metastatic lymph nodes in pancreatic DAC.