Outcome of children with relapsed high-risk neuroblastoma in Japan and analysis of the role of allogeneic hematopoietic stem cell transplantation

BACKGROUND

In Japan, allogeneic hematopoietic stem cell transplantation is widely performed for recurrent neuroblastomas. This retrospective study aimed to investigate the prognosis of recurrent neuroblastoma in Japan and explore the effectiveness of allogeneic hematopoietic stem cell transplantation.

METHODS

Clinical characteristics and data on the treatment of patients with high-risk neuroblastoma who experienced first progression between 2003 and 2010 after attaining complete remission or partial remission were collected from hospitals participating in the Japanese Neuroblastoma Research Group.

RESULTS

Data from 61 patients who fulfilled these criteria were collected. The median interval from disease onset to first progression was 19 months (range, 7-65 months), whereas the median observation time of the surviving patients was 18 months (range, 1-69 months). All patients were treated with chemotherapy, where 22 and 3 patients received allogeneic and autologous hematopoietic stem cell transplantation, respectively. Seven patients were alive in second complete remission, and 39 died, including two in complete remission. The 3-year progression-free survival and overall survival rates were 15.3% (SE: 6.1%) and 16.9% (SE: 6.5%), respectively. For patients with allogeneic hematopoietic stem cell transplantation, the 3-year progression-free survival and overall survival were 28.3% (standard error, 12.0%) and 24.3% (standard error, 11.5%), respectively, and for patients without allogeneic hematopoietic stem cell transplantation, the 3-year progression-free survival and overall survival were 6.0% (standard error 5.5%) and 12.0% (standard error 7.6%), respectively. The duration of initial remission (≥ 18 months) and implementation of allogeneic hematopoietic stem cell transplantation were independently predictive of progression-free survival (P = 0.002 and P = 0.017), whereas for overall survival, only allogeneic hematopoietic stem cell transplantation was predictive (P = 0.012).

CONCLUSION

Although allogeneic hematopoietic stem cell transplantation contributed to some improvement in prognosis, it was insufficient.

Combination of a synthetic retinoid and a DNA demethylating agent induced differentiation of neuroblastoma through retinoic acid signal reprogramming

BACKGROUND

The CpG island methylator phenotype of neuroblastoma (NBL) is strongly associated with poor prognosis and can be targeted by 5-aza-2'-deoxycytidine (5-aza-dC). Differentiation therapy is a standard maintenance therapy for high-risk NBLs. However, the in vivo effect of tamibarotene, a synthetic retinoic acid, and the efficacy of its combination with 5-aza-dC have not been studied. Here, we conducted a preclinical study to assess the in vivo tamibarotene effect and the combination.

METHODS

Treatment effects were analysed by in vitro cell growth and differentiation state and by in vivo xenograft suppression. Demethylated genes were analysed by DNA methylation microarrays and geneset enrichment.

RESULTS

Tamibarotene monotherapy induced neural extension and upregulation of differentiation markers of NBL cells in vitro, and tumour regression without severe side effects in vivo. 5-Aza-dC monotherapy suppressed tumour growth both in vitro and in vivo, and induced demethylation of genes related to nervous system development and function. Pre-treatment with 5-aza-dC in vitro enhanced upregulation of differentiation markers and genes involved in retinoic acid signaling. Pre-treatment with 5-aza-dC in vivo significantly suppressed tumour growth and reduced the variation in tumour sizes.

CONCLUSIONS

Epigenetic drug-based differentiation therapy using 5-aza-dC and TBT is a promising strategy for refractory NBLs.

Phase I study of tamibarotene monotherapy in pediatric and young adult patients with recurrent/refractory solid tumors

PURPOSE

Tamibarotene is a synthetic retinoid that inhibits proliferation and induces differentiation of malignant cells by binding to the retinoic acid receptor α/β. Previous in vitro studies have shown that some pediatric solid tumors with retinoic acid receptors differentiate in response to retinoic acid. We conducted a phase I dose-escalation study to determine the recommended dose of tamibarotene for further study in pediatric and young adult patients with recurrent/refractory solid tumors.

METHODS

Pediatric and young adult patients with recurrent/refractory solid tumors were administered tamibarotene at 4, 6, 8, 10, and 12 mg/m²/day for 14 or 21 days of a 28 day cycle. Safety, efficacy, and pharmacokinetics of tamibarotene were evaluated.

RESULTS

Twenty-two patients (median age 8 years) were enrolled in this study. No dose-limiting toxicity (DLT) was encountered, and tamibarotene was generally well tolerated. Two patients experienced severe adverse events (AEs), leading to discontinuation of the treatment. One grade 4 venous thrombosis and one grade 2 erythema multiforme were observed, which promptly resolved after tamibarotene discontinuance. The grade 4 venous thrombosis was a severe AE but not DLT because it occurred after the evaluation period. Pharmacokinetic analyses showed a dose-dependent increase in the maximum drug concentration (C_max) and area under the concentration-time curve (AUC). None of the patients achieved a complete response or partial response. Seven patients had stable disease lasting longer than 18 weeks.

CONCLUSIONS

The recommended dose for phase II study of tamibarotene in pediatric and young adult patients with refractory solid tumors is 12 mg/m²/day for 21 days in a 28 day cycle.

[Gemcitabine and Docetaxel for the Treatment of Relapsed and Refractory Malignant Rhabdoid Tumor of Kidney and Atypical Teratoid Rhabdoid Tumor]

Gemcitabine and Docetaxel(GEM/DTX)are well known chemotherapeutic drugs for the treatment of soft tissue sarcomas. However, the efficacy of these drugs in the treatment of malignant rhabdoid tumors(MRTs)has not been well described. We used GEM/DTX as salvage chemotherapy for relapsed and refractory MRTs, including 2 patients with malignant rhabdoid tumor of the kidney(MRTK)and 2 with atypical teratoid rhabdoid tumor(ATRT). At the best, partial response was observed in 3 patients(2 MRTK and 1 ATRT). The remaining patient with ATRT had stable disease. Localized edema in the field of recent radiation therapy was discovered in 2 patients. In addition, one had pleural effusion without any evidence of tumor progression. GEM/DTX can be used as a potential chemotherapeutic drug for relapsed or refractory MRTs, although attention should be paid to its unique adverse events.

A Phase I/IIa Study of Antidisialoganglioside Antibody Dinutuximab in Japanese Patients With Neuroblastoma

Japanese patients with neuroblastoma completing induction therapy and high-dose chemotherapy received antidisialoganglioside antibody dinutuximab 17.5 mg/m2 for 4 days during each of 5 consecutive 28-day cycles. Patients also received macrophage colony-stimulating factor (M-CSF) or granulocyte colony-stimulating factor (G-CSF) during cycles 1, 3, and 5 combined with interleukin-2 teceleukin during cycles 2 and 4. A total of 25 patients (11 in the M-CSF group and 14 in the G-CSF group) were enrolled, and dose-limiting toxicity was assessed in the first 12 patients (6 in each group). The recommended doses of dinutuximab, M-CSF, and G-CSF were determined to be 17.5 mg/m2, 6.0×106 U/m2, and 5 µg/kg/d, respectively, whereas that of teceleukin was 0.75×106 IU/m2 during week 1 and 1×106 IU/m2 during week 2. The most common grade 3 or 4 adverse events in both groups were neutrophil count decreased, platelet count decreased, pyrexia, and alanine aminotransferase increased. Four patients (2 in each group) discontinued the treatment because of adverse events. At the end of the study, survival was confirmed in 22 patients (9 in the M-CSF group and 13 in the G-CSF group). From these results, we concluded that this combination regimen is a feasible treatment for Japanese patients with neuroblastoma.

Monitoring Ponatinib in a Child with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia

Ponatinib is a third-generation tyrosine kinase inhibitor (TKI) reported to show a higher efficacy for adult Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) than other TKIs. However, few studies describe ponatinib for pediatric Ph+ALL; therefore, the efficacy, safety, and optimal dosage have not been determined. Here, we report a 3-year-old girl with Ph+ALL treated by a ponatinib-containing regimen with therapeutic drug monitoring in the plasma and cerebrospinal fluid (CSF). In our case, a ponatinib-containing regimen was able to keep minimal residual disease negative, and the pharmacokinetics (PKs) of plasma ponatinib resembled that previously reported in adults. Penetration to the CSF was extremely limited. Thus, ponatinib was feasible and effective for a child with Ph+ALL, although the plasma concentration of ponatinib varied significantly throughout the treatment. The appropriate dosage should be confirmed in a prospective trial, including a detailed PK study.

MBCL-22. EFFICACY OF DOUBLE-CONDITIONING REGIMEN COMPRISING THIOTEPA AND MELPHALAN FOR RELAPSED MEDULLOBLASTOMA – A SINGLE INSTITUTION EXPERIENCE

BACKGROUND

The prognosis of relapsed medulloblastoma was dismal. Recently, we published the promising outcome of metastatic medulloblastomas treated with a double-conditioning regimen comprising high-dose thiotepa and melphalan (HD-TM). Here, we report a single-center study of HD-TM for relapsed medulloblastomas.

MATERIALS AND METHODS

From April 2006 to January 2019, 17 consecutive medulloblastoma patients with the first relapse were identified, and of which 10 received HD-TM were retrospectively reviewed.

RESULTS

The median age at first relapse was 11.9 years (range 1.8–31.7). The median follow-up period was 23.5 months after 1st relapse. Four localized relapses at the posterior fossa and 6 metastatic relapses including 3 with multiple sites were observed. Surgical resection and re-irradiation were administered in 5 and 9 patients, respectively. Two-year PFS and OS after relapse were 21±18.1% and 60±21.9%, respectively, and significantly better than in patients who did not receive HD-TM. Among 7 evaluable patients, tumor shrinkage was observed in 6 after HD-TM administration including 3 patients who were resistant to prior chemotherapy. At the present time, 5 patients are alive with no evidence of disease (NED). The last 5 patients received re-irradiation including 12 Gy craniospinal irradiation (CSI), and 4 are alive with NED. In multivariate analysis for all patients, both HD-TM and re-irradiation were associated with improved OS and PFS, but disseminated relapse had no prognostic value (p=0.56).

CONCLUSION

HD-TM contributes to prolonged survival when combined with re-irradiation. HD-TM might become a curative approach for relapsed medulloblastoma, especially when combined with CSI.

Efficacy of the NCCV Cocktail-1 vaccine for refractory pediatric solid tumors: A phase I clinical trial

Pediatric refractory solid tumors are aggressive malignant diseases, resulting in an extremely poor prognosis. KOC1, FOXM1, and KIF20A are cancer antigens that could be ideal targets for anticancer immunotherapy against pediatric refractory solid tumors with positive expression for these antigens. This nonrandomized, open‐label, phase I clinical trial evaluated the safety and efficacy of the NCCV Cocktail‐1 vaccine, which is a cocktail of cancer peptides derived from KOC1, FOXM1, and KIF20A, in patients with pediatric refractory solid tumors. Twelve patients with refractory pediatric solid tumors underwent NCCV Cocktail‐1 vaccination weekly by intradermal injections. The primary endpoint was the safety of the NCCV Cocktail‐1 vaccination, and the secondary endpoints were the immune response, as measured by interferon‐r enzyme‐linked immunospot assay, and the clinical outcomes including tumor response and progression‐free survival. The NCCV Cocktail‐1 vaccine was well tolerated. The clinical response of this trial showed that 4 patients had stable disease after 8 weeks and 2 patients maintained remission for >11 months. In 4, 8, and 5 patients, the NCCV Cocktail‐1 vaccine induced the sufficient number of peptide‐specific CTLs for KOC1, FOXM1, and KIF20A, respectively. Patients with high peptide‐specific CTL frequencies for KOC1, FOXM1, and KIF20A had better progression‐free survival than those with low frequencies. The findings of this clinical trial showed that the NCCV Cocktail‐1 vaccine could be a novel therapeutic strategy, with adequate effects against pediatric refractory solid tumors. Future large‐scale trials should evaluate the efficacy of the NCCV Cocktail‐1 vaccination.

Double-conditioning regimen consisting of high-dose thiotepa and melphalan with autologous stem cell rescue for high-risk pediatric solid tumors: A second report

BACKGROUND

Pediatric patients with high-risk, relapsed, or refractory solid tumors have a poor prognosis. We have previously reported a dose-finding experience of high-dose chemotherapy consisting of thiotepa and melphalan ("double-conditioning regimen"). Using doses derived from that study, we have treated patients since 2005. We now report a retrospective review of patients treated by this fixed dose.

PROCEDURE

We reviewed 50 patients (median 4 years; range 0-15 years) with high-risk or relapsed/refractory solid tumors treated by this dose-fixed, double-conditioning regimen from April 2005 to May 2014. Doses were thiotepa 800 mg/m² and melphalan 280 mg/m² for children ≥2 years of age, and 32 mg/kg and 6 mg/kg, respectively, for children <2 years of age. Further, doses were reduced according to creatinine clearance with poor renal function.

RESULTS

Nonhematological toxicity was mainly gastrointestinal-grade 3 mucositis (n = 41) and grade 3-4 diarrhea (n = 10). Neurological, renal, and endothelial cell toxicity and sinusoidal obstruction syndrome were not observed. There were two toxic deaths (interstitial viral pneumonia). This regimen demonstrated antitumor activity against several types of tumors. Although the frequency of gastrointestinal toxicity was high, other severe toxicity was not observed.

CONCLUSIONS

Our double-conditioning regimen was very well tolerated and demonstrated antitumor activity. We are moving forward with multi-institutional trials now.

Secondary osteosarcoma in patients previously treated for childhood cancer: Three case reports

The prognosis of childhood cancers has improved markedly, and the proportion of long-term survivors has increased in recent years. However, with the increase in the number of long-term survivors, the development of latent treatment-related adverse effects, such as secondary malignancies, has generated new problems. Secondary cancer is defined as a histologically distinct malignancy that develops at least 2 months after the completion of treatment for primary cancer. Genetic factors and acquired conditions associated with treatment modalities are possible causes of secondary malignancy development. Genetic factors include the presence of Li-Fraumeni syndrome (LFS) and retinoblastoma. In terms of acquired factors, radiation and chemotherapy have been reported to be the most strongly associated with secondary malignancy development. The use of alkylating agents and topoisomerase II inhibitors for the treatment of childhood cancer increases the subsequent risk of secondary tumors. We herein investigated three cases of secondary osteosarcoma several years after treatment for primary cancer. In the three patients, the familial history did not appear to fit the clinical diagnostic criteria of LFS or retinoblastoma. The patients had not received previous radiation therapy to the anatomical site of the secondary cancer. However, high dosages of alkylating agents and topoisomerase II inhibitors had been administered for the treatment of primary cancer. The exact link between chemotherapy and secondary cancer remains elusive, but the possibility of an association should be considered. Following the development of multidisciplinary therapies, long-term follow-up and monitoring of latent adverse effects may be necessary for childhood cancer survivors.

Phase I study of glypican-3-derived peptide vaccine therapy for patients with refractory pediatric solid tumors

The carcinoembryonic antigen glypican-3 (GPC3) is a good target of anticancer immunotherapy against pediatric solid tumors expressing GPC3. In this non-randomized, open-label, phase I clinical trial, we analyzed the safety and efficacy of GPC3-peptide vaccination in patients with pediatric solid tumors. Eighteen patients with pediatric solid tumors expressing GPC3 underwent GPC3-peptide vaccination (intradermal injections every 2 weeks), with the primary endpoint being the safety of GPC3-peptide vaccination and the secondary endpoints being immune response, as measured by interferon (IFN)-γ enzyme-linked immunospot assay and Dextramer staining, and the clinical outcomes of tumor response, progression free survival (PFS), and overall survival (OS). Our findings indicated that GPC3 vaccination was well tolerated. We observed disease-control rates [complete response (CR)+partial response+stable disease] of 66.7% after 2 months, and although patients in the progression group unable to induce GPC3-peptide-specific cytotoxic T lymphocytes (CTLs) received poor prognoses, patients in the partial-remission and remission groups or those with hepatoblastoma received good prognoses. The GPC3-peptide vaccine induced a GPC3-specific CTL response in seven patients, with PFS and OS significantly longer in patients with high GPC3-specific CTL frequencies than in those with low frequencies. Furthermore, we established GPC3-peptide-specific CTL clones from a resected-recurrent tumor from one patient, with these cells exhibiting GPC3-peptide-specific cytokine secretion. The results of this trial demonstrated that the GPC3-peptide-specific CTLs induced by the GPC3-peptide vaccine infiltrated tumor tissue, and use of the GPC3-peptide vaccine might prevent the recurrence of pediatric solid tumors, especially hepatoblastomas, after a second CR.

Sorafenib treatment in children with relapsed and refractory neuroblastoma: an experience of four cases

Metastatic neuroblastoma is an aggressive malignancy with a poor prognosis. Recent findings have shown that sorafenib decreases cell viability and increases apoptosis in human neuroblastoma cell lines. We report an experience of compassionate use of sorafenib in children with treatment‐refractory neuroblastoma. Sorafenib showed transient anti‐tumor activity in all four patients without adverse effects. However, progression was observed after a short stabilization phase. While sorafenib showed minimal anti‐tumor activity in our patients, it might still be effective in patients with neuroblastoma in an earlier stage.