Second Paediatric Strategy Forum for anaplastic lymphoma kinase (ALK) inhibition in paediatric malignancies: ACCELERATE in collaboration with the European Medicines Agency with the participation of the Food and Drug Administration.

The first (2017) and sixth (2021) multistakeholder Paediatric Strategy Forums focused on anaplastic lymphoma kinase (ALK) inhibition in paediatric malignancies. ALK is an important oncogene and target in several paediatric tumours (anaplastic large cell lymphoma [ALCL], inflammatory myofibroblastic tumour [IMT], neuroblastoma and hemispheric gliomas in infants and young children) with unmet therapeutic needs. ALK tyrosine kinase inhibitors have been demonstrated to be active both in ALK fusion-kinase positive ALCL and IMT. ALK alterations differ, with fusions occurring in ALCL, IMT and gliomas, and activating mutations and amplification in neuroblastoma. While there are many ALK inhibitors in development, the number of children diagnosed with ALK driven malignancies is very small. The objectives of this ALK Forum were to (i) Describe current knowledge of ALK biology in childhood cancers; (ii) Provide an overview of the development of ALK inhibitors for children; (iii) Identify the unmet needs taking into account planned or current ongoing trials; (iv) Conclude how second/third-generation inhibitors could be evaluated and prioritised; (v) Identify lessons learnt from the experience with ALK inhibitors to accelerate the paediatric development of other anti-cancer targeted agents in the new regulatory environments. There has been progress over the last four years, with more trials of ALK inhibitors opened in paediatrics and more regulatory submissions. In January 2021, the US Food and Drug Administration approved crizotinib for the treatment of paediatric and young adult patients with relapsed or refractory ALCL and there are paediatric investigation plans (PIPs) for brigatinib and for crizotinib in ALCL and IMT. In ALCL, the current goal is to investigate the inclusion of ALK inhibitors in front-line therapy with the aim of decreasing toxicity with higher/similar efficacy compared to present first-line therapies. For IMT, the focus is to develop a joint prospective trial with one product in children, adolescents and adults, taking advantage of the common biology across the age spectrum. As approximately 50% of IMTs are ALK-positive, molecular analysis is required to identify patients to be treated with an ALK inhibitor. For neuroblastoma, crizotinib has not shown robust anti-tumour activity. A focused and sequential development of ALK inhibitors with very good central nervous system (CNS) penetration in CNS tumours with ALK fusions should be undertaken. The Forum reinforced the strong need for global academic collaboration, very early involvement of regulators with studies seeking possible registration and early academia-multicompany engagement. Innovations in study design and conduct and the use of 'real-world data' supporting development in these rare sub-groups of patients for whom randomised clinical trials are not feasible are important initiatives. A focused and sequenced development strategy, where one product is evaluated first with other products being assessed sequentially, is applicable for ALK inhibitors and other medicinal products in children.

[Registries and studies in the Society for Pediatric Oncology and Hematology (GPOH) - What contribution do they make to progress?] / Register und Studien in der Gesellschaft für Pädiatrische Onkologie und Hämatologie (GPOH) ­ Welchen Beitrag leisten sie zum Fortschritt?

Cancer in children and adolescents under the age of 18 is rare; in 2017, approximately 2220 new cases in Germany were reported to the German Childhood Cancer Registry. The aim of the GPOH has always been to treat as many affected patients as possible in a standardized way, preferably in prospective, controlled studies. The Joint Federal Committee has also laid down this requirement in the paediatric oncology guideline. In a survey among the study chairs of the GPOH, it was determined how the number of clinical trials has changed following the amended drug legislation. In 2002, 33 therapy optimization studies (TOS) of the GPOH were open. Overall, TOS decreased from 33 in 2002 to 2 in 2017. The number of drug trials has increased to 16 by 2017 (almost 1100 patients registered). At the time, the number of clinical registries has increased to 28 with a total of more than 1800 registered patents. This observation shows that the clinical registers have taken on a new significance in paediatric oncology. Three examples are used to examine what contributions registries can make in relation to studies on the treatment of patients and to scientific progress. In summary, the experience gained so far from the examples discussed illustrates that studies and registries mutually represent a meaningful and necessary addition to the study group structure in paediatric oncology.

Non-anaplastic peripheral T-cell lymphoma in children and adolescents--a retrospective analysis of the NHL-BFM study group.

Mature (peripheral) T-cell lymphoma (PTCL) other than anaplastic large cell lymphoma is a heterogeneous group of diseases and exceedingly rare in children and adolescents. Survival rates range between 46% and 85%. This study reports the disease characteristics, treatment and outcome of all patients with the diagnosis of mature TCL registered in the Berlin-Frankfurt-Munster non-Hodgkin lymphoma database between 1986 and 2012. All diagnoses were centrally reviewed and revised by clinico-pathological correlation according to the criteria of the current World Health Organization classification. Of the 69 patients originally registered as having PTCL, the diagnosis was confirmed in 38 of them. Most patients were treated with an anaplastic large cell lymphoma (ALCL)-like therapy regimen. Patients with PTCL-not otherwise specified comprised the largest group and showed a 5-year event-free survival rate of 61 ± 11%. Patients suffering from Natural Killer/T-cell- and hepatosplenic TCL had the poorest outcome. Our results suggest that the outcomes of children with mature TCL other than ALCL depend on the subtype and are worse than in all other paediatric lymphomas. The clinical experience presented in this largest study on paediatric mature TCL may serve as basis for future collaborative international prospective clinical trials.

Relapsed or refractory anaplastic large-cell lymphoma in children and adolescents after Berlin-Frankfurt-Muenster (BFM)-type first-line therapy: a BFM-group study.

PURPOSE: To evaluate risk factors for outcome in children and adolescents with relapse of anaplastic large-cell lymphoma (ALCL) after comparable first-line therapy. PATIENTS AND METHODS: We analyzed a population-based cohort of 74 children with relapsed ALCL after Berlin-Frankfurt-Muenster-type first-line therapy between April 1990 and December 2003. The recommended salvage strategy was reinduction chemotherapy followed by autologous hematopoietic stem-cell transplantation (SCT). RESULTS: With a median follow-up time of 8.4 years (range, 4.5 to 16.4 years), the 5-year overall survival (OS) rate after first relapse was 57% ± 6%. Survival correlated with time of relapse and clinically advanced dissemination. Five-year OS of 16 patients who experienced progression during first-line therapy was 25% ± 11% compared with 66% ± 6% for 58 patients with a later relapse (P = .002). Five-year OS of 11 patients with bone marrow or CNS involvement was 27% ± 13% compared with 62% ± 6% for 63 patients without involvement (P = .001). Five-year event-free survival (EFS) and OS of 39 children who received the recommended autologous SCT were 59% ± 8% and 77% ± 7%, respectively. EFS after autologous SCT was significantly associated with time to relapse (progression: n = 3; EFS, 0; later relapse: n = 36; EFS, 64% ± 8%; P = .014) and CD3 expression (CD3 negative: n = 25; EFS, 72% ± 9%; CD3 positive: n = 11; EFS, 18% ± 12%; P < .001), but not with site of relapse, conditioning regimen, or graft manipulation. No relapses occurred among 10 patients with relapsed CD3-positive ALCL treated with allogeneic SCT. CONCLUSION: Reinduction chemotherapy followed by autologous SCT proved feasible and efficacious for patients with a first relapse of CD3-negative ALCL after first-line therapy. Patients with progression during first-line therapy or relapsed CD3-positive ALCL may benefit from allogeneic SCT.

Inhibition of anaplastic lymphoma kinase (ALK) activity provides a therapeutic approach for CLTC-ALK-positive human diffuse large B cell lymphomas.

ALK positive diffuse large B-cell lymphomas (DLBCL) are a distinct lymphoma subtype associated with a poor outcome. Most of them feature a t(2;17) encoding a clathrin (CLTC)-ALK fusion protein. The contribution of deregulated ALK-activity in the pathogenesis and maintenance of these DLBCLs is not yet known. We established and characterized the first CLTC-ALK positive DLBCL cell line (LM1). LM1 formed tumors in NOD-SCID mice. The selective ALK inhibitor NVP-TAE684 inhibited growth of LM1 cells in vitro at nanomolar concentrations. NVP-TAE684 repressed ALK-activated signalling pathways and induced apoptosis of LM1 DLBCL cells. Inhibition of ALK-activity resulted in sustained tumor regression in the xenotransplant tumor model. These data indicate a role of CLTC-ALK in the maintenance of the malignant phenotype thereby providing a rationale therapeutic target for these otherwise refractory tumors.

Distribution of NPM1-ALK and X-ALK fusion transcripts in paediatric anaplastic large cell lymphoma: a molecular-histological correlation.

Anaplastic large cell lymphomas (ALCL) in children express anaplastic lymphoma kinase (ALK) fusion genes, most commonly NPM1-ALK. The distribution of X-ALK among 66 childhood ALCLs was analysed. One ALCL was ALK-negative. Reverse transcription polymerase chain reaction detected NPM1-ALK in 58 tumours, all showing nuclear and cytoplasmic ALK staining. The remaining seven ALCL stained for ALK in the cytoplasm only: two expressed TPM3-ALK, one ATIC-ALK, one MYH9-ALK; three no TPM3-, TFG-, ATIC-, CLTC- or MYH9-ALK. Almost 90% of paediatric ALK-positive ALCLs express NPM1-ALK. There was complete concordance between ALK staining pattern and the presence of a typical/variant ALK fusion partner.

Flow cytometric detection of circulating tumour cells in nucleophosmin/anaplastic lymphoma kinase-positive anaplastic large cell lymphoma: comparison with quantitative polymerase chain reaction.

Quantification of occult circulating tumour cells in blood or bone marrow (BM) enables the identification of patients with a high risk for relapse in nucleophosmin/anaplastic lymphoma kinase (NPM-ALK)-positive anaplastic large cell lymphoma (ALCL). We have developed a flow cytometric (FCM) assay to quantify the rare ALK- and CD30-positive ALCL cells. When ALCL cells were admixed with normal peripheral blood or BM, ALK- and CD30-positive cells could be detected above background level at an added concentration of 10(-5) for all three cell lines tested. Sensitivity and costs of the assay were compared with quantitative real-time polymerase chain reaction (PCR) for NPM-ALK. The results of the FCM assay and quantitative PCR for NPM-ALK correlated. The sensitivity of the PCR exceeded that of the FCM by at least one log. Quantitative PCR was more time-consuming and expensive than FCM. Both methods were compared on BM or blood samples from 11 ALCL patients. FCM using antibodies against ALK and CD30 can sensitively and specifically detect the circulating ALCL cells in BM or blood. This method needs to be tested in a larger cohort of patients to determine whether it has sufficient sensitivity to be used as a substitute for quantitative PCR.

Prognostic significance of circulating tumor cells in bone marrow or peripheral blood as detected by qualitative and quantitative PCR in pediatric NPM-ALK-positive anaplastic large-cell lymphoma.

Clinical and histopathological characteristics have limited prognostic value for children with anaplastic large-cell lymphoma (ALCL). We evaluated the presence, extent, and prognostic impact of circulating tumor cells in bone marrow (BM) and peripheral blood (PB) of children and adolescents with NPM-ALK-positive ALCL at diagnosis using qualitative and quantitative polymerase chain reaction (PCR) for NPM-ALK. Numbers of NPM-ALK transcripts were normalized to 10(4) copies ABL (NCNs). BM was analyzed from 80 patients and PB from 52. BM was positive for NPM-ALK in 47.5% of patients, and positivity was significantly correlated with clinical stage, mediastinal or visceral involvement, microscopic BM involvement, and histologic subtype. Qualitative and quantitative PCR results in BM and PB strongly correlated. BM PCR was associated with the cumulative incidence of relapses (CI-Rs): CI-R was 50% +/- 10% for 38 PCR-positive and 15% +/- 7% for 42 PCR-negative patients (P < .001). Sixteen patients with more than 10 NCNs NPM-ALK in BM had a CI-R of 71% +/- 14% compared with a CI-R of 18% +/- 6% for 59 patients with 10 or fewer NCNs (P < .001). PB PCR results led to a similar grouping. Thus, quantitative PCR in BM or PB allows identification of 20% of patients experiencing 60% of all relapses with an event-free survival of 20%.

Allogeneic haematopoietic stem cell transplantation in relapsed or refractory anaplastic large cell lymphoma of children and adolescents--a Berlin-Frankfurt-Münster group report.

Patients with refractory or early relapsed anaplastic large cell lymphoma (ALCL) have a poor chance of survival. We report 20 children and adolescents with high-risk relapsed or refractory ALCL who underwent allogeneic haematopoietic stem cell transplantation (HSCT). We retrospectively analysed 20 patients who relapsed between December 1991 and April 2003 during (six patients) or soon after first-line Berlin-Frankfurt-Münster-type chemotherapy (14 patients) and underwent allogeneic HSCT. Nine patients received allogeneic HSCT after the first relapse and 11 after multiple relapses. Eight patients received their transplants from matched sibling donors, eight from unrelated donors and four from haploidentical family donors. The conditioning regimen was based on total body irradiation in 15 patients. Two patients relapsed after allogeneic HSCT and died. Three patients died of transplant-related toxicity. Event-free survival at 3 years after allogeneic transplant was 75 +/- 10%. There was no influence of donor type or conditioning regimen on outcome. Two of six patients with progressive disease during frontline therapy survived compared with 13/14 patients with a first relapse after frontline therapy. Two of three patients who were transplanted with active lymphoma and all five patients who received allogeneic HSCT for relapse following autologous HSCT survived disease-free. Allogeneic HSCT is effective and has acceptable toxicity as rescue therapy for high-risk ALCL relapse. It even offers cure for patients refractory to chemotherapy, suggesting a graft-versus-ALCL effect.

RNA interference: new mechanisms for targeted treatment?

Nucleic acid-based sequence-specific therapeutic intervention offers the potential for treatment of particular cancers without side effects. RNA interference (RNAi) induced by small interfering RNA (siRNA) (19-21 bp) is a normal cellular mechanism leading to highly specific and extraordinarily efficient degradation of the corresponding mRNA. The mechanism of RNAi as well as strategies for the design and delivery of siRNA are described. The growing role of RNAi in target validation for cancer-specific genetic aberrations is discussed. We attempt an early assessment of the potential for using RNAi technologies to treat cancer directly, especially hematologic malignancies. Promising targets for specific gene silencing in hematologic oncology include oncogenic fusion proteins and oncogenes activated by point mutations. Potency and specificity of gene silencing are the major advantages of the new RNAi technology over other nucleic acid-based gene targeting approaches. Crucial questions for pharmaceutical interventions remain. Advances in the areas of delivery, systemic spreading and duration of the silencing effect are necessary before the methodology can enter clinical oncology.

Ras-mediated activation of ERK by cisplatin induces cell death independently of p53 in osteosarcoma and neuroblastoma cell lines.

Activation of the mitogen-activated protein kinases ERK1/2 by the chemotherapeutic agent cisplatin has been shown to result in either survival or cell death. The downstream mediators of these opposing effects are unknown, as are the upstream signaling molecules. Activation of ERK is required for accumulation and phosphorylation of p53 following cisplatin treatment. We studied the role of ERK activation after cisplatin treatment under p53-negative and p53-positive conditions using a tetracycline-dependent expression vector in Saos-2 osteosarcoma cells. Dose-dependent activation of ERK first occurred 3-6 h after a 2-h cisplatin incubation and declined after 12-24 h in several tumor cell lines. Incubation of cell lines with the MEK1 inhibitors PD98059 or UO126 after, but not during, cisplatin treatment completely inhibited cisplatin-induced activation of ERK. The activation of ERK by cisplatin was inhibited by transient transfection with dominant-negative Ras-N17 in Saos-2 cells. Treatment of cells with PD98059 or UO126 after cisplatin incubation or inhibition of signaling through ERK by tetracycline-regulated expression of dominant-inhibitory ERK enhanced resistance to cisplatin in p53-negative osteosarcoma cells and reduced cisplatin-induced apoptosis. P53 was stabilized and phosphorylated in a MEK1-dependent manner after cisplatin incubation in Kelly neuroblastoma cells. Inhibition of signaling through ERK increased cell survival after cisplatin treatment in these cells as well. Expression of functional p53 did not change the proapoptotic effects of ERK activation in response to cisplatin in Saos-2 cells. Our results suggest that cisplatin-induced activation of ERK is mediated by Ras. ERK activation increased cisplatin-induced cell death independently of p53 in osteosarcoma and neuroblastoma cell lines.