Pulmonary lesions in early response assessment in pediatric Hodgkin lymphoma: prevalence and possible implications for initial staging

BACKGROUND

Disseminated pulmonary involvement in pediatric Hodgkin lymphoma (pHL) is indicative of Ann Arbor stage IV disease. During staging, it is necessary to assess for coexistence of non-malignant lung lesions due to infection representing background noise to avoid erroneously upstaging with therapy intensification.

OBJECTIVE

This study attempts to describe new lung lesions detected on interim staging computed tomography (CT) scans after two cycles of vincristine, etoposide, prednisolone, doxorubicin in a prospective clinical trial. Based on the hypothesis that these new lung lesions are not part of the underlying malignancy but are epiphenomena, the aim is to analyze their size, number, and pattern to help distinguish true lung metastases from benign lung lesions on initial staging.

MATERIALS AND METHODS

A retrospective analysis of the EuroNet-PHL-C1 trial re-evaluated the staging and interim lung CT scans of 1,300 pediatric patients with HL. Newly developed lung lesions during chemotherapy were classified according to the current Fleischner glossary of terms for thoracic imaging. Patients with new lung lesions found at early response assessment (ERA) were additionally assessed and compared to response seen in hilar and mediastinal lymph nodes.

RESULTS

Of 1,300 patients at ERA, 119 (9.2%) had new pulmonary lesions not originally detectable at diagnosis. The phenomenon occurred regardless of initial lung involvement or whether a patient relapsed. In the latter group, new lung lesions on ERA regressed by the time of relapse staging. New lung lesions on ERA in patients without relapse were detected in 102 (7.8%) patients. Pulmonary nodules were recorded in 72 (5.5%) patients, the majority (97%) being<10 mm. Consolidations, ground-glass opacities, and parenchymal bands were less common.

CONCLUSION

New nodules on interim staging are common, mostly measure less than 10 mm in diameter and usually require no further action because they are most likely non-malignant. Since it must be assumed that benign and malignant lung lesions coexist on initial staging, this benign background noise needs to be distinguished from lung metastases to avoid upstaging to stage IV disease. Raising the cut-off size for lung nodules to ≥ 10 mm might achieve the reduction of overtreatment but needs to be further evaluated with survival data. In contrast to the staging criteria of EuroNet-PHL-C1 and C2, our data suggest that the number of lesions present at initial staging may be less important.

Clinical trial inclusion in patients with relapsed/refractory neuroblastoma following the European Precision Cancer Medicine trial MAPPYACTS

INTRODUCTION

Despite poor survival for patients with relapsed or refractory neuroblastoma, only 10-16% of patients are reported to be included in early phase trials. This study aimed to explore the impact of molecular profiling within the prospective precision cancer medicine trial MAPPYACTS (NCT02613962) on subsequent early phase trial recruitment and treatment by matched targeted therapies in this population.

METHODS AND MATERIALS

Clinical data from all French patients with relapsed/refractory neuroblastoma enrolled in MAPPYACTS were analyzed for subsequent matched/non-matched targeted treatment based on clinical tumor board (CMTB) recommendations.

RESULTS

From 93 patients with neuroblastoma included in French centers, 78 (84%) underwent whole exome and RNA sequencing and were discussed in the CMTB. Higher rate of successful sequencing analysis was observed in patients with relapsed disease compared to those with refractory disease (p = 0.0002). Among the 50 patients that presented with a new disease relapse/progression after the CMTB recommendations, 35 patients (70%) had at least one actionable alteration identified on the tumor at the time of relapse. Eighteen patients (36%) were included in an early phase clinical trial, 11 of these with a matched agent, 7 with a non-matched treatment; 13 patients were included in the AcSé ESMART trial. Five patients (10%) received a matched targeted therapy outside a clinical trial.

CONCLUSION

Patients with neuroblastoma in the European MAPPYACTS trial were more likely to be included in early phase trials compared to previous reports. Early deep sequencing at first treatment failure, comprehensive therapeutic discussions in molecular tumor boards and innovative trials like AcSé -ESMART improve access to innovative therapies for patients with relapsed/refractory neuroblastoma.

CLINICAL TRIAL REGISTRATION

NCT02613962.

Combined germline and somatic human FADD mutations cause autoimmune lymphoproliferative syndrome

BACKGROUND

The autoimmune lymphoproliferative syndrome (ALPS) is a noninfectious and nonmalignant lymphoproliferative disease frequently associated with autoimmune cytopenia resulting from defective FAS signaling. We previously described germline monoallelic FAS (TNFRSF6) haploinsufficient mutations associated with somatic events, such as loss of heterozygosity on the second allele of FAS, as a cause of ALPS-FAS. These somatic events were identified by sequencing FAS in DNA from double-negative (DN) T cells, the pathognomonic T-cell subset in ALPS, in which the somatic events accumulated.

OBJECTIVE

We sought to identify whether a somatic event affecting the FAS-associated death domain (FADD) gene could be related to the disease onset in 4 unrelated patients with ALPS carrying a germline monoallelic mutation of the FADD protein inherited from a healthy parent.

METHODS

We sequenced FADD and performed array-based comparative genomic hybridization using DNA from sorted CD4+ or DN T cells.

RESULTS

We found homozygous FADD mutations in the DN T cells from all 4 patients, which resulted from uniparental disomy. FADD deficiency caused by germline heterozygous FADD mutations associated with a somatic loss of heterozygosity was a phenocopy of ALPS-FAS without the more complex symptoms reported in patients with germline biallelic FADD mutations.

CONCLUSIONS

The association of germline and somatic events affecting the FADD gene is a new genetic cause of ALPS.

[Strategy of the French Society of Childhood Cancer (SFCE) for pediatric nodular lymphocyte predominant lymphoma]

Nodular Lymphocyte predominant Hodgkin lymphoma (NLPHL) are rare lymphomas in pediatric patients comprising less than 10 % of all Hodgkin lymphoma (HL). They are for the most part diagnosed at stage I or II and indolent with lymphadenopathy often preceding the diagnosis by many months/years. Survival is excellent. Historically, patients were treated according to classical HL protocols. Due to high toxicity and excellent prognosis, management of NLPHL shifted to de-escalation protocol with good results. No treatment beyond surgical resection was proposed for localized unique nodal disease completely resected. The closed European protocol (EuroNet PHL LP1) evaluated the efficacy of low intensity chemotherapy protocol based on CVP courses (cyclophosphamide vinblastine prednisone) for stage IA/IIA not fully resected. Final results are not yet available. Advanced stage NLPHL are rare and there is no clinical trial and no consensus treatment in children. The SFCE lymphoma committee recently established recommendations for staging and treatment of limited and advanced NLPHL in children based on current practices and published results. The goal was to allow homogeneous practice on a national scale. If incomplete resection for patients with stage I/IIA combination of low intensity chemotherapy (CVP) and rituximab is recommended. For intermediary and advanced stage intensification with AVD (adriamycine vinblastine dacarbazine) or CHOP courses (cyclophosphamide doxorubicine vincristine prednisone) combined with rituximab are advocated. In children, there is no indication for first-line local treatment with radiotherapy.

Differentiation between rebound thymic hyperplasia and thymic relapse after chemotherapy in pediatric Hodgkin lymphoma

BACKGROUND

Rebound thymic hyperplasia (RTH) is a common phenomenon caused by stress factors such as chemotherapy (CTX) or radiotherapy, with an incidence between 44% and 67.7% in pediatric lymphoma. Misinterpretation of RTH and thymic lymphoma relapse (LR) may lead to unnecessary diagnostic procedures including invasive biopsies or treatment intensification. The aim of this study was to identify parameters that differentiate between RTH and thymic LR in the anterior mediastinum.

METHODS

After completion of CTX, we analyzed computed tomographies (CTs) and magnetic resonance images (MRIs) of 291 patients with classical Hodgkin lymphoma (CHL) and adequate imaging available from the European Network for Pediatric Hodgkin lymphoma C1 trial. In all patients with biopsy-proven LR, an additional fluorodeoxyglucose (FDG)-positron emission tomography (PET)-CT was assessed. Structure and morphologic configuration in addition to calcifications and presence of multiple masses in the thymic region and signs of extrathymic LR were evaluated.

RESULTS

After CTX, a significant volume increase of new or growing masses in the thymic space occurred in 133 of 291 patients. Without biopsy, only 98 patients could be identified as RTH or LR. No single finding related to thymic regrowth allowed differentiation between RTH and LR. However, the vast majority of cases with thymic LR presented with additional increasing tumor masses (33/34). All RTH patients (64/64) presented with isolated thymic growth.

CONCLUSION

Isolated thymic LR is very uncommon. CHL relapse should be suspected when increasing tumor masses are present in distant sites outside of the thymic area. Conversely, if regrowth of lymphoma in other sites can be excluded, isolated thymic mass after CTX likely represents RTH.

DOCK11 deficiency in patients with X-linked actinopathy and autoimmunity

Dedicator of cytokinesis (DOCK) proteins play a central role in actin cytoskeleton regulation. This is highlighted by the DOCK2 and DOCK8 deficiencies leading to actinopathies and immune deficiencies. DOCK8 and DOCK11 activate CDC42, a Rho-guanosine triphosphate hydrolases involved in actin cytoskeleton dynamics, among many cellular functions. The role of DOCK11 in human immune disease has been long suspected but, to the best of our knowledge, has never been described to date. We studied 8 male patients, from 7 unrelated families, with hemizygous DOCK11 missense variants leading to reduced DOCK11 expression. The patients were presenting with early-onset autoimmunity, including cytopenia, systemic lupus erythematosus, skin, and digestive manifestations. Patients' platelets exhibited abnormal ultrastructural morphology and spreading as well as impaired CDC42 activity. In vitro activated T cells and B-lymphoblastoid cell lines from patients exhibited aberrant protrusions and abnormal migration speed in confined channels concomitant with altered actin polymerization during migration. Knock down of DOCK11 recapitulated these abnormal cellular phenotypes in monocytes-derived dendritic cells and primary activated T cells from healthy controls. Lastly, in line with the patients' autoimmune manifestations, we also observed abnormal regulatory T-cell (Treg) phenotype with profoundly reduced FOXP3 and IKZF2 expression. Moreover, we found reduced T-cell proliferation and impaired STAT5B phosphorylation upon interleukin-2 stimulation of the patients' lymphocytes. In conclusion, DOCK11 deficiency is a new X-linked immune-related actinopathy leading to impaired CDC42 activity and STAT5 activation, and is associated with abnormal actin cytoskeleton remodeling as well as Treg phenotype, culminating in immune dysregulation and severe early-onset autoimmunity.

Response-adapted omission of radiotherapy in children and adolescents with early-stage classical Hodgkin lymphoma and an adequate response to vincristine, etoposide, prednisone, and doxorubicin (EuroNet-PHL-C1): a titration study

BACKGROUND

Children and adolescents with early-stage classical Hodgkin lymphoma have a 5-year event-free survival of 90% or more with vincristine, etoposide, prednisone, and doxorubicin (OEPA) plus radiotherapy, but late complications of treatment affect survival and quality of life. We investigated whether radiotherapy can be omitted in patients with adequate morphological and metabolic responses to OEPA.

METHODS

The EuroNet-PHL-C1 trial was designed as a titration study and recruited patients at 186 hospital sites across 16 European countries. Children and adolescents with newly diagnosed stage IA, IB, and IIA classical Hodgkin lymphoma younger than 18 years of age were assigned to treatment group 1 to be treated with two cycles of OEPA (vincristine 1·5 mg/m2 intravenously, capped at 2 mg, on days 1, 8, and 15; etoposide 125 mg/m2 intravenously, on days 1-5; prednisone 60 mg/m2 orally on days 1-15; and doxorubicin 40 mg/m2 intravenously on days 1 and 15). If no adequate response (a partial morphological remission or greater and PET negativity) had been achieved after two cycles of OEPA, involved-field radiotherapy was administered at a total dose of 19·8 Gy (usually in 11 fractions of 1·8 Gy per day). The primary endpoint was event-free survival. The primary objective was maintaining a 5-year event-free survival rate of 90% in patients with an adequate response to OEPA without radiotherapy. We performed intention-to-treat and per-protocol analyses. The trial was registered at ClinicalTrials.gov (NCT00433459) and with EUDRACT, (2006-000995-33) and is completed.

FINDINGS

Between Jan 31, 2007, and Jan 30, 2013, 2131 patients were registered and 2102 patients were enrolled onto EuroNet-PHL-C1. Of these 2102 patients, 738 with early-stage disease were allocated to treatment group 1. Median follow-up was 63·3 months (IQR 60·1-69·8). We report on 714 patients assigned to and treated on treatment group 1; the intention-to-treat population comprised 713 patients with 323 (45%) male and 390 (55%) female patients. In 440 of 713 patients in the intention-to-treat group who had an adequate response and did not receive radiotherapy, 5-year event-free survival was 86·5% (95% CI 83·3-89·8), which was less than the 90% target rate. In 273 patients with an inadequate response who received radiotherapy, 5-year event-free survival was 88·6% (95% CI 84·8-92·5), for which the 95% CI included the 90% target rate. The most common grade 3-4 adverse events were neutropenia (in 597 [88%] of 680 patients) and leukopenia (437 [61%] of 712). There were no treatment-related deaths.

INTERPRETATION

On the basis of all the evidence, radiotherapy could be omitted in patients with early-stage classical Hodgkin lymphoma and an adequate response to OEPA, but patients with risk factors might need more intensive treatment.

FUNDING

Deutsche Krebshilfe, Elternverein für Krebs-und leukämiekranke Kinder, Gießen, Kinderkrebsstiftung Mainz of the Journal Oldtimer Markt, Tour der Hoffnung, Menschen für Kinder, Mitteldeutsche Kinderkrebsforschung, Programme Hospitalier de Recherche Clinique, and Cancer Research UK.

Epstein-Barr Virus in Childhood and Adolescent Classic Hodgkin Lymphoma in a French Cohort of 301 Patients

OBJECTIVE

The aim was to analyze the role of Epstein-Barr virus (EBV) in the bioclinical characteristics of patients treated for classic Hodgkin lymphoma (cHL) in France.

METHODS

Biopathologic data of 301 patients treated for a cHL in/or according to the EuroNet PHL-C1 trial between November 2008 and February 2013 were centrally reviewed.

RESULTS

Median age at diagnosis was 14 (3 to 18) years and the F/M ratio 0.86, 0.47 before 10 years and 0.9 from 11 to 18. CHL subtypes were nodular sclerosis for 266/301 (88%) patients, mixed cellularity for 22/301 (7%), lymphocyte rich for 2/301 (1%), and 11/301 were unclassified. EBV positivity by in situ hybridization was observed for 68/301 (23%) patients, significantly associated with mixed cellularity subtype and male sex, particularly overrepresented in boys below 10 years: 15/23 (65%) versus 28/139 among other male patients (20%). EBV viral load was detectable in 22 of 108 (22%) tested cases and was overrepresented in EBV cHL (13/28) versus non-EBV cHL (9/80) patients. Detailed semiquantitative histologic analysis showed a high number of B-cell residual follicles in EBV cHL relative to EBV-negative HL.

CONCLUSION

Distribution of EBV cHL in children and adolescents is associated with young age and male sex, suggesting a specific physiopathology and may require a differential therapeutic approach.

Response-adapted omission of radiotherapy and comparison of consolidation chemotherapy in children and adolescents with intermediate-stage and advanced-stage classical Hodgkin lymphoma (EuroNet-PHL-C1): a titration study with an open-label, embedded, multinational, non-inferiority, randomised controlled trial

BACKGROUND

Children and adolescents with intermediate-stage and advanced-stage classical Hodgkin lymphoma achieve an event-free survival at 5 years of about 90% after treatment with vincristine, etoposide, prednisone, and doxorubicin (OEPA) followed by cyclophosphamide, vincristine, prednisone, and procarbazine (COPP) and radiotherapy, but long-term treatment effects affect survival and quality of life. We aimed to investigate whether radiotherapy can be omitted in patients with morphological and metabolic adequate response to OEPA and whether modified consolidation chemotherapy reduces gonadotoxicity.

METHODS

Our study was designed as a titration study with an open-label, embedded, multinational, non-inferiority, randomised controlled trial, and was carried out at 186 hospital sites across 16 European countries. Children and adolescents with newly diagnosed intermediate-stage (treatment group 2) and advanced-stage (treatment group 3) classical Hodgkin lymphoma who were younger than 18 years and stratified according to risk using Ann Arbor disease stages IIAE, IIB, IIBE, IIIA, IIIAE, IIIB, IIIBE, and all stages IV (A, B, AE, and BE) were included in the study. Patients with early disease (treatment group 1) were excluded from this analysis. All patients were treated with two cycles of OEPA (1·5 mg/m2 vincristine taken intravenously capped at 2 mg, on days 1, 8, and 15; 125 mg/m2 etoposide taken intravenously on days 1-5; 60 mg/m2 prednisone taken orally on days 1-15; and 40 mg/m2 doxorubicin taken intravenously on days 1 and 15). Patients were randomly assigned to two (treatment group 2) or four (treatment group 3) cycles of COPP (500 mg/m2 cyclophosphamide taken intravenously on days 1 and 8; 1·5 mg/m2 vincristine taken intravenously capped at 2 mg, on days 1 and 8; 40 mg/m2 prednisone taken orally on days 1 to 15; and 100 mg/m2 procarbazine taken orally on days 1 to 15) or COPDAC, which was identical to COPP except that 250 mg/m2 dacarbazine administered intravenously on days 1 to 3 replaced procarbazine. The method of randomisation (1:1) was minimisation with stochastic component and was centrally stratified by treatment group, country, trial sites, and sex. The primary endpoint was event-free survival, defined as time from treatment start until the first of the following events: death from any cause, progression or relapse of classical Hodgkin lymphoma, or occurrence of secondary malignancy. The primary objectives were maintaining 90% event-free survival at 5 years in patients with adequate response to OEPA treated without radiotherapy and to exclude a decrease of 8% in event-free survival at 5 years in the embedded COPDAC versus COPP randomisation to show non-inferiority of COPDAC. Efficacy analyses are reported per protocol and safety in the intention-to-treat population. The trial is registered with ClinicalTrials.gov (trial number NCT00433459) and EUDRACT (trial number 2006-000995-33), and is closed to recruitment.

FINDINGS

Between Jan 31, 2007, and Jan 30, 2013, 2102 patients were recruited. 737 (35%) of the 2102 recruited patients were in treatment group 1 (early-stage disease) and were not included in our analysis. 1365 (65%) of the 2102 patients were in treatment group 2 (intermediate-stage disease; n=455) and treatment group 3 (advanced-stage disease; n=910). Of these 1365, 1287 (94%) patients (435 [34%] of 1287 in treatment group 2 and 852 [66%] of 1287 in treatment group 3) were included in the titration trial per-protocol analysis. 937 (69%) of 1365 patients were randomly assigned to COPP (n=471) or COPDAC (n=466) in the embedded trial. Median follow-up was 66·5 months (IQR 62·7-71·7). Of 1287 patients in the per-protocol group, 514 (40%) had an adequate response to treatment and were not treated with radiotherapy (215 [49%] of 435 in treatment group 2 and 299 [35%] of 852 in treatment group 3). 773 (60%) of 1287 patients with inadequate response were scheduled for radiotherapy (220 [51%] of 435 in the treatment group 2 and 553 [65%] of 852 in treatment group 3. In patients who responded adequately, event-free survival rates at 5 years were 90·1% (95% CI 87·5-92·7). event-free survival rates at 5 years in 892 patients who were randomly assigned to treatment and analysed per protocol were 89·9% (95% CI 87·1-92·8) for COPP (n=444) versus 86·1% (82·9-89·4) for COPDAC (n=448). The COPDAC minus COPP difference in event-free survival at 5 years was -3·7% (-8·0 to 0·6). The most common grade 3-4 adverse events (intention-to-treat population) were decreased haemoglobin (205 [15%] of 1365 patients during OEPA vs 37 [7%] of 528 treated with COPP vs 20 [2%] of 819 treated with COPDAC), decreased white blood cells (815 [60%] vs 231 [44%] vs 84 [10%]), and decreased neutrophils (1160 [85%] vs 223 [42%] vs 174 [21%]). One patient in treatment group 2 died of sepsis after the first cycle of OEPA; no other treatment-related deaths occurred.

INTERPRETATION

Our results show that radiotherapy can be omitted in patients who adequately respond to treatment, when consolidated with COPP or COPDAC. COPDAC might be less effective, but is substantially less gonadotoxic than COPP. A high proportion of patients could therefore be spared radiotherapy, eventually reducing the late effects of treatment. With more refined criteria for response assessment, the number of patients who receive radiotherapy will be further decreased.

FUNDING

Deutsche Krebshilfe, Elternverein für Krebs-und leukämiekranke Kinder Gießen, Kinderkrebsstiftung Mainz, Tour der Hoffnung, Menschen für Kinder, Programme Hospitalier de Recherche Clinique, and Cancer Research UK.

Different Clinical Presentations and Outcomes of Disseminated Varicella in Children With Primary and Acquired Immunodeficiencies

Primary infection with varicella-zoster virus (VZV) causes chickenpox, a benign and self-limited disease in healthy children. In patients with primary or acquired immunodeficiencies, primary infection can be life-threatening, due to rapid dissemination of the virus to various organs [lung, gastrointestinal tract, liver, eye, central nervous system (CNS)]. We retrospectively described and compared the clinical presentations and outcomes of disseminated varicella infection (DV) in patients with acquired (AID) (n= 7) and primary (PID) (n= 12) immunodeficiencies. Patients with AID were on immunosuppression (mostly steroids) for nephrotic syndrome, solid organ transplantation or the treatment of hemopathies, whereas those with PID had combined immunodeficiency (CID) or severe CID (SCID). The course of the disease was severe and fulminant in patients with AID, with multiple organ failure, no rash or a delayed rash, whereas patients with CID and SICD presented typical signs of chickenpox, including a rash, with dissemination to other organs, including the lungs and CNS. In the PID group, antiviral treatment was prolonged until immune reconstitution after bone marrow transplantation, which was performed in 10/12 patients. Four patients died, and three experienced neurological sequelae. SCID patients had the worst outcome. Our findings highlight substantial differences in the clinical presentation and course of DV between children with AID and PID, suggesting differences in pathophysiology. Prevention, early diagnosis and treatment are required to improve outcome.

Assessment of Waldeyer's ring in pediatric and adolescent Hodgkin lymphoma patients-Importance of multimodality imaging: Results from the EuroNet-PHL-C1 trial

BACKGROUND

In the EuroNet Pediatric Hodgkin Lymphoma (EuroNet-PHL) trials, decision on Waldeyer's ring (WR) involvement is usually based on clinical assessment, that is, physical examination and/or nasopharyngoscopy. However, clinical assessment only evaluates mucosal surface and is prone to interobserver variability. Modern cross-sectional imaging technology may provide valuable information beyond mucosal surface, which may lead to a more accurate WR staging.

PATIENTS, MATERIALS, AND METHODS

The EuroNet-PHL-C1 trial recruited 2102 patients, of which 1752 underwent central review including reference reading of their cross-sectional imaging data. In 14 of 1752 patients, WR was considered involved according to clinical assessment. In these 14 patients, the WR was re-assessed by applying an imaging-based algorithm considering information from ¹⁸ F-fluorodeoxyglucose positron emission tomography, contrast-enhanced computed tomography, and/or magnetic resonance imaging. For verification purposes, the imaging-based algorithm was applied to 100 consecutive patients whose WR was inconspicuous on clinical assessment.

RESULTS

The imaging-based algorithm confirmed WR involvement only in four of the 14 patients. Of the remaining 10 patients, four had retropharyngeal lymph node involvement and six an inconspicuous WR. Applying the imaging-based algorithm to 100 consecutive patients with physiological appearance of their WR on clinical assessment, absence of WR involvement could be confirmed in 99. However, suspicion of WR involvement was raised in one patient.

CONCLUSIONS

The imaging-based algorithm was feasible and easily applicable at initial staging of young patients with Hodgkin lymphoma. It increased the accuracy of WR staging, which may contribute to a more individualized treatment in the future.

Long term follow-up of pediatric-onset Evans syndrome: broad immunopathological manifestations and high treatment burden

Pediatric-onset Evans syndrome (pES) is defined by both immune thrombocytopenic purpura (ITP) and autoimmune hemolytic anemia (AIHA) before the age of 18 years. There have been no comprehensive long-term studies of this rare disease, which can be associated to various immunopathological manifestations (IM). We report outcomes of the 151 patients with pES and more than 5 years of follow-up from the nationwide French prospective OBS’CEREVANCE cohort. Median age at final follow-up was 18.5 years (range, 6.8–50.0 years) and the median follow-up period was 11.3 years (range, 5.1–38.0 years). At 10 years, ITP and AIHA were in sustained complete remission in 54.5% and 78.4% of patients, respectively. The frequency and number of clinical and biological IM increased with age: at the age of 20 years, 74% had at least one clinical IM (cIM). A wide range of cIM occurred, mainly lymphoproliferation, dermatological, gastrointestinal/hepatic and pneumological IM. The number of cIM was associated with a subsequent increase in the number of second-line treatments received (other than steroids and immunoglobulins; hazard ratio 1.4, 95% Confidence Interval: 1.15–1.60, P=0.0002, Cox proportional hazards method). Survival at 15 years after diagnosis was 84%. Death occurred at a median age of 18 years (range, 1.7–31.5 years), and the most frequent cause was infection. The number of second-line treatments and severe/recurrent infections were independently associated with mortality. In conclusion, long-term outcomes of pES showed remission of cytopenias but frequent IM linked to high second-line treatment burden. Mortality was associated to drugs and/or underlying immunodeficiencies, and adolescents-young adults are a high-risk subgroup.

Frequent altered distribution of peripheral B-lymphocyte subsets in pediatric and adolescent patients with classical Hodgkin lymphoma

Peripheral lymphopenia is a well-known negative prognostic marker in classical Hodgkin lymphoma (cHL). We characterized the peripheral B-cell compartment in a prospective cohort of 83 pediatric cHL patients. We observed significantly low total B-cell counts (<100 cells/µl) in 31 of 83 patients (37%). More specifically, there was a smaller peripheral IgD^highCD27^- naïve B-cell pool among B-cell lymphopenic patients than for non-B-cell lymphopenic patients (p < 0.01). The B-cell count was lower in patients without in situ Epstein Barr Virus (EBV) expression than among those with in situ EBV expression (p = 0.03). Peripheral B-cell lymphopenia was associated with the presence of poor prognostic features, such as advanced lymphoma stage (p < 0.01) and the presence of B symptoms (p = 0.04). Of interest, B-cell lymphopenia resolved in all six studied patients in long-term remission. Our findings support that cHL tumor-associated factors interfere with the distribution of peripheral B-cell subsets.

Pharmacokinetics of Nilotinib in Pediatric Patients with Philadelphia Chromosome-Positive Chronic Myeloid Leukemia or Acute Lymphoblastic Leukemia

PURPOSE

We investigated nilotinib exposure in pediatric patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) resistant to, relapsed on, refractory to, or intolerant of previous treatment.

PATIENTS AND METHODS

Fifteen patients (aged 1-<18 years) with CML resistant to or intolerant of imatinib and/or dasatinib (n = 11) or Ph+ ALL relapsed on or refractory to standard therapy (n = 4) enrolled in this phase I study. Nilotinib (230 mg/m2 twice daily; equivalent to the adult 400-mg twice-daily dose) was administered orally in 12 or 24 cycles of 28 days. The primary objective was to characterize the pharmacokinetics of nilotinib in pediatric patients.

RESULTS

The area under the concentration-time curve at steady state was slightly lower in pediatric patients versus adults (14,751.4 vs. 17,102.9 ng/h/mL); the geometric mean ratio (GMR; pediatric:adult) was 0.86 [90% confidence interval (CI), 0.70-1.06]. Body surface area-adjusted systemic clearance was slightly higher in pediatric versus adult patients (GMR, 1.30; 90% CI, 1.04-1.62). Nilotinib was generally well tolerated. The most common adverse events were headache, vomiting, increased blood bilirubin, and rash. Three patients with CML achieved major molecular response, and three with Ph+ ALL achieved complete remission.

CONCLUSIONS

Nilotinib 230 mg/m2 twice daily in pediatric patients provided a pharmacokinetics and safety profile comparable with the adult reference dose; clinical activity was demonstrated in both CML and Ph+ ALL. This dose is recommended for further evaluation in pediatric patients. The safety profile was consistent with that in adults.

Risk and Response Adapted Treatment Guidelines for Managing First Relapsed and Refractory Classical Hodgkin Lymphoma in Children and Young People. Recommendations from the EuroNet Pediatric Hodgkin Lymphoma Group

The objective of this guideline is to aid clinicians in making individual salvage treatment plans for pediatric and adolescent patients with first relapse or refractory (R/R) classical Hodgkin lymphoma (cHL). While salvage with standard dose chemotherapy followed by high dose chemotherapy and autologous stem cell transplant is often considered the standard of care in adult practice, pediatric practice adopts a more individualized risk stratified and response adapted approach to salvage treatment with greater use of non-transplant salvage. Here, we present on behalf of the EuroNet Pediatric Hodgkin Lymphoma group, evidence and consensus-based guidelines for standardized diagnostic, prognostic and response procedures to allocate children and adolescents with R/R cHL to stratified salvage treatments.

Outcome of relapse in children and adolescents with B-cell non-Hodgkin lymphoma and mature acute leukemia: A report from the French LMB study

INTRODUCTION

In order to describe relapsed B-cell non-Hodgkin lymphoma and mature acute leukemia in children/adolescents treated with the Lymphomes Malins B (LMB) regimen and their outcome in the rituximab era, relapses in the French LMB2001 study were reviewed.

METHODS

Between February 2001 and December 2011, 33 patients out of 773 (4.3%) relapsed; 27 had Burkitt lymphoma and six large B-cell histology. Median age at diagnosis was 10.1 years. One patient was initially treated in risk group A, 21 in group B, and 11 in group C.

RESULTS

Median time to relapse after diagnosis was 4.5 months (range 2.4-13.6). Thirty-two patients received salvage therapy. Twenty-seven received rituximab mainly in addition to high-dose cytarabine and etoposide (n = 18) and/or ifosfamide, carboplatin, and etoposide (n = 7). First-line salvage chemotherapy response rate was 66% with 47% being complete remission (CR). Twenty-one patients received high-dose chemotherapy (HDC) followed by autologous (n = 13) or allogeneic (n = 8) transplant. With a median follow-up of 6.8 years, the 5-year survival rate after relapse was 36.4% (95% confidence interval [CI] 22-53%). Twelve patients were still alive; all but one (group A) received consolidation treatment. Achieving CR before consolidation was significantly associated with better survival, with a 5-year survival rate of 75% (95% CI 46.8-91.1%) for patients in CR before HDC, 33% (95% CI 9.7-70%) for patients in partial remission, and 0% for nonresponders (P = .033).

CONCLUSION

Survival of children/adolescents with mature B-cell lymphoma/leukemia remains poor after relapse with no apparent improvement with rituximab. Response rates to salvage chemo-immunotherapies are insufficient and new drugs are urgently needed to improve disease control.

Immune checkpoint inhibitors in MITF family translocation renal cell carcinomas and genetic correlates of exceptional responders

Background

Microphthalmia Transcription Factor (MITF)family translocation renal cell carcinoma (tRCC) is a rare RCC subtype harboring TFE3/TFEB translocations. The prognosis in the metastatic (m) setting is poor. Programmed death ligand-1 expression was reported in 90% of cases, prompting us to analyze the benefit of immune checkpoint inhibitors (ICI) in this population.

Patients and methods

This multicenter retrospective study identified patients with MITF family mtRCC who had received an ICI in any of 12 referral centers in France or the USA. Response rate according to RECIST criteria, progression-free survival (PFS), and overall survival (OS) were analyzed. Genomic alterations associated with response were determined for 8 patients.

Results

Overall, 24 patients with metastatic disease who received an ICI as second or later line of treatment were identified. Nineteen (82.6%) of these patients had received a VEGFR inhibitor as first-line treatment, with a median PFS of 3 months (range, 1–22 months). The median PFS for patients during first ICI treatment was 2.5 months (range, 1–40 months); 4 patients experienced partial response (16,7%) and 3 (12,5%) had stable disease. Of the patients whose genomic alterations were analyzed, two patients with mutations in bromodomain-containing genes (PBRM1 and BRD8) had a clinical benefit. Resistant clones in a patient with exceptional response to ipilimumab showed loss of BRD8 mutations and increased mutational load driven by parallel evolution affecting 17 genes (median mutations per gene, 3), which were enriched mainly for O-glycan processing (29.4%, FDR = 9.7 × 10^− 6).

Conclusions

MITF family tRCC is an aggressive disease with similar responses to ICIs as clear-cell RCC. Mutations in bromodomain-containing genes might be associated with clinical benefit. The unexpected observation about parallel evolution of genes involved in O-glycosylation as a mechanism of resistance to ICI warrants exploration.

18F-FDG PET Response of Skeletal (Bone Marrow and Bone) Involvement After Induction Chemotherapy in Pediatric Hodgkin Lymphoma: Are Specific Response Criteria Required?

To determine whether the current ¹⁸F-FDG PET response criterion for skeletal involvement in Hodgkin lymphoma (HL) is suitable, we performed a systematic evaluation of the different types of skeletal involvement and their response on PET after 2 cycles of chemotherapy (PET-2). A secondary objective was to observe the influence of the initial uptake intensity (measured as qPET) and initial metabolic tumor volume (MTV) of skeletal lesions on the PET-2 response. Methods: The initial PET scans of 1,068 pediatric HL patients from the EuroNet-PHL-C1 trial were evaluated for skeletal involvement by central review. Three types of skeletal lesions were distinguished: PET-only lesions (those detected on PET only), bone marrow (BM) lesions (as confirmed by MRI or BM biopsy), and bone lesions. qPET and MTV were calculated for each skeletal lesion. All PET-2 scans were assessed for residual tumor activity. The rates of complete metabolic response for skeletal and nodal involvement on PET-2 were compared. Results: Of the 1,068 patients, 139 (13%) showed skeletal involvement (44 PET-only, 32 BM, and 63 bone). Of the 139 patients with skeletal involvement, 101 (73%) became PET-2-negative in the skeleton and 94 (68%) became PET-2-negative in the lymph nodes. The highest number of PET-2-negative scans in the skeleton was 42 (95%) in the 44 PET-only patients, followed by 22 skeletal lesions (69%) in the 32 BM patients and 37 (59%) in the 63 bone patients. Lesions that became PET-2-negative showed a lower initial median qPET (2.74) and MTV (2 cm³) than lesions that remained PET-2-positive (3.84 and 7 cm³, respectively). Conclusion: In this study with pediatric HL patients, the complete response rate for skeletal involvement on PET-2 was similar to that for nodal involvement. Bone flare seemed to be irrelevant. Overall, the current skeletal PET response criterion-comparison with the local skeletal background-is well suited. The initial qPET and MTV of skeletal lesions were predictive of the PET-2 result. Higher values for both parameters were associated with a worse PET-2 response.

Dasatinib in Pediatric Patients With Chronic Myeloid Leukemia in Chronic Phase: Results From a Phase II Trial

Purpose Safe, effective treatments are needed for pediatric patients with chronic myeloid leukemia in chronic phase (CML-CP). Dasatinib is approved for treatment of adults and children with CML-CP. A phase I study determined suitable dosing for children with Philadelphia chromosome-positive (Ph+) leukemias. Methods CA180-226/NCT00777036 is a phase II, open-label, nonrandomized prospective trial of patients < 18 years of age receiving dasatinib. There are three cohorts: (1) imatinib-resistant/intolerant CML-CP, (2) imatinib-resistant/intolerant CML in accelerated/blast phase or Ph+ acute lymphoblastic leukemia (n = 17), and (3) newly diagnosed CML-CP treated with tablets or powder for oral suspension. Major cytogenetic response > 30% for imatinib-resistant/intolerant patients and complete cytogenetic response (CCyR) > 55% for newly diagnosed patients were of clinical interest. Results Of 113 patients with CML-CP, 14 (48%) who were imatinib-resistant/intolerant and 61 (73%) who were newly diagnosed remained on treatment at time of analysis. Major cytogenetic response > 30% was reached by 3 months in the imatinib-resistant/intolerant group and CCyR > 55% was reached by 6 months in the newly diagnosed CML-CP group. CCyR and major molecular response by 12 months, respectively, were 76% and 41% in the imatinib-resistant/intolerant group and 92% and 52% in newly diagnosed CML-CP group. Progression-free survival by 48 months was 78% and 93% in the imatinib-resistant/intolerant and newly diagnosed CML-CP groups, respectively. No dasatinib-related pleural or pericardial effusion, pulmonary edema, or pulmonary arterial hypertension were reported. Bone growth and development events were reported in 4% of patients. Conclusion In the largest prospective trial to date in children with CML-CP, we demonstrate that dasatinib is a safe, effective treatment of pediatric CML-CP. Target responses to first- or second-line dasatinib were met early, and deep molecular responses were observed. Safety of dasatinib in pediatric patients was similar to that observed in adults; however, no cases of pleural or pericardial effusion or pulmonary arterial hypertension were reported.

Speed of leukemia development and genetic diversity in xenograft models of T cell acute lymphoblastic leukemia

T cell acute lymphoblastic leukemia (T-ALL) develops through accumulation of multiple genomic alterations within T-cell progenitors resulting in clonal heterogeneity among leukemic cells. Human T-ALL xeno-transplantation in immunodeficient mice is a gold standard approach to study leukemia biology and we recently uncovered that the leukemia development is more or less rapid depending on T-ALL sample. The resulting human leukemia may arise through genetic selection and we previously showed that human T-ALL development in immune-deficient mice is significantly enhanced upon CD7⁺/CD34⁺ leukemic cell transplantations. Here we investigated the genetic characteristics of CD7⁺/CD34⁺ and CD7⁺/CD34⁻ cells from newly diagnosed human T-ALL and correlated it to the speed of leukemia development. We observed that CD7⁺/CD34⁺ or CD7⁺/CD34⁻ T-ALL cells that promote leukemia within a short-time period are genetically similar, as well as xenograft-derived leukemia resulting from both cell fractions. In the case of delayed T-ALL growth CD7⁺/CD34⁺ or CD7⁺/CD34⁻ cells were either genetically diverse, the resulting xenograft leukemia arising from different but branched subclones present in the original sample, or similar, indicating decreased fitness to mouse micro-environment. Altogether, our work provides new information relating the speed of leukemia development in xenografts to the genetic diversity of T-ALL cell compartments.

Pediatric-onset Evans syndrome: Heterogeneous presentation and high frequency of monogenic disorders including LRBA and CTLA4 mutations

Evans syndrome (ES) is defined by the combination of autoimmune hemolytic anemia and immune thrombocytopenia. Clinical presentation includes manifestations of immune dysregulation, found in primary immune deficiencies, autoimmune lymphoproliferative syndrome with FAS (ALPS-FAS), Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) and Lipopolysaccharide-Responsive vesicle trafficking Beige-like and Anchor protein (LRBA) defects. We report the clinical history and genetic results of 18 children with ES after excluding ALPS-FAS. Thirteen had organomegaly, five lymphocytic infiltration of non-lymphoid organs, nine hypogammaglobulinemia and fifteen anomalies in lymphocyte phenotyping. Seven patients had genetic defects: three CTLA4 mutations (c.151C>T; c.109+1092_568-512del; c.110-2A>G) identified by Sanger sequencing and four revealed by Next Generation Sequencing: LRBA (c.2450+1C>T), STAT3 gain-of-function (c.2147C>T; c.2144C>T) and KRAS (c.37G>T). No feature emerged to distinguish patients with or without genetic diagnosis. Our data on pediatric-onset ES should prompt physicians to perform extensive screening for mutations in the growing pool of genes involved in primary immune deficiencies with autoimmunity.

Staging Evaluation and Response Criteria Harmonization (SEARCH) for Childhood, Adolescent and Young Adult Hodgkin Lymphoma (CAYAHL): Methodology statement

International harmonization of staging evaluation and response criteria is needed for childhood, adolescence, and young adulthood Hodgkin lymphoma. Two Hodgkin lymphoma protocols from cooperative trials in Europe and North America were compared for areas in need of harmonization, and an evidence-based approach is currently underway to harmonize staging and response evaluations with a goal to enhance comparisons, expedite identification of effective therapies, and aid in the approval process for new agents by regulatory agencies.

Phase II trial of dasatinib (DAS) in pediatric patients (pts) with chronic myeloid leukemia in chronic phase (CML-CP)

10511

Background: Safe and effective treatment options for newly diagnosed (ND) or imatinib (IM) resistant/intolerant (R/I) pediatric CML pts are limited, and a large prospective study is needed. DAS has proven safety and efficacy in adults with ND or IM-R/I CML and is now being evaluated in a phase II trial of pediatric pts. Methods: CA180-226/NCT00777036 is an open-label nonrandomized prospective study of pts aged <18 y in 3 cohorts: (1) CML-CP R/I to IM treated with DAS tablets 60 mg/m2 QD, (2) IM-R/I CML-AP/BP or Ph+ ALL (enrollment closed early due to poor response), and (3) ND CML-CP treated with DAS tablets 60 mg/m2 or DAS 72 mg/m2powder for oral suspension (PFOS) QD. Primary objectives were major cytogenetic response (MCyR) for CML-CP R/I to IM and complete cytogenetic response (CCyR) for ND CML-CP (MCyR >30% and CCyR >55% considered of clinical interest). Results: 113 pediatric CML-CP pts were treated. Cumulative rate of MCyR >30% was reached as early as 3 mo (55%; [95% CI 36, 74]) for IM-R/I CML-CP. Cumulative rate of CCyR >55% was reached as early as 6 mo (64% [95% CI 53, 74] for ND CML-CP; 61% [95% CI 46, 74] for pts on tablets and 70% [95% CI 51, 84] for pts on PFOS). Estimated PFS by 48 mo was >75% for CML-CP R/I to IM and >90% for ND CML-CP. One CML-CP pt R/I to IM died 1 y after stopping DAS from gastrointestinal bleeding. AEs were consistent with those observed in adults, except no DAS-related pleural/pericardial effusion or pulmonary arterial hypertension (PAH) were reported here. Conclusions: In the largest prospective trial of pediatric pts with CML-CP, target responses were met early and increased over time with DAS treatment. The efficacy and safety of DAS were consistent with previous reports in adults, except no cases of pleural/pericardial effusion or PAH were observed. These results suggest DAS is safe and highly effective in the first- or second-line treatment of pediatric CML-CP. Clinical trial information: NCT00777036. [Table: see text]

Advanced stage nodular lymphocyte predominant Hodgkin lymphoma in children and adolescents: clinical characteristics and treatment outcome - a report from the SFCE & CCLG groups

Advanced stage nodular lymphocyte predominant Hodgkin lymphoma (nLPHL) is extremely rare in children and as a consequence, optimal treatment for this group of patients has not been established. Here we retrospectively evaluated the treatments and treatment outcomes of 41 of our patients from the UK and France with advanced stage nLPHL. Most patients received chemotherapy, some with the addition of the anti CD20 antibody rituximab or radiotherapy. Chemotherapy regimens were diverse and followed either classical Hodgkin lymphoma or B non-Hodgkin lymphoma protocols. All 41 patients achieved a complete remission with first line treatment and 40 patients are alive and well in remission. Eight patients subsequently relapsed and 1 patient died of secondary cancer (9 progression-free survival events). The median time to progression for those who progressed was 21 months (5·9-73·8). The median time since last diagnosis is 87·3 months (8·44-179·20). Thirty-six (90%), 30 (75%) and 27 (68%) patients have been in remission for more than 12, 24 and 36 months, respectively. Overall, the use of rituximab combined with multi-agent chemotherapy as first line treatment seems to be a reasonable therapeutic option.

Combined therapy in children and adolescents with classical Hodgkin's lymphoma: A report from the SFCE on MDH-03 national guidelines

Hodgkin's lymphoma (HL) in children and adolescents is highly curable, but children are at risk of long-term toxicity. The MDH-03 guidelines were established in order to decrease the burden of treatment in good-responder patients, and this report should be considered a step toward further optimization of treatment within large collaborative trials. We report the therapy and long-term outcomes of 417 children and adolescents treated according to the national guidelines, which were applied between 2003 and 2007 in France. The patients were stratified into three groups according to disease extension. Chemotherapy consisted of four cycles of VBVP (vinblastine, bleomycin, VP16, prednisone) in localized stages (G1/95 pts/23%), four cycles of COPP/ABV (cyclophosphamide, vincristine, procarbazine, prednisone, adriamycin, bleomycin, vinblastine) cycles in intermediate stages (G2/184 pts/44%) and three cycles of OPPA (vincristine, procarbazine, prednisone, adriamycin) plus three cycles of COPP in advanced stages (G3/138 pts/33%). Radiation therapy of the involved field was given to 97% of the patients, with the dose limited to 20 Gy in good responders (88%). With a median follow-up of 6.6 years, the 5-year event-free survival (EFS) and overall survival (OS) were 86.7% (83.1-89.7%) and 97% (94.5-98.1%), respectively. EFS and OS for G1, G2, and G3 were 98% and 100%, 81% and 97%, and 87% and 95%, respectively. Low-risk patients treated without alkylating agents and anthracycline had excellent outcomes and a low expected incidence of late effects. Intensification with a third OPPA cycle in high-risk group patients, including stage IV patients, allowed for very good outcomes, without increased toxicity.

Long-term outcome of children with pediatric-onset cutaneous and visceral polyarteritis nodosa

OBJECTIVE

To assess the prognostic impact of clinical presentation in children with polyarteritis nodosa (PAN).

METHODS

Children diagnosed between 1986 and 2006 in a tertiary care pediatric rheumatology center were classified as "cutaneous PAN" (group 1), "cutaneous PAN with significant extra-cutaneous features" (group 2) or "visceral childhood PAN" (group 3).

OUTCOME MEASURES

(1) clinical remission off-therapy at last follow-up, (2) requirement and length of glucocorticoid therapy, (3) presence of disease-related sequelae.

RESULTS

Twenty-nine children were included. Sixteen met the Ankara criteria for PAN. Nine patients were qualified as group 1, 11 as group 2, and 9 as group 3. At last follow-up, 15 children were in clinical remission off-therapy: 4 from group 1 (44%), 4 from group 2 (36%) and 7 from group 3 (78%). Glucocorticoid therapy was required for 8 (89%), 7 (64%) and 7 (78%) patients from groups 1, 2 and 3, respectively. Seven children did not require any glucocorticoid therapy. Time-dependent probability of achieving glucocorticoid-free clinical remission was similar between the three groups. Three patients (one from each group) had digital ischemia leading to amputation. There were no significant between-group differences in outcome based on the three outcome measures addressed.

CONCLUSION

Outcome was not strikingly predictable from initial presentation in children with PAN. The organ distribution-based distinction between cutaneous and visceral PAN had little prognostic power in this series.

Interleukin-18 produced by bone marrow-derived stromal cells supports T-cell acute leukaemia progression

Development of novel therapies is critical for T-cell acute leukaemia (T-ALL). Here, we investigated the effect of inhibiting the MAPK/MEK/ERK pathway on T-ALL cell growth. Unexpectedly, MEK inhibitors (MEKi) enhanced growth of 70% of human T-ALL cell samples cultured on stromal cells independently of NOTCH activation and maintained their ability to propagate in vivo. Similar results were obtained when T-ALL cells were cultured with ERK1/2-knockdown stromal cells or with conditioned medium from MEKi-treated stromal cells. Microarray analysis identified interleukin 18 (IL-18) as transcriptionally up-regulated in MEKi-treated MS5 cells. Recombinant IL-18 promoted T-ALL growth in vitro, whereas the loss of function of IL-18 receptor in T-ALL blast cells decreased blast proliferation in vitro and in NSG mice. The NFKB pathway that is downstream to IL-18R was activated by IL-18 in blast cells. IL-18 circulating levels were increased in T-ALL-xenografted mice and also in T-ALL patients in comparison with controls. This study uncovers a novel role of the pro-inflammatory cytokine IL-18 and outlines the microenvironment involvement in human T-ALL development.

qPET - a quantitative extension of the Deauville scale to assess response in interim FDG-PET scans in lymphoma

BACKGROUND

Interim FDG-PET is used for treatment tailoring in lymphoma. Deauville response criteria consist of five ordinal categories based on visual comparison of residual tumor uptake to physiological reference uptakes. However, PET-response is a continuum and visual assessments can be distorted by optical illusions.

OBJECTIVES

With a novel semi-automatic quantification tool we eliminate optical illusions and extend the Deauville score to a continuous scale.

PATIENTS AND METHODS

SUVpeak of residual tumors and average uptake of the liver is measured with standardized volumes of interest. The qPET value is the quotient of these measurements. Deauville scores and qPET-values were determined in 898 pediatric Hodgkin's lymphoma patients after two OEPA chemotherapy cycles.

RESULTS

Deauville categories translate to thresholds on the qPET scale: Categories 3, 4, 5 correspond to qPET values of 0.95, 1.3 and 2.0, respectively. The distribution of qPET values is unimodal with a peak representing metabolically normal responses and a tail of clearly abnormal outliers. In our patients, the peak is at qPET = 0.95 coinciding with the border between Deauville 2 and 3. qPET cut values of 1.3 or 2 (determined by fitting mixture models) select abnormal metabolic responses with high sensitivity, respectively, specificity.

CONCLUSIONS

qPET methodology provides semi-automatic quantification for interim FDG-PET response in lymphoma extending ordinal Deauville scoring to a continuous scale. Deauville categories correspond to certain qPET cut values. Thresholds between normal and abnormal response can be derived from the qPET-distribution without need for follow-up data. In our patients, qPET < 1.3 excludes abnormal response with high sensitivity.

SPRED1, a RAS MAPK pathway inhibitor that causes Legius syndrome, is a tumour suppressor downregulated in paediatric acute myeloblastic leukaemia

Constitutional dominant loss-of-function mutations in the SPRED1 gene cause a rare phenotype referred as neurofibromatosis type 1 (NF1)-like syndrome or Legius syndrome, consisted of multiple café-au-lait macules, axillary freckling, learning disabilities and macrocephaly. SPRED1 is a negative regulator of the RAS MAPK pathway and can interact with neurofibromin, the NF1 gene product. Individuals with NF1 have a higher risk of haematological malignancies. SPRED1 is highly expressed in haematopoietic cells and negatively regulates haematopoiesis. SPRED1 seemed to be a good candidate for leukaemia predisposition or transformation. We performed SPRED1 mutation screening and expression status in 230 paediatric lymphoblastic and acute myeloblastic leukaemias (AMLs). We found a loss-of-function frameshift SPRED1 mutation in a patient with Legius syndrome. In this patient, the leukaemia blasts karyotype showed a SPRED1 loss of heterozygosity, confirming SPRED1 as a tumour suppressor. Our observation confirmed that acute leukaemias are rare complications of the Legius syndrome. Moreover, SPRED1 was significantly decreased at RNA and protein levels in the majority of AMLs at diagnosis compared with normal or paired complete remission bone marrows. SPRED1 decreased expression correlated with genetic features of AML. Our study reveals a new mechanism which contributes to deregulate RAS MAPK pathway in the vast majority of paediatric AMLs.

Phase II study of temozolomide in combination with topotecan (TOTEM) in relapsed or refractory neuroblastoma: a European Innovative Therapies for Children with Cancer-SIOP-European Neuroblastoma study

PURPOSE

To assess objective response rate (ORR) after two cycles of temozolomide in combination with topotecan (TOTEM) in children with refractory or relapsed neuroblastoma.

PATIENTS AND METHODS

This multicenter, non-randomised, phase II study included children with neuroblastoma according to a two-stage Simon design. Eligibility criteria included relapsed or refractory, measurable or metaiodobenzylguanidine (mIBG) evaluable disease, no more than two lines of prior treatment. Temozolomide was administered orally at 150mg/m(2) followed by topotecan at 0.75mg/m(2) intravenously for five consecutive days every 28days. Tumour response was assessed every two cycles according to International Neuroblastoma Response Criteria (INRC), and reviewed independently.

RESULTS

Thirty-eight patients were enroled and treated in 15 European centres with a median age of 5.4years. Partial tumour response after two cycles was observed in 7 out of 38 evaluable patients [ORR 18%, 95% confidence interval (CI) 8-34%]. The best ORR whatever the time of evaluation was 24% (95% CI, 11-40%) with a median response duration of 8.5months. Tumour control rate (complete response (CR)+partial response (PR)+mixed response (MR)+stable disease (SD)) was 68% (95% CI, 63-90%). The 12-months Progression-Free and Overall Survival were 42% and 58% respectively. Among 213 treatment cycles (median 4, range 1-12 per patient) the most common treatment-related toxicities were haematologic. Grade 3/4 neutropenia occurred in 62% of courses in 89% of patients, grade 3/4 thrombocytopenia in 47% of courses in 71% of patients; three patients (8%) had febrile neutropenia.

CONCLUSION

Temozolomide-Topotecan combination results in very encouraging ORR and tumour control in children with heavily pretreated recurrent and refractory neuroblastoma with favourable toxicity profile.

Parental comprehension of the benefits/risks of first-line randomised clinical trials in children with solid tumours: a two-stage cross-sectional interview study

OBJECTIVES

To analyse the parental understanding of informed consent information in first-line randomised clinical trials (RCTs) including children with malignant solid tumours and to assess parents' needs for decision-making.

DESIGN

Observational prospective study.

SETTING

3 paediatric oncology centres in the Parisian region in France.

PARTICIPANTS

53 parents were approached to participate in a RCT for their child with malignant solid tumour, over a 1-year period. 40 parents have been interviewed in our study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Parental understanding of information in RCTs, parents' needs for decision-making. Parents were questioned by a psychologist, independent of the paediatric oncology teams, using a semidirected interview, 1 (M1) and 6 months (M6) after the consent was sought.

RESULTS

18 parents (45%) did not understand the concept of randomisation. Half of the parents could explain neither the aim of the clinical trial nor the potential benefit to their child of inclusion. 35 parents (87.5%) expressed very few specific risks related to the trial. Being mostly French-speaking (p=0.03) and the reading of the information sheet by the parents (p=0.0025) improved their understanding. The parental comprehension did not differ between M1 and M6. The principal factors underlying their decision were confidence in the medical team (39%), wish to access to the best treatment (37%) and the best quality of life (37%).

CONCLUSIONS

Despite medical explanations, parents have limited knowledge in some areas in first-line RCTs and improvements of information process are required. The risks specific to the randomised trial are underestimated by parents and the unproven nature of the treatment is not well-known or understood.

Phase I/II study of brentuximab vedotin in pediatric patients (pts) with relapsed or refractory (RR) Hodgkin lymphoma (HL) or systemic anaplastic large-cell lymphoma (sALCL): Interim phase (ph) I safety data

10028

Background: Brentuximab vedotin (ADCETRIS) is a novel antibody-drug conjugate that targets CD30, a cell surface antigen expressed by HL and sALCL. The ph 1 portion of this study evaluated safety, pharmacokinetics (PK), and recommended ph 2 dose (RP2D) of brentuximab vedotin in pediatric pts with RR CD30-expressing tumors. Methods: Ph 1/2, open-label, multicenter study in pts aged 2 to <18 years with RR HL or sALCL (5 to <18 years for HL). Pts received brentuximab vedotin by IV infusion once every 21 days (Q3wk). Ph 1 start dose was 1.4 mg/kg escalated to 1.8 mg/kg in a traditional 3+3 design. Results: 12 pts (median age 14.5 y; 10 HL; 2 sALCL) received brentuximab vedotin in the ph 1 portion (mg/kg/dose [n]: 1.4, [3]; 1.8 [9]). 1.8 mg/kg cohort was expanded from 6 to 9 pts to raise the ph 1 pediatric experience to 12 pts before the ph 2 portion. At data cut, pts had received a median of 3 cycles (range, 1–8). 11 pts (92%) had ≥1 treatment-emergent adverse event (TEAE): 2 at 1.4 mg/kg, 9 at 1.8 mg/kg. 6 pts (50%) had Gr ≥3 TEAE: 1 at 1.4 mg/kg, 5 at 1.8 mg/kg. The most frequent (≥15%) TEAE were nausea (50%), abdominal pain, diarrhea (25% each), upper abdominal pain, cough, fatigue, hypokalemia, leukopenia, decreased lymphocyte count, pain, paresthesia, vomiting, weight loss (17% each). 1 pt (8%) discontinued due to TEAE (Gr 3 hepatotoxicity). 7 serious AE (SAE) were reported in 4 pts at 1.8 mg/kg: Gr 2 supraventricular tachycardia unrelated to treatment in 1 pt; Gr 3 febrile neutropenia, Gr 3 hepatotoxicity and Gr 3 cardiac failure (not a cardiac event per later analysis) in 1 pt; Gr 3 bronchospasm and Gr 2 laryngeal edema in 1 pt; 1 cardiac arrest resulting in death, unrelated to treatment. 2 dose limiting toxicities were reported in 1 pt in the 1.8 mg/kg cohort (SAE: prolonged Gr 3 liver event, Gr 3 febrile neutropenia). PK data will be presented. Conclusions: Brentuximab vedotin is generally well tolerated in pediatric pts with RR CD30-positive HL or sALCL up to 1.8 mg/kg Q3wk. For the majority of pts, toxicities were generally mild to moderate and did not lead to discontinuation. 1.8 mg/kg is the RP2D for pediatric and adult pts. The ph 2 portion is ongoing. Clinical trial information: NCT01492088.