Paediatric Strategy Forum for medicinal product development of chimeric antigen receptor T-cells in children and adolescents with cancer: ACCELERATE in collaboration with the European Medicines Agency with participation of the Food and Drug Administration.

The seventh multi-stakeholder Paediatric Strategy Forum focused on chimeric antigen receptor (CAR) T-cells for children and adolescents with cancer. The development of CAR T-cells for patients with haematological malignancies, especially B-cell precursor acute lymphoblastic leukaemia (BCP-ALL), has been spectacular. However, currently, there are scientific, clinical and logistical challenges for use of CAR T-cells in BCP-ALL and other paediatric malignancies, particularly in acute myeloid leukaemia (AML), lymphomas and solid tumours. The aims of the Forum were to summarise the current landscape of CAR T-cell therapy development in paediatrics, too identify current challenges and future directions, with consideration of other immune effector modalities and ascertain the best strategies to accelerate their development and availability to children. Although the effect is of limited duration in about half of the patients, anti-CD19 CAR T-cells produce high response rates in relapsed/refractory BCP-ALL and this has highlighted previously unknown mechanisms of relapse. CAR T-cell treatment as first- or second-line therapy could also potentially benefit patients whose disease has high-risk features associated with relapse and failure of conventional therapies. Identifying patients with very early and early relapse in whom CAR T-cell therapy may replace haematopoietic stem cell transplantation and be definitive therapy versus those in whom it provides a more effective bridge to haematopoietic stem cell transplantation is a very high priority. Development of approaches to improve persistence, either by improving T cell fitness or using more humanised/fully humanised products and co-targeting of multiple antigens to prevent antigen escape, could potentially further optimise therapy. Many differences exist between paediatric B-cell non-Hodgkin lymphomas (B-NHL) and BCP-ALL. In view of the very small patient numbers with relapsed lymphoma, careful prioritisation is needed to evaluate CAR T-cells in children with Burkitt lymphoma, primary mediastinal B cell lymphoma and other NHL subtypes. Combination trials of alternative targets to CD19 (CD20 or CD22) should also be explored as a priority to improve efficacy in this population. Development of CD30 CAR T-cell immunotherapy strategies in patients with relapsed/refractory Hodgkin lymphoma will likely be most efficiently accomplished by joint paediatric and adult trials. CAR T-cell approaches are early in development for AML and T-ALL, given the unique challenges of successful immunotherapy actualisation in these diseases. At this time, CD33 and CD123 appear to be the most universal targets in AML and CD7 in T-ALL. The results of ongoing or planned first-in-human studies are required to facilitate further understanding. There are promising early results in solid tumours, particularly with GD2 targeting cell therapies in neuroblastoma and central nervous system gliomas that represent significant unmet clinical needs. Further understanding of biology is critical to success. The comparative benefits of autologous versus allogeneic CAR T-cells, T-cells engineered with T cell receptors T-cells engineered with T cell receptor fusion constructs, CAR Natural Killer (NK)-cell products, bispecific T-cell engager antibodies and antibody-drug conjugates require evaluation in paediatric malignancies. Early and proactive academia and multi-company engagement are mandatory to advance cellular immunotherapies in paediatric oncology. Regulatory advice should be sought very early in the design and preparation of clinical trials of innovative medicines, for which regulatory approval may ultimately be sought. Aligning strategic, scientific, regulatory, health technology and funding requirements from the inception of a clinical trial is especially important as these are very expensive therapies. The model for drug development for cell therapy in paediatric oncology could also involve a 'later stage handoff' to industry after early development in academic hands. Finally, and very importantly, strategies must evolve to ensure appropriate ease of access for children who need and could potentially benefit from these therapies.

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.

Favorable Trisomies and ETV6-RUNX1 Predict Cure in Low-Risk B-Cell Acute Lymphoblastic Leukemia: Results From Children's Oncology Group Trial AALL0331.

PURPOSE: Children's Oncology Group (COG) AALL0331 tested whether pegaspargase intensification on a low-intensity chemotherapy backbone would improve the continuous complete remission (CCR) rate in a low-risk subset of children with standard-risk B-acute lymphoblastic leukemia (ALL). METHODS: AALL0331 enrolled 5,377 patients with National Cancer Institute standard-risk B-ALL (age 1-9 years, WBC < 50,000/µL) between 2005 and 2010. Following a common three-drug induction, a cohort of 1,857 eligible patients participated in the low-risk ALL random assignment. Low-risk criteria included no extramedullary disease, < 5% marrow blasts by day 15, end-induction marrow minimal residual disease < 0.1%, and favorable cytogenetics (ETV6-RUNX1 fusion or simultaneous trisomies of chromosomes 4, 10, and 17). Random assignment was to standard COG low-intensity therapy (including two pegaspargase doses, one each during induction and delayed intensification) with or without four additional pegaspargase doses at 3-week intervals during consolidation and interim maintenance. The study was powered to detect a 4% improvement in 6-year CCR rate from 92% to 96%. RESULTS: The 6-year CCR and overall survival (OS) rates for the entire low-risk cohort were 94.7% ± 0.6% and 98.7% ± 0.3%, respectively. The CCR rates were similar between arms (intensified pegaspargase 95.3% ± 0.8% v standard 94.0% ± 0.8%; P = .13) with no difference in OS (98.1% ± 0.5% v 99.2% ± 0.3%; P = .99). Compared to a subset of standard-risk study patients given identical therapy who had the same early response characteristics but did not have favorable or unfavorable cytogenetics, outcomes were significantly superior for low-risk patients (CCR hazard ratio 1.95; P = .0004; OS hazard ratio 5.42; P < .0001). CONCLUSION: Standard COG therapy without intensified pegaspargase, which can easily be given as an outpatient with limited toxicity, cures nearly all children with B-ALL identified as low-risk by clinical, early response, and favorable cytogenetic criteria.

Increased Toxicity Among Adolescents and Young Adults Compared with Children Hospitalized with Acute Lymphoblastic Leukemia at Children's Hospitals in the United States.

Purpose: Adolescent and young adult (AYA) patients (15-39 years old) with acute lymphoblastic leukemia (ALL) have less favorable outcomes and higher treatment-related mortality as compared with older children with ALL. Minimal data exist regarding how well AYA patients tolerate the intensity of chemotherapy at doses and regimens designed for children, and the toxicities suffered by this population at children's hospitals have not been thoroughly characterized. Methods: Pediatric Health Information Systems database was queried to analyze health care outcomes in pediatric (ages 10-14) and AYA patients (ages 15-39) with ALL hospitalized between January 1999 and December 2014. We extracted relevant ICD-9 data for each patient related to grades 3 or 4 toxicities as outlined by the NCI. Results: A total of 5345 hospital admissions met inclusion criteria, representing 4046 unique patients. Of these admissions, 2195 (41.1%) were in the AYA age group, and the remainder were in the 10-14-year-old group. AYA patients had a significantly higher incidence of intensive care unit stay but no difference in median hospital stay nor mortality. AYA patients had increased toxicities in almost every organ system as compared with older children. Conclusions: In this large multicenter US database study, we found an overall increased number of toxicities among AYA patients with ALL in children's hospitals. Compared with children between the ages of 10 and 15, AYA patients developed disproportionately higher toxicities from drugs commonly used in pediatric protocols for ALL. Prospective studies are needed to assess whether dose modifications for certain chemotherapeutics may improve the toxicity profile and health care burden of AYA patients with ALL treated in children's hospitals.

Outcome in Children With Standard-Risk B-Cell Acute Lymphoblastic Leukemia: Results of Children's Oncology Group Trial AALL0331.

PURPOSE: Children's Oncology Group (COG) AALL0331 tested whether intensified postinduction therapy that improves survival in children with high-risk B-cell acute lymphoblastic leukemia (ALL) would also improve outcomes for those with standard-risk (SR) ALL. PATIENTS AND METHODS: AALL0331 enrolled 5,377 patients between 2005 and 2010. All patients received a 3-drug induction with dexamethasone, vincristine, and pegaspargase (PEG) and were then classified as SR low, SR average, or SR high. Patients with SR-average disease were randomly assigned to receive either standard 4-week consolidation (SC) or 8-week intensified augmented Berlin-Frankfurt-Münster (BFM) consolidation (IC). Those with SR-high disease were nonrandomly assigned to the full COG-augmented BFM regimen, including 2 interim maintenance and delayed intensification phases. RESULTS: The 6-year event-free survival (EFS) rate for all patients enrolled in AALL0331 was 88.96% ± 0.46%, and overall survival (OS) was 95.54% ± 0.31%. For patients with SR-average disease, the 6-year continuous complete remission (CCR) and OS rates for SC versus IC were 87.8% ± 1.3% versus 89.1% ± 1.2% (P = .52) and 95.8% ± 0.8% versus 95.2% ± 0.8% (P = 1.0), respectively. Those with SR-average disease with end-induction minimal residual disease (MRD) of 0.01% to < 0.1% had an inferior outcome compared with those with lower MRD and no improvement with IC (6-year CCR: SC, 77.5% ± 4.8%; IC, 77.1% ± 4.8%; P = .71). At 6 years, the CCR and OS rates among 635 nonrandomly treated patients with SR-high disease were 85.55% ± 1.49% and 92.97% ± 1.08%, respectively. CONCLUSION: The 6-year OS rate for > 5,000 children with SR ALL enrolled in AALL0331 exceeded 95%. The addition of IC to treatment for patients with SR-average disease did not improve CCR or OS, even in patients with higher MRD, in whom it might have been predicted to provide more value. The EFS and OS rates are excellent for this group of patients with SR ALL, with particularly good outcomes for those with SR-high disease.

Excellent long-term survival of children with Down syndrome and standard-risk ALL: a report from the Children's Oncology Group.

The Children's Cancer Group 1991 study was a clinical trial for children with National Cancer Institute standard-risk acute lymphoblastic leukemia (ALL). This trial demonstrated that 5 doses of vincristine and escalating IV methotrexate (MTX) without leucovorin rescue in the interim maintenance (IM) phases resulted in superior event-free survival (EFS) when compared with 2 doses of vincristine, oral (PO) MTX, PO mercaptopurine, and dexamethasone. This report describes a favorable outcome of this regimen in patients with Down syndrome (DS). Forty-four patients with DS were randomized to the arms containing PO MTX during IM, and 31 to those containing IV MTX. Ten-year EFS rates for patients with DS randomized to IV MTX vs PO MTX were 94.4% ± 5.4% vs 81.5% ± 6.6%, respectively. IV methotrexate with strict escalation parameters, as given in this study, was well tolerated, although the mean total tolerated dose received was lower in patients with DS than in those without DS. There was no increase in hepatic toxicity, systemic infections, or treatment-related deaths in patients with DS during IM on either the IV or PO MTX arms, as compared with those without DS. The incidence of mucositis was increased in patients with DS as compared with patients without DS, particularly among patients who received IV MTX. This trial was registered at www.clinicaltrials.gov as #NCT00005945.

Trilineage Hematopoiesis Induced by Low-dose Eltrombopag in a Patient With Fanconi Anemia can be Used as a Bridge to Hematopoietic Stem Cell Transplant.

Fanconi anemia (FA) is an autosomal recessive, progressive bone marrow failure disorder characterized by congenital defects and marked cancer predisposition. Hematopoietic stem cell transplant is the therapy of choice for FA patients with progressive pancytopenia. These patients receive multiple transfusions for cytopenias. Oxymetholone has been used with variable success to improve cytopenias. Eltrombopag has been shown to induce bilineage or trilineage hematopoiesis in aplastic anemia and patients with myelodysplastic marrow. We report a case of FA where eltrombopag in conjunction with oxymetholone induced trilineage hematopoiesis and eliminated transfusion requirement before transplant, thereby enhancing favorable outcome after hematopoietic stem cell transplant.

Outcome of children with multiply relapsed B-cell acute lymphoblastic leukemia: a therapeutic advances in childhood leukemia & lymphoma study.

The survival of pediatric patients with multiply relapsed and/or refractory (R/R) B-cell acute lymphoblastic leukemia has historically been very poor; however, data are limited in the current era. We conducted a retrospective study to determine the outcome of multiply R/R childhood B-ALL treated at 24 TACL institutions between 2005 and 2013. Patient information, treatment, and response were collected. Prognostic factors influencing the complete remission (CR) rate and event-free survival (EFS) were analyzed. The analytic set included 578 salvage treatment attempts among 325 patients. CR rates (mean ± SE) were 51 ± 4% for patients with bone marrow R/R B-ALL who underwent a second salvage attempt, 37 ± 6% for a third attempt, and 31 ± 6% for the fourth through eighth attempts combined. For patients achieving a CR after their second, third, and fourth through eighth attempts, the 2 year EFS was 41 ± 6%, 13 ± 7%, and 27 ± 13% respectively. Our results showed slight improvement when compared to previous studies. This is the largest and most recent study to date that evaluates the outcome of this patient population. Our data will provide detailed reference for the evaluation of new agents being developed for childhood B-ALL.

Adolescent and Young Adult Oncology, Version 2.2018, NCCN Clinical Practice Guidelines in Oncology.

This selection from the NCCN Guidelines for Adolescent and Young Adult (AYA) Oncology focuses on treatment and management considerations for AYA patients with cancer. Compared with older adults with cancer, AYA patients have unique needs regarding treatment, fertility counseling, psychosocial and behavioral issues, and supportive care services. The complete version of the NCCN Guidelines for AYA Oncology addresses additional aspects of caring for AYA patients, including risk factors, screening, diagnosis, and survivorship.

Epstein-Barr Virus-associated Mucocutaneous Ulcer in a Patient With T-Cell Acute Lymphoblastic Leukemia: Importance of Accurate Diagnosis and Conservative Management.

Epstein-Barr virus-associated mucocutaneous ulcer (EBV-MCU) is a recently characterized entity that falls under the spectrum of EBV-lymphoproliferative disorders. First described in 2010 by Dojcinov et al, it is an EBV-driven localized proliferation of B cells, occurring in mucocutaneous tissues including the skin, the oropharynx, and the gastrointestinal tract of immunosuppressed patients in the absence of an intact T-cell repertoire. Typically, it has been described in elderly patients with age-related immunosenescence and patients who are on immunosuppressive therapy. However, only 2 cases have been reported in pediatric, adolescent, and young adult age groups, with all these patients manifesting after solid organ transplant. To the best of our knowledge there are no case reports of EBV-MCU occurring in association with hematologic malignancy. Here, we present a case of EBV-MCU in a young adult patient with T-cell acute lymphoblastic leukemia. Our report serves to promote awareness among clinicians regarding this newly described and extremely rare clinical entity in young immunosuppressed patients. In addition, we highlight the importance of accurate diagnosis to prevent overtreatment of this indolent, often self-resolving disease that has a significant clinicopathologic overlap with other aggressive forms of EBV-lymphoproliferative disorders that require more intensive therapy.

L-asparaginase in the treatment of patients with acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is a hematologic malignancy that predominantly occurs in children between 2 and 10 years of age. L-asparaginase is an integral component of treatment for patients with ALL and since its introduction into pediatric treatment protocols in the 1960s, survival rates in children have progressively risen to nearly 90%. Outcomes for adolescent and young adult (AYA) patients, aged 15-39 years and diagnosed with ALL, have historically been less favorable. However, recent reports suggest substantially increased survival in AYA patients treated on pediatric-inspired protocols that include a greater cumulative dose of asparaginase. All  currently available asparaginases share the same mechanism of action - the deamination and depletion of serum asparagine levels - yet each displays a markedly different pharmacokinetic profile. Pegylated asparaginase derived from the bacterium Escherichia coli is used as first-line therapy; however, up to 30% of patients develop a treatment-limiting hypersensitivity reaction. Patients who experience a hypersensitivity reaction to an E. coli-derived asparaginase can continue treatment with Erwinia chrysanthemi asparaginase. Erwinia asparaginase is immunologically distinct from E. coli-derived asparaginases and exhibits no cross-reactivity. Studies have shown that with adequate dosing, therapeutic levels of Erwinia asparaginase activity can be achieved, and patients switched to Erwinia asparaginase due to hypersensitivity can obtain outcomes similar to patients who do not experience a hypersensitivity reaction. Therapeutic drug monitoring may be required to ensure that therapeutic levels of asparaginase activity are maintained.

Outcome of Children with Standard-Risk T-Lineage Acute Lymphoblastic Leukemia--Comparison among Different Treatment Strategies.

BACKGROUND: Children with T-lineage acute lymphoblastic leukemia ALL (T-ALL) historically have had inferior outcomes compared with the children with precursor-B ALL (B-ALL). After 1995, the Children's Cancer Group (CCG) treated patients with B- and T-ALL according to the National Cancer Institute (NCI) risk criteria, basing risk stratification on age and white blood cell (WBC) count regardless of immunophenotype. The Pediatric Oncology Group (POG) treated all the patients with T-ALL on separate, generally more intensive protocols than those used to treat the patients with B-ALL. PROCEDURE: We compared the outcomes of children with T-ALL and NCI standard-risk (SR) criteria treated on CCG and POG trials between 1996 and 2005. CCG SR-ALL 1952 and 1991 enrolled 80 and 86 patients with T-ALL, respectively, utilizing a reduced intensity Berlin-Frankfurt-Münster backbone. Treatment was intensified for slow early responders and only patients with overt central nervous system leukemia received cranial irradiation. Eighty-four patients with T-ALL and SR features were enrolled on POG 9404 comprising more intensive therapy with all patients receiving cranial irradiation. RESULTS: The 7-year event-free survival (EFS) for patients with SR T-ALL on CCG 1952, CCG 1991, and POG 9404 were 74.1 ± 5.8%, 81.8 ± 5.3%, and 84.2 ± 4.3%, respectively (P = 0.18). Overall 7-year survivals were 86.1 ± 4.6%, 88.3 ± 4.4%, 89.1 ± 3.6%, respectively (P = 0.84). CONCLUSIONS: Comparable high rates of EFS and long-term survival were achieved with all three regimens, with the CCG regimens utilizing a less intensive chemotherapy backbone without prophylactic cranial irradiation for patients with SR T-ALL.

Comparative Toxicity by Sex Among Children Treated for Acute Lymphoblastic Leukemia: A Report From the Children's Oncology Group.

BACKGROUND: Epidemiologic studies find sex-based differences in incidence, survival, and long-term outcomes for children with cancer. The purpose of this study was to determine whether male and female patients differ with regard to acute treatment-related toxicities. PROCEDURES: We reviewed data collected on the Children's cancer group (CCG) high-risk acute lymphoblastic leukemia (ALL-HR) study (CCG-1961), and compared male and female patients' toxicity incidence and related variables in the first four phases of treatment. Similar analyses were performed with standard-risk ALL (ALL-SR) patients enrolled in CCG-1991. RESULTS: Among ALL-HR patients, females had significantly more hospital days, delays in therapy, grade 3 or 4 toxicities (e.g., gastrointestinal, liver), and supportive care interventions (e.g., transfusions, intravenous antibiotics) than males. Females were significantly more likely to have died of treatment-related causes than males (Hazard ratio = 2.8, 95%CI = 1.5-5.3, P = 0.002). Five months after beginning the treatment, the cumulative incidence of treatment-related deaths was 2.6% for females and 1.2% for males. Similar disparities were found among ALL-SR patients, with females experiencing significantly more hospital days and treatment-related toxicities than males. CONCLUSIONS: This study complements cancer survivorship studies that also report an increase in treatment-related late effects among females. Risk profiles appear to be different for male and female patients, with females having greater risk of developing both acute and long-term treatment-related toxicities. The underlying biological mechanisms for these sex differences are poorly understood and warrant further study in order to determine how sex-based outcome disparities can be addressed in future clinical trials and practice.

Escalating intravenous methotrexate improves event-free survival in children with standard-risk acute lymphoblastic leukemia: a report from the Children's Oncology Group.

Children's Cancer Group-1991 selected 2 components from the Children's Cancer Group studies shown to be effective in high-risk acute lymphoblastic leukemia and examined them in children with National Cancer Institute standard-risk acute B-precursor lymphoblastic leukemia. These were (1) vincristine and escalating IV methotrexate (MTX) without leucovorin rescue during the interim maintenance (IM) phases and (2) addition of a second delayed intensification (DI) phase. Eligible patients (n = 2078) were randomly assigned to regimens containing either oral (PO) MTX, PO mercaptopurine, dexamethasone, and vincristine or IV MTX during IM phases, and regimens with either single DI or double DI. Five-year event-free survival (EFS) and overall survival for patients on the PO MTX arms were 88.7% ± 1.4% and 96% ± 0.9% versus 92.6% ± 1.2% and 96.5% ± 0.8% for those on the IV MTX arms (P = .009, P = .66). Five-year EFS and overall survival for patients who received single DI were 90.9% ± 1.3% and 97.1% ± 0.8% versus 90.5% ± 1.3% and 95.4% ± 3.8% for those who received double DI (P = .71, P = .12). No advantage was found for a second DI; however, replacement of PO MTX, PO mercaptopurine, vincristine, and dexamethasone during IM with vincristine and escalating IV MTX improved EFS.

Oral 6-mercaptopurine versus oral 6-thioguanine and veno-occlusive disease in children with standard-risk acute lymphoblastic leukemia: report of the Children's Oncology Group CCG-1952 clinical trial.

The Children's Cancer Group 1952 (CCG-1952) clinical trial studied the substitution of oral 6-thioguanine (TG) for 6-mercaptopurine (MP) and triple intrathecal therapy (ITT) for intrathecal methotrexate (IT-MTX) in the treatment of standard-risk acute lymphoblastic leukemia. After remission induction, 2027 patients were randomized to receive MP (n = 1010) or TG (n = 1017) and IT-MTX (n = 1018) or ITT (n = 1009). The results of the thiopurine comparison are as follows. The estimated 7-year event-free survival (EFS) for subjects randomized to TG was 84.1% (+/- 1.8%) and to MP was 79.0% (+/- 2.1%; P = .004 log rank), although overall survival was 91.9% (+/- 1.4%) and 91.2% (+/- 1.5%), respectively (P = .6 log rank). The TG starting dose was reduced from 60 to 50 mg/m(2) per day after recognition of hepatic veno-occlusive disease (VOD). A total of 257 patients on TG (25%) developed VOD or disproportionate thrombocytopenia and switched to MP. Once portal hypertension occurred, all subjects on TG were changed to MP. The benefit of randomization to TG over MP, as measured by EFS, was evident primarily in boys who began TG at 60 mg/m(2) (relative hazard rate [RHR] 0.65, P = .002). The toxicities of TG preclude its protracted use as given in this study. This study is registered at http://clinicaltrials.gov as NCT00002744.

Potent, transient inhibition of BCR-ABL with dasatinib 100 mg daily achieves rapid and durable cytogenetic responses and high transformation-free survival rates in chronic phase chronic myeloid leukemia patients with resistance, suboptimal response or intolerance to imatinib.

BACKGROUND: Dasatinib 100 mg once daily achieves intermittent BCR-ABL kinase inhibition and is approved for chronic-phase chronic myeloid leukemia patients resistant or intolerant to imatinib. To better assess durability of response to and tolerability of dasatinib, data from a 2-year minimum follow-up for a dose-optimization study in chronic-phase chronic myeloid leukemia are reported here. DESIGN AND METHODS: In a phase 3 study, 670 chronic-phase chronic myeloid leukemia patients with resistance, intolerance, or suboptimal response to imatinib were randomized to dasatinib 100 mg once-daily, 50 mg twice-daily, 140 mg once-daily, or 70 mg twice-daily. RESULTS: Data from a 2-year minimum follow-up demonstrate that dasatinib 100 mg once daily achieves major cytogenetic response and complete cytogenetic response rates comparable to those in the other treatment arms, and reduces the frequency of key side effects. Comparable 2-year progression-free survival and overall survival rates were observed (80% and 91%, respectively, for 100 mg once daily, and 75%-76% and 88%-94%, respectively, in other arms). Complete cytogenetic responses were achieved rapidly, typically by 6 months. In patients treated with dasatinib 100 mg once daily for 6 months without complete cytogenetic response, the likelihood of achieving such a response by 2 years was 50% for patients who had achieved a partial cytogenetic response, and only 8% or less for patients with minor, minimal, or no cytogenetic response. Less than 3% of patients suffered disease transformation to accelerated or blast phase. CONCLUSIONS: Intermittent kinase inhibition can achieve rapid and durable responses, indistinguishable from those achieved with more continuous inhibition.

Dasatinib 100 mg once daily minimizes the occurrence of pleural effusion in patients with chronic myeloid leukemia in chronic phase and efficacy is unaffected in patients who develop pleural effusion.

BACKGROUND: Dasatinib, a highly potent BCR-ABL inhibitor, is an effective treatment for patients with chronic myeloid leukemia in chronic phase (CML CP) after resistance, suboptimal response, or intolerance to prior imatinib. In a phase 3 dose optimization trial in patients with CML CP (CA180-034), the occurrence of pleural effusion was significantly minimized with dasatinib 100 mg once daily (QD) compared with other treatment arms (70 mg twice daily [twice daily], 140 mg QD, or 50 mg twice daily). METHODS: To investigate the occurrence and management of pleural effusion during dasatinib treatment, and efficacy in patients with or without pleural effusion, data from CA180-034 were analyzed. RESULTS: With 24-month minimum follow-up, 14% of patients treated with dasatinib 100 mg QD incurred pleural effusion (grade 3: 2%; grade 4: 0%) compared with 23% to 26% in other study arms. The pleural effusion rate showed only a minimal increment from 12 to 24 months. In the 100 mg QD study arm, median time to pleural effusion (any grade) was 315 days, and after pleural effusion, 52% of patients had a transient dose interruption, 35% had a dose reduction, 57% received a diuretic, and 26% received a corticosteroid. Three patients in the 100 mg QD study arm discontinued treatment after pleural effusion. Across all study arms, patients with or without pleural effusion demonstrated similar progression-free and overall survival, and cytogenetic response rates were higher in patients with a pleural effusion. CONCLUSIONS: Pleural effusion is minimized with dasatinib 100 mg QD dosing and its occurrence does not affect short- or long-term efficacy.

Intrathecal triple therapy decreases central nervous system relapse but fails to improve event-free survival when compared with intrathecal methotrexate: results of the Children's Cancer Group (CCG) 1952 study for standard-risk acute lymphoblastic leukemia, reported by the Children's Oncology Group.

The Children's Cancer Group (CCG) 1952 clinical trial for children with standard-risk acute lymphoblastic leukemia (SR-ALL) compared intrathecal (IT) methotrexate (MTX) with IT triples (ITT) (MTX, cytarabine, and hydrocortisone sodium succinate [HSS]) as presymptomatic central nervous system (CNS) treatment. Following remission induction, 1018 patients were randomized to receive IT MTX and 1009 ITT. Multivariate analysis identified male sex, hepatomegaly, CNS-2 status, and age younger than 2 or older than 6 years as significant predictors of isolated CNS (iCNS) relapse. The 6-year cumulative incidence estimates of iCNS relapse are 3.4% +/- 1.0% for ITT and 5.9% +/- 1.2% for IT MTX; P = .004. Significantly more relapses occurred in bone marrow (BM) and testicles with ITT than IT MTX, particularly among patients with T-cell phenotype or day 14 BM aspirate containing 5% to 25% blasts. Thus, the estimated 6-year event-free survivals (EFS) with ITT or IT MTX are equivalent at 80.7% +/- 1.9% and 82.5% +/- 1.8%, respectively (P = .3). Because the salvage rate after BM relapse is inferior to that after CNS relapse, the 6-year overall survival (OS) for ITT is 90.3% +/- 1.5% versus 94.4% +/- 1.1% for IT MTX (P = .01). It appears that ITT improves presymptomatic CNS treatment but does not improve overall outcome.

Detection of central nervous system leukemia in children with acute lymphoblastic leukemia by real-time polymerase chain reaction.

Accurate detection of central nervous system (CNS) involvement in children with newly diagnosed acute lymphoblastic leukemia (ALL) could have profound prognostic and therapeutic implications. We examined various cerebrospinal fluid (CSF) preservation methods to yield adequate DNA stability for polymerase chain reaction (PCR) analysis and developed a quantitative real-time PCR assay to detect occult CNS leukemia. Sixty CSF specimens were maintained in several storage conditions for varying amounts of time, and we found that preserving CSF in 1:1 serum-free RPMI tissue culture medium offers the best stability of DNA for PCR analysis. Sixty CSF samples (30 at diagnosis and 30 at the end of induction therapy) from 30 children with ALL were tested for CNS leukemic involvement by real-time PCR using patient-specific antigen receptor gene rearrangement primers. Six of thirty patient diagnosis samples were PCR-positive at levels ranging from 0.5 to 66% leukemic blasts in the CSF. Four of these patients had no clinical or cytomorphological evidence of CNS leukemia involvement at that time. All 30 CSF samples drawn at the end of induction therapy were PCR-negative. The data indicate that real-time PCR analysis of CSF is an excellent tool to assess occult CNS leukemia involvement in patients with ALL and can possibly be used to refine CNS status classification.