Improved outcome after relapse in children with acute myeloid leukaemia

In the Nordic Society for Paediatric Haematology and Oncology paediatric study acute myeloid leukaemia (AML) 93, event-free survival was 50% and overall survival was 66%, indicating that many patients were cured following relapse. Factors influencing outcome in children with relapsed AML were investigated. The study included all 146 children in the Nordic countries diagnosed with AML between 1988 and 2003, who relapsed. Data on disease characteristics and relapse treatment were related to outcome. Sixty-six percentage achieved remission with survival after relapse (5 years) 34 +/- 4%. Of 122 patients who received re-induction therapy, 77% entered remission with 40 +/- 5% survival. Remission rates were similar for different re-induction regimens but fludarabine, cytarabine, granulocyte colony-stimulating factor-based therapy had low treatment-related mortality. Prognostic factors for survival were duration of first complete remission (CR1) and stem cell transplantation (SCT) in CR1. In early relapse (<1 year in CR1), survival was 21 +/- 5% compared with 48 +/- 6% in late relapse. For children receiving re-induction therapy, survival in early relapse was 29 +/- 6% and 51 +/- 6% in late. Patients treated in CR1 with SCT, autologous SCT or chemotherapy had a survival of 18 +/- 9, 5 +/- 5 and 41 +/- 5%, respectively. Survival was 62 +/- 6% in 64 children given SCT as part of their relapse therapy. A significant proportion of children with relapsed AML can be cured, even those with early relapse. Children who receive re-induction therapy, enter remission and proceed to SCT can achieve a cure rate of 60%.     

Treatment of children with acute myeloid leukaemia who relapsed after allogeneic haematopoietic stem cell transplantation

Despite improvements in diagnosis and treatment, 30–40% of children with acute myeloid leukaemia (AML) experience relapse. For those who relapse after allogeneic haematopoietic stem cell transplantation (allo‐HSCT), the prognosis is particularly poor, with limited reported literature on these patients. We reviewed the clinical course of 49 children with AML (28 males, 21 females) who received allo‐HSCT between 1993 and 2011, and who had subsequently relapsed. Study endpoints included (i) complete remission (CR) rate after intensive chemotherapy, and prognostic factors for CR, (ii) disease‐free survival (DFS) and overall survival (OS) for patients who achieved CR and (iii) OS for recipients of intensive chemotherapy and prognostic factors for OS . Of the 36 patients who received intensive chemotherapy after post‐HSCT relapse, 26 (72%) achieved CR. For patients who achieved CR, 5‐year DFS and OS were 32·6 ± 10·2% and 44·4 ± 11·1%, respectively. For all recipients of intensive chemotherapy, 5‐year OS was 31·6 ± 8·7%. Cumulative incidence of treatment‐related death was 14·4%. All three recipients of second HSCT died. Amongst prognostic factors predicting improved survival, only disease status at HSCT (early first CR vs. others) proved significant in multivariate study (Hazard Ratio 2·42, 95% Confidence Interval 1·02–5·74, P = 0·045). Treatment with curative intent was able to salvage a minor but important subset of children with AML who relapsed post‐allogeneic transplant.     

Efficacy of fractionated gemtuzumab ozogamicin combined with cytarabine in advanced childhood myeloid leukaemia

Gemtuzumab ozogamicin (GO) monotherapy is reported to yield a 20-30% response rate in advanced acute myeloid leukaemia (AML). This study examined the efficacy and tolerability of GO combined with cytarabine (GOCYT) in children with refractory/relapsed CD33(+) AML. Seventeen children received GO 3 mg/m(2) on days 1, 4 and 7 plus cytarabine 100 mg/m(2)/d for 7 d on a compassionate-use basis. Seven patients then received GO-based consolidation. At the outset of GOCYT, two patients were refractory; eight patients were in refractory first relapse; six patients had relapsed after stem cell transplantation (SCT); and one patient [del(5q) therapy-related AML (t-AML)] had not yet been treated. Mean follow-up was 17 months (8-33 months). Ten responses were obtained after GOCYT induction, including complete remission (CR) or CR without complete recovery of platelets (CRp) in six patients (35%). The responses improved in three children who received GOCYT consolidation, increasing the CR + CRp rate to 53%. SCT was subsequently performed in eight responders. Grade 3-4 adverse events consisted of haematological disorders (n = 17, 100%) and documented infections (n = 5, 29%). No cases of sinusoidal obstructive syndrome occurred. Three patients were alive at the cut-off date for this analysis, all of whom had responded to GOCYT. GOCYT combination therapy yielded a high response rate (53%) and showed acceptable toxicity in heavily pretreated children with refractory/relapsed AML. These results warrant a larger prospective study.     

A prognostic model for survival after salvage treatment with FLAG‐Ida +/− gemtuzumab‐ozogamicine in adult patients with refractory/relapsed acute myeloid leukaemia

The combination of fludarabine, cytarabine, idarubicin, and granulocyte colony‐stimulating factor (FLAG‐Ida) is widely used in relapsed/refractory acute myeloid leukaemia (AML). We retrospectively analysed the results of 259 adult AML patients treated as first salvage with FLAG‐Ida or FLAG‐Ida plus Gentuzumab‐Ozogamicin (FLAGO‐Ida) of the Programa Español de Tratamientos en Hematología (PETHEMA) database, developing a prognostic score system of survival in this setting (SALFLAGE score). Overall, 221 patients received FLAG‐Ida and 38 FLAGO‐Ida; 92 were older than 60 years. The complete remission (CR)/CR with incomplete blood count recovery (CRi) rate was 51%, with 9% of induction deaths. Three covariates were associated with lower CR/CRi: high‐risk cytogenetics and t(8;21) at diagnosis, no previous allogeneic stem cell transplantation (allo‐SCT) and relapse‐free interval <1 year. Allo‐SCT was performed in second CR in 60 patients (23%). The median overall survival (OS) of the entire cohort was 0·7 years, with 22% OS at 5‐years. Four independent variables were used to construct the score: cytogenetics, FLT3‐internal tandem duplication, length of relapse‐free interval and previous allo‐SCT. Using this stratification system, three groups were defined: favourable (26% of patients), intermediate (29%) and poor‐risk (45%), with an expected 5‐year OS of 52%, 26% and 7%, respectively. The SALFLAGE score discriminated a subset of patients with an acceptable long‐term outcome using FLAG‐Ida/FLAGO‐Ida regimen. The results of this retrospective analysis should be validated in independent external cohorts.     

Outcome after first relapse in adult patients with Philadelphia chromosome‐negative acute lymphoblastic leukaemia

To analyse the outcome of adult patients who developed a first relapse of acute lymphoblastic leukaemia (ALL), we collected the clinical data of 332 patients with Philadelphia‐chromosome (Ph) negative ALL, aged 16–65 years, who relapsed after first complete remission (CR1) between 1998 and 2008 in 69 institutions all over Japan, including 58 patients who relapsed after allogeneic haematopoietic stem cell transplantation (Allo‐HSCT) in CR1. The overall survival (OS) was 43·4% at 1 year, and 16·3% at 5 years from relapse in patients who received chemotherapy alone in CR1. Among patients who relapsed after chemotherapy alone in CR1, 123 (52·5%) achieved a second remission (CR2) following salvage chemotherapy, of whom 62 subsequently underwent Allo‐HSCT during CR2. Allo‐HSCT in CR2 was significantly associated with better OS. Moreover, the type of salvage chemotherapy influenced OS from relapse. A doxorubicin, vincristine, and predonisone‐based (AdVP‐type) regimen was related to better OS in patients with longer CR1 (more than 1 year), but was related to worse OS in patients with shorter CR1. In conclusion, the prognosis of patients with relapsed Ph‐negative ALL is poor. Allo‐HSCT after a first relapse could improve the prognosis. Selection of the optimal salvage chemotherapy might depend on the duration of CR1.     

Outcome of relapse after allogeneic HSCT in children with ALL enrolled in the ALL‐SCT 2003/2007 trial

Relapse remains the major cause of treatment failure in children with high‐risk acute lymphoblastic leukaemia (ALL) undergoing allogeneic haematopoietic stem‐cell transplantation (allo‐SCT). Prognosis is considered dismal but data on risk factors and outcome are lacking from prospective studies. We analysed 242 children with recurrence of ALL after first allo‐SCT enrolled in the Berlin‐Frankfurt‐Munster (BFM) ALL‐SCT‐BFM 2003 and ALL‐SCT‐BFM international 2007 studies. Median time from allo‐SCT to relapse was 7·7 months; median follow‐up from relapse after allo‐SCT until last follow‐up was 3·4 years. The 3‐year event‐free survival (EFS) was 15% and overall survival (OS) was 20%. The main cause of death was disease progression or relapse (86·5%). The majority of children (48%) received salvage therapy without second allo‐SCT, 26% of the children underwent a second allo‐SCT and 25% received palliative treatment only. In multivariate analyses, age, site of relapse, time to relapse and type of salvage therapy were identified as significant prognostic factors for OS and EFS, whereas factors associated with first SCT were not statistically significant. Combined approaches incorporating novel immunotherapeutic treatment options and second allo‐SCT hold promise to improve outcome in children with post allo‐SCT relapse.     

Salvage treatment for children with refractory first or second relapse of acute myeloid leukaemia with gemtuzumab ozogamicin: results of a phase II study

The prognosis of children with relapsed/refractory acute myeloid leukaemia (AML) is poor, and new therapies are needed. Gemtuzumab ozogamicin (GO) is an anti‐CD33 antibody linked to the antitumor antibiotic calicheamicin. We conducted an investigator‐initiated phase II study with GO to assess its efficacy and safety, administering two dosages of 7·5 mg/m² with a 14 d‐interval. Thirty children who were refractory to re‐induction at first relapse or suffered from second relapse of AML received a total of 64 infusions of GO. The response rate [complete remission (CR) and CR with insufficient platelet recovery] was 37%. Nine patients were subsequently transplanted (median time to transplant, 4 weeks, range 3–21 weeks), and three of these patients are currently in continuous CR with a median follow‐up of >3 years, and can considered to be cured. This resulted in a statistically significant survival advantage for children who responded to GO versus those who did not [27% (standard error 13%) vs. 0%, respectively, P = 0·001]. All other children died, mainly from progressive disease. The treatment was generally well tolerated by most patients. The frequency of transient transaminatis was low. All but one patient received defibrotide prophylaxis during the transplant procedure, and no cases of veno‐occlusive disease were noted. This study showed a favourable safety/efficacy profile of single‐agent GO in children with refractory first or second relapse of AML.     

Comparison of umbilical cord blood allogeneic stem cell transplantation vs. auto‐SCT for adult acute myeloid leukemia patients in second complete remission at transplant: a retrospective study on behalf of the SFGM‐TC

This retrospective study considered the outcomes of 181 patients with acute myeloid leukemia (AML) transplanted in second complete remission (CR2) between January 2005 and April 2012 and who received either a myeloablative autologous stem cell transplant (Auto‐SCT; n = 82; median age: 48 years; median follow‐up: 45 months) or an umbilical cord blood (UCB) allogeneic SCT (n = 99, median age: 46 years; median follow‐up: 36 months; conditioning regimens: myeloablative n = 21, reduced n = 78; single unit n = 37, double units n = 62). Although the Auto group showed a significant better prognostic profile at transplant, with longer median interval between diagnosis and time of graft, higher incidence of good‐risk cytogenetics and lower number of previously transplanted patients, 3‐year OS and LFS were similar between both groups (Auto: 59 ± 6% vs. 50 ± 6%, P = 0.45; and 57 ± 6% vs. 46 ± 6%, P = 0.37). In multivariate analysis, UCB allo‐SCT was associated with lower relapse incidence (HR: 0.3, 95% CI: 0.11–0.82, P = 0.02), but higher non‐relapse mortality (NRM) (HR: 4.16; 95% CI: 1.46–11.9, P = 0.008). Results from this large study suggest that UCB allo‐SCT provides better disease control than auto‐SCT, which is especially important in the setting of high‐risk disease. However, this disease control advantage is counterbalanced by higher toxicity, highlighting the need for novel approaches aiming to decrease NRM after UCB allo‐SCT.     

Survival after cord blood transplantation from unrelated donor as a second hematopoietic stem cell transplantation for recurrent pediatric acute myeloid leukemia

The Japan Cord Blood Bank Network (JCBBN) reports the treatment of 22 children with acute myeloid leukemia (AML) who received umbilical cord blood transplantation from unrelated donors (CBT) as their second hematopoietic stem cell transplantation (HSCT). Provided by the JCBBN, between February 1997 and September 2006, 22 patients had CBT as a second HSCT. In the initial HSCT, eight received autologous, seven received CBT, and the remaining had allogenic BMT. At the time of CBT as a second HSCT, seven were in the second complete remission (CR2), two in the third CR (CR3), the remaining were not in remission. Reduced intensity conditioning (RIC) conducted for 10 cases and myeloablative conditioning (MAC) for 12 cases. The overall survival rate was 31.3%, 5 years after CBT. Second complete remission at second transplantation was favorable prognosis (58.3 ± 18.6%, compared with 17.1 ± 10.8% for the non-CR group. Mortality after CBT as a second HSCT accounted for 15 cases, 8 from treatment-related mortality. In conclusion, CBT combined with RIC as second HSCT may be useful against a recurrence of AML in children after the initial HSCT.     

Gemtuzumab ozogamicin: first clinical experiences in children with relapsed/refractory acute myeloid leukemia treated on compassionate-use basis

Gemtuzumab ozogamicin (GO; Mylotarg) was developed to treat CD33(+) acute myeloid leukemia (AML). To date, only studies in adults and preliminary data from a phase 1 study in children have been reported. We report data on 15 children with relapsed/refractory CD33(+) AML who were treated with GO monotherapy on compassionate use basis (4-9 mg/m(2) up to 3 courses). Eight children showed a reduction in bone marrow blasts to 5% or less, including 5 in complete remission without full platelet recovery (CRp). Three of the 5 children with CRp received transplants almost directly following the last GO course, without awaiting further platelet regeneration. Hence in these children no clear discrimination between complete remission (CR) and CRp could be made. In 6 of 8 responding patients further treatment was given consisting of stem cell transplantation (SCT). Two patients are still alive, currently 6 and 9 months after SCT. Hematologic toxicity was difficult to assess due to subsequent SCT or leukemia. Side effects, in one patient each included veno-occlusive disease, transient grade 3 hyperbilirubinemia, transient grade 3 transaminase elevation, and grade 3 hypotension during GO administration. No infections or mucositis occurred. This report demonstrates clinical efficacy of GO in a subset of relapsed/refractory pediatric CD33(+) AML patients and suggests that intensive postremission therapy after remission induction by GO may result in durable responses in some patients, although follow-up is still short. Further studies are needed to determine the efficacy and safety of GO in children with AML.     

Very poor long‐term survival in past and more recent studies for relapsed AML patients: The ECOG‐ACRIN experience

This study examines the long‐term OS of relapsed AML patients who were enrolled to 9 successive ECOG‐ACRIN trials for newly diagnosed AML, during 1984‐2008. The objectives were to examine whether there is a trend of improvement in the survival of relapsed AML patients in the more recent studies and to search for prognostic factors that are associated with long‐term OS after relapse. A total of 3012 patients were enrolled, 1779 (59.1%) achieved CR1 and of these, 58.9% relapsed. The median follow‐up was 9.7 years. The median OS from relapse was 0.5 years and the 5‐year OS was 10 (±1)%. These results were similar even for the most recent studies. A multivariate model showed that age, cytogenetics at diagnosis, duration of CR1 and undergoing allogeneic transplantation were significantly associated with OS from relapse. Even among patients who relapsed with better prognostic factors; age < 40 and CR1 > 12 months, there was no significant OS difference between the studies. In conclusion, this large cohort appears to confirm that the survival of AML patients postrelapse continues to be dismal and has not improved during the past quarter of a century.     

Treatment outcome in children and adolescents with relapsed Hodgkin lymphoma – results of the UK HD3 relapse treatment strategy

The purpose of this national retrospective study was to evaluate the outcome in children with relapsed or primary refractory Hodgkin lymphoma [HL] after a primary chemotherapy alone treatment strategy. Between 2000 and 2005 , 80 children with relapsed [n = 69] or primary refractory [n = 11] HL were treated on a standardized treatment protocol of 4–6 cycles of EPIC [etoposide, prednisolone, ifosfa3mide and cisplatin] chemotherapy. Radiotherapy was recommended to all relapsed sites. High dose therapy with stem cell rescue [SCT] was recommended for patients with poor response. The 5‐year overall survival [OS] and progression‐free survival from relapse was 75·8% [64·8–83·9] and 59·9% [48·3–69·7] respectively. Duration of first remission was strongly associated with OS; risk of death was decreased by 53% [Hazard ratio (HR): 0·47, 95% confidence interval (CI): 0·19–1·18] for those with a time from end of treatment to relapse of 3–12 months (compared to <3 months) and reduced by 80% (HR 0·20, 95% CI: 0·04–0·90) for those >12 months after end of treatment. Other poor prognostic factors included advanced stage disease at relapse and B symptoms at first diagnosis. The most important factor associated with salvage failure was time to relapse . Survival outcome in children with primary refractory HL is poor.     

Outcome of children with relapsed acute myeloid leukemia following initial therapy under the AML99 protocol

The outcomes of children with relapsed acute myeloid leukemia (AML) are known to be poor, but remain obscure. We retrospectively analyzed 71 patients who had relapsed following first-line treatment under the AML99 protocol. We investigated the time and site of recurrence, response to re-induction therapy, and performance of hematopoietic stem cell transplantation (HSCT) in relapsed cases, and performed a multivariate analysis to identify prognostic factors. The 5-year overall-survival (OS) rate after relapse was 37 %. Of 71 patients, three died without any anti-leukemic therapy and two underwent allogeneic HSCT. The remaining 66 patients received re-induction chemotherapy, and 33 (50 %) achieved second CR (CR2). Twenty-two of 25 (88 %) late relapse patients and 11 of 41 (27 %) early relapse patients achieved CR2 (P < 0.001). Twenty-nine CR2 cases and 35 non-CR2 cases underwent allogeneic HSCT. The 5-year OS rate was significantly higher in patients who underwent HSCT in CR2 than those in non-CR2 (66 vs. 17 %, P < 0.000001). Multivariate analysis indicated that early relapse (P < 0.05) and the positivity of the FMS-like tyrosine kinase 3—internal tandem duplication (P < 0.05) were adverse prognostic factors for survival. In conclusion, the etiology of relapsed pediatric AML needs to be elucidated and effective chemotherapy should be administered to obtain CR2.     

Maintenance lenalidomide in combination with 5‐azacitidine as post‐remission therapy for acute myeloid leukaemia

In this Phase 1b study, the safety and tolerability of maintenance therapy, comprising lenalidomide (0–25 mg, days 5–25) in combination with azacitidine (50–75 mg/m², days 1–5) every 28 d, was explored in 40 patients with acute myeloid leukaemia (AML) in complete remission after chemotherapy. Eligibility included AML in first complete remission (CR1) with adverse risk karyotype (n = 8), fms‐related tyrosine kinase 3‐internal tandem duplication (FLT3‐ITD) (n = 5), age ≥60 years (n = 31) or AML in second remission (CR2) (n = 14). Dose‐limiting toxicity was not reached. Common toxicities were haematological, infection, injection pain, constipation, fatigue and diarrhoea. In CR1, median relapse‐free (RFS) and overall survival (OS) was 12 and 20 months, respectively. In CR2, median RFS was 11 months, with median OS not yet reached. Among 29 patients with intermediate cytogenetic risk, RFS was 50% at 24 months. There were five patients with concomitant FLT3‐ITD and nucleophosmin (NPM1) mutation; none have relapsed and all are still alive after 17–39 months. Maintenance lenalidomide/azacitidine augmented the function of cytotoxic T lymphocytes, particularly in patients with NPM1 mutation. The lenalidomide/azacitidine maintenance combination was effective in suppressing residual DNA (cytosine‐5‐)‐methyltransferase 3 alpha (DNMT3A)‐positive disease, resulting in sustained remission in patients with concurrent NPM1 mutation. Azacitidine/lenalidomide as maintenance therapy for high‐risk AML warrants further exploration.     

Relapse in teenage and young adult patients treated on a paediatric minimal residual disease stratified ALL treatment protocol is associated with a poor outcome: results from UKALL2003

Outcomes for teenage and young adult (TYA) patients with acute lymphoblastic leukaemia (ALL) who relapse on contemporary risk‐adapted paediatric protocols are largely unknown and there is no consensus on optimal salvage strategies. We assessed the treatment and outcome of TYA patients (aged 16–24 years) recruited to the UKALL2003 trial, who relapsed following attainment of complete morphological remission. Forty‐two of 223 patients (18·8%) relapsed, the majority (n = 26, 62%) on treatment. Thirty‐eight (90%) patients received salvage treatment, with 22 (58%) achieving second remission (CR2) and 21 patients receiving an allogeneic haematopoietic cell transplant (alloHSCT). Post‐relapse outcomes were poor with a 5‐year overall survival (OS) of 23% (95% confidence interval; 11–37%). Outcomes for patients relapsing on active treatment were inferior to those relapsing after completing treatment (5‐year OS 9% vs. 52%, log‐rank P = 0·001). No patient with B cell ALL relapsing on treatment was alive at the end of the study period. TYA patients with ALL who relapse on the UK paediatric protocol, UKALL2003, are largely unsalvageable with conventional approaches aimed at achieving CR2 followed by alloHSCT. Future efforts should be aimed at identifying those patients who are destined to relapse and exploring novel treatment approaches for this high‐risk group and for those who do relapse.     

Results of a multicentre UK‐wide retrospective study evaluating the efficacy of brentuximab vedotin in relapsed,refractory classical Hodgkin lymphoma in the transplant naive setting

Relapsed or refractory classical Hodgkin lymphoma (cHL) is associated with a poor outcome when standard chemotherapy fails. Brentuximab vedotin (BV) is an anti‐CD30 monoclonal antibody‐drug conjugate licensed for use at relapse after autologous stem cell transplant (ASCT) or following two prior therapies in those unsuitable for ASCT. There are limited data assessing the ability of BV to enable curative SCT. We performed a UK‐wide retrospective study of 99 SCT‐naïve relapsed/refractory cHL. All had received 2 prior lines and were deemed fit for transplant but had an insufficient remission to proceed. The median age was 32 years. Most had nodular sclerosis subtype, Eastern Cooperative Oncology Group performance status 0–1 and advanced stage disease. The median progression‐free survival (PFS) was 5·6 months and median overall survival (OS) was 37·2 months. The overall response rate was 56% (29% complete response; 27% partial response). 61% reached SCT: 34% immediately post‐BV and 27% following an inadequate BV response but were salvaged and underwent deferred SCT. Patients consolidated with SCT had a superior PFS and OS to those not receiving SCT (P < 0·001). BV is an effective, non‐toxic bridge to immediate SCT in 34% and deferred SCT in 27%. 39% never reached SCT with a PFS of 3·0 months, demonstrating the unmet need to improve outcomes in those unsuitable for SCT post‐BV.     

Sequential continuous infusion of fludarabine and cytarabine associated with liposomal daunorubicin (DaunoXome) (FLAD) in primary refractory or relapsed adult acute myeloid leukemia patients

A large proportion of adult patients with acute myeloid leukemia (AML) relapse after treatment, and some of them are resistant to primary induction chemotherapy. Sixty-one patients from seven hematological centers with poor-risk AML, primary refractory (n = 16), or relapsed (n = 45) were treated with a salvage regimen, including fludarabine (2 days) and cytarabine (3 days) in a sequential continuous infusion, associated with liposomal daunorubicin (3 days) (FLAD). Complete response rate was 44% and 56% for refractory and relapsed patients, respectively, with an overall response rate of 52% (32 of 61). Twenty-two patients (36%) were resistant to the salvage therapy. Seven patients (12%) died early during chemotherapy, four of them because of sepsis. Nineteen patients in complete remission (CR) underwent a stem-cell transplant (SCT) procedure: five autologous, nine from a HL-A identical sibling, and five from HL-A matched unrelated donors. Post-treatment aplasia and mucositis were major toxicities. Twenty patients (62.5%) relapsed after this treatment in a median of 7.3 months; ten patients relapsed after a SCT procedure. Nine patients are alive and disease free; three of them were rescued after a further cytotoxic treatment. The FLAD regimen proved to be an effective and well-tolerated treatment, with acceptable toxicity in this group of high-risk patients. A better response rate was obtained in the subgroup of relapsed patients, compared to patients treated for refractory disease. More then half (five of nine) of long-surviving patients are those who were submitted to a transplant procedure; thus, the main indication for FLAD seems to be to try to induce a rapid CR with minimum toxicity in order to perform a transplant as soon as possible.     

Induction chemotherapy followed by allogeneic bone marrow transplantation or aggressive consolidation chemotherapy in childhood acute myeloblastic leukemia: A prospective study from the French Society of Pediatric Hematology and Immunology (SHIP)

In the LAME89/91 protocol, children with acute myeloid leukemia (AML) who achieved complete remission (CR) after induction chemotherapy, were treated either with allogeneic bone marrow transplantation (BMT) if they had an HLA-compatible related donor or with chemotherapy including high-dose cytarabine. The objectives of this study were to describe the overall results of this strategy and to compare the two post-remission arms. Two hundred and thirty-one children were enrolled in the protocol. Induction chemotherapy consisted of a combination of cytarabine and mitoxantrone. A CR was achieved in 204 children (88%). Fifty-one of them had an HLA-identical sibling donor and were eligible for BMT. These 51 patients, as well as two additional children who had a one antigen HLA-mismatched father, received BMT during first CR. Consequently, 53 patients were analysed in the BMT group and 151 in the chemotherapy group. With a mean follow up duration in the study of 38 ± 2 months, overall event-free survival (EFS) was 47 ± 7% at 4 years for the 231 patients entered into the protocol. The 4-year disease-free survival (DFS) was 53 ± 8% for the 204 patients who achieved complete remission after induction therapy. The 4-year probability of relapse was 28 ± 14% in the BMT group and 47 ± 9% in the chemotherapy group (p = 0.02). The risk of therapy-related death was 6.2% for BMT and 8.1% for chemotherapy. DFS was 68 ± 14% in the BMT group and 48 ± 9% in the chemotherapy group (p = 0.02). We conclude that allogeneic BMT from a matched sibling donor is the treatment of choice for reducing the relapse risk and for increasing DFS in children with AML in first CR.     

Chimeric antigen receptor T-cell therapy as a bridge to haematopoietic stem cell transplantation for refractory/relapsed B-cell acute lymphoblastic leukemia

Although chimeric antigen receptor T cells (CAR-T) targeted at CD19 or CD22 have achieved high complete remission (CR) in refractory/relapsed B-cell acute lymphoblastic leukaemia (B-ALL), it is uncertain if allogeneic haematopoietic stem cell transplantation (allo-HSCT) should be performed after CAR-T therapy to accomplish a sustainable remission. Fifty-two cases with relapsed/refractory B-ALL who underwent allo-HSCT after CR by CD19 or CD22 CAR-T were enrolled. The median time from CAR-T infusion to allo-HSCT was 50 (34–98) days. Myeloablative reduced-intensity conditioning (RIC) with total body irradiation/fludarabine-based or busulfan/fludarabine-based regimens was used. Incidences of grade II–IV acute graft-versus-host disease (aGVHD) and severe aGVHD were 23·1% and 5·8% respectively. Of 48 evaluable cases, 16 developed chronic GVHD (cGVHD) and in three of them the pattern was extensive. With a median follow-up of 334 (41–479) days, one-year overall survival and event-free survival (EFS) were 87·7% and 73·0%. One-year relapse rate and transplant-related mortality (TRM) were 24·7% and 2·2% respectively. With quick bridge to allo-HSCT after CAR-T therapy, high EFS for refractory/relapsed B-ALL has been achieved in this relatively large cohort. Our myeloablative RIC regimens have resulted in low incidences of aGVHD, cGVHD, viral reactivation and very low TRM even majority of transplants from haploidentical donors. Long-term follow-up is warranted.     

Retrospective analysis of treatment outcomes in 70 patients with t(8;21) acute myeloid leukemia

We conducted a retrospective study to evaluate outcomes and prognostic factors of newly diagnosed patients with t(8;21) acute myeloid leukemia (AML). There were 70 patients (43 men and 27 women) with a median age of 48 years old (range, 17～76 years old). Sixty-five patients achieved complete remission (CR) after induction chemotherapy. Fifty-seven patients received consolidation chemotherapy based on the policy of not performing allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the time of first CR. Twenty-seven of the 57 patients relapsed (relapse rate, 47%). The median time from the achievement of the first CR to relapse was 307 days (96～1,256 days). A white blood cell count of more than 25,400/μl at diagnosis was associated with a higher relapse rate than a white blood cell count of less than or equal to 25,400/μl (75% vs. 43%, P=0.04). Nineteen of the 25 relapsed patients who received re-induction therapy experienced a second CR (second CR rate, 76%). Twenty-six patients (5 with first CR, 12 with second CR, and 9 without remission) received allo-HSCT. The five-year overall survival and disease-free survival rates were 61% and 45%, respectively. Patients with t(8;21) AML had a high CR rate, but about half of them relapsed. However, this report could not show prognostic factors for the identification of patients who should receive allo-HSCT at the time of their first CR.