ALBERT

Description: Background L-asparaginase (L-ASP) is a key drug in the treatment of acute lymphoblastic leukemia (ALL). However the toxicity profile, especially hypersensitivities up to acute allergic reactions is a major drawback. GRASPA (eryaspase (proposed INN) or E-Coli L-Asparaginase encapsulated into red blood cells) is a new product under development with the aim of improving the tolerance of this enzyme. Asparagine is actively transported through the membrane of red blood cells (RBC) where it is hydrolyzed by the encapsulated L-ASP, the erythrocytes acting as "bioreactors". The RBC membrane shields against the anti-L-ASP antibody then avoiding binding to encapsulated L-ASP. Recently, a Phase III pivotal study of GRASPA in combination with COOPRALL chemotherapy protocols in patients with relapsed ALL demonstrated highly significant safety profile and clinical activity compared to control. However, there is an unmet medical need for patients who cannot receive current formulations of L-ASP. An expanded access program has recently been initiated in France to provide access for treatment with GRASPA in patients who are unable to receive other forms of L-ASP. Methods: This is a non randomized multicenter open label study, currently initiated in France. The primary objective of the EAP is to evaluate the tolerability of GRASPA. Patients under 55y of age presenting with de novo, relapsed or refractory ALL who are at risk to receive any other available L-ASP formulation are enrolled into this program. Patients with known allergic reactions to E.Coli L-ASP are also eligible. GRASPA is administrated every 2 to 3 weeks at a dose equivalent to 150 IU/kg of L-ASP during all chemotherapy courses intended to contain an asparaginase. Chemotherapy protocols are given according to the Investigator's choice. Patients are assessed regularly for safety and tolerability. The primary endpoint is tolerability; Key secondary endpoints include asparaginase activity, asparagine depletion, and clinical remission rates. An independent Safety Monitoring Board (DSMB) is set up, which will assess toxicities on yearly basis. Results As of time of June 2015, 13 patients were enrolled into the program. The first DSMB meeting reviewed the outcome of the first 7 patients enrolled into the program. Of the 7 pts (range 3 - 49 years), 5 males and 2 females were enrolled. Four pts presented with refractory disease and 3 with relapse, with all patients had evidence of allergies to 2 prior asparaginases (double allergies). There were 2 pts presenting with limiting toxicities, in the form of myelosupression, and streptococcal infection. There was no modification to the protocol recommended by the first DSMB An updated safety and clinical activity information on all patients will be provided. Conclusion: The EAP provides a potential treatment alternative for ALL patients, who are unable, or at risk of developing hypersensitivity reactions to prior asparaginases. The initial results from this program suggests that GRASPA is well tolerated, and may have a potential benefit in patients with double allergies. The program will be expanded to other European countries Disclosures Bertrand: ERYTECH Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees. Dombret:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Recher:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Chugai: Research Funding; Amgen: Research Funding; Sunesis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Salako:ERYTECH Pharma: Employment. Godfrin:ERYTECH Pharma: Employment. El Hariry:ERYTECH Pharma: Employment.

Description: Background: Since the last decades, pediatric ALL classification has integrated new cytogenetic and genomic data, and several genetic risk factors are identified for treatment stratification. Hyperdiploidy, which is the most common cytogenetic abnormality pattern of pediatric B-lineage ALL, is known since the early 80s and is found in 25-30% of cases. It has been recognized as an isolated good prognostic factor, especially High Hyperdiploidy (HeH), defined by a modal chromosome number higher than 50. In addition, treatment descalations were performed based on NCI criteria for low risk ALL (low leucocytosis 〈 10 x 109/L and/or age from 1 to ²10 years old) and/or lack of high risk features. Aim: The aim of this study was to assess whether age, under or over 10 years old, has a prognostic impact on the outcome in children presenting B-cell ALL with low risk criteria, and whether therapeutic intensification might improve the outcome within each age group. Methods: Among 2039 patients treated in EORTC 58951 (BFM backbone) from 1998 to 2008, 370 children with B-cell ALL and low risk criteria such as HeH (with classical profile of chromosome gains), low leucocytosis (〈 10x109/L), a lack of CNS or gonadal involvement and a lack of very high features (poor response to prephase) were included in this study. Hyperdiploidy was determined either by cytogenetics or flow cytometry. Patients were stratified into 2 risk groups: very low risk (VLR) group or standard risk (AR1) group. VLR group was defined by the criteria indicated above. It led to a less intensive treatment, particularly lower number of injections of anthracyclines and alkylating agents. AR1 group included children with surreptitious or hemorrhagic CNS involvement, and/or HeH with mismatch between modal chromosome number and DNA index. The upper limit of age in the EORTC 58951 was less than 18 years. Main endpoints were Event-Free Survival (EFS) and Overall Survival (OS). Results: Overall patients with low risk hyperdiploid B-cell ALL features treated according to a VLR or AR1 protocol had 6-year EFS and OS rates of 90.3% and 96.2% respectively. These results were comparable to previous published studies on hyperdiploidy in childhood B-lineage ALL. All patients but one reached complete remission after the induction phase. There were 315 children aged less than 10 years old and 55 patients aged 10 to 17 years old. Among children aged 10 years and older treated in VLR or AR1 groups, 6-year EFS and OS rates were respectively 86.7% and 96.4%. In comparison, among less than 10 year old childrentreated in VLR or AR1 groups, 6-year EFS and OS rates were respectively 89.8% (p=0.42) and 95.9% (p=0.93). Age did not appear as a significant prognostic factor in the outcome. Furthermore, among children aged 10 years and older, those treated in the standard risk group (AR1) had 6-year EFS and OS rates of 90% and 100% respectively. This seemed better than for children treated in the very low risk group, with respectively 84% and 92% rates. However, no significant gain was found for children who received standard risk treatment (for EFS and OS rates: p=0.47 and p=0.12 respectively). Relapse and treatment toxicity rates were comparable in both groups. Concerning long-term cardiac toxicity, despite the fact that no significant difference was found between the two risk groups of treatment, standard treatment leads to higher dose of anthracyclines and an increased theoretical risk of cardiac toxicity. Conclusion: In conclusion, age did not appear as a significant prognostic factor in outcome of children treated for a low risk B-cell ALL. Moreover, among children aged 10 years and older, therapeutic intensification in standard risk group did not lead to a significant gain in outcome. However, results are not significant, partly due to a low number of patients, and larger studies should be performed to evaluate whether these children could benefit from a less intensive treatment. Disclosures No relevant conflicts of interest to declare.

Description: Background Asparaginase is a cornerstone in the treatment of ALL, but its utility is limited by toxicities including hypersensitivity. Clinical allergy is associated with inactivation of asparaginase by antibodies, which can also neutralize asparaginase without any clinical signs of hypersensitivity (silent inactivation). GRASPA (eryaspase - proposed INN) is an L-asparaginase encapsulated into the red blood cells. In a recent Phase III trial, it has shown to prolong the asparaginase activity and significantly reduce the incidence of allergic reactions in pts with relapsed ALL. Methods This open, randomized international Phase 3 study enrolled pts with relapsed ALL. The co-primary endpoints were the mean duration of asparaginase (ASPA) activity 〉 100 IU/L and incidence of hypersensitivity reactions during induction phase. Key secondary endpoints were safety, tolerability, complete remission and minimal residual disease rate, PK, and anti-ASPA antibodies (A-Abs) at baseline. Pts (n=80), aged 1-55 years without prior hypersensitivity were randomized to GRASPA (150 IU/kg, n=26, Arm A) or native L-asparaginase (L-ASP, 10,000 IU/m², n=28, Arm B). Additionally, 26 pts with prior hypersensitivity were treated with GRASPA in a single stratum (Arm C). All pts received COOPRALL protocol as a backbone chemotherapy. Here we report the impact of A-Abs on safety and efficacy of GRASPA. Assessments were performed at Day 4, 13, 18, and 27 (F1/F2 block), Day 6, 15, and 27 (VANDA block), and Day 6, 12 (R2/R1 block). Results At baseline, 23%, 25%, and 58% of pts had +ve A-Abs status in Arms A, B, and C, respectively. The mean duration of total ASPA activity (Days) adjusted for baseline antibody status is presented below, and shows that activity slightly differed with positive status; however, GRASPA maintained higher activity compared to L-ASP: Table 1. GRASPA L-ASP GRASPA L-ASP GRASPA (Arm C) Antibody status Negative Positive Negative Positive N 20 21 6 7 11 15 Mean (SD) 22.4 (3.6) 10.31 (8.1) 14.17 (5.1) 6.5 (4.0) 18.9 (6.8) 18.4 (6.2) Median 22.4 8.3 12.2 7.0 21.8 21.7 Min; Max 10.2; 30.7 0.0; 25.0 9.8; 21.8 1.9; 14.0 9.1; 27.9 6.9; 25.0 The incidence of hypersensitivity reactions were 0%, 7/21 (33%), and 2/11 (18%) in pts with negative A-Abs, compared to 0%, 6/7 (85.7%), and 1/15 (7%) in pts with positive A-Abs, in arms A, B and C, respectively. The CR rate during induction was 75%, 48%, and 64% in pts with negative A-Abs, compared to 33%, 14% and 48% in pts with positive A-Abs, in arms A, B and C, respectively. Conclusion These results show that about one third of pts without evidence of prior hypersensitivity have silent A-Abs activation. Positive A-Abs appeared to attenuate the clinical activity in all treatments arms. GRASPA consistently demonstrated activity and improved hypersensitivity regardless of A-Abs status, and therefore, GRASPA is a suitable option for patients with relapsed ALL. Disclosures Bertrand: ERYTECH Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees. Thomas:ERYTECH Pharma: Consultancy. Vey:Celgene: Honoraria; Roche: Honoraria; Janssen: Honoraria. Bonin:ERYTECH Pharma: Employment. Godfrin:ERYTECH Pharma: Employment. El Hariry:ERYTECH Pharma: Employment.

Description: Abstract 134 Background: Asparaginase (ASP) is an essential component in combination chemotherapy for childhood ALL and NHL, as indicated by several randomized trials. However, the optimal number of ASP administrations is still unknown. We conducted a randomized phase III trial comparing conventional E.coli ASP regimen (short-ASP, 12 doses) with prolonged E.coli ASP therapy (long-ASP, 24 doses). Methods: The European Organization for Research and Treatment of Cancer Children's Leukemia Group (EORTC-CLG) phase III 58951 trial was open to de novo ALL or NHL patients (pts) 〈 18 y. This BFM-based study addressed 2 main randomized questions. The first evaluated the value of dexamethasone (DEX, 6mg/m2/d) vs prednisolone (PRED, 60mg/m2/d) in induction for all pts. In the second question all non-very high risk (VHR) pts were randomized for either short- or long-ASP. All patients had to receive 8×10000 U/m2 in induction. In the short-ASP arm pts had to receive 4×10000 U/m2 in late intensification; pts in the long-ASP arm had to receive 8×5000 U/m2E.coli ASP injections in consolidation and 8 (4×10000 U/m2 + 4×5000U/m2) in late intensification. Patients with grade ≥2 allergy to E.coli ASP had to be switched to equivalent doses of Erwinia or PEG ASP. Central randomization was stratified by the 1st randomized arm, risk group (VLR, AR1, AR2) and center. The primary endpoint of the study was disease-free survival (DFS), secondary endpoints were overall survival (OS) and toxicity. Intention-to-treat analysis was performed. Results: Between December 1998 and August 2008, 2038 patients were randomized for the 1st question and 1552 pts, ALL (n=1481) and NHL (n=71), were randomly assigned to receive long-ASP (n=775) or short-ASP (n=777). At a median follow-up of 7 years there were 97 vs 112 events in the long- vs short-ASP group (see table). The 8-year DFS rate was 87.0% in the long-ASP and 84.2% in short-ASP group (hazard ratio (HR) = 0.87, 95% CI 0.66–1.14, 2-sided logrank p=0.30). The 8-year OS rate was comparable in both treatment arms: 92.6% in the long-ASP group and 91.3% in the short-ASP group (HR = 0.89, 95% CI 0.61–1.29, 2-sided log rank p=0.53). Similar treatment differences were observed in each risk group, in randomized arm (PRED vs DEX), and B- and T-lineage ALL pts. The incidence of grade 3–4 infection was higher in the long- vs short-ASP group during consolidation (25.2% vs 14.5%) and late intensification (22.6% vs 15.9%). This difference was more pronounced in pts who were randomly assigned to DEX (see table). In the long- vs short-ASP group grade 2–4 allergy to ASP was 22.5% vs 0.3% in consolidation and 10.3% vs 21.5% in late intensification. During the whole treatment period, the incidence of grade 2–4 allergy was 30.5% in the long-ASP arm and 21.7% in the short-ASP arm. In the long- vs short-ASP arm approximately 67% vs 95% pts received at least the total number of E.coli or equivalent ASP administrations as planned according to the treatment arm. Conclusion: At long follow-up (median= 7 yrs) prolonged E.coli asparaginase therapy in consolidation and late intensification for VLR and AR pts did not improve significantly the outcome. Intensive ASP treatment did increase infection rate in consolidation and late intensification and resulted in more grade 2–4 allergic reactions. In the future, we aim to improve outcome rates by the use of PEG ASP and monitoring of asparaginase activity and antibody formation. Disclosures: No relevant conflicts of interest to declare.

Description: Abstract 133 Background: T-cell acute lymphoblastic leukemia (ALL) accounts for 15% of ALL cases in children and has been associated with a higher risk for central nervous system (CNS) relapse and a worse prognosis. In EORTC trials 58831 and 2, standard risk (SR) patients (pts) were not irradiated but received intermediate dose methotrexate (MTX) courses; for medium and high risk pts, high dose (HD) MTX was added to the treatment regimen and the administration of cranial radiotherapy (RT) was randomised. The omission of RT didn't result in an increase of CNS or systemic relapse and consequently, CNS-directed chemotherapy was substituted for RT in all following trials. The long-term outcome of T-ALL pts in the subsequent phase III trials (58881 and 58951) are presented here. Methods: The BFM backbone for ALL treatment was applied to all EORTC-CLG trials since 1983. As CNS treatment in study 58881, SR pts received 4 HD MTX courses (5 g/m2) in interval therapy and 10 IT MTX injections during the intensive treatment phases. Pts with CNS-3 status at diagnosis received 2 additional IT injections during induction, 2 during consolidation and 6 HD MTX courses + IT during maintenance. T-ALL pts with poor prephase response (PPR) at day 8 or who didn't achieve complete remission (CR) after induction were included in the very high risk (VHR) group. VHR CNS-directed chemotherapy included 10 IT MTX injections, 6 IT triple and 10 HD MTX courses during intensive treatment phases, followed by 4 IT MTX injections during maintenance (the latter for CNS-3 pts only). In the 58951 trial, all T-ALL pts had an intensified induction. The CNS-directed therapy of all average risk T-ALL pts was intensified to 11 HD MTX courses, 1 IT with MTX and 15 triple IT. MRD ≥ 1% at the end of induction was added as VHR criterium. All non-transplanted VHR pts received 1 IT MTX injection, 19 IT triple and 9 HD MTX courses. Several randomized questions were addressed in both trials of which most relevant for T-ALL pts: in study 58881 the comparison E.coli asparaginase (ASP) Medac versus (vs) “other ASP” (= Erwinia ASP or E.coli ASP Bayer); in trial 58951 1) the comparison dexamethasone (DEX 6 mg/m2/d) vs prednisolone (PRED 60 mg/m2/d) in induction and 2) conventional vs prolonged E.coli ASP for non-VHR pts. Results: 303 and 296 T-ALL pts were included in trials 58881 and 58951 resp, representing 14.5% and 15.2% of all pts. Outcome results and type of events for the entire 58881 and 58951 cohorts and according to several subgroups are presented in the table. The 8-year isolated and overall CNS relapse incidences were 6.8% and 10.9% in study 58881, 5.3% and 8.5% in study 58951. The 8-year EFS, DFS and OS improved remarkably in study 58951. In the latter trial, outcome improvement was particularly seen in pts with initial WBC100x10E9/L and for pts with PPR treated in the DEX arm (HR (99%CI): 1.52 (0.63;3.64) and 1.47 (0.64;3.35)). Prolonged ASP treatment did not improve outcome of the whole T-ALL 58951 cohort. Conclusion: Prophylactic and therapeutic RT can safely be omitted from frontline treatment of children with T-ALL. Adequate ASP therapy, intensified induction treatment and CNS directed therapy can result in a significant improvement of the outcome of at least 2/3rd of T-ALL pts, particularly those with initial WBC

Description: We evaluate the prevalence and risk factors of the metabolic syndrome (MS) in young adults surviving childhood leukemia. During the years 2007 to 2008, assessment of MS was proposed to all adults included in the Leucémie de l'Enfant et de l'Adolescent program, a French prospective multicentric cohort of leukemia survivors. Among 220 eligible patients, 184 (83.6%) had complete evaluation. Median age at evaluation and follow-up duration were 21.2 and 15.4 years. Overall prevalence of MS was 9.2% (95% confidence interval, 5.5-14.4). There was no association of MS with sex, age at diagnosis, leukemia subtype, steroid therapy, and central nervous system irradiation. Patients were stratified according to 4 therapeutic modalities: chemotherapy alone (n = 97), chemotherapy and central nervous system irradiation (n = 27), hematopoietic stem cell transplantation (HSCT) without (n = 17) or with (n = 43) total body irradiation (TBI). MS occurred in 5.2%, 11.1%, 5.9%, and 18.6% of them, respectively. The higher risk observed in the HSCT-TBI group was significant in univariate and in multivariate analysis (odds ratio [OR] = 3.9, P = .03). HSCT with TBI was associated with a higher rate of hypertriglyceridemia (OR = 4.5, P = .004), low level of high-density lipoprotein cholesterol (OR = 2.5, P = .02), and elevated fasting glucose (OR = 6.1, P = .04) So, TBI is a major risk factor for MS. Further studies are warranted to explain this feature.

Description: Background Asparaginase is a cornerstone in the treatment of ALL, but its utility is limited by toxicities including hypersensitivity. Clinical allergy is associated with inactivation of asparaginase by antibodies, which can also neutralize asparaginase without any clinical signs of hypersensitivity (silent inactivation). GRASPA (eryaspase - proposed INN) is an L-asparaginase encapsulated into the red blood cells. In a recent Phase III trial, it has shown to prolong the asparaginase activity and significantly reduce the incidence of allergic reactions in pts with relapsed ALL. Methods This open, randomized international Phase 3 study enrolled pts with relapsed ALL. The co-primary endpoints were the mean duration of asparaginase (ASPA) activity 〉 100 IU/L and incidence of hypersensitivity reactions during induction phase. Key secondary endpoints were safety, tolerability, complete remission and minimal residual disease rate, pharmacokinetic (PK), pharmacodynamics (PD) and anti-ASPA antibodies at baseline. Pts (n=80), aged 1-55 years without prior hypersensitivity were randomized to GRASPA (150 IU/kg, n=26, Arm A) or native L-asparaginase (L-ASP, 10,000 IU/m², n= 28, Arm B). Additionally, 26 pts with prior hypersensitivity were treated with GRASPA in a single stratum (Arm C, GRASPA-s). All pts received COOPRALL protocol as a backbone chemotherapy. Here we report the report the PK of asparaginase activity, and PD effects. Results A total of 80 pts enrolled into the trial. A total 100% and 96% of patients had at least one day with asparaginase level 〉100 IU/L during induction, with GRASPA and L-ASP, respectively. Only one patient in L-Asp group did not reach this threshold. All patients in Arm C have also achieved total blood asparaginase level 〉 100 IU/L during induction. Prolonged ASPA activity was maintained across several key subpopulations as follows: Table 1. GRASPA L-ASP GRASPA L-ASP Age group Children Adults  N 21 21 5 7  Mean (SD) 20.8 (5.3) 11.4 (7.3) 19.3 (5.5) 3.2 (2.8)  Median 22.0 8.3 22.1 2.3 Risk Score S1/S2 S3/S4  N 16 15 10 13  Mean (SD) 20.2 (6.0) 12.0 (8.6) 20.9 (3.9) 6.3 (4.4)  Median 22.4 9.0 22.0 6.2 F1-F2/VANDA F1-F2 VANDA  N 16 15 10 13  Mean (SD) 19.5 ± 6.5 11.5 (9.0) 22.0 (0.2) 6.9 (4.2)  Median 22.9 8.8 22.0 6.9 The total ASPA activity 〉100 IU/L until the loss of that activity demonstrated that the activity was retained in the majority of pts in the GRASPA arm (89%) compared to only 26% in the L-ASP arm. The median times from first assessment of activity 〉 100 IU/L to loss of activity was not reached in the GRASPA arm by Day 28, but was 15 days in the L-ASP arm. The difference was statistically significant (table below). Similar trend was also observed with GRASPA-s. Table 2. Time from first assessment showing ASPA activity 〉 100 IU/L until loss of ASPA activity 〉 100 IU/L Number (%) of events Median [95% CI] Hazard ratio 95% CI Logrank test: p-value for superiority L-ASPN= 28 27 (96.4) 15[11; 21] 0.14 0.07, 0.28

Description: Background Cranial radiotherapy (CRT) is associated with early and late side effects. Intrathecal (IT) and systemic chemotherapy could successfully replace CRT in most protocols for standard risk ALL. However, in medium and high risk ALL patients (pts) its omission is still debatable. Aim We investigated the long-term outcome, the occurrence of second malignant neoplasms (SMN) and the incidence of late toxicities in pts randomized for receiving or not CRT in the EORTC 58832 study. Methods From 1983 to 1989, ALL children under 18 years (yrs) were included in EORTC Children Leukemia Group BFM-oriented studies, either 58831, for standard risk pts (Riehm-Langerman Risk Factor (RF) 〈 1.2), or 58832, for medium risk (RF 1.2-1.69) and high risk pts (RF ≥1.7). Pts with central nervous system (CNS) involvement at diagnosis were ineligible. The present report focusses on pts included in the 58832 trial (randomized for receiving or not prophylactic CRT). Prophylactic CNS therapy consisted of 4 high-dose methotrexate (HD-MTX) injections (2500 mg/m2) during consolidation and 7 IT MTX injections scheduled during the treatment period. Pts still in complete remission (CR) after the end of late intensification were randomized for receiving prophylactic CRT (standard arm) or not (experimental arm) before the start of continuation therapy. Dose of CRT was age dependent: 24 Gy (〉 2 yrs), 20 Gy (1-2 yrs) and 16 Gy (〈 1 yr). Endpoints were: disease-free survival (DFS) (event: relapse, death in CR), incidence of SMN, event-free survival (EFS) (event: relapse, death in CR, SMN), incidence of late toxicities, and overall survival (OS) from randomization. Results 788 pts were included in the 58831/58832 study. Among them, 189 were randomized in the 58832 study to receive CRT (n=93) or No CRT (n=96). A total of 6 pts did not meet eligibility criteria, 2 had an early relapse, 3 had an early protocol violation and 2 refused allocated treatment. Finally, 176 randomized pts were included in the analyses: 84 in the CRT group and 92 in the No CRT group. The median follow-up was 20 yrs (range 4-32 yrs). Omission of CRT did not increase the 25-yr incidence of isolated CNS relapse, any CNS relapse or non-CNS relapse (4.8 vs 6.5; 11.9 vs 8.7 and 16.7 vs 21.8 in the CRT vs No CRT arms, respectively). No relapses occurred after 10 yrs. The 25-yr DFS rates were similar in both arms: 70.2% with CRT and 67.4% without CRT; No CRT vs CRT hazard ratio (HR)=1.08, 95% CI (0.63, 1.83). CRT was associated with an increase of the 25-yr SMN incidence: 13.2% with CRT and 3.9% without CRT. In the CRT arm, 9 pts (10.7%) developed SMN: 2 acute myeloid leukemias (AML), 1 non-Hodgkin lymphoma, 1 thyroid carcinoma, 4 meningiomas and 1 malignant histiocytosis. One SMN (meningioma) occurred after a CNS combined relapse. Three pts developed second SMN (meningiomas): 1 after an AML and 2 after a first meningioma. In the No CRT arm, 3 pts (3.3%) had SMN: 1 pleomorphic xanthoastrocytoma, 1 melanoma and 1 adenocarcinoma of the ileum. One SMN occurred after a bone marrow (BM) relapse. The 25-yr EFS rates were similar in both arms: 60.3% with CRT and 63.2% without CRT, HR=0.90, 95% CI (0.55, 1.46). CRT was also associated with an increase of late CNS and endocrine toxicities. Five pts (19.2% of the pts with available data) developed leukoencephalopathy in the CRT arm, versus 2 pts (8.7%) in the No CRT arm. Noteworthy, 1 of those 2 pts received CRT for a BM relapse, while the other received total body irradiation for a CNS relapse. Stroke was observed in 2 pts (7.7%) who received CRT. In contrast, there was no clear increase of the incidence of cognitive disturbance after CRT: 33.3% in the CRT arm vs 25.0% in the No CRT arm. Regarding endocrine toxicities, GH deficiency, hypothyroidism and precocious puberty were more frequent in the CRT arm: 53.1% vs 29.6%, 27.8% vs 0% and 29.4% vs 0%, respectively. Finally, the 25-yr OS rates were similar in both arms: 78.5% with CRT and 78.1% without CRT, HR=1.00, 95% CI (0.53, 1.88). Conclusion In medium and high risk pts without CNS involvement at diagnosis and treated with HD-MTX in the EORTC trial 58832 (1983-1989), omission of CRT did not increase the risk of CNS or non-CNS relapse. On long-term evaluation, CRT was associated with a higher incidence of SMN, late CNS and endocrine toxicities. These long-term results indicate that prophylactic CRT can be safely omitted in childhood medium and high risk ALL pts receiving IT and systemic chemotherapy (including HD-MTX) as CNS prophylaxis. Table Table. Disclosures No relevant conflicts of interest to declare.

Description: Purpose The long-term impact of treatment in infants with acute leukemia (AL) is poorly understood and of concern. Patients and methods We analyzed the incidence, in the L.E.A. cohort, of and risk factors for late sequelae in the survivors of infant AL diagnosed before the age of one year, according to group: type of AL, transplantation, sex, and age ≤ or 〉 6 months. Of 113 survivors, 55 had had lymphoblastic AL and 58 myeloblastic AL. The median follow-up was 11.7 years [1.9-34.7]. Sixty-three were treated with chemotherapy only (and four with central nervous system irradiation) and 50 received transplantation (with a chemotherapy-based regimen except for three). Results The most frequently observed sequelae included problems of height, body mass index, and gonadal or thyroid function (Figure 1). We found a mean of 1.3 +/-0.1 sequelae per patient. In multivariate analysis, treatment after the age of six months significantly decreased the incidence of major growth failure (OR 0.38, p = 0.04) and low weight (OR 0.3, p = 0.02) (Figure 2). Transplants performed in first remission did not affect the occurrence of late effects (p = 0.2) (Figure 3). Parent-reported child quality of life (QoL) scores were similar among groups and to the normative population. Adults had diminished QoL as measured by psychosocial subscales relative to French norms but with no difference between groups. Conclusion Altogether, these results highlight the need for comprehensive follow-up with hormone replacement therapy and psychological intervention. Our results in a large cohort with very limited use of irradiation, did not show an increased risk of late sequelae relative to older children. We conclude, that transplantation should be considered when warranted, as there is no increased risk of late effects. Disclosures No relevant conflicts of interest to declare.