ALBERT

Description: The treatment of acute promyelocytic leukemia has improved considerably after recognition of the effectiveness of all-trans-retinoic acid (ATRA), anthracycline-based chemotherapy, and arsenic trioxide (ATO). Here we report the use of all 3 agents in combination in an APML4 phase 2 protocol. For induction, ATO was superimposed on an ATRA and idarubicin backbone, with scheduling designed to exploit antileukemic synergy while minimizing cardiotoxicity and the severity of differentiation syndrome. Consolidation comprised 2 cycles of ATRA and ATO without chemotherapy, followed by 2 years of maintenance with ATRA, oral methotrexate, and 6-mercaptopurine. Of 124 evaluable patients, there were 4 (3.2%) early deaths, 118 (95%) hematologic complete remissions, and all 112 patients who commenced consolidation attained molecular complete remission. The 2-year rate for freedom from relapse is 97.5%, failure-free survival 88.1%, and overall survival 93.2%. These outcomes were not influenced by FLT3 mutation status, whereas failure-free survival was correlated with Sanz risk stratification (P[trend] = .03). Compared with our previously reported ATRA/idarubicin-based protocol (APML3), APML4 patients had statistically significantly improved freedom from relapse (P = .006) and failure-free survival (P = .01). In conclusion, the use of ATO in both induction and consolidation achieved excellent outcomes despite a substantial reduction in anthracycline exposure. This trial was registered at the Australian New Zealand Clinical Trials Registry (www.anzctr.org.au) as ACTRN12605000070639.

Description: Key Points High WBC is an independent predictor of early HD in APL.

Description: Background Acute promyelocytic leukemia (APL) is commonly complicated by complex coagulopathy. The early use of all-trans retinoic acid (ATRA) appears to have reduced induction mortality; however, with modern regimens the risk of early hemorrhagic death remains at about 5-10% in clinical trials and up to 30% in population-based studies. Previously identified as markers of bleeding risk in this setting are: white blood cell count (WBC), peripheral blood blast count, platelet count, fibrinogen, prothrombin time (PT), activated partial thromboplastin time (aPTT) and creatinine. Nonetheless, uncertainty remains as to which ones are independent predictors. Materials and Methods The database for study was from APL patients enrolled on three large clinical trials that used ATRA for induction: APML3 (single arm of ATRA + idarubicin ± prednisone), APML4 (single arm of ATRA + idarubicin + arsenic trioxide + prednisone) and ECOG 2491 (intergroup I0129, consisting of daunorubicin + cytarabine vs ATRA). Known determinants of bleeding were assessed at baseline and considered as potential predictors of hemorrhagic death in the first 30 days of induction. In univariate analysis, using Wilcoxon Rank Sum and Fisher’s exact test, we looked at the association of the parameters mentioned above with hemorrhagic death within 30 days of induction. Results A total of 619 patients were enrolled: ECOG 2491 (intergroup I0129) - 394, APML3 - 101, and APML4 -124. Among these, thirty (4.8%) deaths from bleeding during the first 30 days (early deaths, ED) following induction were recorded. Baseline characteristics of the patients are shown in Table 1 and Table 2. Initial coagulation parameters (PT, aPTT and fibrinogen) were not available for the ECOG trial. Parameters with significant differences between the ED cases and the remaining of the cohort included WBC (median: 7.4 vs 2.4 /Kmcl respectively, p

Description: The vast majority of acute promyelocytic leukemia (APL) cases are characterized by the formation of a PML/RARA fusion gene. Disruptions of retinoic acid receptor α (RARα) function have also been described in four types of variant APL in which an alternative partner gene (PLZF, NPM, NUMA, or STAT5B) is fused to RARA. We describe a novel variant APL with a RARA fusion formed by a complex gene rearrangement which is undetectable by conventional cytogenetics. A 66 yr old male with a history of mild thrombocytopenia was diagnosed with APL based on the blood and marrow morphology, the coagulopathy, and a microspeckled PML immunofluorescence pattern. The bone marrow immunophenotype was negative for CD2, CD19, CD34, CD56, CD117 and HLA-DR, and with weak expression of CD13, CD33 and CD11b, a pattern atypical for APL. The diagnostic bone marrow karyotype was 47,XY,+22[5]/46,XY[30] with no t(15;17)(q22;q21). FISH with the Vysis LSI PML/RARA dual fusion translocation probe did not show any fusion signals but there was splitting of an RARA signal on one 17q. A second probe, the Vysis LSI RARA break apart probe, showed deletion of the 5′ RARA probe and the 3′ RARA probe appeared to localize more distally than normal. The Cytocell PML/RARA ES probe also showed no fusion signals but one RARA signal appeared smaller. The diagnostic marrow was negative for PML/RARA transcripts by RT-PCR using PML and RARA specific primers, but an atypical product was observed. Sequencing of this product showed partial homology to the PRKAR1A gene that maps to 17q24 and encodes the regulatory subunit type I-alpha (RIα) of cyclic AMP-dependent protein kinase A. RT-PCR using PRKAR1A and RARA specific primers amplified two transcript splice variants of a PRKAR1A/RARA fusion gene. The shorter out-of-frame fusion transcript lacked PRKAR1A exon 3 and encoded a carboxy-truncated RIα protein. The longer in-frame fusion transcript resulted from cryptic splicing of the first 100 bases of PRKAR1A exon 3 to RARA exon 3, and encoded a chimeric RIα-RARα fusion protein that contained the dimerization domain of RIα and the same carboxy terminal domains of RARα that are found in all other known RARA rearrangements in APL. FISH using a BAC probe (RP11–120M18) encompassing the PRKAR1A gene identified signals on both copies of 17q; a strong signal on the normal 17 and a weaker signal on der(17). Before cytogenetic, FISH and molecular results were available, the patient was registered on the Australasian Leukaemia and Lymphoma Group’s APML4 treatment protocol which includes ATRA, age-adjusted idarubicin and arsenic trioxide. Arsenic was ceased on day 22 due to toxicity. Morphological and cytogenetic FISH complete remission was documented on day 35. A bone marrow biopsy eleven months from original diagnosis showed no evidence of leukemia and PRKAR1A/RARA RT-PCR was indicative of molecular remission. This novel PRKAR1A/RARA gene rearrangement identified in a variant APL is the fifth variant APL in which the RARA partner gene has been identified and the second known rearrangement of PRKAR1A in a malignant disease.

Description: Background DLBCL is the most common subtype of non-Hodgkin lymphoma in elderly patients (age ≥70). R-CHOP is the standard of care for upfront treatment of fit patients, but may not be tolerated in patients with advanced age and/or comorbidities. There is no established standard of care for this group of patients and dose reduction (R-miniCHOP) or avoidance/replacement of anthracyclines are common strategies, aiming to deliver tolerable immunochemotherapy and provide meaningful outcomes and potential cure. R-CEEP is a dose-reduced regimen that incorporates etoposide and an alternate anthracycline epirubicin. We describe our single-centre experience with R-CEEP for elderly (age ≥70) or unfit patients (CIRS-G 〉6) with newly-diagnosed or relapsed DLBCL deemed unsuitable for R-CHOP. Method All patients receiving R-CEEP for a histological diagnosis of DLBCL at Royal Prince Alfred Hospital from 2000 to 2019 were retrospectively reviewed. R-CEEP (rituximab 375mg/m2 day 1, cyclophosphamide 300mg/m2 day 1, epirubicin 50mg/m2 day 1, etoposide 100mg/m2 day 1 and prednisolone 50mg daily for days 1-5) was delivered every 14 or 21 days at physician discretion planning for 6 cycles. GCSF and antimicrobial prophylaxis were used at physician discretion. The cardiac ejection fraction was assessed as satisfactory (〉50%) prior to commencement. Baseline demographics, R-IPI, co-morbidities as assessed by CIRS-G, treatment response and adverse events (AEs) were recorded. Results Data from 61 patients were reviewed; 54 received R-CEEP for de novo DLBCL and 7 for DLBCL with a background of previously-treated lymphoma (1 DLBCL; 6 low-grade NHL). The median age at diagnosis was 80 (range 34-93), with 79% aged 75 and 28% aged 85. Thirty-three patients (54%) were female; 87% had Ann Arbor stage III/IV and 52% had R-IPI 3-5. Median CIRS-G was 9 (range 2-20) with 74% of patients having CIRS-G 〉6. GCSF prophylaxis was used in 67%. The median follow-up was 2.7 years (range 0.1-10.0 years). Overall response was 54/61 (89%), with complete response (CR) in 42 (69%), partial response (PR) in 12 (20%) and progressive disease (PD) in 1 (2%). Response was not assessed in 6 patients due to early treatment discontinuation for palliation or AEs (4), cerebral palsy (1) and loss to follow-up (1). In patients receiving R-CEEP as upfront therapy, CR was obtained in 38/54 (70%), PR in 10/54 (19%) and 6 were not assessed as above. In the 7 patients receiving R-CEEP as salvage therapy, 4 obtained CR, 2 PR and 1 had PD. Median PFS and OS for the total cohort were 5.2 and 9.4 years respectively; for de novo DLBCL patients, 7.1 and 9.4 years and for patients receiving salvage therapy, 1.1 and 2.0 years. There was no statistically significant difference in PFS or OS when comparing patients aged 6, or CIRS-G ≤9 and 〉9. Relapsed disease was identified in 19 patients (31%) during follow-up. Of the 75 AEs reported, grade 3/4 AEs accounted for 67%. Infective complications were the most frequent (53%; 40) and febrile neutropenia accounted for 8 AEs. Grade 3/4 haematological toxicity occurred in 19% (14). Despite this, the majority (43/61; 70%) received six cycles of R-CEEP. In the remaining 18 patients, 5 completed 6 cycles with dose-reduction and 13 patients discontinued therapy due to serious AEs (9), treatment intolerance (2) or patient preference (2). Of the 29 deaths recorded during the follow-up period, 18 were due to relapsed/progressive disease; 5 to infection (4 of these in CR, 0.5 to 9 years after the end of treatment, and 1 of urinary sepsis in a patient 3 months after early treatment discontinuation due to toxicity) and 6 to unrelated causes. Discussion We demonstrate that R-CEEP is an effective and deliverable immunochemotherapy in elderly or unfit patients with DLBCL. Furthermore, survival outcomes were not impacted by CIRS-G 〉9 or age ≥80, illustrating efficacy and tolerability even in patients predicted to have a particularly poor prognosis. Our cohort outcomes are not inferior to those reported in elderly fit patients treated with other dose-reduced regimens including R-miniCHOP (Peyrade et al, Lancet Oncology 2011) and R-miniCEOP (with epirubicin; Merli et al, Leukemia and Lymphoma 2012). This data supports the use of R-CEEP as an alternative immunochemotherapy option for patients with DLBCL who may not be candidates for R-CHOP. Disclosures Iland: Celgene: Other: Speaker honorarium. Ho:La Jolla: Other: investigator meeting travel costs; Novartis: Other: investigator meeting travel costs; Janssen: Other: investigator meeting travel costs; Celgene: Other: investigator meeting travel costs.

Description: Many acute myeloid leukemia (AML) patients achieve a complete remission (CR) with chemotherapy but relapse is common. Removal of residual disease remains the greatest challenge. Allogeneic transplantation (alloHCT) addresses this through an immune-mediated graft versus leukemia effect (GVL), but has high morbidity and mortality. Therapeutic dendritic cell (DC) vaccination has the potential to provide immune control with limited toxicity. Previous trials using monocyte-derived DC (Mo-DC) have demonstrated modest clinical effects. This is understandable as Mo-DC have demonstrably poor migration in vivo and relatively inferior antigen processing and presentation compared to blood dendritic cells (BDC). We have developed a more practical, functionally superior vaccine composed of natural blood DC (BDC). This is achieved using the human-mouse chimeric monoclonal antibody CMRF-56 to enrich BDC from patient peripheral blood after a short incubation.We assessed the potential for preparing a CMRF-56+ BDC vaccine from AML patients in CR. We developed an extended flow cytometry panel to distinguish different BDC subsets from blasts in AML, sorted them to confirm morphology, then used TruCount methodology to enumerate them at diagnosis, post-chemotherapy (5-28 weeks) and post alloHCT. We correct previous reports that suggested BDC numbers are normal at AML diagnosis by demonstrating that the Lineage- HLA-DR+ CD11c+ cells commonly classified as myeloid DC contain myeloblasts. Exclusion of myeloblasts, revealed that CD1c and CD141 BDC are grossly depleted at AML diagnosis to 567/mL and 24/mL, 4% and 3% respectively of the the levels of healthy aged-matched controls (HC) (n=9; n=13), but recovered to 7323/mL and 294/mL, representing 57% and 39% HC levels (n=12) during CR1, and to 10282/mL and 299/mL, representing 80% and 40% of HC after alloHCT (n=6). In contrast, plasmacytoid dendritic cells (pDC) levels were 2229/mL and 27% of HC at diagnosis, but failed to recover further remaining at 1453/mL or 18% of HC at CR1 and at 1986/mL and 24% of HC post alloHCT. CD1c BDC from AML patients in CR upregulated the CMRF-56 antigen,. similarly to HC (n=5, p=0.4) but primary AML blasts did not, enabling myeloblast free, CMRF-56+ BDC purifications. CMRF-56+ BDC isolated from AML patients in CR expanded anti-viral and Wilms' Tumour 1-specific autologous CD8+ T cells in vitro. However, patients who failed standard induction chemotherapy and required fludarabine-containing salvage regimens produced good CMRF-56+ BDC preparations but did not expand functional T cells. These data support the feasabillity of preparing a functional BDC vaccine from AML patients in CR using CMRF-56 immune selection and highlight the potential detrimental effects of specific chemotherapeutics on cellular therapy. BDC vaccination may consolidate chemotherapy induced CR in AML, or enhance GVL post alloHCT, by stimulating specific immune responses to control residual disease. Disclosures Hsu: DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Bryant:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Fromm:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Papadimitrious:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Orellana:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Suen:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Yang:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Weatherburn:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Gasiorowski:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Iland:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Brown:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Joshua:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Ho:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Gibson:DendroCyte BioTech Ltd: Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Clark:DendroCyte BioTech Ltd: Equity Ownership, Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd. Hart:DendroCyte BioTech Ltd: Equity Ownership, Other: Laboratory IP contracted via ANZAC Research Institute to DendroCyte BioTech Ltd.

Description: BACKGROUND The combination of ATRA and anthracycline-based chemotherapy has traditionally been regarded as the gold standard for induction and consolidation in previously untreated APL patients (pts), with ATO usually reserved for relapse. Recent data in Sanz low-risk (LR) and intermediate-risk (IR) APL indicate ATRA + ATO is superior to ATRA + chemotherapy (N Engl J Med 2013), but the optimal therapy for high-risk (HiR) pts remains unclear. In an attempt to improve anti-leukemic efficacy whilst limiting reliance on anthracyclines for all risk categories of APL, the ALLG incorporated ATO into an ATRA + reduced chemotherapy backbone, and the results of an interim analysis with a median follow-up of 2 years (yr) have been published (Blood 120:1570, 2012). Herein, we report results of the protocol-specified final analysis, conducted when all surviving pts had been followed for at least 2 yr after completion of consolidation. METHODS As published, APML4 protocol treatment comprised: (i) induction with ATRA (45 mg/m2 d1-36), IDA (12 mg/m2 d2,4,6,8), ATO (0.15 mg/kg d9-36), prophylactic prednisone (1 mg/kg d1-10) and aggressive hemostatic support; (ii) consolidation with ATRA and ATO (continuous in cycle 1, intermittent in cycle 2); (iii) 2 yr oral maintenance with ATRA, 6-mercaptopurine and methotrexate. Between 2004-2009, 124 evaluable pts were accrued, and median follow-up by the censor-reversing Kaplan-Meier method in this final analysis is 4.2 yr. RESULTS Median age was 44 (3-78) yr, median white cell count was 2.4 x 109/L (0.1-85.8), and median platelet count 22 x 109/L (2-173). Risk groups were 33 LR, 67 IR, 23 HiR, 1 unknown. FLT3 mutations were present in 44%, and 11% had ≥ 2 additional cytogenetic abnormalities (2+ACA). There were 4 (3.2%) deaths during induction (myocardial infarction d1, cerebral hemorrhage d3 and d7, cerebral edema and seizures d30). Grade 3-4 non-hematological adverse events included differentiation syndrome in 14%, and frequent but reversible biochemical hepatic and gastrointestinal toxicity. Q-Tc prolongation 〉 500 msec occurred in 14%, but there were no cases of ventricular arrhythmias or torsades de pointe. Significant neurological and cutaneous toxicity were infrequent. After induction, 118 pts (95%) achieved hematological complete remission; 112 commenced consolidation, and all were in molecular remission after cycle 2. A total of 5 relapses and 3 deaths have occurred post-induction, but none of the deaths were attributable to protocol therapy. Severe adverse events were less common during the chemotherapy-free consolidation cycles, especially cycle 2. The frequency of grade 3-4 neutropenia was 62% in cycle 1 and 27% in cycle 2, but there was no grade 3-4 thrombocytopenia. The following table lists event-free survival (EFS), disease-free survival (DFS), overall survival (OS) and cumulative incidence of relapse (CIR): Table All pts LR IR HiR 2 yr 5 yr 2 yr 5 yr 2 yr 5 yr 2 yr 5 yr EFS 92% 90% 97% 97% 93% 89% 83% 83% DFS 97% 95% 100% 100% 97% 93% 95% 95% OS 94% 94% 97% 97% 96% 96% 87% 87% CIR 3% 5% 0% 0% 3% 7% 5% 5% In univariate analysis, 2+ACA predicted for inferior DFS (P = .04), whereas age 〉 70 was associated with increased risk of early death (ED, P = .02), inferior EFS (P = .0002), and inferior OS (P = .001). Neither Sanz risk category nor FLT3 mutation status was significantly correlated with these outcome endpoints (all P 〉 .05). In multivariate analysis, the significant associations of 2+ACA (P = .04 for DFS) and age 〉 70 (P = .0002 for EFS, P = .005 for OS) were retained. In addition, Sanz risk category was correlated with EFS (P[trend] = .003) and OS (P[trend] = .02). When compared with our previous ALLG APML3 trial (ATRA + IDA for induction and consolidation without ATO; Haematologica 2012), treatment with APML4 was associated with substantial and statistically significant improvements (see Figure) in EFS (P = .002), DFS (P = .001) and OS (P = .02). The significance of trial assignment was retained in multivariate analysis when APML3 and APML4 data were combined. CONCLUSIONS APML4 is a potent anti-leukemic regimen with manageable toxicity and a low ED rate. EFS and OS remain impressive with mature follow-up, and were influenced primarily by advanced age and Sanz risk category. The CIR was 5%, and was only associated with 2+ACA. Our results support the inclusion of ATO in induction and consolidation as front-line therapy for APL whilst simultaneously limiting cumulative anthracycline exposure. Figure 1 Figure 1. Disclosures Off Label Use: Arsenic trioxide is currently only registered in the US, Europe and Australia for the treatment of relapsed APL. This report includes its use in the initial treatment of APL.

Description: Background: Current risk stratification for patients with acute promyelocytic leukemia (APL) is based solely on the presenting white blood cell count. There are conflicting data concerning the prognostic relevance of additional cytogenetic abnormalities (ACA) beyond t(15;17) and whether the presence of such abnormalities might influence treatment decisions for patients with APL. This is especially unclear among patients receiving ATO given that many existing data are from patients treated prior to incorporation of ATO into treatment paradigms. We sought to determine the prognostic importance of ACA and complex karyotype (CK) in influencing event-free survival in patients with APL. Methods: We analyzed patients with APL evaluated at our center since 2005 and patients treated in the Australasian Leukaemia and Lymphoma Group APML4 study (frontline ATRA + ATO + idarubicin,Lancet Haematology2015). We included all patients with baseline karyotype and those without karyotype but with FISH at diagnosis revealing ACA. Chart review extracted patient, disease, and clinical data. Only patients who commenced induction therapy with an ATO-based regimen were included in this analysis to ensure uniformity of the study population and applicability of results to contemporary clinical practice in APL. We also included patients deceased early in the disease course (1 ACA beyond t(15;17). Coagulopathy was defined as either APTT/mean laboratory normal APTT 〉1.5, INR 〉1.5 (PT/mean laboratory normal PT 〉1.5 when INR and ISI unavailable), or fibrinogen