Abstracts of the 62nd Annual Scientific Meeting of the British Society for Haematology

The proceedings contain 252 papers. The topics discussed include: immunogenicity of Covid-19 vaccination in patients with myelodysplastic syndromes;antibody responses to SARS-CoV-2 vaccination in patients with acute leukemia and high-risk MDS on active anti-cancer therapies;CD9 derepression drives cellular differentiation and restores immune recognition in pediatric acute myeloid leukemia;follow-up of patients with FLT3-mutated relapsed or refractory acute myeloid leukemia in the phase 3 ADMIRAL trial;efficacy and safety of Maribavir as a rescue treatment for investigator assigned therapy in transplant recipients with refractory or resistant cytomegalovirus infections in the SOLSTICE study: phase 3 trial results;long-term survival benefit of eculizumab treatment in patients with paroxysmal nocturnal hemoglobinuria: data from the international PNH registry;and analysis of anemia persistence and related adverse events in patients with paroxysmal nocturnal hemoglobinuria treated with pegcetacoplan.

Safety and Efficacy of Azacitidine with Venetoclax for Newly Diagnosed Intensive Chemotherapy Ineligible, and Relapsed or Refractory Acute Myeloid Leukemia in Arab Population: A Single-Center, Retrospective Study

Background: Venetoclax combined with hypomethylating agents is a new standard of care for newly diagnosed patients with acute myeloid leukemia (AML) 75 years or older, or unfit for intensive chemotherapy. As precision therapy in AML expanded with the addition of venetoclax among others in the therapeutic armamentarium of AML, efficacy and safety reports in ethnic minorities are limited, with a background of well recognized inter-ethnic differences in drug response. Phase III data from VIALE-A, as well as VIALE-C, was limited for the Arab population as no site opened in the Arab world. We herein report our experience on the use of venetoclax with azacitidine in patients with newly diagnosed or relapsed/refractory AML in the Arab population. Methods: Retrospective-single center review on the use of Azacitidine with venetoclax in older patients (aged ≥60 years) with newly diagnosed AML, not eligible for intensive chemotherapy;secondary AML and relapsed or refractory AML. All patients self-identified of Arabic ethnicity. Patients who received previous BCL2-inhibitor therapy were excluded. Patients who received at least one dose of treatment (Azacitidine ≥3 days, >14 days of venetoclax) were included in the intention to treat analysis. Patients typically received azacitidine 75 mg/m2 intravenously for 7 days with oral venetoclax 400 mg daily for induction, with appropriate dose adjustment for concomitant use of azoles. This is followed by the same regimen in consolidation, with adjustment according to response and side effects at the treating physician's discretion. The primary endpoint was overall survival. The secondary endpoints include response rate, safety, and relapse-free survival. Results: Between July 2019, and July 2021, we identified 19 patients;13 (68%) had newly diagnosed AML (ND-AML), and 6 (32%) had relapsed or refractory AML (R/R AML). The median age was 70 years (17-82). In the ND-AML, most patients had an adverse ELN 2017 AML (69%) with 23% having either intermediate or adverse AML (Negative for CBF, NPM1, FLT3-ITD and biCEBPA, but missing NGS data for adverse mutations Tp53/ASXL1 and RUNX1). Only one patient was classified as intermediate-risk AML. The overall response rate in the ND-AML was 77%, with 46% achieving complete remission (CR), and 23% CR with incomplete count recovery (CRi) [Table]. One patient achieved PR after the first cycle (blast 7% by morphology and 1.5% by flow cytometry) and did not have a subsequent bone marrow evaluation, however had a full count recovery. Among the responders in the ND-AML cohort, 4 deaths were noted. One death was related to COVID-19 associated pneumonia, one due to graft failure (at day 42 post Haplo-SCT), one due to septic shock, and one was related to relapse disease. The overall survival and relapse-free survival for ND-AML were 5.6 months for both [Figure]. In the R/R AML, 66% had prior HMA exposure, and all patients did receive high-intensity chemotherapy. The median number of prior treatments was 3 (1-5). the response rate was 80% (4/5), with 60% achieving CR. All patients are still alive with a median follow-up of 7.6 months. One patient had progressive disease. One patient is early to evaluate and was not included in the response analysis [Table]. The 30-day mortality was zero in both ND-AML and R/R AML cohorts. Conclusions: In a majority of adverse risk ND-AML, and in heavily pretreated R/R AML, the response rate and overall survival is comparable to what has been previously reported. Our data support the use of this regimen in older patients with newly diagnosed AML, patients with relapsed or refractory disease, and those with adverse-risk features. This analysis is limited by the small number of patients, and by the lack of ELN 2017 favorable-risk AML. Future prospective and randomized studies are needed to clarify activity and safety in the Arab population, as well as in the high-risk AML subset. [Formula presented] Disclosures: No relevant conflicts of interest to declare.

Successful Treatment of Acute Myeloid Leukemia with CPX-351 in 2 Patients in the United Kingdom during the COVID-19 Pandemic

Introduction: The COVID-19 pandemic hit the United Kingdom in early 2020. High infection rates prompted concern for immunocompromised patients, including patients with AML receiving intensive chemotherapy. CPX-351 (Europe: Vyxeos ® Liposomal;US: Vyxeos ®), a dual-drug liposomal encapsulation of daunorubicin and cytarabine in a synergistic 1:5 molar ratio, is approved for the treatment of newly diagnosed therapy-related AML (t-AML) or AML with myelodysplasia-related changes (AML-MRC) in adults in Europe and in adults and pediatric patients aged ≥1 year in the United States. Despite concerns about intensive chemotherapy-related myelosuppression, the National Cancer Research Institute AML Working Group recommends that CPX-351 should continue to be administered in patients with adverse-risk cytogenetics and/or secondary AML during the pandemic. We report 2 patients with AML who were successfully treated with CPX-351 in the United Kingdom during the COVID-19 pandemic. Methods: The patients were diagnosed and managed per institutional guidelines. Two patients received CPX-351 induction (daunorubicin 44 mg/m 2 + cytarabine 100 mg/m 2) on Days 1, 3, and 5 (Days 1 and 3 for second induction) and CPX-351 consolidation (daunorubicin 29 mg/m 2 + cytarabine 65 mg/m 2) on Days 1 and 3, all by 90-minute IV infusion, during the pandemic. Results: The first patient was a 67-year-old male who presented with generalized fatigue in June 2020 with comorbidities of type 2 diabetes, diabetic nephropathy, and leg ulcers. Blood counts demonstrated a hemoglobin count of 79 g/L, white blood cell count of 0.7×10 9, platelet count of 58×10 9/L, and neutrophil count of 0.2×10 9/L. A bone marrow biopsy revealed AML-MRC with 40% blasts, and the patient had wild-type FLT3, NPM1, and SRSF2. The patient achieved morphologic and cytogenetic remission after 2 CPX-351 induction cycles. The patient then received 1 CPX-351 consolidation cycle but was not a candidate for transplant due to diabetic nephropathy. Tolerability improved with each cycle;the patient experienced neutropenic sepsis during the first induction, a flare up of leg ulcers and cellulitis during the second induction, and no tolerability concerns during the consolidation cycle. After the first induction, recovery of neutrophils and platelets occurred around Day 35 and Day 28, respectively (Figure 1), and counts recovered more quickly with each cycle. This patient was managed without contracting COVID-19 or experiencing any pandemic-related complications. The second patient was a 69-year-old female who presented with pancytopenia in February 2020 with no significant past medical or drug history. Her hemoglobin count was 66 g/L, white blood cell count was 0.6×10 9/L, platelet count was 17×10 9/L, and neutrophil count was 0.3×10 9/L. The patient was diagnosed with AML-MRC with mutated NPM1, SRSF2, IDH2, and JA2. During the first CPX-351 induction cycle, the patient contracted COVID-19. Some symptoms were present, but the patient did not become significantly unwell from COVID-19. Despite count recovery, the patient remained positive by nasal/oral PCR swab test for several weeks, delaying the delivery of the second CPX-351 induction cycle. After the second CPX-351 cycle began, the patient once again became positive for COVID-19 by PCR swab. The patient remained positive for longer than the first infection but was largely asymptomatic during the cycle (apart from a bout of sepsis). After a period of approximately 3 months from the previous CPX-351 cycle, the patient received a CPX-351 consolidation cycle and achieved complete remission with no measurable residual disease by NPM1 mutation in the bone marrow (Figure 2). The patient was eligible for transplant but declined. Conclusions: Two patients with AML-MRC were successfully treated with CPX-351 during the COVID-19 pandemic, despite one of the patients contracting and variably testing positive for the disease. During the pandemic, it is important to weigh the benefits of treating AML with curative intent versus the risks of immuno uppression and potential COVID-19 infection. Individualized decisions must be made for each patient based on disease, treatment, and COVID-19 risk factors through discussion with a multidisciplinary team. Although treating patients with AML with CPX-351 during the pandemic can be challenging, it remains an option for appropriate patients with newly diagnosed t-AML or AML-MRC. [Formula presented] Disclosures: Munisamy: Roche: Speakers Bureau;Jazz Pharmaceuticals: Speakers Bureau. Choudhuri: AstraZeneca, Bristol-Myers Squibb, Jazz Pharmaceuticals, and Pfizer: Consultancy.

A new translocation partner for CBFB in acute myeloid leukemia, t(10;16)(p13;q22)

Cytogenetic abnormalities involving chromosome 16 are found in 5– 8% of acute myeloid leukemia (AML). These are typically a pericentric inversion inv(16)(p13.1q22) or a translocation, t(16;16)(p13.1;q22), involving the MYH11 and CBFB genes localized to chromosome 16p13.1 and 16q22, respectively. In addition, less common rearrangements include deletion of the long arm of chromosome 16, del(16) (q22), and cryptic insertions involving the MYH11 and the CBFB genes with otherwise normal karyotypes. In this report, we present the first AML case with a new translocation involving the CBFB gene. The more common CBFB - MYH11 fusion product resulting from the inversion and/or translocation of chromosome(s) 16 leads to an AML with monocytic and granulocytic differentiation and abnormal eosinophil component with large, purple to violet color eosinophilic granules. This entity typically corresponds to the adult AML-M4Eo in French-American- British (FAB) Classification and now called AML with inv(16)(p13.1q22) or t(16;16)(p13.1;q22);CBFB-MYH1 in the new 2017 WHO Classification. Patients may present with myeloid sarcoma at initial diagnosis or at relapse. We present a case of an 80-year-old male with a history of prostate cancer post radiotherapy who was referred for COVID-19 testing. A complete blood count with differential revealed neutropenia and a macrocytic anemia. A bone marrow biopsy and a bone marrow aspirate confirmed a diagnosis of AML with 33% blasts including myeloblasts and promonocytes. Interphase fluorescence in situ hybridization (FISH) analysis with a break-apart probe for CBFB showed an abnormal hybridization pattern consistent with rearrangement of CBFB in 66% of nuclei. Chromosome analysis revealed an abnormal karyotype with two related clones: 47,XY, t(10;16)(p13;q22),+22[4]/48,idem,+8[16]. Sequential GTG-FISH confirmed that the 3’ region of CBFB was translocated to 10p13 in the t(10;16) and the 5’ region remained on 16q. Based on the karyotype, the patient’s bone barrow exhibits clonal evolution having acquired additional chromosome abnormalities (trisomy 22 and trisomy 8). Molecular studies by next generation sequencing showed NRAS p.Gln61Lys mutation with a VAF of 11.21%. No genomic alterations were detected in KIT, KRAS or FLT3 genes. AML with inv(16)(p13.1q22) or t(16;16)(p13.1;q22) is associated with a high rate of complete remission and favorable overall survival when treated with intensive consolidation therapy. However, their prognostic advantage may be affected by additional cytogenetic abnormalities and/or other gene mutations. Specifically, trisomy 22, is a frequent abnormality additional to inv(16) detected as a secondary finding which has been associated with an improved outcome when compared to the prognosis associated with inv(16) alone. Furthermore, KIT (in 30–40%), FLT3 (in 14%), NRAS (in 45%) and KRAS (in 13%) mutations are common in this AML type. The prognostic implications of KIT mutation (especially involving exon 8) do not appear to be significantly poor prognostic compared to other AML types. On the other hand FLT3-TKD mutations and trisomy 8 are associated with a worse outcome. The patient is currently receiving Vidaza 75 mg/m2, days 1–7 of a 28 days cycle with Venetoclax mg daily of a 28-day cycle and his clinical prognosis is currently unclear. Further analysis by DNA sequencing may help to characterize the molecular nature of the fusion gene product resulting from the novel t(10;16)(p13;q22). To the best of our knowledge, this is the first reported case of an AML patient with translocation t(10;16)(p13;q22) involving the CBFB gene. Given the rarity and lack of additional information regarding the effects of this abnormality, the prognosis and survival cannot be predicted.

What is beyond NPM1 and FLT3 ITD Mutationsas Prognostic Indicators in AML- Experiencefrom a Tertiary Care Centre

Introduction: Acute Myeloid Leukaemia (AML) is one of the mostcommon haematological malignancies in adults. Molecular mutationsin AML are major determinants of the patient's response to therapyand outcomes. Nucleophosmin 1 (NPM1) confers a good prognosiswhile fms-like tyrosine kinase-3 gene (FLT3-ITD) is associated witha poor prognosis.Aims &Objectives: To study the prognostic molecular markers andcytogenetics of all newly diagnosed and de novo AML cases andassess the impact of the same on treatment outcome.Materials &Methods: 23 patients with newly diagnosed (adult andpaediatric) de novo AML from Jan 2021 to Aug 2021 at GauhatiMedical College, Guwahati were included in this study. We analysedthe bone marrow aspirates, clinical significance of NPM1, CEBPA,FLT3 (by real time PCR) with disease progression. Cytogenetics bykaryotyping and immunophenotypic parameters were also documented and corelated with disease progression.Result: There were (12/23)52.2% males and (11/23)47.8% female. 2patients (8.7%) were positive for FLT3 and 4(17.4%) were positivefor NPM1. (7/23)30.4% patients had t(8,21) of which 3 had normalkaryotype while 2 patients (8.7%) had turner's genotype(45,X). 4patients (17.4%) expired while receiving Induction chemotherapy, ofwhich one had 45,X,t(8,21)genotype, one had NPM1 mutation andone expired during 3 rd cycle of consolidation due to covid 19pneumonia. 6(26.1%) patients had treatment failure following intensive induction therapy of which 2 had t(8,21) with normalkaryotype(40%) and one had NPM1 mutation with wildtype FLT3.All patients with NPM1 mutation were negative for CD34 andHLADR. All patients with NPM1 and FLT3 uniformly expressed CD33.Conclusions: 3/6 patients had failure of induction in spite of havingstandard risk cytogenetics. So, next generation sequencing (NGS) iswarranted upfront for all diagnosed AML cases. It should now beincorporated as a standard of care in the management of AML. Onepatient with turner's genotype and t(8,21) expired during inductiontherapy, hence, prognostic significance of 45,X needs to be furthervalidated in AML.

Venetoclax with Azacitidine or Low Dose Cytarabine As an Alternative to Intensive Chemotherapy in Fit Adults during the COVID19 Pandemic: Real World Data from the UK National Health Service

Background Based on early evidence of a high rate of coronavirus mortality in patients with acute myeloid leukaemia (AML) undergoing intensive chemotherapy (IC), the national health service (NHS) in the United Kingdom temporarily made venetoclax available as an alternative therapy, with the aim of reducing both mortality and healthcare resource use. From late April 2020, venetoclax was available to patients aged >16y with NPM1 mutation without FLT3 internal tandem duplication (ITD), patients aged >50y with NPM1, IDH1 or IDH2 mutations (regardless of FLT3 status) and patients aged >60y without favourable-risk cytogenetics. Venetoclax could be given with either azacitidine or low-dose cytarabine (LDAC), with the latter recommended mainly for patients with NPM1 mutation. We report a health-system-wide real world data collection for toxicity and patient outcomes across 65 NHS Hospitals. Methods Each patient was registered on a central NHS database. Clinicians certified that their patient met the above criteria, had not received previous AML treatment, and was fit for induction chemotherapy. Anonymised data were retrospectively collected by treating physicians. Venetoclax dose, duration and toxicity information was requested for the first 4 cycles of therapy. Response definitions were as per European Leukaemia Network (ELN) guidelines. A total of 870 patients have been registered on the scheme, with outcomes reported here for those with follow-up information at a data cut on 1st August 2021. Results There were 301 patients, median age 72y (range 34 - 90) with 62% male. The majority (81%) had an ECOG performance status of 0-1. AML was secondary to a previous haematological disorder in 33%, therapy-related in 10% and de novo in the remaining 57%. MRC cytogenetic risk was intermediate in 70% and adverse in 27%. NPM1 mutations were detected in 28% and FLT3-ITD in 12%. Next-generation sequencing results were available in 86% of patients, which detected mutations in IDH1 or IDH2 in 28%, ASXL1 in 20%, RUNX1 in 17% and TP53 in 12%. The ELN risk was favourable for 23%, intermediate for 30% and adverse for 44%. A majority received venetoclax in combination with azacitidine (85%), with the remaining 15% receiving LDAC. The LDAC cohort was enriched for de novo AML (76% vs 54%) and NPM1-mutated disease (56% vs 23%). Most patients (81%) followed the recommended initial schedule of venetoclax 100mg daily for 28 days in combination with posaconazole or voriconazole. Patients spent a median 14 days in hospital in cycle 1, then a median of 0 days for cycles 2-4. In cycles 1, 2, 3 and 4, the median number of days for recovery of neutrophils to >0.5x10 9/L was 33, 25, 24 and 14 respectively, and the median number of days to recovery of platelets to >50x10 9/L was 22, 3, 0 (no drop below 50) and 0. The composite complete remission (CR) / CR with incomplete haematological recovery (CRi) rate was 70%. MRD data is being collected. The best response was morphological leukaemia free state (MLFS) in 2%, partial remission in 7% and refractory disease in 11%. CR/CRi was higher in de novo (78%) compared to secondary AML (57%, p=0.02);NPM1 mutated (78% vs 67%, p=0.02) and IDH1/IDH2 mutated disease (85% vs 62%, p=0.02). ELN favourable risk patients had the highest CR/CRi rate (85%, intermediate 71%, adverse 60%, p=0.01). Median follow-up was 8.2 months (95%CI 7.8 - 9.0) with median overall survival (OS) 12.8 months (95%CI 10.9 - not reached). Mortality at day 30 was 5.7% and day 60 was 8.4%. 12-month overall survival was 51%, increasing to 71% in those who achieved CR/CRi. Survival was poorer in secondary (HR 1.9, p <0.01) and therapy-related AML (HR 2.1, p=0.02), better in NPM1 mutated (HR 0.6, p=0.02) and IDH mutated (HR 0.5, p=0.02) disease and poorer with TP53 mutation (HR 2.0, p=0.01). Overall survival did not differ for patients treated with LDAC compared to azacitidine (HR 1.1, p=0.7). Conclusion This large real-world study demonstrates CR/CRi and survival rates comparable to those reported in prospective clinical trials. Importantly, during t e COVID-19 pandemic, the adoption of venetoclax regimens permitted the great majority of treatment to be delivered as an outpatient with significant resource saving at a time of critically constrained inpatient resources. The data support prospective comparisons of venetoclax-based regimens to IC in fit adults with AML particularly in older patients with de novo AML, NPM1-mutated and IDH-mutated disease. [Formula presented] Disclosures: Belsham: Celgene: Other: meeting attendance;Abbvie: Other: meeting attendance. Khan: Abbvie: Honoraria;Astellas: Honoraria;Takeda: Honoraria;Jazz: Honoraria;Gilead: Honoraria;Novartis: Honoraria. Khwaja: Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Astellas: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Latif: Kite: Consultancy, Honoraria, Speakers Bureau;Jazz: Consultancy, Honoraria;Daiichi Sankyo: Consultancy, Honoraria;Novartis: Consultancy, Honoraria;Amgen: Consultancy, Honoraria;Abbvie: Consultancy, Honoraria;Astellas: Consultancy, Honoraria, Speakers Bureau;Takeda UK: Speakers Bureau. Loke: Pfizer: Honoraria;Amgen: Honoraria;Janssen: Honoraria;Novartis: Other: Travel;Daichi Sankyo: Other: Travel. Murthy: Abbvie: Other: support to attend educational conferences. Smith: ARIAD: Honoraria;Pfizer: Speakers Bureau;Daiichi Sankyo: Speakers Bureau. Whitmill: Daiichi-sankyo: Other: travel fees;EHA in stockholm: Other: conference support. Craddock: Novartis Pharmaceuticals: Other: Advisory Board;Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding. Dillon: Shattuck Labs: Membership on an entity's Board of Directors or advisory committees;Jazz: Other: Education events;Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: educational events;Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Session chair (paid to institution), Speakers Bureau;Menarini: Membership on an entity's Board of Directors or advisory committees;Astellas: Consultancy, Other: Educational Events, Speakers Bureau;Amgen: Other: Research support (paid to institution);Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Research Support, Educational Events.

Clinical Characteristics and Outcomes of Patients with Newly Diagnosed De Novo Acute Myeloid Leukemia (AML) during the COVID-19 Pandemic

Introduction The COVID-19 pandemic disrupted non-urgent and preventive medical care. During the early peak of the pandemic, an estimated 41% of US adults delayed or avoided medical care (Czeisler et al, CDC, 2020). While there were documented declines in the number of emergency department visits for myocardial infarction, stroke and hyperglycemia, similar data is not available related to acute myeloid leukemia (AML) (Lange et al, CDC, 2020). A delay in the diagnosis of AML could lead to presentation when patients are less able to withstand chemotherapy or have a higher disease burden which could compromise overall survival (OS). In this retrospective analysis, we aim to elucidate if there was a difference in clinical, cytogenetic, or molecular presentations and if there was an effect on early mortality as determined by overall survival at 1 and 6 months. Methods We compared the clinical, cytogenetic, and baseline molecular genetics of consecutive adult patients diagnosed with de novo AML at Dana-Farber Cancer Institute/Brigham and Women's (DFCI/BWH) Hospital from March 23, 2020, the date of the Massachusetts COVID State of Emergency, to August 23, 2020 to a historical cohort of similar patients between presenting between March 23, 2017 and August 23, 2020. Data was obtained from the Hematological Malignancy Data Repository and via review of the medical record. Patients were excluded from this cohort if they were diagnosed with acute promyelocytic leukemia, had known antecedent myeloid malignancy, or if they did not have DFCI/BWH 96-gene next-generation sequencing panel (RHP) performed at the time of diagnosis. Baseline clinical, laboratory, cytogenetic, and molecular characteristics and outcomes were compared between the pre-pandemic and pandemic cohorts using chi-squared, Fisher's exact, and Wilcoxon rank sum analyses (where appropriate) at a significance of p<0.05. Results Thirty-eight AML patients presented during the COVID-19 pandemic (PAN) and 308 in the pre-pandemic (PREPAN) period. There was no statistically significant difference in the monthly rate of new patients presenting in PREPAN and PAN cohorts (8 vs. 6 new patients/month, p=0.73). The median age at presentation (64 PREPAN vs. 65 PAN, p=0.77), sex, and therapeutic approach (intensive, non-intensive, supportive care, other) were not statistically different between cohorts. Presenting white blood cell count, platelet count, and fibrinogen were not different between cohorts, while hematocrit was significantly lower in the PAN cohort (23.8% vs. 26.0%, p=0.001). There was a trend for a higher median blast percentage (28.5% vs. 13%, p=0.09) in the PAN cohort. There were no differences between the cohorts in the median number of cytogenetic abnormalities, nor in the incidence of complex karyotype, (25.3% vs. 23.7%) across PREPAN and PAN respectively. There were also no significant differences in the European LeukemiaNet (ELN) risk classification scores across the PREPAN and PAN time periods, with 57.8% vs. 52.6% of total patients presenting with adverse risk disease respectively. When specific mutations of TP53, NPM1, and FLT3 were evaluated, only FLT3 demonstrated a statistical difference with a higher proportion in the pandemic group (p=0.04). OS at 1-month (97.4% and 93.2%, p=0.15) and 6-months (71.1% and 75.0%, p-0.87) were not statistically different in the PREPAN and PAN cohorts, respectively. Conclusion These data represent a novel analysis of the presenting clinical, cytogenetic and molecular characteristics of de novo AML during the COVID-19 pandemic. In contrast to other diseases, we did not see fewer de novo AML presentations during the peak of the COVID pandemic. While the reasons are unknown and require validation in large cohorts, the symptoms of leukemia including symptomatic anemia (low hematocrit) and higher WBC and blast count possibly driven by FLT3 mutations may drive patients to seek emergent clinical evaluation despite COVID pandemic barriers. The lack of difference in cytogenetic or other prognostic entities may demonstrate a lack of ymptom correlation causing patients to present for care. The higher incidence of FLT3 mutations and lower hematocrit could reflect more symptomatic presentation of AML during the COVID pandemic. Since these differences may be a surrogate for a higher disease burden, it will be important to compare outcomes at longer time points. [Formula presented] Disclosures: DeAngelo: Pfizer: Consultancy;Novartis: Consultancy, Research Funding;Jazz: Consultancy;Incyte: Consultancy;Forty-Seven: Consultancy;Autolus: Consultancy;Amgen: Consultancy;Agios: Consultancy;Takeda: Consultancy;Glycomimetrics: Research Funding;Blueprint: Research Funding;Abbvie: Research Funding;Servier: Consultancy. Stone: Bristol Meyers Squibb: Consultancy;Astellas: Membership on an entity's Board of Directors or advisory committees;BerGen Bio: Membership on an entity's Board of Directors or advisory committees;Boston Pharmaceuticals: Consultancy;Innate: Consultancy;Foghorn Therapeutics: Consultancy;Gemoab: Membership on an entity's Board of Directors or advisory committees;Glaxo Smith Kline: Consultancy;Celgene: Consultancy;Elevate Bio: Membership on an entity's Board of Directors or advisory committees;OncoNova: Consultancy;Syntrix/ACI: Membership on an entity's Board of Directors or advisory committees;Syndax: Membership on an entity's Board of Directors or advisory committees;Janssen: Consultancy;Agios: Consultancy, Research Funding;Amgen: Membership on an entity's Board of Directors or advisory committees;Aprea: Consultancy;Arog: Consultancy, Research Funding;Jazz: Consultancy;Macrogenics: Consultancy;Novartis: Consultancy, Research Funding;Actinium: Membership on an entity's Board of Directors or advisory committees;Abbvie: Consultancy;Syros: Membership on an entity's Board of Directors or advisory committees;Takeda: Consultancy. Garcia: AstraZeneca: Research Funding;Prelude: Research Funding;Pfizer: Research Funding;Genentech: Research Funding;Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees;Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees;AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Winer: Abbvie: Consultancy;Takeda: Consultancy;Novartis: Consultancy.

Gilteritinib for Relapsed Acute Myeloid Leukaemia with FLT3 Mutation during the COVID-19 Pandemic: Real World Experience from the UK National Health Service

Background Early data suggest that patients undergoing salvage chemotherapy for relapsed or refractory (R/R) acute myeloid leukaemia (AML) have poor outcomes if infected with SARS-CoV-2, and nosocomial transmission has been a major problem worldwide. Gilteritinib is effective in R/R FLT3 mutated AML, is significantly less immunosuppressive and does not require hospital admission, however at the start of the pandemic this was not yet approved for routine use in all countries. In the United Kingdom, the National Health Service (NHS) made gilteritinib available as an emergency measure from late April 2020 to patients aged >16y with R/R FLT3 mutated AML, with the aim of reducing both mortality and healthcare resource use. We report a health-system-wide real world data collection for toxicity and patient outcomes across 27 NHS Hospitals. Methods Each patient was registered on a central NHS database, with clinicians certifying that their patient met the above criteria. Anonymised data were retrospectively collected by treating physicians. Gilteritinib dose, duration and toxicity information was requested for the first 4 cycles of therapy. Response definitions were as per European Leukaemia Network (ELN) guidelines. A total of 81 patients have been registered on the scheme, with outcomes reported here for those with follow-up information at a data cut on 1st August 2021. Results Fifty patients were included with a median age of 59y (range 19 - 77) and 50% male. The majority (83%) had an ECOG performance status of 0-1. AML was secondary to a previous haematological disorder in 12%, therapy-related in 4% and de novo in the remaining 84%. The disease was refractory to the last therapy in 38%. Most patients had previously received 1 (65%) or 2 (33%) lines of therapy, including intensive chemotherapy in a majority (86%). A FLT3 inhibitor had previously been administered to 45% and 35% were post allogeneic transplant. The FLT3 mutation was an internal tandem duplication (ITD) in 80% and tyrosine kinase domain (TKD) mutation in 22%. NPM1 mutations were detected in 34%. Next-generation sequencing results were available for 94% of patients, with mutations in IDH1 or IDH2 in 12.5%, ASXL1 in 2%, RUNX1 in 21% and no TP53 mutations. Patients spent a median 3.5 days in hospital in cycle 1, 0 days in cycles 2 and 3 and 1 day in cycle 4. In cycles 1, 2, 3 and 4, the median number of days of grade 4 neutropenia was 18, 7, 7.5, and 6.5 respectively, and the grade 4 thrombocytopenia was 2, 7, 0.5 and 0.5. The composite complete remission (CR) / CR with incomplete haematological recovery (CRi) rate was 27%. MRD data is being collected. The best response was morphological leukaemia free state (MLFS) in 4%, partial remission (PR) in 25% and refractory disease in 38%. The rate of combined CR/CRi did not differ in those with previous exposure to FLT3 inhibitors (23% vs 32%, p=0.6) or with past allogeneic transplant (29% vs 27%, p=0.3). There were no CR/CRi in patients with adverse cytogenetic risk. Median follow-up was 10.5 months (95%CI 7.3 - 12.3) with median overall survival (OS) 6.7 months (95%CI 4.5 - not reached). Mortality at day 30 was 0% and day 60 was 14%. 12-month overall survival was 38%. Patients who achieved a CR/CRi had a 12-month OS of 83%, and for PR this was 35%. Survival did not differ in those with previous FLT3 inhibitor exposure (HR 1.0, p>0.9) or allogeneic transplant (HR 0.63, p=0.3). Seven patients (14%) so far have been bridged with gilteritinib to allogeneic transplant. Conclusion Our data demonstrate that gilteritinib is well tolerated and clinically active in adults with relapsed FLT3 mutated AML. Importantly, during the COVID-19 pandemic, its availability has permitted the great majority of treatment to be delivered as an outpatient with significant resource saving at a time of critically constrained inpatient resources. Patients who achieve CR/CRi have good short-term outcomes and are able to proceed to a potentially curative allogeneic stem cell transplant. [Formula presented] Disclosures: Belsham: Celgene: Other: meeting attendance;Abbvie: Other: meeting attendance. Byrne: Incyte: Honoraria. Khan: Abbvie: Honoraria;Astellas: Honoraria;Takeda: Honoraria;Jazz: Honoraria;Gilead: Honoraria;Novartis: Honoraria. Khwaja: Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Astellas: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;Abbvie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Latif: Kite: Consultancy, Honoraria, Speakers Bureau;Jazz: Consultancy, Honoraria;Daiichi Sankyo: Consultancy, Honoraria;Novartis: Consultancy, Honoraria;Amgen: Consultancy, Honoraria;Abbvie: Consultancy, Honoraria;Astellas: Consultancy, Honoraria, Speakers Bureau;Takeda UK: Speakers Bureau. Loke: Amgen: Honoraria;Daichi Sankyo: Other: Travel Support;Janssen: Honoraria;Novartis: Other: Travel Support;Pfizer: Honoraria. Munisamy: Jazz Pharmaceuticals: Speakers Bureau;Roche: Speakers Bureau. Murthy: Abbvie: Other: support to attend educational conferences. Smith: Daiichi Sankyo: Speakers Bureau;Pfizer: Speakers Bureau;ARIAD: Honoraria. Craddock: Novartis Pharmaceuticals: Other: Advisory Board;Celgene/BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding. Dillon: Amgen: Other: Research support (paid to institution);Astellas: Consultancy, Other: Educational Events, Speakers Bureau;Menarini: Membership on an entity's Board of Directors or advisory committees;Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Session chair (paid to institution), Speakers Bureau;Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: educational events;Jazz: Other: Education events;Shattuck Labs: Membership on an entity's Board of Directors or advisory committees;Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Research Support, Educational Events.

CPX-351 for Acute Myeloid Leukaemia: Real World Results Are Comparable to Trial Outcomes and Exceeds Them in Non-Adverse Risk Patients- a Multicentre Experience from West Midlands Hospitals on Behalf of West Midlands Research Consortium ( WMRC) UK

Patients with secondary AML or MDS derived AML have poor outcomes compared to de-novo AML. The benefits of intensive chemotherapy without anticipated transplant consolidation have been previously doubted. Outcomes in USA trial centres have not often been closely replicable in real world settings. From November 2018 CPX-351 has been available in the UK for secondary AML, therapy related AML, AML with MDS related Karyotype (AML-MRC) and licensed but not funded for AML with myelodysplastic related changes. Objectives Here we report our experience specifically on patient outcomes and toxicity across 5 Hospitals in West Midlands, UK Methods Patients receiving CPX 351 outcomes were evaluated retrospectively from 2018 to 2021. Baseline genetics, CPX 351 indications, patient's comorbidities, overall survival, remission status, number of cycles delivered, early mortality, reasons for early discontinuation, intensive care admission and time for neutrophil recovery (>0.5) was recorded. Time-to-event outcomes reported here are from a data cut on 01-06-21 Results In a total cohort of 57 patients baseline characteristics are shown on table 1 and compared with the original trial CPX-351 group. Median follow up was 376 days (range 21 to 1248 days). The mean age was 63, 17 patients were under 60, 31 males and 26 females. The most common indication for CPX-351 was AML with antecedent MDS/MPN 51% (N=29), therapy related 14% (N=8), MDS related karyotype (AML-MRC) 19% (N=11) and 16% (N=9) other patients. Mean Charleston co-morbidity score was 2.7 (range 0-6), 10.5% (N=6) had previous non myeloid malignancies, 8.7% (N=5) had prior ischaemic heart disease, only 3.5% (N=2) had ejection fractions under 50%. The most common mutations were TP53 21% (N=12), ASXL1 15.7% (N=9), TET2 15.7% (N=9), IDH2 10.5% (N=6), RUNX1 10.5% (N=6), SRSF2 7% (N=4), JAK2 3.5% (N=2), FLT3 5% (N=3), NPM1 5%(N=3) and IDH1 5% (N=3). MRC cytogenetic risk was adverse in 19 patients (33%), intermediate in 35 patients (61%) and favourable in 3 patients (5%). 30 patients (53%) had adverse European Leukaemia Network classification, 17 (30%) had intermediate and 10 (17%) had favourable. 30-day mortality was 3/57 (5%), 60-day mortality was 6 (10.5%) comparable to the 5.9% and 10.6% rates for the original trial. 9% or 5/57 patients were admitted to ITU with 2 survivors beyond 60 days. Neutropenic fever requiring antibiotics was 100% whereas only 5/57 (9%) had radiological evidence of fungal infection. Only one patient died from COVID 19. The mean time to neutrophil recovery was 35 days with a range of 12 to 84 days. 29 patients completed 1 cycle, 25 completed 2 cycles, only 3 completed 3 cycles. The reasons for stopping were death, refractory disease, drop in performance status, alternative chemotherapy chosen or moving to transplantation (39%). Composite remission rate including CRi was 61% 36/57, adverse ELN group demonstrated 50% 15/30, intermediate 76% 13/17 and favourable 80% 8/10. Mutated P53 was associated with a 50% 6/12 rate whereas in wild type P53 the remission rate was 60% 30/45. Overall median survival from diagnosis was 429 days [95% CI 274 to 788 days]. To compare with the original trial, we removed the under 60s and those with less than 1 year follow up, in this cohort of 30 patients the median survival was 289 days (9.5 months) with 95% CI of 255 to 476 days. P53 mutated patients had an estimated median survival of 257 days versus wild type p53 with 524 days hazard ratio of 2.418 (CI 1.077 to 5.248) with p value of 0.032. Median survival for ELN groups was 373 days (adverse), 413 days (intermediate) and not reached for favourable. Of the 36 patients who achieved a remission, 22 went on to receive an allogenic transplant with follow from 254 to 1248 days, median survival estimated 706 days (95% CI 429-not reached). Patients in remission who haven't received a transplant have a similar estimated survival of 788 days (305-not reached) pending longer follow up. Conclusion This is the first UK multicentre analysis to show comparable results to the landmark trial ( edian survival 9.5 months in equivalent cases). The improved overall remission rate 61% versus the 47% in the trial and the longer median survival 14 months versus 9.5 months in the trial is expected given the younger age and increase in favourable risk genetics. This study therefore supplies further data of CPX-351 efficacy in younger patients not included in the original studies and may now be used as a standard comparator arm. [Formula presented] Disclosures: No relevant conflicts of interest to declare.

Implementation of a High-Dose Cytarabine Outpatient Program for Acute Myeloid Leukemia Patients in a Limited-Source Setting

Background: The management of acute myeloid leukemia (AML) patients usually requires long inpatient treatments that can affect the limited care facilities, the quality of life, and increases healthcare costs. Additionally, leukemia treating centers in developing countries face limited sources to deliver high-dose chemotherapies as inpatient treatments. Therefore, several reports have established the feasibility and safety of outpatient consolidation. We aimed to implement a high-dose cytarabine outpatient program for AML in a limited-source institution at a public center in Peru.Methods: We conducted a prospective pilot study starting in January 2019 and ending before the COVID-19 Pandemic in March 2020. Eligible patients were ≥ age 14, met inclusion criteria for inpatient induction regimens, were without active infection, and had the following: normal chest x-ray and biochemistry, complete remission after one cycle of 7+3 induction. Logistical requirements included a 3-hours distance residence near the treatment center, caregiver support, trained nursing staff, infusion room capacity, and participation in follow-up. Patients received prophylactic antimicrobials such as oral levofloxacin, fluconazole, and acyclovir and were admitted to the hospital for predetermined complications of therapy (fever, G3-4 toxicity, febrile neutropenia, bleeding or refractory thrombocytopenia). Risk stratification was based on conventional cytogenetics and multiplex PCR using Leukemia.net criteria. Results: Forty-two patients were included during the study period. The median age was 38 years (16-63) and Female/Male ratio 4:3. According to Leukemia.net, 24% were classified as high, 50% intermediate and 26% as low risk group. Including FLT3 mutations in 26% of cases. Twenty-two and 20 subjects received 1-2 and 3-4 cycles of ambulatory HiDAC, respectively. About one-third of cases had emergency admissions during consolidation and 74% complete at least 3 cycles of cytarabine. Only 4 patients underwent sibling-donor allo-SCT. Sixty-four percent experienced relapses, and at 2 years follow-up only 21 subjects were alive. Median OS was 15 months, a better survival was shown among patients who received 3-4 cycles of ambulatory HiDAC (2-year OS 18 vs 23%, p=0.031). Conclusion: Our pilot study shows the feasibility to deliver HiDAC as outpatient consolidation in selected AML cases in a limited setting. Additionally, a high rate of relapses and poor survival was noted in our cohort that requires further consideration. Disclosures: No relevant conflicts of interest to declare.

Myocardial infarction versus COVID-19 blood secretome

Background: Both myocardial infarction (MI) and COVID-19 are characterized by cytokine storm in blood. Purpose: The objective of this study was to compare the concentration of 39 cytokines, chemokines, and growth factors in blood sera of patients with MI, COVID-19 (COV), and healthy donors. Methods: Patients' blood was collected within 1-2 days after hospitalization in the cardiovascular or COVID intensive care units. All COV patients were in a severe condition;all had increased C reactive protein, 86 and 95% had increased ferritin and D-dimers levels accordingly, 8-10 times decreased lymphocyte numbers. The analysis of the humoral factors in blood serum of MI (n=22), COV (n=23) and donors (n=27) was performed using a 39-plex cytometric analysis. Results: Among all factors analyzed TGFa, IL-1b, 2, 3, 5, 9, 13, 17A were almost not detectable both in patient and donor sera. The concentrations of the other 31 humoral factors in normal sera differed significantly from 0 to 22000 pg/mL. We divided them into house-keeping factors HKF ranged from 1000 to 22000 pg/mL;sentinel innate immunity factors SIF (30-200 pg/mL), and acute phase factors APF (0-30 pg/mL). HKF were detected in all samples. Among SIF and APF IL-1a, G-CSF, IFNa2, IL-7, MIP-1a, IL- 12, and IFNg were detected in 56-80% donor blood while IL-1RA, MCP-3, IL-2, 6, 10, 12, 15, FLT-3F, GM-CSF, TNF-b - only in 10-55%. At the same time all MI patients were 100% positive in all these factors showing extensive activation of blood secretome. Among low incidence APF cytokines in COV patients, percentage of IL-1RA, MCP-3, IFNa2, IL-6, 10, 15, FLT-3L negative sera decreased 3-5 times;and all sera were positive for MIP-1a and IL-12. At the same time TNF-a level decreased significantly from 0 in control to 85% of negative sera in COV patients. Summarized results are shown as the ratios of factor concentrations in MI or COV sera to normal control (Fig). Blood secretome of MI changed more significantly than of COV patients. The major factors (shown in red) in MI were IL-6, IL-12, IFNg, FLT-3L, GM-CSF, and IL-15, which increased 12, 9, 6, 6, 6, and 5 times accordingly. In COV sera IL-6, IL-10, IP-10, and MCP-3 increased by 28, 12, 10, and 9 times accordingly. Less expressed however significant increases are marked with asterisks. Conclusions: Acute MI is characterized by severe disturbances in blood secretome with an increased level of 25 out of 39 factors studied. Contrary to it, in COV patients the levels of IL-6, 10, IP-10, and MCP-3 were more enhanced while only 15 out of 31 exceeded normal levels.

Two types of humoral response in acute myocardial infraction

Background: Atherothrombosis and myocardial infarction are accompanied by the development of an inflammatory reaction. The severity of the immune reaction and its role in the acute myocardial infarction (AMI) remain contradictory to date. Purpose: The objective of this study was to analyze 39 cytokines and chemokines in the serum of patients hospitalized with AMI compared to the healthy volunteers. Methods: All patients included in the study were COVID-19 negative. Patients' blood was collected within 1-2 days after hospitalization in the cardiology department. Cytokine and chemokine detection in the serum of patients (n=20) and donors (n=20) was performed using a 39-plex set of cytometric beads. Results: Among all factors analyzed TGFa, IL-17A, IL-1b, 3, 5, 9 were not detected both in patient and donor sera. Three groups of factors were identified in the normal serum: housekeeping chemokines and vascular factors (F1) ranged from 1000 to 22000 pg/mL (Fig. a);sentinel innate immunity factors F2 (Fig. b), 30-200 pg/mL;and acute phase factors F3 (Fig. c, d), 0-30 pg/mL, detected only in 0-30% of donors but in all AMI patients. Severe imbalance was found in AMI sera at all three levels including chemokine, growth factors, and cytokines. Among AMI patients 65% (Gr1) demonstrated 2-4 times increased level (Fig. a, grey brackets) while 35% (Gr2) had a decreased level of F1 factors in a comparison with donor sera. There was not significant difference between clinical features of the patients in Gr1 and Gr2. GRO, PDGF-AA, and sCD40L levels decreased 35, 15, and 10 times accordingly. Gr1 and Gr2 also differed in F2 and some F3 concentrations: Gr1 had 3-5 times increased level of multiple factors (Fig, b), among them - IL-6, IL-8, and IL-10 were increased 5, 6, and 14 times. At the same time Gr2 had a normal level of these factors (Fig, b, blue brackets). Finally, multiple cytokines and growth factors F3 were significantly increased in both AMI groups (Fig, b, d, red brackets). Of note, IL-12, IFN-g, IL-15, GM-CSF, FLT-3T were increased 8, 6, 5, 5, 5 times accordingly in pooled Gr1+Gr2. There were no correlations found between cytokine profiles in Gr1 and Gr2 and their clinical parameters. Conclusions: Two types of humoral response in AMI patients were identified which differed in the levels of GRO, PDGF-AA, and sCD40L. IL-6 as well as TNF-a can not serve as master cytokines because their levels were increased only in Gr1 patients. These data show that Th1 cytokine increase is specific for AMI. Further studies are needed to identify groups of patients who may be exposed to new therapeutic targets.