Clinical Lymphoma, Myeloma & Leukemia, Vol.22, Suppl.2 - October 2022

Abstracts Clinical Lymphoma, Myeloma & Leukemia October 2022 S250 or CCR (azacitidine, intermediate- or low-dose Ara-C, or supportive care). Co-occurring mutations were identified by targeted NGS of BMMC DNA. Total 2-hydroxyglutarate was determined by LC/ MS. Results: Of 319 patients enrolled, 88 (28%; 43 enasidenib, 45 CCR) had m IDH2 -R1 7 2 and 229 ( 7 2%; 115 enasidenib, 114 CCR) had m IDH2 -R140. Median baseline 2-hydroxyglutarate level and IDH2 VAF were similar between arms and m IDH2 subgroups. Patients with m IDH2 -R1 7 2 had fewer baseline mutations (median 4 [range 2-8]) than those with m IDH2 -R140 (5 [1-11]) (P<0.0001). Common co-mutations were SRSF2 and RUNX1 in the R140 cohort (59% each) and DNMT3A in the R1 7 2 cohort (5 7 %). Compared with R1 7 2, R140 was enriched with SRSF2 , FLT3 (-ITD/-TKD), NPM1 , RUNX1 , and JAK2, whereas DNMT3A and TP53 were more common with R1 7 2. In Cox multivariate analysis including m IDH2 variant, DNMT3A status, and number of baseline mutations, m IDH2 -R1 7 2 was significantly correlated with improved OS (P=0.04 vs R140) in the enasidenib arm, and number of baseline mutations was significantly (P<0.01) associated with OS in the CCR arm. Median OS in the R1 7 2 subgroup was 14.6 months with enasidenib vs 7 .8 months with CCR (HR, 0.59 [95%CI 0.35-0.98]; P=0.039); 1-year survival rates were 62% and 30%. In the R140 subgroup, median OS was 5. 7 months in both arms (0.93 [0. 7 0-1.24]; P=0.61), and 1-year survival rates were 29% and 25% with enasidenib and CCR. Co n clusio n s: Mutational burden and co-mutational profiles differed between patients with m IDH2 -R140 and m IDH2 -R1 7 2 relapsed/refractory AML. In the R1 7 2 subgroup, median OS and 1-year survival rate with enasidenib were approximately double those with CCR. Keywords: AML, enasidenib, IDH2 , relapsed/refractory, biomarkers, Phase III AML-434 Retrospective Review of Outcomes in Newly Diagnosed Leukemia Patients Aged 65 and Older When Admitted to the Hospital: A Single Center Experience Colby Canter BS, Gerhard Hildebrandt MD, Chaitanya Iragavarapu MD, Reinhold Munker MD, Ayman Qasrawi MD, Reshma Ramlal MD, Gregory Monohan MD University of Kentucky, Lexington, USA Co n text: Acute leukemia patients have a diminished survival inversely proportional to their age. 5-year overall survival in younger AML patients is 50%, however reduced to <10% if age > 7 0. Factors contributing include poor performance status, decreased response to induction therapy, increased treatment related mortality, unfavorable cytogenetics and secondary leukemia. Objecti v e: Report observed characteristics and outcomes of elderly leukemia patients. D esig n : Retrospective chart reviewof newly diagnosed acutemyeloid leukemia (AML) patients >65 admitted from 7 /1/2015 through 6/30/2021. Demographic information, classification, duration of hospital stay, blood products administered, treatment, discharge condition, 3 and 6 month remission, and survival data collected. Setti n g: Academic medical center. Patie n ts: 149 patients identified. AML[n=130], acute promyelocytic leukemia (APL)[n=9], and acute leukemia not otherwise specified (AML-NOS)[n=10]. I n ter v e n tio n s: 9 7 patients treated. AML treatment: Induction therapy, daunorubicin and cytarabine (liposomal), or hypomethylating agent +/-venetoclax. APL treatment: all-trans retinoic acid (ATRA) +/- arsenic trioxide (ATO). One patient with AML-NOS received hypomethylator. Mai n Outco m e: Patients separated into three groups: < 7 0[n=55], 7 0 to 7 4[n=52], and > 7 5[n=60]. Percent of patients who did not receive any therapy increased as age group increased (21.8%, 32. 7 %, and 41. 7 %). Length of hospital stay, reflective of treatment, was greatest in the younger population (28 days, 1 7 .6 days, and 15.3 days). 6-month survival 51% younger, 42.3% middle and 23.4% for eldest cohort. Treatment related mortality (TRM) including transitioning to hospice care increased as age increased (29%, 34% and 50%). Results: 25/130 patients received induction chemotherapy. Nineteen patients were < 7 0. The expected TRM for the younger cohort was 10.68% (1 – 41%) and 10.1% (1-20%) for elder cohort. The observed TRM was 10.5% in the younger cohort and 50% in the older cohort. Most of the eldest AML patients received a hypomethylating mono- or combination therapy. Nearly 50% of all AML were discharged home. The 6-month survival was 50% for younger, 26.8% for middle and 13.3% for eldest cohort. Nine APL patients were identified with 5 being in the eldest cohort. Only 3(33.3%) survived 6 months. None of the patients with AML- NOS were alive at 6 months. Co n clusio n s: Acute leukemia in the elderly population remains a challenge with poor outcomes despite considering patient’s age and performance status. Keywords: AML, elderly, leukemia AML-437 Real-World Effectiveness of Enasidenib (ENA) in Older Patients With Relapsed/Refractory (R/R) Isocitrate Dehydrogenase-2 (IDH2)- Mutated Acute Myeloid Leukemia (AML) Ali McBride PharmD, MS 1 , Andrew J. Klink PhD, MPH 2 , Amanda J. Ullman PhD, BSc 1 , Djibril Liassou MSc 2 , Cherrishe Brown-Bickerstaff PhD, MPH 2 , Ajeet Gajra MD 2 1 Bristol Myers Squibb, Princeton, USA. 2 Cardinal Health Specialty Solutions, Dublin, USA Study Purpose : Older age at first relapse and Black race are prognostic indicators of worse survival for patients with AML. ENA was the first drug approved in the United States (US) for the treatment of adults with R/R IDH2 -mutated AML. This study assessed real-world clinical outcomes in patients with onset of R/R IDH2 -mutated AML at  60 years of age who received ENA versus other therapies as first-line (1L) R/R AML treatment. Black patients were assessed as a subgroup. Methods: This physician- abstracted, retrospective, multisite, chart-review study was conducted in US-based community oncology practices. Patients receiving 1L ENA between 01/2018 and 06/2019, or other 1L therapy between 01/2016 and 0 7 /201 7 , were selected for analysis.