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

Abstracts Clinical Lymphoma, Myeloma & Leukemia October 2022 S204 ultrasound in 80%, chest or abdomen CT in 25%, and CT-guided biopsy in 10%). Co n clusio n s: EBV was the most common viral infection. Leukemia was rare in our cohort, and alarming signs included persistent fever >2 weeks, non-regressive bone aches, and splenomegaly. Keywords: ALL, splenomegaly, lymphadenopathy, leukemia, risk and childhood ALL-424 Updated Results from the Phase II Study of Blinatumomab in Combination With Ponatinib in Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Fadi G. Haddad MD, Hagop Kantarjian MD, Nicholas J. Short MD, Marina Konopleva MD, PhD, Nitin Jain MD, Xuelin Huang PhD, Farhad Ravandi MD, William Wierda MD, PhD, Gautam Borthakur MD, Koji Sasaki MD, PhD, Ghayas Issa MD, Yesid Alvarado MD, Naveen Pemmaraju MD, Guillermo Garcia-Manero MD, Jennifer Thankachan RN, Rebecca Garris MSW, Elias Jabbour MD The University of Texas MD Anderson Cancer Center, Houston, USA Co n text: Blinatumomab and ponatinib both induce high rates of complete molecular remission (CMR) in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL). Their combination may generate durable responses and decrease the reliance on allogeneic stem cell transplantation (allo- SCT). Objecti v e: To evaluate the combination of blinatumomab and ponatinib in patients with Ph-positive ALL. Study D esig n a n d Participa n ts: Patients with newly-diagnosed (ND) or relapsed/ refractory (R/R) Ph-positive ALL were treated on this phase II trial. Blinatumomab was given for up to 5 cycles at standard doses, and ponatinib was started at 30mg daily during cycle 1, then lowered to 15mg daily upon achieving CMR. Among responders, ponatinib was maintained for a minimum of 5 years. Patients received 12 doses of prophylactic intrathecal chemotherapy. Mai n Outco m e Measures: The primary endpoint was the CMR rate in the ND cohort, and the overall response rate (ORR; CR and CRi) in the R/R cohort. Results: Forty-nine patients were treated: 35 ND (median age, 5 7 years; range, 22-83 years) and 14 R/R (median age, 38 years; range, 24-61 years). Among R/R patients, 43% were in Salvage  2. One early death within 4 weeks was observed among ND patients due to intracranial hemorrhage, none among R/R patients. The ORR was 96% in the ND cohort and 92% in the R/R cohort, with respective CMR rates of 85% and 7 9%. Only one patient with ND disease underwent allo-SCT because of persistently detectable BCR::ABL1 transcript levels; 6 patients (46%) with R/R disease underwent subsequent allo-SCT. After a median follow-up of 11 months (range, 1-46 months), no relapses were observed in the ND cohort with similar 2-year OS and EFS rates of 93%. In the R/R cohort, the estimated 2-year OS and EFS rates were 61% and 42%, respectively. This combination showed a favorable safety profile, with most adverse events of grade 1-2. One patient discontinued ponatinib due to toxicity. Co n clusio n s: The chemotherapy-free combination of blinatumomab and ponatinib demonstrated robust clinical activity in Ph-positive ALL, with high rates of CMR and durable remissions. This strategy will potentially obviate the need for chemotherapy and allo-SCT in many patients, particularly in the frontline setting. Keywords: ALL, blinatumomab, ponatinib, BCR::ABL1, tyrosine kinase inhibitors, chemotherapy-free, Phase II ALL-436 Association Between ABO and Rh Blood Groups and Pediatric Hematological Malignances in Armenia Armen Petrosyan MD 1 , Ashot Palanjyan MD 1 , Irina Melnichenko MD 1,2 , Margarita Hakobyan MD 3 , Arthur Dabikian MD 1,3 , Lilit Sargsyan MD 1,2 , Lala Vagharshakyan MD 1,2 , Samvel Danielyan MD 3 , Gevorg Tamamyan MD. MSc, PhD, DSc 1,2,4 , Andranik Shamilyan MD 3 1 Department of Pediatric Oncology and Hematology, Yerevan State Medical University, Yerevan, Armenia. 2 Pediatric Cancer and Blood Disorders Center of Armenia, Hematology Center After Prof. R.H. Yeolyan, Yerevan, Armenia. 3 Hematology Center after Prof. R.H. Yeolyan, Yerevan, Armenia. 4 Immune Oncology Research Institute, Yerevan, Armenia Co n text: Despite the higher incidence of hematological malignances, their etiology is not clearly understood. In some reports, the risk of these diseases and survival are associated with ABO blood groups and rhesus. According to World Population Review, Armenia belongs to the ten countries with the highest prevalence of type A+ blood. Objecti v e: The investigation of the association between pediatric hematological malignances and both ABO and Rh blood groups in Armenia. D esig n : Retrospective analysis of ABO blood groups and Rh factor in children with cancer aged 0-18 years between 1995 and 2021 were performed. All the statistical information was taken from clinical records available in Hematology Center after Prof. R.H. Yeolyan. Results: The number of children diagnosed with hematological malignances was 7 98. Male/female ratio was 1.5. Among 5 77 children with acute lymphoblastic leukemia (ALL), A+ blood group was the most common (43.6 7 % [252]), followed by O+ (25.48% [14 7 ]), B+ (10.92% [63]), AB+ (6.93% [40]), A- (5.89 % [34]), O- (4.33% [25]) and B- (2.08% [12]), AB- (0.69% [4]). A+ was also the highest (46.42% [39]) in 84 children with acute myeloid leukemia (AML) in comparison to the other groups: O+ (20.2% [1 7 ]), B+ (14.2% [12]), AB+ (2.38% [2]), A- (5.95% [5]), O- (8.3% [ 7 ]), B- (2.38% [2]). Unlike the patients with ALL and AML, the increase of AB+ portion was discovered among 81 cases of Hodgkin lymphoma (HL): A+ (38.2% [31]), O+ (23.5% [19]), B+ (11.1% [9]), AB+ (13.58% [11]), A- ( 7 .4% [6]), O- (3. 7 % [3]), B- (1.23% [1]), AB- (1.23% [1]). The blood group of 16 patients with chronic myeloid leukemia (CML) included O+ (3 7 .5% [6]); A+ (31.25% [5]), B+ (6.25% [1]), AB+ (6.25% [1]), A- (18. 7 5% [3]). ABO blood group distribution in 40 cases of non-Hodgkin lymphoma (NHL) was O+