Abstracts Clinical Lymphoma, Myeloma & Leukemia September 2023 S250 AUL is a rare type of acute leukemia that shows no evidence of differentiation along any lineage. We present a rare clinical case of AUL, and we face diagnosis (molecular biology technical platforms) and therapeutic challenges. 16-year-old patient, with no pathological history. Medical history goes back to 1 month before his admission for progressive installation of bilateral cervical lymphadenopathy associated with an anemic syndrome and fever. Initial clinical examination revealed a left submandibular lymphadenopathy 6 cm. Biological findings: Complete blood count: Hemoglobin: 5.4 g/dL; MCV: 90 fL, white blood cells: 830/mm3; PNN 144/mm3 Lc: 648/mm3; platelets: 258000/mm3. First bone marrow aspiration (BMA): R++ M++: 34% blast cells, heterogeneous sizes. MPO negative. Cytological appearance in favor of an acute leukemia, most probably megakaryoblastic. The concomitant first immunophenotyping was inconclusive. A second BMA was done R: ++ M: +/-. 78% Blast cells, MPO negative. Bone marrow biopsy: A rich bone marrow with cellular infiltration of undetermined origin and immunohistochemical aspect shows a moderate blastic infiltration on the order of 20%, with positive Tdt, suggesting an acute lymphoblastic leukemia. Immunophenotyping was done 3 times, still unconclusive. And the last one: 49% granular, 1% monocytes, 12% lymphocytes, and 38% blast cells expressing the markers CD33, CD71, CD36, CD105 intracytoplasmic. MPO, cytCD3, CD19, CD79a negative. Karyotype was normal. Molecular biology: the search for recurrent fusion transcripts in acute leukemia and myeloproliferative syndromes was negative. Analysis by high-throughput sequencing (NGS): BCOR exon 4 c.688_689insGGGG: p.A230GfsX72 (VAF 47%), BCORL1 exon 6 c.3733G>T: p.G1245X (VAF 1.02%), KDM6A exon 27 c.4028_4029insAAGCCAATAGTCC: p.M1343IfsX4 (VAF 44%). Mutations in the BCOR, BCORL1 and KDM6A genes. Gene copy number analysis found trisomy 22 and a subclonal deletion of the PAX5 (9p) locus. Molecular profile compatible with the diagnosis of UAL. Therapeutically, the patient received induction with an ALL high-risk protocol with complete remission. Management of AUL in daily practice is still difficult and treating with chemotherapy with or without allotransplantation is a challenge. Keywords: ALL, acute undifferentiated leukemia, molecular biology, therapeutic protocol, case ALL-389 Venetoclax in the Treatment of Relapsed Refractory Early T Cell Precursor ALL (ETP‑ALL). Case Report and Review of The Literature Fatima Khadadah MD, Mahmoud Hasaneen MD, Ramesh Pandita MD, Rasha Ghonema MD, Mohan Ram MD, Salem Alshemmari MD, Abdulaziz Hamadah MD, Anita Kunhikrishnan MD, Ahmad Alhuraiji MD Kuwait Cancer Control Center, Kuwait, Kuwait ETP-ALL is a recently recognized, high-risk subgroup of ALL characterized by early differentiation arrest and distinct genetic and transcriptional features. ETP-ALL exhibits inferior response rates to chemotherapy with high rates of relapse and treatment refractoriness leading to dismal outcomes. Here, we report on a 30-year-old man with refractory ETP-ALL who responded to a combination of venetoclax and HyperCVAD as second-line therapy. This patient presented with shortness of breath and hoarseness in December 2022. His laboratory values were as follows: CBC – WBC 2.1×109/L, Hb 70 g/L, PLT 376×109/L; DC: P 41.1, L 53.1, Mo 5.4%, LDH 274 U/L. His mediastinum appeared wide on chest X-ray. Bone marrow findings were consistent with ETP-ALL expressing CD99, CD7, CD13, CD33, cytoplasmic CD3, HLADR and TdT. Chest computed tomography showed an 8-cm mass encasing the mediastinal vessels/bronchi. Bone marrow cytogenetics showed normal karyotyping (46,XY) with BCR-ABL1 and 14q11negative fluorescence in situ hybridization and molecular testing showed WT1 P376*(25.14%), RUNX1 R320*(24%). The patient received induction with the DFCI protocol (pediatric inspired); however, on Day 26, bone marrow showed 20% lymphoblasts. Therefore, the patient was salvaged with HyperCVAD + 7 days of venetoclax, which he tolerated well. He achieved complete remission with negative minimal residual disease on 8-colour multiparameter flow cytometry. He received a total of 3 cycles and was referred for allogenic stem cell transplantation because he had a fully-matched sibling. Venetoclax is a selective BH3 mimetic inhibitor of BCL2, an anti-apoptotic protein conferring enhanced survival in leukemia cells including chronic lymphocytic leukemia, acute myeloid leukemia and ALL. Preclinical studies have shown that venetoclax is also active against ALL cells that are dependent on BCL2 and BCLXL for survival. Interestingly, cells from the ETP-ALL subtype are especially sensitive to BCL2 inhibition, suggesting that venetoclax is a potentially effective drug for the treatment of this adverse risk subgroup. Approximately 165 cases were reported in 8 studies between 2019 and 2022 about the use of venetoclax with different types of chemotherapy in ALL with promising results. We are going to summarize data about the use of venetoclax in T-ALL. Keywords: T-ALL, ETP-ALL, WBC, case ALL-419 Can Doses of Post‑Transplantation Cyclophosphamide in Haploidentical Stem Cell Allografts Be Reduced? Juan Carlos Olivares-Gazca MD1,2, María de Lourdes Pastelín-Martínez MD1,3, Merittzel Abigail Montes-Robles MD1,3, Moisés Manuel Gallardo-Pérez MSc1,2, Edgar Jared Hernández-Flores MD1,2, Max Robles-Nasta MD1,2, Daniela Sánchez-Bonilla MD1,2, Guillermo José RuizDelgado MD1,2, Guillermo José Ruiz-Argüellez MD1,2 1Centro de Hematología y Medicina Interna, Clínica Ruiz, Puebla, Mexico. 2Universidad Popular Autónoma del Estado de Puebla, Puebla, Mexico. 3Universidad Anáhuac, Puebla, Mexico Context: Allogeneic hematopoietic cell transplantation (HSCT) remains the most important curative modality for several hematologic malignancies, but a human leukocyte antigens- (HLA- ) matched sibling or unrelated donor is not always available, particularly for ethnic minorities and multiethnic families. We have shown that haploidentical-HSCT (Haplo-HSCT) can be conducted
RkJQdWJsaXNoZXIy MTk3NTQxMg==