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4528 Olverembatinib-Based Therapy in Patients with Philadelphia Chromosome-Positive Acute Leukemia: A Multi-Centre Retrospective Study from China

Program: Oral and Poster Abstracts
Session: 632. Chronic Myeloid Leukemia: Clinical and Epidemiological: Poster III
Hematology Disease Topics & Pathways:
Research, Clinical Practice (Health Services and Quality), Clinical Research, CML, Chronic Myeloid Malignancies, Diseases, Real-world evidence, Adverse Events, Myeloid Malignancies
Monday, December 9, 2024, 6:00 PM-8:00 PM

Mei Bao1*, Jian Huang, MD, PhD2, Huiying Qiu3*, Suning Chen, MD, PhD4*, Shengli Xue3*, Xiaofei Yang5*, Zhenfang Liu, MD6*, Chunyan Chen7*, Linhua Yang8*, Yanping Ma8*, Li Meng, MD9*, Yanli Zhang, MD10*, Li Weiming11*, Qin Wen, MD12*, Guohui Li, MD13*, Lijie Yang, MD14*, Yanqiu Han15*, Xiaodong Wang16*, Yan Wen, MD17*, Congmeng Lin18*, Hai Yi, MD19*, Xingli Zhao20*, Yanqing Zhang, MD21*, Yang Song22* and Qian Jiang, MD23

1Peking University People's Hospital, Beijing, China
2Department of Hematology, The First Affiliated Hospital, Zhejiang University School of Medicine, YIWU, ZHEJIANG, China
3National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, China
4The First Affiliated Hospital of Soochow University, Suzhou, China
5National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, China
6The First Affiliated Hospital of Guangxi Medical University, Nanning, China
7Department of Hematology, Qilu Hospital of Shandong University, Jinan, China
8Department of Hematology, The Second Hospital of Shanxi Medical University, Taiyuan, China
9Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
10Department of Hematology, Henan Cancer Hospital, Zhengzhou, China
11Department of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
12Xinqiao Hospital, Army Medical University, Chongqing, China
13Xi'an International Medical Center Hospital, Xian, CHN
14Xi'an international Medical Center, Xi'An, China
15The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
16Department of Hematology, Sichuan Academy of Medical Sciences Sichuan Provincial, Sichuan, CHN
17The First People's Hospital of Yunnan Province, Yunnan, China
18Zhangzhou Municipal Hospital of Fujian Province, Zhangzhou, China
19Department of Hematology, The General Hospital of Western Theater Command, Chengdu, China
20Tianjin People's Hospital, Tianjin, China
21Shenzhen Hospital of Southern Medical University, Shenzhen, China
22Central Hospital of Dalian University of Technology, Dalian, China
23National Clinical Research Center for Hematologic Disease, Peking University People’s Hospital, Peking University Institute of Hematology, Beijing, Beijing, China

Background Olverembatinib, a novel 3G-TKI, has promising outcome in patients with TKI resistant and/or intolerant chronic or accelerated phase CML. However, there are rare data in patients with Ph-positive acute leukemia.

Objectives To assess the efficacy and safety olverembatinib-based therapy in patients with CML in myeloid blast phase (CML-MBP) or lymphoid blast phase (CML-LBP) and relapsed or refractory acute lymphoblastic leukemia (R/R Ph-positive ALL), and explore co-variates associated with survival.

Methods Data of patients with CML-MBP, CML-LBP or R/R Ph-positive ALL receiving olverembatinib-based therapy from academic centers in China were retrospectively interrogated. Diagnosis was according to the WHO 2016 criteria. Event-free survival (EFS) was defined as interval from starting olverembatinib-based therapy to no MaHR by 3 months, relapse (> 5% blasts in bone marrow or occurrence of blast in blood or new extramedullary disease), or death from any cause or censored at the last follow-up. Survival was defined as interval from starting olverembatinib-based therapy to death from any cause or censored at the last follow-up. Cox regression model was utilized to identify co-variates associated with survival.

Results A total of 153 patients with CML-MBP (n = 68, 44%), CML-LBP (n = 39, 25%) or R/R Ph-positive ALL (n = 46, 30%) were enrolled, 20 of them were newly diagnosed CML-MBP or CML-LBP. 86 (56%) were male. Median age was 50 (IQR, 34-58) years. 52 (34%) had ≥ 1 comorbidity(ies). Median interval from diagnosis of CML to starting olverembatinib-based therapy was 12 (IQR, 6-47) months. 39 (25%) had 2 prior TKIs; 24 (16%), ≥ 3 prior TKIs. 15 (10%) patients had no response to prior TKI-therapy; 66 (43%) achieved the best response of CHR; 42 (27%), ≥ MCyR. BCR::ABL1 mutation status detected by Sanger sequencing at baseline was available for 137 patients: 45 (33%) harbored a single T315I mutation; 6 (4%), T315I plus additional mutations; 25 (18%), other mutations; 61 (45%), no mutation.

29 (19%) patients received olverembatinib monotherapy; 124 (81%), olverembatinib combined with AML-like or ALL-like chemotherapy. With a median follow-up of 9 (IQR, 5-15) months, 82 (77%) patients with CML-MBP or CML-LBP returned to chronic phase; 40 (59%) with CML-MBP, 31 (79%) with CML-LBP and 38 (83%) with R/R Ph-positive ALL achieved MaHR by 3 months (p = 0.007); 19 (19/64, 30%) with CML-MBP, 20 (20/37, 54%) with CML-LBP and 36 (36/44, 82%) with R/R Ph-positive ALL, MCyR (p < 0.001). 44 (29%) patients with in the chronic phase or MaHR received transplant, 34 experienced relapse, 61 died of acute leukemia (n = 48, 79%), severe infection (n = 6, 10%), transplant-related mortality (n = 5, 8%), or COVI-19 (n = 2, 3%). At last follow-up, 65 (42%) patients still on olverembatinib-based therapy. Patients with CML-LBP showed the longest EFS (24 vs. 3 vs. 7 months, p = 0.013) and survival (not reached vs. 9 vs. 15 months, p = 0.021) compared to those with CML-MBP and R/R Ph-positive ALL. 1-year probabilities of EFS (59% vs. 29% vs. 39%, p = 0.013) and survival (74% vs. 39% vs. 53%, p = 0.027) in the patients with CML-LBP were the highest. Patients receiving transplant had higher 1-year probabilities of EFS (72% vs. 27%, p < 0.001) and survival (84% vs. 40%, p < 0.001) than those receiving non-transplant therapy.

In multi-variable analyses CML-MBP or R/R Ph-positive ALL (vs. CML-LBP, HR = 3.1 [1.3, 7.8], p = 0.014; HR = 4.3 [1.5, 12.8], p = 0.008), poor response to prior TKI-therapy (p = 0.012), no MaHR (HR = 2.2 [1.2, 4.1], p = 0.015) or BCR::ABL1 > 10% (HR = 2.8 [1.2, 6.7], p = 0.020) by 3 months, and non- transplant therapy (HR = 3.3 [1.3, 8.3], p = 0.012) were significantly-associated with worse survival.

Of 141 evaluable patients, 115 (82%) experienced ≥ 1 treatment-related adverse events (TRAE). 84 (62%) patients developed grade 4 hematological TRAE. The most common non-hematologic TRAE was pulmonary infection (29%), followed by increased aminotransferase (21%) and fatigue (20%). Cardio-cerebrovascular TRAE were observed in 23 (16%) patients including hypertension (n = 12, 52%), heart failure (n = 6, 26%), deep venous thrombosis (n = 5, 22%), and cerebral infarction (n = 2, 9%).

Conclusions Olverembatinib-based therapy is effective and tolerable in Ph-positive acute leukemia. CML-MBP, R/R Ph-positive ALL, inferior response to prior TKI-therapy, no MaHR or BCR::ABL1 > 10% by 3 months, and non-transplant therapy predicted worse survival.

Disclosures: No relevant conflicts of interest to declare.

*signifies non-member of ASH