-Author name in bold denotes the presenting author
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1707 Outcomes of Allogeneic Transplantation for Adult T-Cell Leukemia/Lymphoma in Adolescents and Young Adult (AYA) and Young Patients

Program: Oral and Poster Abstracts
Session: 624. Hodgkin Lymphomas and T/NK Cell Lymphomas: Clinical and Epidemiological: Poster I
Hematology Disease Topics & Pathways:
Research, Biological therapies, Lymphomas, Clinical Research, T Cell lymphoma, Diseases, real-world evidence, Therapies, registries, Lymphoid Malignancies, Transplantation
Saturday, December 9, 2023, 5:30 PM-7:30 PM

Hidehiro Itonaga, MD, PhD1, Takuya Fukushima, MD, PhD2, Koji Kato, M.D., Ph.D.3*, Nobuaki Nakano, M.D.4*, Takeharu Kato, M.D., Ph.D.5*, Takashi Tanaka, MD6*, Tetsuya Eto, MD, PhD7*, Yasuo Mori, M.D., Ph.D.8*, Toshiro Kawakita, MD, PhD9*, Naoyuki Uchida, MD, PhD10, Yasushi Sawayama, M.D., Ph.D.11*, Takahiro Fukuda, MD, PhD6*, Yoshinobu Kanda12*, Yoshiko Atsuta, MD, PhD13*, Makoto Yoshimitsu, MD, PhD14 and Shigeo Fuji, MD, PhD15*

1Transfusion and Cell Therapy Unit, Nagasaki University Hospital, Nagasaki city, NSK, Japan
2Laboratory of Hematoimmunology, University of the Ryukyus, Nishihara-Cho, Okinawa, JPN
3Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medicine, Fukuoka, Japan
4Department of Hematology, Imamura General Hospital, Kagoshima, Japan
5Department of Hematology, Nagasaki University Hospital, Nagasaki, Japan
6Department of Hematopoietic Stem Cell Transplantation, National Cancer Center Hospital, Tokyo, Japan
7Department of Hematology, Hamanomachi Hospital, Fukuoka, JPN
8Hematology, Oncology & Cardiovascular medicine, Kyushu University Hospital, Fukuoka, JPN
9Department of Hematology, National Hospital Organization Kumamoto Medical Center, Kumamoto, Japan
10Department of Hematology, Toranomon Hospital, Tokyo, Japan
11Department of Hematology, Sasebo City General Hospital, Sasebo, Japan
12Division of Hematology, Jichi Medical University Saitama Medical Center, Saitama, Japan
13Japanese Data Center For Hematopoietic Cell Transplantation, Nagakute, Japan
14Department of Hematology and Rheumatology, Kagoshima University Hospital, Kagoshima, Japan
15Osaka International Cancer Center Institute, Osaka, Japan

Introduction

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) provides a durable remission for patients with adult T-cell leukemia/lymphoma (ATL). Reduced-intensity regimens (RIC) have been increasingly used in ATL patients due to their old age and higher non-relapse mortality. However, the role of RIC regimen has not been fully evaluated among ATL patients aged <50 years. We here conducted a nationwide study to evaluate the prognostic impact of conditioning intensity on the post-transplant outcomes in ATL patients aged <50 years.

Methods

The clinical data of patients aged <50 years who underwent their first allo-HSCT between January 2001 and December 2020 were collected from the Transplant Registry Unified Management Program of the Japan Society for Hematopoietic Cell Transplantation. Cox proportional hazards regression models were used to evaluate variables potentially affecting overall survival (OS), graft-versus-host disease (GVHD)- and relapse-free survival (GRFS), and chronic GVHD-free survival (CRFS). Fine and Gray proportional hazards models were used to evaluate variables potentially affecting cumulative incidences of relapse (CIR) and non-relapse mortality (NRM). CIR and NRM were estimated using cumulative incidence curves to accommodate competing events. A two-sided P-value ≤0.05 was considered to be significant. To examine the effect modification, a threshold for P interaction <0.10 was used to indicate significant differences across prespecified subgroups.

Results

This study included 73 and 330 patients who were <40 years old (adolescents and young adults [AYA] patients) and 40-49 years old (young patients), respectively. In AYA patients, the median age at HSCT was 36 years (range, 20-39). RIC regimen was used in 16 out of 57 AYA patients (21.9%), and in 74 out of 330 young patients (22.4%) (P=1.000). There was no significant difference of the patient characteristics regarding comorbidity, performance status at HSCT, disease status, clinical subtype, and donor type.

The estimated 3-year OS rates were 61.8% and 43.1% in AYA and young patients, respectively (P=0.005); the estimated 3-year CRFS rates were 35.8% and 22.6% in AYA and young patients, respectively (P=0.008); and the estimated 3-year GRFS rates were 26.7% and 15.1% in AYA and young patients, respectively (P=0.006). The estimated 3-year CIR were 36.3% and 39.3% in AYA and young patients, respectively (P=0.407); and the estimated 3-year NRM were 17.0% and 23.4% in AYA and young patients, respectively (P=0.113). In addition, the use of RIC regimen was associated with lower NRM than that of MAC regimen (P=0.015), but there was no significant difference of OS, CRFS, GRFS, and CIR between MAC and RIC regimens. The multivariate analyses revealed that young patients were significantly associated with worse OS (Hazard ratio (HR) [95% confidential interval], 1.62 [1.10-2.39]; P=0.015), CRFS (HR, 1.51 [1.10-2.06]; P=0.010), and GRFS (HR, 1.49 [1.11-1.99]; P=0.008) than AYA patients. The utilization of RIC regimen was significantly associated with lower NRM (HR, 0.46 [0.24-0.86]; P=0.015).

To find the optimal selection of conditioning intensity (MAC vs. RIC) by patient’s age, we next evaluated the effect modification. In the subgroup analysis, there was significant interaction of conditioning intensity with patient’s age (P interaction=0.002) in NRM but not in OS, CRFS, GRFS, and CIR. Among AYA patients, the estimated 1-year NRM were 12.5% and 18.8% in MAC and RIC regimens, respectively (P=0.085). Among young patients, the estimated 1-year NRM were 23.5% and 8.2% in MAC and RIC regimens, respectively (P<0.001).

Conclusion

The present study clarified that AYA patients exhibited better post-transplant outcomes than young patients, indicating the prognostic value of patient’s age in ATL patients aged <50 years. Moreover, no significant differences were observed in OS, CRFS, GRFS, and CIR between RIC and MAC regimens, but the utilization of RIC regimen would reduce the risk of non-relapse death among young patients. These facts suggested that RIC regimen could be an alternative option for ATL patients aged 40-49 years.

Disclosures: Kato: AbbVie, Bristol-Myers Squibb, Celgene, Chugai, Daiichi Sankyo, Eisai, Janssen, Kyowa Kirin, Novartis, Ono: Research Funding; AbbVie, AstraZeneca, Celgene, Chugai Pharmaceutical, Daiichi Sankyo, Eisai, Janssen, Novartis: Consultancy; Bristol-Myers Squibb, Celgene, Dainippon-Sumitomo, Janssen, Kyowa Kirin, MSD, Mundi, Ono: Honoraria. Kanda: Precision: Speakers Bureau; AbbVie: Research Funding, Speakers Bureau; Towa Pharma: Speakers Bureau; CSL Behring: Speakers Bureau; Japan Blood Products Organization: Research Funding, Speakers Bureau; Otsuka Pharmaceutical: Research Funding, Speakers Bureau; AstraZeneca: Speakers Bureau; Human Life CORD: Speakers Bureau; Sumitomo Pharma: Research Funding, Speakers Bureau; Amgen: Speakers Bureau; Takeda Pharmaceutical: Research Funding, Speakers Bureau; Meiji Seika Pharma: Speakers Bureau; Asahi Kasei Pharma: Research Funding, Speakers Bureau; Daiichi Sankyo: Research Funding, Speakers Bureau; Saitama Hokeni Kyokai: Speakers Bureau; MSD: Speakers Bureau; Kyowa Kirin: Research Funding, Speakers Bureau; Janssen Pharmaceutical: Speakers Bureau; Sanofi: Speakers Bureau; Pfizer: Speakers Bureau; Chugai Pharmaceutical: Research Funding, Speakers Bureau; Novartis: Speakers Bureau; Bristol Myers Squibb: Speakers Bureau; Alexion Pharma: Speakers Bureau; Shionogi Pharma: Research Funding; Nippon Shinyaku: Speakers Bureau; Wakunaga Pharmaceutical: Speakers Bureau; Taiho Pharmaceutical: Research Funding; FUJIFILM Wako Pure Chemical: Speakers Bureau; Eisai: Research Funding, Speakers Bureau; Nippon Kayaku: Research Funding; JCR Pharmaceuticals: Research Funding. Atsuta: Otsuka Pharmaceutical Co., Ltd: Speakers Bureau; Novartis Pharma KK: Speakers Bureau; JCR Pharmaceuticals Co., Ltd.: Consultancy; Meiji Seika Pharma Co, Ltd.: Honoraria; CHUGAI PHARMACEUTICAL CO., LTD.: Speakers Bureau. Yoshimitsu: Novartis: Honoraria; Takeda: Honoraria; Nihon Shinyaku: Honoraria; Bristol Meyers Squibb: Honoraria; Sanofi: Honoraria; Otsuka Pharmaceutical: Honoraria; CSL Behring: Honoraria; Chugai: Honoraria; Daiichi Sankyo: Honoraria; Ono Pharmaceuticals: Honoraria; Meiji Seika: Honoraria.

*signifies non-member of ASH