Xenopax for the treatment of steroid-refractory acute graft-versus-host disease: the RELAX study

Le-Qing Cao; Wen-Xuan Huo; Er-Lie Jiang; Yue-Wen Fu; Xiao-Jun Xu; Ping-Chong Lei; Ming-Feng Zhao; Zhi Chen; Shu-Xia Guo; Xiao-Bing Huang; Yan-Ming Zhang; Xian-Jing Wang; Guan-Chen Bai; Feng-Bo Jin; Qing-Sheng Li; Ming-Yang Deng; Hao Zhang; Xin-Feng Wang; Xiao-Jun Huang; Xiao-Dong Mo

doi:10.1186/s40779-025-00640-0

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Xenopax for the treatment of steroid-refractory acute graft-versus-host disease: the RELAX study

RESEARCH | Updated：2026-05-08

- Xenopax for the treatment of steroid-refractory acute graft-versus-host disease: the RELAX study
- Military Medical Research Vol. 13, Issue 3, Pages: 400-412(2026)
- Affiliations：
  
  1.Peking University People’s Hospital, Peking University Institute of Hematology, National Clinical Research Center for Hematologic Disease, Beijing Key Laboratory of Cell and Gene Therapy for Hematologic Malignancies, Peking University, Beijing 100044, China
  2.State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China
  3.Department of Hematology, Henan Cancer Hospital, Affiliated Cancer Hospital of Zhengzhou University, Zhengzhou 450008, China
  4.Children’s Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou 310052, China
  5.Department of Hematology, Henan Provincial People’s Hospital, Zhengzhou 450003, China
  6.Department of Hematology, Tianjin First Central Hospital, Tianjin 300192, China
  7.Department of Hematology, Wuhan Children’s Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430016, China
  8.Department of Hematology, People’s Hospital of Zhengzhou, Zhengzhou 450003, China
  9.Department of Hematology, Sichuan Provincial People’s Hospital, Affiliated Hospital of University of Electronic Science and Technology of China, Chengdu 610072, China
  10.Department of Hematology, Huai’an Second People’s Hospital, Huai’an 223002, Jiangsu, China
  11.Department of Hematology, the Third People’s Hospital of Zhengzhou, Zhengzhou 450003, China
  12.Department of Hematology, the Affiliated Tai’an City Central Hospital of Qingdao University, Tai’an 271000, Shandong, China
  13.Anhui Public Health Clinical Center, the First Affiliated Hospital of Anhui Medical University, Hefei 230022, China
  14.The First Affiliated Hospital of Anhui Medical University, Hefei 230022, China
  15.Department of Hematology, the Second Xiangya Hospital, Central South University, Changsha 410011, China
  16.Department of Hematology, Affiliated Hospital of Jining Medical University, Jining 272067, Shandong, China
  17.Department of Hematology, Affiliated Hospital of Nantong University, Nantong 226001, Jiangsu, China
  18.Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Author bio：
  
  * Xiao-Dong Mo moxiaodong@pkuph.edu.cn
- Funds：
- DOI：10.1186/s40779-025-00640-0
  CLC：
- Received：02 December 2024，
  
  Accepted：08 August 2025，
  
  Online First：29 September 2025，
  
  Published：2026-03
- Accepted：
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Le-Qing Cao, Wen-Xuan Huo, Er-Lie Jiang, et al. Xenopax for the treatment of steroid-refractory acute graft-versus-host disease: the RELAX study[J]. Military Medical Research, 2026, 13(3): 400-412.
DOI：

Le-Qing Cao, Wen-Xuan Huo, Er-Lie Jiang, et al. Xenopax for the treatment of steroid-refractory acute graft-versus-host disease: the RELAX study[J]. Military Medical Research, 2026, 13(3): 400-412. DOI： 10.1186/s40779-025-00640-0.

摘要

Abstract

Background

Steroid-refractory (SR) acute graft-versus-host disease (aGVHD) is the major cause of early mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Xenopax

a novel and the only available humanized interleukin-2 (IL-2) receptor antagonist

has been approved as a category 2 biological product by the National Medical Products Administration. This study aims to evaluate the efficacy

safety

and prognostic factors of xenopax treatment for SR-aGVHD in real-world settings.

Methods

This was a multicenter

retrospective analysis that included SR-aGVHD patients who received xenopax at 17 hospitals across China. The data were collected from the electronic medical records in transplant databases. The primary endpoint was the 28-day overall response rate (ORR)

encompassing both partial and complete responses. This study also included independent historical SR-aGVHD cohorts treated with best available treatments (BATs

= 1009) as controls.

Results

In total

172 SR-aGVHD patients were included in this study. Xenopax was administered either as monotherapy (

= 60) or in combination with other second-line treatments (

= 112). The ORR was 64.5% [95% confidence interval (CI) 57.3–71.7%

]

on day 28 and 82.6% (95% CI 76.9–88.3%) at any time after xenopax treatment. The 2-year probabilities of disease-free survival

overall survival

non-relapse mortality (NRM)

and relapse after xenopax treatment were 57.0% (95% CI 49.9–65.0%)

68.0% (95% CI 61.4–75.4%)

24.2% (95% CI 18.0–30.9%)

and 19.0% (95% CI 12.8–25.2%)

respectively. The ORR and survival were similar between patients with and without prior second-line treatments. The conditioning regimen and human leukocyte antigen disparity did not impact the efficacy of xenopax treatment. According to the multivariate analysis

the presence of grade III–IV aGVHD did not adversely affect the therapeutic response or survival. Xenopax also showed some superiority over BATs in historical cohorts.

Conclusions

Our real-world findings suggest that xenopax is an effective and safe treatment for SR-aGVHD.

关键词

Keywords

references

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