Safety, tolerability, pharmacokinetics, pharmacodynamics, and immunogenicity of STSA-1002, recombinant anti-human C5a fully human monoclonal antibody, in a randomized, first-in-human phase I study in healthy adults
et al., Frontiers in Pharmacology, doi:10.3389/fphar.2026.1838620, NCT05497635, Jun 2026
Phase I RCT of 26 healthy adults (20 STSA-1002, 6 placebo) showing STSA-1002, a fully human anti-C5a monoclonal antibody, was safe and well-tolerated at multiple intravenous doses (5, 10, and 20 mg/kg weekly for 4 weeks).
Fang et al., 18 Jun 2026, Double Blind Randomized Controlled Trial, placebo-controlled, China, peer-reviewed, mean age 31.1, 17 authors, study period October 2022 - April 2023, trial NCT05497635 (history).
Contact: wangxh@bjsjth.cn.
Abstract:
OPEN ACCESS
EDITED BY
Maciej Cedzynski, Polish Academy of Sciences, Poland
REVIEWED BY Vasantha-Srinivasan Prabhakaran, Chonnam National University, Republic of Korea Universidad Autonoma del Estado de
Ana Luisa Robles-Piedras, Hidalgo, Mexico
*CORRESPONDENCE Xinghe Wang, wangxh@bjsjth.cn
RECEIVED 25 March 2026 REVISED 15 May 2026 ACCEPTED 25 May 2026 PUBLISHED 18 June 2026
CITATION
Fang Y, Wang X, Qi L, Tong Y, Wei Y, Li Z, Liu C, Liu J, Cheng X, Liu X, Liu F, Li Y, Li Y, Liu L, Sun M, Wang Y and Wang X (2026) Safety, tolerability, pharmacokinetics, pharmacodynamics, and immunogenicity of STSA-1002, recombinant anti-human C5a fully human monoclonal antibody, in a randomized, first-in-human phase I study in healthy adults. Front. Pharmacol. 17:1838620.
[doi: 10.3389/fphar.2026.1838620](https://doi.org/10.3389/fphar.2026.1838620)
COPYRIGHT
© 2026 Fang, Wang, Qi, Tong, Wei, Li, Liu, Liu, Cheng, Liu, Liu, Li, Li, Liu, Sun, Wang and Wang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
[Safety, tolerability, pharmacokinetics, pharmacodynamics, and immunogenicity of STSA-1002, recombinant anti-human C5a fully human monoclonal antibody, in a randomized, first-in-human phase I study in healthy adults](https://www.frontiersin.org/articles/10.3389/fphar.2026.1838620/full)
Yingying Fang 1 , Xiaoqian Wang 2 , Lu Qi 1 , Yuanxu Tong 1 , Yali Wei 1 , Zhong Li 2 , Chen Liu 1 , Ju Liu 1 , Xiaoqiang Cheng 1 , Xiaoyun Liu 1 , Fang Liu 2 , Yinjuan Li 1 , Yan Li 1 , Long Liu 1 , Mingli Sun 1 , Yu Wang 1 and Xinghe Wang 1 *
1 Department of Phase I Clinical Trial Center, Beijing Shijitan Hospital, Capital Medical University, Beijing, China, 2 Staidson Biopharmaceuticals (Beijing) Co., Ltd, Beijing, China
STSA-1002 is a fully human monoclonal antibody targeting C5a, which plays a critical role in the pathogenesis of virus-induced acute respiratory distress syndrome ARDS (v-ARDS). We investigated safety, pharmacokinetics, pharmacodynamics, and anti-drug antibodies of increasing multiple intravenous doses of STSA-1002 in healthy adults. In vitro studies, STSA-1002 was a high-affinity, selective anti-human C5a monoclonal antibody blocking C5amediated reactive oxygen species (ROS) production. Building on the published preclinical results, a randomized, double-blind, placebo-controlled, doseescalation study was done at a Phase I unit in China. A total of 60 adverse events (AEs) were reported. In the STSA-1002 group (n = 20), 47 AEs occurred in 18 participants (90.0%), corresponding to a mean of 2.6 AEs per participant. In the placebo group (n = 6), 13 AEs occurred in all 6 participants (100%), corresponding to a mean of 2.2 AEs per participant. Grade 2 or greater study drug-related adverse events included neutrophil count decreased, white blood cell count decreased, and aminotransferase increased. Cmax and AUC0-t increased in an approximately dose-proportional manner. After the first dose, the mean concentration of free C5a in all dose groups was suppressed to below the lower limit of quantification. This suppression was..
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"abstract": "<jats:p>\n STSA-1002 is a fully human monoclonal antibody targeting C5a, which plays a critical role in the pathogenesis of virus-induced acute respiratory distress syndrome ARDS (v-ARDS). We investigated safety, pharmacokinetics, pharmacodynamics, and anti-drug antibodies of increasing multiple intravenous doses of STSA-1002 in healthy adults.\n <jats:italic>In vitro</jats:italic>\n studies, STSA-1002 was a high-affinity, selective anti-human C5a monoclonal antibody blocking C5a-mediated reactive oxygen species (ROS) production. Building on the published preclinical results, a randomized, double-blind, placebo-controlled, dose-escalation study was done at a Phase I unit in China. A total of 60 adverse events (AEs) were reported. In the STSA-1002 group (n = 20), 47 AEs occurred in 18 participants (90.0%), corresponding to a mean of 2.6 AEs per participant. In the placebo group (n = 6), 13 AEs occurred in all 6 participants (100%), corresponding to a mean of 2.2 AEs per participant. Grade 2 or greater study drug-related adverse events included neutrophil count decreased, white blood cell count decreased, and aminotransferase increased. C\n <jats:sub>max</jats:sub>\n and AUC\n <jats:sub>0-t</jats:sub>\n increased in an approximately dose-proportional manner. After the first dose, the mean concentration of free C5a in all dose groups was suppressed to below the lower limit of quantification. This suppression was maintained in all health volunteers until D42 (5 mg/kg) and D56 (10 mg/kg and 20 mg/kg) after multiple doses. Besides, STSA-1002 could downregulate the levels of myeloperoxidase (MPO), neutrophil elastase (NE), and proteinase 3 (PR3). Overall, multiple infusions of STSA-1002 up to 20 mg/kg appear to be safe and well tolerated in healthy participants in China. The safety, PK, and PD data support the continued evaluation of STSA-1002 in larger Phase II studies.\n </jats:p>\n <jats:p>\n <jats:bold>Clinical Trial Registration:</jats:bold>\n <jats:ext-link>https://clinicaltrials.gov/</jats:ext-link>\n , ID NCT05497635.\n </jats:p>",
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