全球研发 | 潜在FIC前列腺癌三抗TCE HLX3902（STEAP1×CD3×CD28）完成全球首例患者给药

2026年7月30日 – 复星医药子公司复宏汉霖（2696.HK）宣布，基于公司自主创新型免疫细胞衔接器（Immune cell engager）平台开发的第二款创新T细胞衔接器（T cell engager，TCE）HLX3902（STEAP1×CD3×CD28三特异性抗体）用于转移性去势抵抗性前列腺癌（mCRPC）及其他晚期实体瘤治疗的I期临床研究(HLX3902-FIH101)于中国境内完成全球首例患者给药。此前，HLX3902已获中国及澳大利亚临床许可，公司将于两地同步开展临床研究，以加速评估该新药在前列腺癌等晚期实体瘤患者中的安全性、耐受性和疗效。

HLX3902是由复宏汉霖自主研发并拥有完全知识产权的创新型靶向STEAP1、CD3和CD28的三特异性抗体药物，能够同时激活CD3和CD28来增强T细胞对表达STEAP1 肿瘤细胞的杀伤能力，并通过对T细胞激活第一信号（CD3）和第二信号（CD28）的优化，增强T细胞的激活、增殖和存活能力，延长抗肿瘤免疫应答的持续时间，使其在低T细胞浸润的环境中依然展现出优异的抗肿瘤活性。

临床前研究显示，HLX3902可诱导靶点依赖性的T细胞活化及细胞毒性，在低效应细胞/靶细胞比下优于传统CD3双特异性TCE。重复抗原刺激模型表明，其CD28共刺激信号可增强T细胞活化、增殖及记忆T细胞扩增，从而维持持久杀伤作用。体内C4-2/hPBMC及阿比特龙耐药PDX/hPBMC模型中，HLX3902抗肿瘤活性显著增强，伴随T细胞浸润和功能提升。此外，在食蟹猴研究中，HLX3902展现了良好的耐受性和可控的安全性。

作为潜在全球首个靶向STEAP1的三抗TCE分子，HLX3902的开发体现了公司多特异性免疫细胞衔接器平台从技术构建向临床验证阶段的持续推进与能力兑现。此前，基于该平台开发的首个创新分子HLX3901（DLL3xDLL3xCD3xCD28四特异性TCE）亦在临床前研究中展现出同类最优的治疗潜力，并已完成首次人体临床试验的首例患者给药，实现了创新技术转化的关键跨越。

未来，复宏汉霖将持续秉持“以患者为中心”的研发理念，依托平台化、系统化的创新体系，加速推进具有全球竞争力的差异化创新管线布局，为全球患者提供更可及、更有效的治疗选择。

关于HLX3902-FIH101

本研究是一项评估HLX3902在转移性去势抵抗性前列腺癌（mCRPC）及其他晚期实体瘤患者中的安全性、耐受性、药代动力学特征以及初步疗效的开放性、首次人体Ia期临床研究。研究共设置0.005 mg至1.5 mg的8个剂量水平，每4周为一个治疗周期，其中0.005 mg剂量组采用加速滴定设计，其余7个剂量组采用「3+3」剂量递增设计。本研究的主要目的为评估HLX3902在mCRPC及其他晚期实体瘤患者中的安全性和耐受性，确定其最大耐受剂量（MTD）。主要终点为剂量限制性毒性（DLT）事件的发生率和HLX3902的MTD。

Henlius' Announced First Patient Dosed for Its STEAP1×CD3×CD28 Tri-specific TCE HLX3902

July 30, 2026 – Shanghai Henlius Biotech, Inc. (2696.HK) announced that its second innovative T cell engager (TCE), HLX3902, a tri-specific antibody targeting STEAP1×CD3×CD28 developed on the company’s proprietary immune cell engager platform, has completed the first patient dosing in its first-in-human(FIH) study (HLX3902-FIH101) in China for the treatment of metastatic castration-resistant prostate cancer (mCRPC) and other advanced solid tumours. The study has also received clinical trial authorization in Australia. To accelerate early efficacy and safety evaluation of the product, the company has initiated multi-regional clinical trials (MRCT) simultaneously in China and Australia.

HLX3902 is an innovative trispecific antibody with proprietary intellectual property, capable of simultaneously engaging CD3 and CD28 to enhance T-cell-mediated killing of STEAP1-expressing tumour cells. By optimizing both the primary (CD3) and co-stimulatory (CD28) signals, HLX3902 promotes T-cell activation, proliferation, and survival, prolonging antitumor immune responses even in tumours with low T-cell infiltration.

Preclinical studies demonstrated that HLX3902 induces target-dependent T-cell activation and cytotoxicity, outperforming traditional CD3-based bispecific TCEs at low effector-to-target ratios. Repeated antigen stimulation models further confirmed that CD28 co-stimulation enhances T-cell activation, proliferation, and memory T-cell expansion, sustaining long-term cytotoxic effects. In vivo, HLX3902 showed significant antitumor activity in both C4-2/hPBMC and abiraterone-resistant PDX/hPBMC models, accompanied by increased T-cell infiltration and functional activity. In cynomolgus monkeys, HLX3902 demonstrated favourable tolerability and a controllable safety profile.

As a potentially first-in-class STEAP1-targeting trispecific T-cell engager, the development of HLX3902 validates the continued evolution of Henlius’ multispecific immune cell engager platform from technology construction to clinical translation. Previously, HLX3901, the Company’s first-in-class DLL3×CD3×CD28×CD28 tetravalent T-cell engager developed on the platform, demonstrated best-in-class potential in preclinical studies and has successfully completed first-in-human dosing, marking a key transition from platform establishment to clinical validation.

Looking forward, Henlius will remain committed to a patient-centric R&D philosophy and a systematic, platform-based innovation strategy to advance differentiated, globally competitive therapies, providing broader access to effective treatments for patients worldwide.

About HLX3902-FIH101

This is an open-label, first-in-human(FIH) phase 1a clinical trial to evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of HLX3902 in patients with metastatic castration-resistant prostate cancer (mCRPC) and other advanced solid tumors. The study includes eight dose levels ranging from 0.005 mg to 1.5 mg, with each treatment cycle lasting 4 weeks. The 0.005 mg dose cohort employs an accelerated titration design, while the remaining seven dose cohorts use a “3+3” dose-escalation design. The primary objectives of this study are to evaluate the safety and tolerability of HLX3902 in patients with mCRPC and other advanced solid tumors, and to determine its maximum tolerated dose (MTD). The primary endpoints are the incidence of dose-limiting toxicities (DLTs) and the MTD of HLX3902.