China's NMPA approves Adcentrx Therapeutics' ADRX-0405 STEAP1 ADC for clinical trials: a new milestone in biotechnological innovation

Introduction

On June 8, 2026, clinical-stage biotechnology company Adcentrx Therapeutics announced that its antibody-drug conjugate (ADC) ADRX-0405 has received clinical trial approval (IND) from the China National Medical Products Administration (NMPA). This approval enables Adcentrx to include Chinese clinical centers in its ongoing global Phase 1a/1b clinical trial (NCT06710379), evaluating the safety and efficacy of ADRX-0405 in patients with advanced solid tumors, including metastatic castration-resistant prostate cancer (mCRPC), gastric cancer, and non-small cell lung cancer.

Industry Background

As an important branch of precision medicine, antibody-drug conjugates (ADCs) have achieved significant breakthroughs in the field of oncology in recent years. ADCs achieve precise killing of tumor cells while reducing damage to normal tissues by combining highly toxic payloads with targeted antibodies. However, ADC development faces challenges such as stability and payload delivery efficiency. STEAP1 (six-transmembrane epithelial antigen of the prostate 1) is a membrane protein highly expressed in prostate cancer and various solid tumors, with limited expression in normal tissues, making it an attractive ADC target. Currently, there are no approved STEAP1-targeted ADCs globally, and ADRX-0405 is expected to become the first clinical candidate targeting this antigen.

Key Progress

ADRX-0405 utilizes Adcentrx's proprietary i-Conjugation technology platform, which employs cleavable linkers and stable conjugation chemistry to achieve a drug-to-antibody ratio (DAR) of 8, maximizing payload delivery to solid tumors. Preclinical studies have shown favorable pharmacokinetics, safety, and significant efficacy of ADRX-0405 in multiple animal tumor models. This NMPA IND approval is another important milestone following FDA approval in the United States, allowing Adcentrx to enroll patients simultaneously in both China and the United States. The company plans to complete the Phase 1a dose-escalation portion in the fourth quarter of 2026.

Market Impact

The global multi-center development strategy of ADRX-0405 (including China) is expected to accelerate patient enrollment and generate clinical data with greater ethnic diversity, which is crucial for subsequent global registration and commercialization. From a market perspective, prostate cancer is the second most common cancer among men worldwide, and mCRPC patients have a significant unmet need for novel therapies. If ADRX-0405 demonstrates excellent safety and efficacy in early clinical trials, it may fill the gap for STEAP1-targeted ADCs and drive increased investment from relevant companies (e.g., domestic ADC developers) in this target. Additionally, the NMPA's expedited review pathways for innovative ADCs (such as breakthrough therapy designation) may further shorten development timelines and attract more capital into this field.

Challenges and Risks

Despite the potential of ADRX-0405, ADC development still faces numerous challenges.Despite the potential of ADRX-0405, ADC development still faces numerous challenges. First, the low expression of STEAP1 in some normal tissues may lead to off-target toxicity, which needs to be closely monitored in clinical trials. Second, the field is highly competitive, with multiple companies developing ADCs targeting STEAP1 and other therapies (such as bispecific antibodies, radiopharmaceuticals). Additionally, differences in regulatory environments between China and the U.S., as well as the coordination and management of multi-center studies, pose potential challenges in practical execution. Adcentrx must fully validate safety and the optimal dose in Phase 1 trials to advance subsequent development.

Future Outlook

In the next 3-5 years, if ADRX-0405 successfully completes Phase 1 and Phase 2 clinical trials, it is expected to become the first globally approved STEAP1-targeted ADC, offering new treatment options for patients with solid tumors such as prostate cancer. Meanwhile, Adcentrx's i-Conjugation technology platform is also expected to expand to other targets and indications, driving continuous innovation in ADC technology. From a capital perspective, the ADC field remains a hot spot for biotech investment, especially under the dual-filing strategy in China and the U.S., where companies with global clinical development capabilities are more favored.

Conclusion

The IND approval of ADRX-0405 not only marks Adcentrx's entry into the global clinical development stage but also highlights the core position of biotechnological innovation in precision oncology. With the simultaneous advancement in both the Chinese and U.S. markets, the emerging target of STEAP1 ADC will enter a critical validation period, and differentiation of technology platforms will become key to corporate competitiveness.