Adcentrx Begins Phase 1b Trials with ADRX-0706 Nectin-4 ADC

Adcentrx Therapeutics, a clinical-stage biotechnology enterprise headquartered in San Diego and Shanghai, has initiated the Phase 1b segment of their ongoing Phase 1a/b clinical trial for ADRX-0706, a novel therapeutic aimed at combating advanced solid tumors. This marks a pivotal moment in the development of ADRX-0706, underscoring the promising results observed in the preceding Phase 1a dose escalation study.

The commencement of the Phase 1b trial follows encouraging outcomes from the Phase 1a phase, which highlighted ADRX-0706’s potential as a best-in-class treatment. Key findings from Phase 1a indicated a notable safety profile and distinctive pharmacokinetic properties, including a significantly lower occurrence of serious adverse events such as peripheral neuropathy. Moreover, preliminary efficacy across various dose levels and tumor types offers crucial clinical validation for Adcentrx's proprietary Antibody-Drug Conjugate (ADC) platform, which incorporates their pioneering i-Conjugation® technology and the novel auristatin payload AP-052.

The Phase 1a/b study, which is the first of its kind involving human subjects, is being carried out at multiple locations across the United States and China. The initial Phase 1a involved a dose-escalation study of ADRX-0706, aimed at determining the drug's safety and tolerability in patients with specific advanced solid tumors, as well as identifying the optimal dose for subsequent trials. With the Phase 1b segment now underway, the focus will shift to further evaluating the safety and tolerability of ADRX-0706, assessing its preliminary efficacy, and determining the optimal dosage for urothelial cancer, triple-negative breast cancer, and cervical cancer. An initial data readout from the Phase 1b trial is anticipated in the fourth quarter of 2025.

ADRX-0706 represents a fully proprietary ADC product candidate developed by Adcentrx. The antibody component targets Nectin-4, a cell surface adhesion protein that is highly expressed in numerous solid tumors while being minimally present in normal tissues. Nectin-4 is linked to poor disease prognosis and serves as a validated target for ADCs. The antibody in ADRX-0706 is conjugated to a proprietary tubulin inhibitor payload, AP052, through Adcentrx’s innovative i-Conjugation® technology, which employs a cleavable linker and stable conjugation chemistry. This platform technology facilitates the creation of a highly stable ADC with a drug-antibody ratio of eight (DAR 8), significantly expanding the therapeutic window as evidenced in preclinical studies.

In preclinical models, ADRX-0706 exhibited a favorable pharmacokinetic and safety profile and demonstrated significant efficacy across a wide range of tumor types, both in vitro and in vivo. The ongoing Phase 1a/b clinical trial aims to further investigate these promising findings in a clinical setting.

Adcentrx Therapeutics is committed to advancing breakthroughs in the development of protein conjugate therapeutics for cancer and other life-threatening diseases. Leveraging their pioneering i-Conjugation® technology, the company is working on a robust pipeline of ADCs with first-in-class potential. The organization’s dedication to innovative ADC technologies places them at the forefront of therapeutic development in oncology.

For more details about the ADRX-0706 Phase 1a/b clinical trial, please refer to Study ID NCT06036121 on ClinicalTrials.gov.