Senhwa Biosciences, Inc. has announced a significant clinical development milestone with its first-in-class investigational agent Pidnarulex (CX-5461) set to be evaluated in combination with the antibody–drug conjugate trastuzumab deruxtecan (Enhertu) in a phase 1b clinical trial. The study will focus on patients with HER2-positive solid tumours and breast cancer, including those with HER2-low expression and metastatic disease.

The announcement follows Senhwa’s recent clinical collaboration with BeOne Medicines to explore combination approaches using a marketed PD-1 inhibitor in cold tumours, highlighting the company’s expanding strategy in combination oncology therapies. The CX-5461 and Enhertu study is supported by the US National Cancer Institute’s NExT programme, which is backing multiple CX-5461 clinical studies, including combination regimens. This trial also marks CX-5461’s entry into the rapidly expanding ADC therapeutic landscape.

CX-5461 is the most advanced G-quadruplex (G4) stabiliser currently in clinical development. Early-phase studies sponsored by SU2C-CCTG in Canada have demonstrated encouraging activity in breast cancer and other solid tumours. Senhwa believes that combining CX-5461’s novel mechanism of action with Enhertu’s targeted ADC platform could improve outcomes in HER2-low patients and open new treatment avenues.

Enhertu, co-developed by AstraZeneca and Daiichi Sankyo, is the first HER2-directed ADC approved for HER2-low and HER2-ultralow metastatic breast cancer. The therapy uses a HER2-targeting monoclonal antibody to selectively deliver the cytotoxic payload deruxtecan into tumour cells, enabling potent anti-tumour activity while limiting damage to normal tissue.

The global ADC market is projected to grow at a compound annual growth rate of over 28%, reaching an estimated USD 47 billion by 2029. Industry analysts note that Senhwa’s strategy of combining CX-5461 with an established ADC positions the company to participate directly in this high-growth oncology segment.

While HER2-targeted therapies have reshaped the treatment of breast and gastric cancers, their effectiveness in HER2-low solid tumours remains an unmet need. Experts suggest that if CX-5461 demonstrates synergy with ADC-based delivery, it could expand therapeutic options across additional tumour types and offer a meaningful competitive advantage.

With global pharmaceutical companies intensifying their focus on ADCs, successful clinical outcomes from this trial could pave the way for future licensing deals and strategic partnerships. Analysts further indicate that positive data would enhance Senhwa’s global profile in oncology, support long-term value creation and strengthen investor confidence.

Founded in 2012 and listed on the Taipei Exchange in 2017, Senhwa Biosciences focuses on human-efficacy-driven drug development. The company continues to advance its oncology pipeline and integrate next-generation ADC technologies with its proprietary assets, with the goal of becoming a globally recognised oncology innovator headquartered in Asia.