Boan Biotech Announces Successful Completion of Phase Ia Clinical Trial of BA1302 (CD228-Directed ADC) in China

Objective Responses observed in multiple types of advanced solid tumors, showing potential to treat a variety of cancers

Boan Biotech today announced the completion of the monotherapy dose-escalation portion (Phase Ia) of a Phase I clinical trial of BA1302 in China. BA1302 is a novel CD228-directed antibody-drug conjugate (ADC) developed by Boan Biotech. The results indicated that BA1302 showed anti-tumor activity across various types of advanced solid tumors in patients who had experienced disease progression after previously receiving multiple lines of treatment. The drug candidate also showed a favorable overall safety and tolerability profile.

Boan Biotech believes that BA1302 is currently the only CD228-directed ADC at clinical stage globally. With a low expression in normal tissues, CD228 is highly expressed in various types of solid tumors, including melanoma, breast cancer, esophageal cancer, squamous non-small cell lung cancer, head and neck squamous cell carcinoma, mesothelioma, colon cancer, and pancreatic cancer, making it an ideal target for ADCs. BA1302 employs a cleavable hydrophilic linker to conjugate the cytotoxic payload MMAE to an anti-CD228 monoclonal antibody via cysteines in the hinge region. This design enables the antibody to specifically deliver the payload into the tumor tissues, exerting anti-tumor effects while reducing the toxicity and expanding the therapeutic window.

The Phase I trial in China is a multicenter, open-label study designed to evaluate the safety, tolerability, pharmacokinetics, immunogenicity, and preliminary antitumor activity of BA1302 as a monotherapy in patients with advanced solid tumors. As of August 1, 2026, the Phase Ia portion of the trial had evaluated seven dose levels ranging from 0.2 mg/kg to 3.6 mg/kg. A total of 36 subjects with different types of advanced solid tumors were enrolled in the trial. 31 of them were treated at a dose level of 2.0 mg/kg or higher. Among all the subjects enrolled in the trial, 83.3% of them had metastases in two or more organs, 66.7% of them had received at least two lines of prior treatment, and most of them had experienced disease progression following treatments with chemotherapy, targeted therapy or immunotherapy. Data from the Phase Ia trial showed that:

Preliminary anti-tumor activity was observed in multiple types of solid tumors. Partial Responses (PRs) were observed in subjects with triple-negative breast cancer, esophageal carcinoma, melanoma, and cervical cancer. Specifically, one of the two subjects with triple-negative breast cancer achieved a PR, one of the three subjects with CD228-positive esophageal cancer achieved a PR, one of the twelve subjects with melanoma treated at a dose of 2.0 mg/kg or higher achieved a PR, and the only subject with cervical cancer achieved a PR. These results are indicative of the preliminary efficacy of BA1302. At present, overall progression-free survival (PFS) and overall survival (OS) data remain immature.

BA1302 demonstrated a favorable overall safety and tolerability profile. Common treatment-related adverse events (TRAEs) were hematologic toxicities and changes in liver enzyme levels. The vast majority of TRAEs were mild to moderate in severity (Grade 1 to 2 according to CTCAE v5.0) and improved or resolved with appropriate treatment.
Following the Phase Ia trial, Boan Biotech will proceed to the Phase Ib dose-expansion trial to further evaluate the potential of BA1302 against key cancer types. In terms of BA1302’s global development, the company has received clearance from the U.S. Food and Drug Administration (FDA) to proceed with the clinical trial of BA1302 in the U.S. The FDA has also granted BA1302 the Orphan Drug Designation for both squamous non-small cell lung cancer and pancreatic cancer.

Jiang Hua, Chairlady and Chief Executive Officer of Boan Biotech, said:"The preliminary efficacy and safety of BA1302 shown in the Phase Ia trial were encouraging, which further enhanced our confidence in CD228 as a therapeutic target and in the potential of BA1302. The anti-tumor activity of the drug candidate as a monotherapy for multiple types of solid tumors and its potential to be developed as part of a combination therapy may open up a new pathway for the targeted treatment of cancers. We will accelerate the global development of BA1302 and continue to explore its clinical value in a broader range of indications."

The encouraging results of BA1302 in the Phase Ia trial also demonstrated the ability of Boan Biotech to turn innovation on its ADC platform into clinical value. The company has established an integrated ADC platform covering key capabilities in antibody discovery, linker and payload development, conjugation process development, and analytical characterization. It is also advancing next-generation approaches, including novel high-potency payloads, glycan site-specific conjugation, bispecific ADCs, dual-payload ADCs, and Probody ADCs. Boan Biotech has established a pipeline of innovative drug candidates, including BA1302 (a CD228-directed ADC), BA1301 (a CLDN18.2-directed ADC), and BA1304 (an EGFR/B7-H3-directed bispecific ADC), while continuing to expand the application of ADC technology in precision oncology.