JACOBIO-B (HKEX: 01167) has announced that the first patient in China has been dosed in its Ib/III phase clinical trial evaluating the pan-KRAS inhibitor JAB-23E73 in combination with nab-paclitaxel and gemcitabine as a first-line treatment for KRAS-mutated pancreatic cancer.

The initiation of this study is supported by encouraging preliminary clinical data from an ongoing Phase I trial, previously detailed in the company's 2025 annual report. As of the data cutoff date of January 15, 2026, 42 patients with solid tumors (all having received at least two prior lines of therapy) had been enrolled in China. Among these, only 11.9% (5/42) experienced Grade 3 treatment-related adverse events (TRAEs), with no Grade 4 or 5 TRAEs reported. Furthermore, there were no Grade 3 or higher adverse events such as rash, mucositis, nausea, vomiting, or diarrhea.

Within the predicted effective dose range of ≥160 mg, 13 evaluable pancreatic cancer patients (including 2 second-line patients, the rest being third-line or higher) demonstrated an objective response rate (ORR) of 38.5%. These results confirm the drug's favorable safety and tolerability profile alongside its notable preliminary anti-tumor potential.

JAB-23E73 is an orally administered, internally developed pan-KRAS inhibitor with significant clinical development promise. JACOBIO-B has granted AstraZeneca (LSE/STO/NYSE: AZN) exclusive licensing rights for the drug globally, excluding China (excluding Hong Kong SAR, Macau SAR, and Taiwan). For mainland China, the two companies are engaged in joint development and co-commercialization.

KRAS mutations are highly prevalent in pancreatic cancer. The formal commencement of this study marks a critical milestone in the development pathway for JAB-23E73.