#China #Chengdu #Kelun-Biotech #Lung Cancer #Lunbotinib

Kelun-Biotech Unveils Groundbreaking Phase II Results for Lunbotinib Fumarate in RET Fusion-Positive NSCLC

In an impressive showcase at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting held in Chicago, Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. presented pivotal Phase II data on its next-generation selective RET inhibitor, lunbotinib fumarate (A400/EP0031). This innovative treatment is specifically designed for patients suffering from advanced rearranged during transfection (RET) fusion-positive non-small cell lung cancer (NSCLC). The insights were shared by Professor Qing Zhou from Guangdong Provincial People's Hospital, who underlined the drug's potential to reshape treatment options for a patient population with limited alternatives.

The significance of the findings is enhanced by the acceptance of a New Drug Application (NDA) for lunbotinib fumarate by the National Medical Products Administration (NMPA) of China. This application is crucial for the treatment of adult patients with locally advanced or metastatic RET fusion-positive NSCLC.

Study Structure and Results

The Phase II clinical trial involved 71 patients who had previously undergone platinum-based chemotherapy and immunotherapy, referred to as pre-treated patients, and 92 treatment-naïve patients who had not received any prior systemic therapy. A data cutoff date of October 29, 2025, was implemented for analysis, with median follow-up durations of 22.6 months for pre-treated individuals and 20.7 months for treatment-naïve patients.

Remarkably, the confirmed objective response rate (ORR), as assessed by an Independent Review Committee (IRC), reached 81.3% (with a confidence interval of 71.8–88.7) in treatment-naïve patients and an impressive 87.1% (95% CI 77.0–93.9) among those pre-treated. The median duration of response (mDOR) and median progression-free survival (mPFS) were yet to be reached for the treatment-naïve group, while the pre-treated cohort demonstrated an mDOR of 25.7 months and mPFS of 27.5 months.

Among the subset of 40 patients presenting with central nervous system (CNS) metastases at baseline, the results were notably promising, with a complete response (CR) rate of 30% and an exceptional disease control rate (DCR) of 92.5% (95% CI 79.6–98.4).

Safety and Tolerability

One of the key takeaways from the study is the robust safety profile of lunbotinib fumarate. Treatment-related adverse events (TRAEs) were predominantly classified as Grade 1–2, with only 1.2% of patients permanently discontinuing treatment due to TRAEs and no treatment-related deaths reported during the study. This manageable safety profile augments the attractiveness of lunbotinib fumarate as a therapeutic option, implying that it could be a viable treatment for patients with RET fusion-positive NSCLC, regardless of their prior therapy lines.

Next Steps and Future Development

Professor Qing Zhou highlighted the evolution of lunbotinib fumarate from its initial Phase I presentation at ASCO 2023 to the strong Phase II results now available. The data indicates that lunbotinib fumarate can effectively deliver durable responses across both treatment-naïve and pre-treated patients, particularly focusing on its remarkable efficacy in those with CNS metastases. This next-generation selective RET inhibitor is poised to emerge as a significant additional treatment option for this challenging cancer type.

As a novel approach to cancer care, lunbotinib fumarate is not only cornering the market in its respective indications but also signifies an important advancement in the ongoing battle against NSCLC. Further evaluations will continue as the drug progresses through regulatory pathways and begins to broaden its impact in clinical settings.

Conclusion

Kelun-Biotech is committed to resolving critical unmet medical needs within oncology, and with lunbotinib fumarate's promising data, the company is on a firm path toward achieving that goal. As they navigate through regulatory processes and ongoing clinical studies, the hope remains that this innovative treatment will facilitate better quality care for patients with RET fusion-positive NSCLC, providing them with much-needed options and improved prognoses.