Kelun-Biotech's Lunbotinib Shows 87% Response Rate in Lung Cancer

Kelun-Biotech’s lung cancer drug lunbotinib showed an 87.1% objective response rate in pre-treated patients, according to new data presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting.

"The presentation of these exciting data from the pivotal trial represents a significant step in the development of this agent for patients globally," said Professor Sir Christopher Evans, Chairman of Kelun's partner Ellipses Pharma.

In the pivotal Phase II study, the next-generation RET inhibitor also demonstrated an 81.3% response rate in treatment-naïve patients. Median progression-free survival (PFS) was 27.5 months for pre-treated patients and was not reached for the treatment-naïve cohort, with 24-month PFS rates of 52.1% and 59.9%, respectively.

The strong results have prompted Kelun-Biotech to submit a New Drug Application (NDA) to China’s National Medical Products Administration (NMPA), positioning lunbotinib as a potent new option for RET-fusion positive non-small cell lung cancer (NSCLC).

The data, from the pivotal Phase II study of lunbotinib (A400/EP0031), demonstrated robust efficacy in patients with RET-fusion positive NSCLC. Among patients with baseline brain metastases, the objective response rate was 82.6% in the pre-treated group and 75.0% in the treatment-naïve group, with six patients in each cohort achieving a complete intracranial response. The NDA has been accepted for review by the NMPA. Ellipses Pharma holds the rights to develop and commercialize the drug outside of Greater China.

Kelun-Biotech also presented positive results from a second major study at ASCO, the Phase III OptiTROP-Lung05 trial. This study evaluated sacituzumab tirumotecan (sac-TMT), an antibody-drug conjugate, in combination with Merck’s Keytruda for first-line treatment of PD-L1 positive advanced NSCLC.

The combination therapy cut the risk of tumor progression or death by 65% compared to Keytruda alone, showing a hazard ratio of 0.35. The median PFS was not reached in the combination arm, versus 5.7 months for the Keytruda monotherapy group. An sNDA for this combination has been accepted for priority review in China.

The dual data presentations signal Kelun-Biotech's emergence as a major player in oncology with a strong pipeline. Investors will now watch for NMPA approval decisions for both lunbotinib and the sac-TMT combination, which could unlock significant revenue streams for the company and its partners.

This article is for informational purposes only and does not constitute investment advice.