Kelun‑Biotech Shows 87% Response Rate for RET‑Fusion Lung Cancer in Phase II ASCO Data

Why It Matters

The Phase II results position lunbotinib fumarate as a potential third‑generation RET inhibitor that could outpace existing therapies on both efficacy and brain‑metastasis control. For patients with RET‑fusion NSCLC—a subset representing roughly 1‑2% of all lung cancers—the data offer a new line of treatment that may delay or replace the need for chemotherapy and immunotherapy, improving quality of life and survival. Regulatory acceptance of the NDA by the NMPA signals a rapid path to market in China, the world’s second‑largest pharmaceutical market. Coupled with the Ellipses Pharma licensing deal, Kelun‑Biotech could soon launch globally, intensifying competition among RET‑targeted agents and potentially driving down prices while expanding access to a therapy that addresses both systemic and central nervous system disease.

Key Takeaways

• Phase II ORR: 87.1% in pre‑treated, 81.3% in treatment‑naïve RET‑fusion NSCLC patients
• Median PFS of 27.5 months in pre‑treated cohort; median DOR not reached in treatment‑naïve group
• Intracranial complete‑response rate of 30% among 40 patients with brain metastases
• Treatment‑related discontinuation rate of 1.2%; no treatment‑related deaths reported
• NMPA accepted NDA for lunbotinib fumarate; global rights licensed to Ellipses Pharma

Pulse Analysis

Kelun‑Biotech’s data arrive at a pivotal moment for the RET‑inhibition market. While pralsetinib and selpercatinib have established themselves as first‑line options, both drugs exhibit modest intracranial activity and face resistance mechanisms that limit long‑term benefit. Lunbotinib’s high ORR across lines of therapy and its pronounced CNS efficacy could carve out a niche as a preferred option for patients with brain metastases, a cohort that historically experiences poorer outcomes.

From a commercial perspective, the acceptance of the NDA by the NMPA accelerates Kelun‑Biotech’s revenue timeline, potentially delivering a multi‑billion‑yuan market in China alone. The Ellipses Pharma partnership expands the addressable market to North America and Europe, where regulatory pathways may be more stringent but the pricing power is higher. If the company can secure approvals in these regions, it could leverage its differentiated CNS data to negotiate premium pricing, especially in health‑system environments that value brain‑penetrant agents.

Looking ahead, the key risk lies in the upcoming Phase III confirmatory trials and the ability to demonstrate consistent benefit in larger, more diverse populations. Additionally, the competitive response—potentially accelerated development of next‑generation RET inhibitors by larger pharma—could compress market share. Nonetheless, the current data give Kelun‑Biotech a credible foothold and set the stage for a reshaping of the RET‑fusion treatment paradigm.