On May 22, 2026 Ellipses Pharma ("Ellipses"), a global oncology drug development company with a pipeline of innovative programmes, reported that its partner, Kelun-Biotech, is presenting pivotal trial data for EP0031/A400, for the potential treatment of RET-fusion positive Non-Small Cell Lung Cancer (NSCLC), at the 2026 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting Chicago, May 29 to June 2.
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Efficacy and safety of lunbotinib (A400/EP0031), a next-generation selective RET inhibitor (SRI), from a pivotal phase Ⅱ study in patients with advanced RET-fusion positive non-small cell lung cancer (NSCLC), will be presented as an oral presentation scheduled on May 29, 2026, 14:36-14:48 local time (Abstract #8505: Lung Cancer – Non-Small Cell Metastatic).
The oral presentation of these data at the prestigious ASCO (Free ASCO Whitepaper) annual meeting, represents another major milestone in the global development of EP0031/A400 as a next generation SRI.
The data were generated in Kelun-Biotech’s Phase 2 study (NCT05265091) that evaluated the efficacy and safety of EP0031/A400 90mg orally once daily (QD) in patients with pre-treated and treatment-naïve RET-fusion positive locally advanced, or metastatic, NSCLC. EP0031/A400 demonstrated robust efficacy in both cohorts and an encouraging, manageable tolerability and safety profile. In September 2025 Kelun-Biotech submitted an NDA for the treatment of adult patients with RET fusion-positive locally advanced or metastatic non-small cell lung cancer (NSCLC) which was accepted for review by the NMPA of China.
EP0031/A400 is being developed jointly by Ellipses and Kelun-Biotech. Ellipses has been granted an exclusive licence to develop, manufacture and commercialise this agent outside Greater China and certain Asian countries under the code EP0031.
Ellipses has an ongoing Phase 1/2 trial in US, EU, UK and UAE (EP0031-101 NCT05443126). Phase 2 cohorts are currently evaluating the combination of EP0031/A400 with platinum doublet chemotherapy in patients with RET-fusion positive NSCLC that are naïve to or have previously received 1st generation SRI. Data supporting the strong preclinical rationale for this combination strategy were recently presented at the annual European Lung Cancer Congress 2026 (ESMO Open Volume 11, Suppl 3, https://www.sciencedirect.com/science/article/pii/S2059702926007490).
Professor Sir Christopher Evans, Chairman, Ellipses Pharma, commented: "We congratulate our partners Kelun-Biotech on the tremendous progress they have made with the development of EP0031/A400 in China. The presentation of these exciting data from the pivotal trial represents a significant step in the development of this agent for patients globally. Ellipses is immensely proud to be partnering with Kelun-Biotech and continues to make significant progress with the development of EP0031/A400 for patients outside Greater China."
Professor Tobias Arkenau, Global Head of Drug Development and Chief Medical Officer, Ellipses Pharma, commented: "Congratulations to our colleagues at Kelun-Biotech on the acceptance of these data for oral presentation at ASCO (Free ASCO Whitepaper). These data further establish the credentials of EP0031/A400 as a promising next-generation SRI. We look forward to continuing to build our data in the Ellipses trial to ensure EP0031/A400 is brought to Western patients as early as possible.’
About EP0031/A400
EP0031/A400 has broad and potent activity against the spectrum of common RET fusions and mutations, as well as RET resistance mutations that have been shown to emerge on progression on 1st gen SRIs. EP0031 has a differentiated preclinical profile compared with 1st gen SRIs with greater potency and antitumour activity in SRI naïve and SRI resistant PDX models as well as greater tissue permeability, with increased exposure in the CNS and improved survival in orthotopic models.
Data from the dose finding and optimisation cohorts, which evaluated EP0031/A400 as a monotherapy, were presented at ASCO (Free ASCO Whitepaper) in June 2025, showing promising evidence of activity, including CNS responses, in patients with advanced NSCLC that had received prior 1st generation Selective RET Inhibitor (SRI), with encouraging safety and tolerability (Journal of Clinical Oncology Volume 43, Number 16_suppl View Source).
In November 2023, Ellipses announced it had secured Orphan Drug designation for EP0031/A400 from the US Food and Drug Administration (FDA) for EP0031/A400 for the treatment of RET-fusion positive tumours.
About RET altered malignancies
Activating RET mutations and rearrangements have been identified as actionable drivers of oncogenesis in numerous tumour types and are most prevalent in non-small cell lung and thyroid cancer. It is estimated that RET mutations and rearrangements may be responsible for ~2% of all solid tumours. After the successful development of first generation SRIs and an increasing understanding of escape mechanisms to these agents, there is an unmet need to develop new treatments that can address acquired resistance, including the development of next-generation SRIs.
(Press release, Ellipses Pharma, MAY 22, 2026, View Source [SID1234666026])