Ellipses Pharma has announced that its partner, Kelun Biotech, has had its new drug application (NDA) for the next-generation selective RET inhibitor EP0031/A400 accepted for review by China’s CDE under the NMPA.
This acceptance for review, a key step in the regulatory approval process, is based on the positive results from the two pivotal Phase 2 cohorts of the KL400-I/II-01 study advanced RET-fusion positive NSCLC.
The Phase 2 stage of the KL400-I/II-01 study 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 favourable efficacy in both cohorts and an encouraging, manageable tolerability and safety profile.
Professor Sir Christopher Evans is chairman of Ellipses Pharma.
He said: “We are delighted and greatly encouraged that EP0031/A400 has been accepted for review by the Chinese regulatory authorities – a very significant step in the development of this very promising treatment for patients globally.
“These are very exciting times for Ellipses.”
EP0031/A400 is being developed jointly by Ellipses and Kelun Biotech.
Ellipses has 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).
Data from the dose finding and optimisation cohorts were presented at ASCO 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.
The trial is continuing with recruitment of Phase 2 cohorts of patients with and without prior 1stgeneration SRI.
In November 2023, Ellipses announced it had secured Orphan Drug designation for EP0031/A400 from the US Food and Drug Administration (FDA) and the following year, it secured Fast Track designation from the FDA for EP0031/A400 for the treatment of RET-fusion positive NSCLC.
Ellipses expects to complete its Phase 2 trials of EP0031/A400 in 2026 before submission to relevant regulatory authorities in non-Chinese geographies.
Ellipses Pharma has a robust pipeline of best-in-class programmes, including three programmes in Phase 2 clinical development and an additional programme entering Phase 1 early in 2026.
Professor Tobias Arkenau is global health of drug development and chief medical officer at Ellipses Pharma.
He said: “EP0031/A400 has great potential as a new treatment option for patients with RET fusion-positive NSCLC, which remains a progressive and fatal condition for many people worldwide despite available treatment options.”
Dr. Michael Ge, CEO of Kelun-Biotech, added: “We are very pleased to report positive results from the clinical study of A400/EP0031 in treating RET-fusion positive NSCLC, which gives us confidence in its future clinical potential.
“As a tumour agnostic precision therapy, A400/EP0031 represents our significant strategic positioning in the solid tumour field.
“We look forward to working closely with the regulatory authorities in China and our international partner Ellipses Pharma to expedite the review process for A400/EP0031, bringing this innovative therapy to patients with RET-fusion positive NSCLC as soon as possible.”
