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Kelun-Biotech and Ellipses A400 (EP0031) Cleared to Start Ph2 Clinical Development by US FDA

Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the “Company”) is pleased to announce that our key product A400, a small molecule rearranged during transfection (RET) kinase inhibitor program (also known as KL590586 or EP0031), has been cleared by the United States Food and Drug Administration (FDA) to progress into Phase 2 clinical development.

A400 (EP0031) is a second-generation selective RET inhibitor (SRI) with broad activity against common RET fusions and mutations. Designed to address clinical needs not met by first-generation SRIs. Targeting RET-driven cancers, next-generation SRIs offer potentially more diverse treatment options and may further improve patient prognosis.

- In March 2021, the Company granted Ellipses Pharma Limited (“Ellipses”), a U.K. based international drug development company, an exclusive, royalty-bearing, sublicensable license to develop, manufacture and commercialize A400 (EP0031) in all countries excluding Greater China, North Korea, South Korea, Singapore, Malaysia and Thailand.

- In June 2022, the FDA approved an investigational new drug (IND) application for A400 (EP0031), and a Phase 1/2 trial is ongoing in patients with malignant tumors with RET gene alteration.

- In November 2023, A400(EP0031) was granted Orphan Drug Designation by the FDA for the treatment of RET fusion-positive solid tumors.

- In March 2024, A400 (EP0031) was granted Fast Track Designation by the FDA for the treatment of RET fusion-positive non-small cell lung cancer (NSCLC).

In preclinical studies, A400 (EP0031) demonstrated favorable inhibitory activity against key RET kinases in-vitro and in-vivo. A400 (EP0031) also demonstrated good penetration of the blood brain barrier in animal models.

Data shared at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting on A400 (EP0031) showed promising anti-tumor efficacy in patients with advanced RET+ solid tumors, highlighted by ORR of 80.8% and 69.7% for 1L and 2L+ advanced RET+ NSCLC, respectively, based on results from its ongoing Phase 1/2 trial. In both cases, DCR of over 96% were reported.

According to the information published on the website of ASCO, clinical data from the Phase 1 dose escalation and expansion study of A400 (EP0031) in patients with SRI-naïve or pretreated advanced RET-altered NSCLC and other tumors will be presented by our partner Ellipses at the 2024 ASCO Annual Meeting on June 3, 2024, local time.

Kelun-Biotech is committed to developing innovative drugs in response to global unmet clinical needs. The company will also accelerate the development of the drug in China and work with our partner Ellipses to advance the global development and commercialization of A400 (EP0031) for the benefit of more oncology patients around the world.

About Ellipses Pharma Limited

Ellipses Pharma is a global drug development company based in London, focused on accelerating the development of cancer treatments through an innovative drug development model that combines unbiased vetting to de-risk initial asset selection with an uninterrupted funding flow to minimise the time it takes to advance lead products through clinical trials and reach patients.

About Kelun-Biotech

Kelun-Biotech(6990.HK)is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. The company focuses on major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. The Company is committed to becoming a leading global enterprise in the field of innovative drugs. At present, the Company has 33 ongoing innovative projects in major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, including 14 projects in the clinical stage with several global trials being conducted simultaneously in multiple countries, including China, Europe, and the United States. The company has established one of the world’s leading proprietary ADC platforms, OptiDC, and has four ADC projects in the clinical stage (two of which are in the Phase III or NDA stage) and several projects in the preclinical stage. For more information, please visit

Business Development Team

Monday, May 6, 2024

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