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CHENGDU, China, Sept. 23, 2025 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the "Company") announced that a new drug application (NDA) for the Company's small molecule rearranged during transfection (RET) kinase inhibitor A400 (also known as EP0031) was accepted for review by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China for the treatment of adult patients with RET-fusion positive locally advanced, or metastatic non-small cell lung cancer (NSCLC). This acceptance for review is based on the positive results from the two pivotal Phase 2 cohorts of the KL400-I/II-01 study for both 1L and 2L+ advanced RET-fusion positive NSCLC.

Cohort 1 and 2, the Phase 2 stage of the KL400-I/II-01 study, evaluate the efficacy and safety of A400/EP0031 90mg orally once daily (QD) for the treatment of patients with pre-treated and treatment-naïve RET-fusion positive locally advanced, or metastatic NSCLC, respectively. Primary efficacy endpoints of the two pivotal cohorts were reached, where A400/EP0031 demonstrated favorable efficacy in pretreated and treatment-naïve NSCLC including patients with prior immunotherapy or brain metastases. A400/EP0031 also demonstrated an encouraging, manageable tolerability and safety profile.

Dr. Michael Ge, CEO of Kelun-Biotech said, "We are 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 tumor agnostic precision therapy, A400/EP0031 represents our significant strategic positioning in the solid tumor field. We look forward to working closely with regulatory authorities to expedite the review process for A400/EP0031, bringing this innovative therapy to patients with RET-fusion positive NSCLC as soon as possible."

About RET-fusion positive NSCLC

RET gene fusions represent one of the rare yet significant driver mutation types in NSCLC. In Chinese NSCLC patients, the incidence of RET gene fusions ranges from 1.4% to 2.5%[1]. Patients with RET fusions derive limited benefit from conventional treatments. In recent years, the emergence of novel highly selective inhibitors has led to breakthroughs in the clinical management of advanced RET-fusion positive NSCLC patients. However, their therapeutic benefits are limited, in part, by acquired RET drug-resistant mutations and safety issues such as hypertension and hematological toxicity, underscoring the need for novel selective RET inhibitors with improved safety and better efficacy against drug-resistant mutations.

About A400/EP0031

A400/EP0031 is a novel next-generation selective RET inhibitor for NSCLC, medullary thyroid cancer (MTC) and other solid tumors with a high prevalence of RET alterations. The Company is currently conducting a phase 1b/2 clinical study for RET+ MTC and solid tumor in China. The results from the Phase 1 study of A400/EP0031 in patients with advanced RET-mutant MTC were presented at the 2025 ASCO Annual Meeting.

In March 2021, the Company granted Ellipses Pharma Limited, a U.K.-based international oncology drug development company, an exclusive license to develop, manufacture and commercialize this agent outside Greater China and certain Asian countries under the code EP0031.

In March 2024, it was announced that EP0031/A400 was granted Fast Track designation by the Food and Drug Administration (FDA) for the treatment of RET-fusion positive NSCLC. In April 2024, EP0031/A400 was cleared by the FDA to progress into Phase 2 clinical development and is now open in the United States, United Kingdom, Europe and United Arab Emirates.

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 more than 30 ongoing key innovative drug projects, of which 3 projects have been approved for marketing, 2 projects are in the NDA stage and more than 10 projects are in the clinical stage. The company has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 1 ADC project approved for marketing, 1 ADC project in NDA stage and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://kelun-biotech.com/

Kelun-Biotech announces that KL590586 (EP0031) (small molecule RET kinase inhibitor, also named A400) program, licensed to global ex-China partner Ellipses Pharma, has been granted Orphan Drug Designation (ODD) by the US Food and Drug Administration (FDA) for the treatment of RET fusion-positive solid tumors.

Orphan drugs are drugs used for the prevention, treatment and diagnosis of rare diseases. The FDA grants ODD for investigational treatments for rare diseases, such as RET fusion-positive solid tumours, defined as affecting fewer than 200,000 people in the United States. The designation is an important milestone in the development of innovative drugs, it is expected to accelerate the progress of clinical trials in the United States. ODD qualifies the developer for certain incentives with the goal of accelerating drug development for patients, including tax credits and seven years of market exclusivity in the US upon approval by the FDA.

A400 (EP0031) is a next generation selective RET inhibitor (SRI) with broad activity against common RET fusions and mutations. Therefore, A400 (EP0031) may overcome resistance mechanisms to first generation SRIs. In preclinical studies, A400 (EP0031) demonstrated favourable 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. At present, Kelun-Biotech is conducting A400 (EP0031) pivotal clinical study in China for RET-positive non-small cell lung cancer.

In March 2021, Kelun-Biotech granted Ellipses an exclusive license for A400 (EP0031) in certain territories including the US and Europe, with Kelun-Biotech retaining certain rights in Greater China and parts of the Asia-Pacific region such as Korea, Singapore, Malaysia.

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

About RET altered malignancies

RET fusions and mutations are present in a wide range of tumors, including non-small cell lung cancer, medullary thyroid cancer and other types of thyroid cancer, as well as colorectal cancer, so targeting RET gene changes is promising as a treatment for all types of cancer. However, for patients with RET gene alteration, the effect of traditional chemotherapy and immunotherapy is limited, especially for patients with drug resistance after first-generation SRI treatment, the acceptable treatment options are limited, and the prognosis is poor, and there are still unmet clinical needs.

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 establishing an globalized drug development and industrialization platform for the unmet medical needs in China and worldwide. The Company is committed to becoming an leading global enterprise in the field of innovation drugs.

At the 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 multiple global trials conducted simultaneously in several regions including China, Europe, and the United States. The company has established one of the world’s leading in-house developed ADC platform, OptiDC, and has four ADC projects in the clinical stage (two of which are in the phase III or NDA stage, respectively) and several projects in the preclinical stage.

For more information, please visit https://kelun-biotech.com/.

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. For more information, please visit www.ellipses.life

Kelun-Biotech announced that the U.S. Food and Drug Administration (FDA) has recently approved the Investigational New Drug Application (IND) of the company’s small molecule RET kinase inhibitor A400 (KL590586) submitted by its collaboration partner Ellipses Pharma (internally named EP0031) for RET gene mutated malignant tumors. The approval is a key step for A400/EP0031 to start a global Phase I/II clinical study.

A400/EP0031 is a next-generation highly specific small-molecule RET kinase inhibitor (SRI). Kelun-Biotech has initiated the clinical study of A400/EP0031 in China and is currently in the dose-escalation stage. This approved Phase I/II clinical study in the U.S. will recruit patients with thyroid cancer and non-small cell lung cancer patients with RET gene mutation, including those who have previously received treatment with first-generation RET inhibitors. The safety, tolerability, and efficacy of A400/EP0031 will be evaluated.

The study is planned to be conducted at sites in the United States and Europe, with the first patient in the dose-escalation phase expected to complete enrollment in the third quarter of 2022. In addition, Ellipses Pharma will soon submit applications to regulators in the U.K. and E.U. to accelerate the launch of clinical research centers outside the U.S.

KLUS Pharma, Business Development
Kelun-Biotech, Business Development

Tuesday, June 28, 2022