Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. has announced that its new drug application for the small molecule rearranged during transfection (RET) kinase inhibitor A400, also known as EP0031, has been accepted for review by the National Medical Products Administration (NMPA) of China. The drug is intended for the treatment of adult patients with RET-fusion positive locally advanced or metastatic non-small cell lung cancer (NSCLC). This acceptance is based on positive results from two pivotal Phase 2 cohorts of the KL400-I/II-01 study. The results from the Phase 1 study of A400/EP0031 in patients with advanced RET-mutant medullary thyroid carcinoma $(MTC)$ were presented at the 2025 ASCO Annual Meeting. Additionally, the drug was granted Fast Track designation by the FDA in March 2024 and cleared for Phase 2 clinical development in April 2024, with trials now open in the United States, United Kingdom, Europe, and United Arab Emirates.