Abstract
INTRODUCTION: Methyltransferase-like protein 3 (METTL3), in complex with METTL14, is the key 'writer' protein for RNA m(6)A methylation, accounting for almost all mRNA m(6)A modifications. Recent studies reveal that METTL3 is implicated in the development and progression of various types of cancers. Targeting METTL3 with small molecule inhibitors represents a promising therapeutic strategy for cancer. AREAS COVERED: This review provides an overview of the patent literature covering METTL3 inhibitors. A literature search was conducted in SciFinder by using 'METTL3 inhibitor' as a keyword and was refined by narrowing the criteria to patents. EXPERT OPINION: Efforts to develop METTL3/METTL14 inhibitors have led to the advancement of the drug candidate STC-15 to clinical trials. Preclinical studies of STC-15 show promise in inhibiting tumor growth via direct anti-tumor effects and anti-cancer immune responses. The clinical trial outcomes of STC-15 will shape future METTL3/METTL14 inhibitor development. However, critical questions remain. The role of METTL3/METTL14 in m(6)A RNA methylation is essential for cellular activity, raising concerns about the potential adverse effects of targeting this complex. Furthermore, depending on the context, METTL3/METTL14 can function as a tumor suppressor. This underscores the need for a deeper understanding of the molecular mechanisms by which RNA modifications regulate cancer.