Merck (MRK.US) has started a phase 3 clinical trial of its small-molecule cancer drug in China, worth over $1.3 billion.

According to the latest announcement on the China Drug Clinical Trial Register and Information Disclosure Platform, Merck & Co., Inc. (MRK.US) has launched a Phase 3 clinical trial for its oral 1st-in-class drug MK-3543 (bomedemstat) for the treatment of essential thrombocythemia. Bomedemstat is an oral lipoxygenase-like 1 (LSD1) inhibitor, which Merck acquired from Imago BioSciences for approximately $1.35 billion in 2022, thus obtaining the lead candidate drug.

LSD1 is a lysosomal protein that functions as a demethylase. It is overexpressed in many types of cancer, leading to increased cellular differentiation, proliferation, migration, and invasiveness. Bomedemstat is one of the faster-moving products in the field of LSD1-targeted inhibitors. The product was originally developed by Imago BioSciences, and Merck acquired Imago for approximately $1.35 billion in 2022, thus obtaining the lead candidate drug.

In nonclinical studies, bomdemstat demonstrated robust anti-tumor activity in a range of myeloid malignancies. The product has also been granted orphan drug designation and fast track designation by the US FDA for the treatment of essential thrombocythemia (ET) and myelofibrosis (MF), respectively.

Public information shows that Merck is conducting a pivotal Phase 3 randomized clinical trial to evaluate the efficacy of bomdemstat in treating patients with essential thrombocythemia. The launch of this Phase 3 study in China indicates that the drug will also be studied in a Chinese patient population for its efficacy and safety.