On November 22, Ascent Pharmaceuticals announced that the European Commission has recently granted the company a Class 1 new drug Oribatinib (HQP1351) orphan drug designation for the treatment of chronic myeloid leukemia (CML).

CML is a rare hematological malignant disease with an annual incidence rate of 2.43/10000 in the 27 EU countries. With the launch of tyrosine kinase inhibitors (TKI) targeting BCR-ABL, the treatment of CML has been innovated. Although the first and second generation drugs BCR-ABL TKI have significant clinical benefits for the treatment of CML, acquired resistance has always been the main challenge for the treatment of CML.

Mutations in the kinase region of BCR-ABL are one of the important mechanisms of acquired drug resistance. Among them, T315I mutation is one of the common types of drug-resistant mutations, and the incidence in drug-resistant CML can reach about 25%. CML patients with T315I mutation are resistant to all current first- and second-generation BCR-ABL inhibitors. Therefore, there is an urgent clinical need for a third-generation BCR-ABL inhibitor that can effectively treat T315I mutant CML.