Radotinib (INN; trade name Supect), also known by its investigational code IY5511, is an oral Bcr-Abl tyrosine-kinase inhibitor used in the treatment of Philadelphia chromosome–positive (Ph⁺) chronic myeloid leukemia (CML). It was developed by Il-Yang Pharmaceutical Co., Ltd (South Korea) and is marketed domestically by Daewoong Pharmaceutical Co., Ltd. Radotinib was approved in South Korea in 2012 for patients with resistance or intolerance to other tyrosine kinase inhibitors such as imatinib.

Radotinib is indicated for the treatment of adult patients with Ph+ CML in the chronic phase who are resistant or intolerant to prior therapy with first-generation tyrosine kinase inhibitors such as imatinib. Its use remains limited to South Korea, where it is prescribed under the brand name Supect.

Radotinib is a selective inhibitor of the Bcr-Abl tyrosine kinase, the abnormal fusion protein expressed in Ph⁺ CML. It also inhibits the platelet-derived growth factor receptor (PDGFR). By blocking Bcr-Abl–mediated signaling, radotinib suppresses proliferation of leukemic cells.

In 2011, Il-Yang initiated a Phase III, multinational, randomized study comparing radotinib with imatinib as first-line therapy in newly diagnosed Ph⁺ CML. A Phase II trial demonstrated efficacy and safety in patients resistant or intolerant to other Bcr-Abl inhibitors, with major cytogenetic response rates comparable to second-generation drugs such as nilotinib.

Common adverse effects observed in clinical studies included hematologic toxicities (thrombocytopenia, neutropenia, anemia), gastrointestinal events, and elevations in liver transaminases.

Radotinib received regulatory approval in South Korea in 2012. As of 2025, it has not been approved by the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA).