SK Biopharm said on the 12th that it received U.S. Food and Drug Administration (FDA) approval for an investigational new drug (IND) application for a phase 1 clinical trial of the radiopharmaceutical (RPT) therapy "SKL35501" and the imaging diagnostic agent "SKL35502." It is the first among domestic corporations to receive FDA phase 1 IND approval for an alpha-emitter–based RPT new drug.
RPT is a treatment that directly attacks cancer cells using radioactive substances. Among these, alpha emitters have very short radiation range but high energy, which can destroy cancer cell DNA while minimizing damage to surrounding normal tissue. With higher target specificity than conventional radiation therapy, it is drawing attention as a next-generation anticancer technology.
Based on this approval, SK Biopharm is pursuing global clinical development centered on the United States while also submitting the same clinical trial protocol to the Ministery of Food and Drug Safety for review. The company plans to conduct trials in the United States and Korea in parallel to speed up development.
Phase 1 targets patients with advanced solid tumors that highly express a specific receptor called "NTSR1." The main subjects are patients who did not respond to existing treatments or who relapsed. As the first-in-human trial conducted simultaneously at multiple hospitals in Korea and the United States, it will initially assess safety and the appropriate dose, and then expand the trial focusing on cancer types where effects are observed.
The therapy "SKL35501" is designed to bind to NTSR1, which is highly expressed in cancer cells, and deliver alpha particles from the radionuclide actinium-225 intensively to tumor tissue. Through this, it is expected to enhance treatment efficacy while reducing damage to normal tissue.
SK Biopharm will also apply a strategy that uses the imaging diagnostic agent "SKL35502." First, it will use the diagnostic drug to confirm NTSR1 expression, and then administer the therapy to the corresponding patient. This is a "theranostics" strategy that uses a single target for both diagnosis and treatment, allowing a more precise assessment of treatment response.
In Jul. 2024, SK Biopharm entered the RPT field for the first time by in-licensing the pipeline from the global corporations Full-Life Technologies. Since then, it has built a foundation covering research and development and raw material procurement by bringing in additional pipelines and signing raw material supply contracts with radionuclide production corporations in the United States, Belgium, and Germany.
Lee Dong-hoon, SK Biopharm's president, said, "With this FDA clinical approval, we are set to accelerate global clinical development in radiopharmaceuticals," and added, "Alongside our existing central nervous system (CNS) business, we plan to grow RPT into a next-generation anticancer growth pillar."