GSK’s Risvutatug Rezetecan Receives Orphan Drug Designation for Small-Cell Lung Cancer in Japan

GSK plc has announced that its investigational B7-H3-targeted antibody-drug conjugate (ADC), risvutatug rezetecan (Ris-Rez), has been granted Orphan Drug Designation (ODD) by Japan’s Ministry of Health, Labour and Welfare for the treatment of small-cell lung cancer (SCLC).

The designation is supported by early clinical data from the phase I ARTEMIS-001 trial, which demonstrated durable responses in patients with extensive-stage SCLC (ES-SCLC). This marks the sixth regulatory designation for Ris-Rez, which is being explored across multiple solid tumours, including lung, prostate, and colorectal cancers.

Lung cancer is the second most common cancer in Japan, with SCLC accounting for approximately 10–15% of cases. Among these, around 70% are classified as extensive-stage disease, where the cancer has spread within the lungs or to other parts of the body.

ES-SCLC remains a highly aggressive and difficult-to-treat condition, characterised by high relapse rates, limited treatment options, and poor long-term survival. Most patients experience disease progression following initial therapy, with median overall survival under current standard-of-care treatments estimated at around eight months.