GSK plc (LON:GSK, NYSE: GSK) has announced that risvutatug rezetecan (or Ris-Rez, for short), a B7-H3-targeted antibody-drug conjugate (ADC), has received Orphan Drug Designation (ODD) from Japan’s Ministry of Health, Labour and Welfare for the treatment of small-cell lung cancer (SCLC). The ODD was supported by preliminary clinical data showing durable responses in patients with extensive-stage SCLC (ES-SCLC) who were treated with Ris-Rez in the phase I ARTEMIS-001 clinical trial.[1] This is the sixth regulatory designation for Ris-Rez, which is being developed in a range of solid tumours, including lung, prostate and colorectal cancers.
Lung cancer is the second most common cancer in Japan, and SCLC makes up 10-15% of cases.[2],[3] Of patients with SCLC, 70% have ES-SCLC, meaning the cancer has spread throughout one or both lungs and/or to other parts of the body.[4] ES-SCLC is an aggressive and difficult-to-treat cancer with limited treatment options and poor long-term survival. Most patients with ES-SCLC relapse after initial treatment and the median overall survival with standard-of-care for these patients is approximately 8 months.[5]
About Ris-Rez
Ris-Rez is a novel investigational B7-H3-targeted antibody-drug conjugate composed of a fully human anti-B7-H3 monoclonal antibody covalently linked to a topoisomerase inhibitor payload. GSK acquired exclusive worldwide rights (excluding China’s mainland, Hong Kong, Macau, and Taiwan) from Hansoh Pharma to progress clinical development and commercialisation of Ris-Rez. GSK’s global phase III trial (NCT07099898) for Ris-Rez in relapsed ES-SCLC began in August 2025.
Regulatory designations received for Ris-Rez to date include ODDs from the US Food and Drug Administration (FDA) in SCLC and the European Medicines Agency (EMA) in a category of cancer that includes SCLC, called pulmonary neuroendocrine carcinoma; Priority Medicines (PRIME) Designation from the EMA for relapsed or refractory ES-SCLC; and Breakthrough Therapy Designations for relapsed or refractory ES-SCLC and relapsed or refractory osteosarcoma from the US FDA.[6],[7],[8]
[1] Wang J, et al. Presented at IASLC WCLC 2024.
[2] GLOBOCAN 2022 https://gco.iarc.who.int/media/globocan/factsheets/populations/392-japan-fact-sheet.pdf Accessed 9 March 2026
[3] Japan Lung Cancer Society. Lung Cancer Clinical Practice Guidelines 2025 Edition. Available at https://www.haigan.gr.jp/publication/guideline/examination/2025/
[4] SEER Explorer Surveillance Research Program, National Cancer Institute, accessed 27 October 2025.
[5] G. Mountzios, et al. Tarlatamab in small-cell lung cancer after platinum-based chemotherapy. N Engl J Med, 393 (2025), pp. 349-361. DOI: 10.1056/NEJMoa2502099
[6] GSK. GSK receives US FDA Breakthrough Therapy Designation for its B7-H3-targeted antibody-drug conjugate in relapsed or refractory extensive-stage small-cell lung cancer. Available at: https://www.gsk.com/en-gb/media/press-releases/gsk-receives-us-fda-breakthrough-therapy-designation/.
[7] GSK. GSK’s B7-H3-targeted antibody-drug conjugate, GSK’227, receives EMA Priority Medicines (PRIME) Designation in relapsed extensive-stage small-cell lung cancer. Available at: https://www.gsk.com/en-gb/media/press-releases/b7-h3-targeted-antibody-drug-conjugate-receives-ema-priority-medicines-designation-in-relapsed-extensive-stage-small-cell-lung-cancer/.
[8] GSK. GSK’s B7-H3-targeted antibody-drug conjugate, GSK’227, receives US FDA Breakthrough Therapy Designation in late-line relapsed or refractory osteosarcoma. Available at: https://www.gsk.com/en-gb/media/press-releases/gsk-b7-h3-targeted-antibody-drug-conjugate-gsk227-receives-us-fda-breakthrough-therapy-designation-in-late-line-relapsed-or-refractory-osteosarcoma/.
