GSK secures Japan orphan drug designation for risvutatug rezetecan advancing treatment options in small-cell lung cancer

GSK secures Japan orphan drug designation for risvutatug rezetecan advancing treatment options in small-cell lung cancer

(IN BRIEF) GSK plc has received Orphan Drug Designation in Japan for its investigational antibody-drug conjugate risvutatug rezetecan (Ris-Rez) for the treatment of small-cell lung cancer, supported by early clinical data showing durable responses in patients with extensive-stage disease. SCLC, particularly in its extensive stage, is associated with high relapse rates, limited treatment options, and poor survival outcomes, highlighting the need for new therapies. Ris-Rez, which targets the B7-H3 protein, represents a novel approach designed to deliver targeted cancer treatment while minimizing systemic impact. The therapy is currently in a global phase III trial and has already received multiple regulatory designations worldwide, including from the FDA and EMA. This latest designation further reinforces the potential of Ris-Rez as part of GSK’s oncology pipeline aimed at addressing unmet needs across several solid tumour types.

(PRESS RELEASE) LONDON, 23-Mar-2026 — /EuropaWire/ — GSK plc has announced that its investigational therapy risvutatug rezetecan (Ris-Rez), a B7-H3-targeted antibody-drug conjugate, has been granted Orphan Drug Designation 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 findings demonstrating sustained responses in patients with extensive-stage small-cell lung cancer (ES-SCLC) who were treated with Ris-Rez in the phase I ARTEMIS-001 study. This marks the sixth regulatory recognition for the therapy as GSK continues to advance its development across multiple solid tumour indications.

Lung cancer remains one of the most prevalent cancers in Japan, with SCLC accounting for approximately 10 to 15 percent of cases. A significant proportion of these patients—around 70 percent—are diagnosed with extensive-stage disease, where the cancer has spread within the lungs or to other parts of the body. ES-SCLC is known for its aggressive progression, high relapse rates, and limited treatment options, with standard therapies offering a median overall survival of about eight months.

Ris-Rez is designed as a next-generation antibody-drug conjugate targeting the B7-H3 protein, combining a fully human monoclonal antibody with a topoisomerase inhibitor payload. This approach aims to deliver targeted treatment directly to cancer cells while minimizing damage to healthy tissue. GSK obtained exclusive global rights to develop and commercialize the therapy—excluding certain regions in China—through an agreement with Hansoh Pharma.

The therapy is currently being evaluated in a global phase III clinical trial for patients with relapsed ES-SCLC, which commenced in August 2025. In addition to the recent designation in Japan, Ris-Rez has received multiple regulatory recognitions worldwide, including Orphan Drug Designations from the US Food and Drug Administration for SCLC and from the European Medicines Agency for pulmonary neuroendocrine carcinoma. It has also been granted Priority Medicines designation by the EMA and Breakthrough Therapy Designations from the FDA for both relapsed ES-SCLC and osteosarcoma.

GSK continues to position Ris-Rez as a promising candidate within its oncology pipeline, with potential applications across several solid tumour types, including lung, prostate, and colorectal cancers. The company’s broader strategy focuses on combining scientific innovation with advanced technologies to address significant unmet medical needs in oncology and improve outcomes for patients facing difficult-to-treat cancers.

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

About GSK

GSK is a global biopharma company with a purpose to unite science, technology, and talent to get ahead of disease together. Find out more at www.gsk.com.

Cautionary statement regarding forward-looking statements

GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Such factors include, but are not limited to, those described in the “Risk Factors” section in GSK’s Annual Report on Form 20-F for 2025.

References

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/.

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SOURCE: GlaxoSmithKline plc