SHANGHAI, September 13, 2026—Hansoh Pharmaceutical Group Co., Ltd. (Hansoh Pharma, 03692.HK) Hansoh Pharma today presented the interim analysis results from the Phase 3 ARTEMIS-008 study of risvutatug rezetecan (HS-20093/GSK57642227, or Ris-Rez) as a Late-Breaking Abstract (LBA) during the first Presidential Symposium at the 2026 World Conference on Lung Cancer (WCLC). The study evaluated Ris-Rez versus standard-of-care topotecan in patients with relapsed SCLC following failure of platinum-based therapy. At the prespecified interim analysis, the study met its primary endpoint of OS, demonstrating a statistically significant and clinically meaningful improvement in survival.

Ris-Rez is a proprietary B7-H3-directed antibody-drug conjugate (ADC) independently developed by Hansoh Pharma. It consists of a fully human anti-B7-H3 monoclonal antibody conjugated to a topoisomerase I inhibitor (TOP1i) payload through a cleavable tetrapeptide linker. Ris-Rez is currently being evaluated globally in pivotal Phase 3 studies in non-small cell lung cancer (NSCLC), osteosarcoma, prostate cancer and esophageal cancer. On September 2, 2026, the biologics license application for Ris-Rez for the treatment of SCLC was accepted by the National Medical Products Administration (NMPA) of China. The biologics license application (BLA) for Ris-Rez for the treatment of SCLC following failure of prior platinum-based chemotherapy has also been granted Priority Review by the NMPA. To date, Ris-Rez has received 13 regulatory designations, including Breakthrough Therapy Designation and Orphan Drug Designation, across China, the United States, Japan, and Europe.

The interim results from ARTEMIS-008 presented at WCLC 2026 demonstrated a statistically significant and clinically meaningful improvement in OS with Ris-Rez versus topotecan, making ARTEMIS-008 the first randomized Phase 3 study globally to demonstrate an OS benefit with a B7-H3-directed ADC in SCLC. Ris-Rez is also the first and only B7-H3-directed ADC to demonstrate a statistically significant survival benefit across multiple tumor types. With positive Phase 3 results now established, Ris-Rez has reached a key milestone in the clinical development of B7-H3-directed ADCs, advancing from clinical study toward regulatory submission in China. Hansoh Pharma is continuing to advance development of Ris-Rez across multiple tumor types, with the goal of bringing innovative treatment options developed in China to patients worldwide. GSK holds exclusive rights to develop and commercialize Ris-Rez outside mainland China, Hong Kong, Macau and Taiwan, and is advancing a broad global clinical development program across lung cancer, prostate cancer and other solid tumors.

LBA presentation details:

● Presentation Title: Risvutatug Rezetecan (a B7-H3-Directed ADC) Versus Topotecan in Relapsed SCLC: Primary Results of Phase 3 ARTEMIS-008

● Session: Presidential Symposium

● Abstract No.: PL02.04

● Date/Time: September 13, 2026 at 9:11-9:21 AM KST / UTC +9

● Presenter: Pro. Jie Wang/Cancer Hospital Chinese Academy of Medical Science

About the ARTEMIS-008 Study

ARTEMIS-008 is a randomized, open-label, Phase 3 study in which 461 patients were randomized 1:1 to receive risvutatug rezeteccan or topotecan. The prespecified interim analysis, reviewed by the Independent Data Monitoring Committee (IDMC), confirmed that the study met its primary endpoint. As of June 6, 2026 (median follow-up: 12.2 months): 

Efficacy

◆ Overall survival: Median OS was 18.5 vs. 10.3 months (HR=0.46; 95% CI: 0.35-0.62; p＜0.001), a 54% reduction in the risk of death; 12-month OS rates were 64.5% vs. 43.3%. Benefit was consistent across all prespecified subgroups, including platinum sensitivity, brain metastases, prior PD-(L)1 inhibitor use, and disease stage.

◆ Progression-free survival: Median PFS was 7.2 vs. 3.0 months (HR=0.33; 95% CI: 0.25-0.42).

◆ Tumor response: ORR was 58.3% vs. 12.6%, DCR 90.4% vs. 60.2%, and median duration of response 6.9 vs. 5.6 months. 

Safety

◆ Ris-Rez showed a more favorable safety profile than topotecan: Grade ≥3 treatment-related adverse events (TRAEs) occurred in 60.9% vs. 78.2% of patients, and hematologic toxicities were substantially lower — notably Grade ≥3 platelet count decreases (13.9% vs. 59.7%). Fatal hematologic events occurred only in the topotecan arm; discontinuation or death due to TRAEs was comparable between arms.

◆ The incidence of interstitial lung disease (ILD) events was consistent with the known safety profile of Ris-Rez; most events were Grade 1-2 and resolved with symptomatic management. No Grade 4 or fatal ILD events were reported.

Ris-Rez has reached an important regulatory milestone with the acceptance of its biologics license application by the NMPA, while multiple Phase 3 clinical studies are underway. Guided by unmet patient needs, Hansoh Pharma will continue to advance the clinical development of Ris-Rez across multiple tumor types, aiming to help accelerate the global availability of innovative treatments originating from China that may provide patients worldwide with more effective and accessible treatment options.

About Small Cell Lung Cancer

In 2022, an estimated 1.06 million new cases of lung cancer and 733,300 lung cancer-related deaths were reported in China, making lung cancer the most common cancer and the leading cause of cancer-related mortality in the country ^[1]. Small cell lung cancer (SCLC) accounts for approximately 10%~15% of all lung cancer cases ^[2] and is characterized by its highly aggressive nature, early development of widespread metastases, high risk of recurrence, and poor prognosis ^[3].

SCLC is broadly classified into limited-stage disease (LS-SCLC) and extensive-stage disease (ES-SCLC). Treatment for LS-SCLC may include surgery and concurrent chemoradiotherapy; however, the 5-year survival rate remains only approximately 30%~35% ^[4]. Approximately 60%~70% of patients with SCLC are diagnosed with extensive-stage disease, for which palliative systemic therapy, primarily chemotherapy, is the mainstay of treatment. Patients with ES-SCLC have a particularly poor prognosis, with a median overall survival of only 7~12 months ^[5] and a 2-year survival rate of approximately 22% ^[6], underscoring the high unmet medical need and the urgency of developing innovative therapies.

References

[1] Zheng RS, Chen R, Han BF, et al. Cancer incidence and mortality in China, 2022. Chinese Journal of Oncology. 2024;46(3):221-231.

[2] Kim SY, Park HS, Chiang AC. Small Cell Lung Cancer: A Review. JAMA. 2025 Jun 3;333(21):1906-1917.

[3] Rudin CM, Brambilla E, Faivre-Finn C, Sage J. Small-cell lung cancer. Nat Rev Dis Primers. 2021;7(1):3.

[4] Higgins KA, Gorgens S, Sudmeier LJ, Faivre-Finn C. Recent developments in limited stage small cell lung cancer. Transl Lung Cancer Res. 2019;8(Suppl 2): S147-S152.

[5] Wang S, Zimmermann S, Parikh K, Mansfield AS, Adjei AA. Current Diagnosis and Management of Small-Cell Lung Cancer. Mayo Clin Proc. 2019;94(8):1599-1622.

[6] Rudin CM, Brambilla E, Faivre-Finn C, Sage J. Small-cell lung cancer. Nat Rev Dis Primers. 2021;7(1):3.