● Mocertatug rezetecan (HS-20089,a B7-H4-Targeted ADC), as monotherapy and in combination with bevacizumab, showed anti-tumor activity with a manageable safety profile in heavily pre-treated patients with platinum-sensitive ovarian cancer (PSOC) .
February 28 2026, Shanghai, China
Hansoh Pharmaceutical Group Co., Ltd. (“Hansoh Pharma,” 03692.HK) today announced the presentation of data from two clinical studies evaluating mocertatug rezetecan (HS-20089 / GSK5733584) at the 27th European Society of Gynaecological Oncology Congress (ESGO 2026), held February 26–28, 2026, in Copenhagen, Denmark.
Mocertatug rezetecan is a B7-H4-targeted antibody–drug conjugate (ADC) under clinical development for gynaecological cancers, including endometrial and.ovarian cancers. At ESGO 2026, data were presented evaluating mocertatug rezetecan administered as monotherapy and in combination with bevacizumab in patients with platinum-sensitive ovarian cancer (PSOC). Across the two studies, mocertatug rezetecan showed anti-tumor activity with a safety profile consistent with previous studies.
The data were generated from two open-label studies.
· HS-20089-201, a Phase 2 study, evaluating the efficacy, safety, pharmacokinetics, and immunogenicity of mocertatug rezetecan in Chinese patients with recurrent or metastatic ovarian and endometrial cancer. Results from the PSOC cohort were presented as a poster.
· HS-20089-103, a Phase 1 study, evaluating combination regimens of mocertatug rezetecan in advanced solid tumors.Data from the PSOC cohort receiving mocertatug rezetecan in combination with bevacizumab were selected for presentation as a Late-Breaking Abstract (LBA) mini-oral session.
These findings contribute to the broader understanding and potential value of topoisomerase 1 inhibitor ADCs in platinum sensitive ovarian cancer, where long-term clinical data remain limited.
In addition, previously reported data presented at the 2025 ESMO Congress and the 2025 International Gynecologic Cancer Society (IGCS) Annual Meeting showed anti-tumor activity of mocertatug rezetecan in platinum-resistant ovarian cancer (PROC)[1-2]. A Phase 3 clinical study in patients with PROC is ongoing in China (NCT06855069) and a GSK-led global Phase 3 study (NCT07286266) will be initiated in early 2026.
The details are as follows:
1、Poster
◆ Presentation Title: Mocertatug rezetecan, a B7-H4 targeted antibody drug conjugate, in patients with heavily pretreated platinum-sensitive ovarian cancer (PSOC): results of an open label, phase 2 study
◆ Presenting Session: Poster Walks
◆ Abstact No: #76/P06-01
◆ Presentation time: February 27, 2026 17：20-18:20(CET)
◆ Presenter: Guangwen Yuan（National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing,China）
◆ Results:
· Mocertatug rezetecan monotherapy demonstrated promising and durable antitumor activity in heavily pretreated patients with PSOC. At a median follow-up of 16.6 (range: 0.8, 19.1) months, 3 patients achieved completed response(CR), resulting in a confirmed overall response rate (cORR) of 64.5% . The median duration of Response (mDoR) was 13.8 months and the median progression-free survival (mPFS) was 14.1 months.
· Mocertatug rezetecan monotherapy demonstrated a manageable safety profile in PSOC, consistent with prior clinical experience. The most common grade ≥3 TEAEs were hematologic laboratory abnormalities, primarily decreased neutrophil count, decreased white blood cell count, and anaemia.
2、LBA-mini oral
◆ Presentation Title: Mocertatug rezetecan, a B7-H4-targeted antibody-drug conjugate, in combination with bevacizumab in patients with platinum-sensitive ovarian cancer: results from a phase 1 study
◆ Presenting Session: Mini Oral Session 3: Ovarian Cancer
◆ Abstract No: #202/MO3-8
◆ Presentation time: February 27, 2026, 14:55- 15:55 PM(CET)
◆ Presenter: Changyu Wang(Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China）
◆ Results:
· Mocertatug rezetecan in combination with bevacizumab demonstrated promising antitumor activity in patients with PSOC. At a median follow-up of 3.9 (range: 2.8, 8.3) months, 26 patients achieved a confirmed complete response (CR) or partial response (PR), resulting in a confirmed overall response rate (cORR) of 72.2%. Two additional patients had an unconfirmed PR, and the rest 8 patients achieved stable disease (SD) with tumor shrinkage.
· The observed safety profile of mocertatug rezetecan in combination with bevacizumab in patients with PSOC was manageable and was consistent with the known safety profiles previously reported for both mocertatug rezetecan and bevacizumab. No new or overlapping toxicity was observed.
About mocertatug rezetecan
Mocertatug rezetecan is a B7-H4–targeted antibody–drug conjugate (ADC) discovered and developed by Hansoh Pharma for the treatment of ovarian cancer and other solid tumors. The programme has entered Phase 3 clinical development in China for platinum-resistant ovarian cancer and is also being evaluated in studies for endometrial cancer and other solid tumors.
In October 2023, Hansoh Pharma granted GSK an exclusive worldwide license, excluding China’s mainland, Hong Kong, Macau and Taiwan. GSK is advancing global development through the BEHOLD programme that includes the Phase 1/2 BEHOLD-1 (NCT06431594) and BEHOLD-2 (NCT06796907) studies. GSK will initiate multiple Phase 3 trials in ovarian and endometrial cancers in 2026, including the BEHOLD Ovarian01 study (NCT07286266) and BEHOLD-Endometrial01 (NCT07286331).In May 2025, mocertatug rezetecan received Breakthrough Therapy Designation from the National Medical Products Administration (NMPA) for platinum-resistant recurrent epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer.
About Platinum Sensitivet Ovarian Cancer
Ovarian cancer (OC) is one of the most prevalent gynecological malignancies. In 2022, approximately 324,603 new cases of ovarian cancer were diagnosed worldwide, making it the eighth most common malignancy among women. With around 206,956 deaths that year, ovarian cancer was the eighth leading cause of cancer-related mortality among female patients.
In China, the incidence in 2022 was 61,060, with a mortality of 32,646[3] PSOC is primarily treated with platinum-based chemotherapy, either alone or in combination with bevacizumab[4], achieving a high initial response rate. Platinum-based therapy becomes less effective with successive recurrences[5], cumulative toxicities[6], and prior exposure to PARP inhibitors[7], highlighting the need for more effective and tolerable therapies.
About Hansoh Pharma
Hansoh Pharma is a leading innovation-driven pharmaceutical enterprise headquartered in China. With the mission of "continuous innovation for better life", the company focuses on major disease therapeutic areas such as oncology, anti-infectives, central nervous system (CNS), metabolism and autoimmunity. Hansoh Pharma has launched 7 innovative drugs that generate product sales in China, with the revenue from innovative drugs and collaborative products exceeding 80%, forming a rich product pipeline. The company has consistently ranked among the top 100 global pharmaceutical companies and is recognized as one of the top 3 pharmaceutical R&D enterprises in China, and is designated as a National Key High-Tech Enterprise and a National Technology Innovation Demonstration Enterprise. Hansoh Pharma was listed on the Hong Kong Stock Exchange in June 2019 (stock code: 03692.HK).
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References
1. ESMO 2025 | HANSOH PHARMA PRESENTS THE PHASE 2 STUDY FINDINGS OF HS-20089 (B7-H4-TARGETED ADC), IN PATIENTS WITH PLATINUM-RESISTANT OVARIAN CANCER (PROC)-Press Releases-Hansoh Pharmaceutical Group Co., Ltd.
2. HANSOH PHARMA ANNOUNCES ORAL PRESENTATION OF PHASE 2 STUDY FINDINGS OF HS-20089 (B7-H4 ADC) IN PLATINUM-RESISTANT OVARIAN CANCER AT IGCS 2025-Press Releases-Hansoh Pharmaceutical Group Co., Ltd.
3. International Agency for Research on Cancer. (2024). Cancer TODAY: GLOBOCAN 2022 (version 1.1). Retrieved April 26, 2025, from Global Cancer Observatory
4. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology: Ovarian Cancer Including Fallopian Tube Cancer and Primary Peritoneal Cancer. Version 2.2025.
5. Kessous, R, et al. Int J Cancer. 2021; 148:2304-2312.
6. Tsao, L.R, et al. Clin Rev Allergy Immunol. 2022; 62:432-448.
7. P Harter, et al. Ann Oncol. 2025 Feb;36(2):185-196.
