# Mabwell to Present Phase II Data for 9MW2821 in ADC-Pretreated Triple-Negative Breast Cancer at ESMO 2026 > Mabwell's Nectin-4 ADC 9MW2821 achieved a 30% objective response rate in 60 Topo I ADC-pretreated TNBC patients, with Phase II data set for ESMO 2026. - Published: 2026-10-19T02:30:06+00:00 - Section: Research & Clinical Trials - Author: News Desk - URL: https://newsforagent.com/news/2026-10-19/mabwell-9mw2821-tnbc-esmo-data - Source: [PR Newswire](https://www.prnewswire.com/news-releases/esmo-2026-preview--mabwell-to-present-clinical-results-for-nectin-4-targeting-adc-9mw2821-in-adc-pretreated-triple-negative-breast-cancer-302911988.html) ## Key takeaways - Mabwell's 9MW2821 produced a 30.0% objective response rate and 80.0% disease control rate in 60 efficacy-evaluable Topo I ADC-pretreated TNBC patients. - Median progression-free survival was 3.7 months and median duration of response was 8.7 months, with median overall survival not yet mature. - Four pivotal Phase III trials of 9MW2821 are underway, covering urothelial carcinoma, cervical cancer and Topo I ADC-pretreated TNBC. [Mabwell](https://akta.pro/company-profiles/0000ajs/mabwell-biotech) will present Phase II clinical data on its Nectin-4-targeting antibody-drug conjugate 9MW2821 in locally advanced or metastatic triple-negative breast cancer at the 2026 European Society for Medical Oncology Congress, the company said. The Shanghai-based biopharmaceutical company reported a 30.0% objective response rate among 60 efficacy-evaluable patients previously treated with a topoisomerase I inhibitor-payload ADC. ## Mabwell's 9MW2821 Phase II Results in TNBC According to [PR Newswire](https://www.prnewswire.com/news-releases/esmo-2026-preview--mabwell-to-present-clinical-results-for-nectin-4-targeting-adc-9mw2821-in-adc-pretreated-triple-negative-breast-cancer-302911988.html), the study (CTR20242376) evaluates 9MW2821 as monotherapy or combined with a PD-1 monoclonal antibody. As of April 10, 2026, the disease control rate was 80.0%, median progression-free survival was 3.7 months, and median duration of response was 8.7 months. Median overall survival was not yet mature, and no new safety signals were observed during the follow-up period. Mabwell said the results indicate a manageable safety profile and positive therapeutic effects. TNBC accounts for approximately 15% to 20% of all breast cancers, and all ADCs approved for TNBC use a topoisomerase I inhibitor payload. After progression on these agents, chemotherapy remains the mainstay of care. 9MW2821 is a Nectin-4-targeting ADC developed on Mabwell's proprietary platform, with cumulative clinical enrollment of over 2,200 patients across urothelial carcinoma, cervical cancer, TNBC and esophageal cancer. Four pivotal Phase III trials are underway, and the therapy has Breakthrough Therapy Designation from the Center for Drug Evaluation for urothelial carcinoma as monotherapy and in combination therapy. ## Mabwell's Hong Kong Listing and Funding History Mabwell is a public company founded in 2017 and headquartered in Shanghai, with an estimated 1,001 to 5,000 employees, according to [akta.pro company records](https://akta.pro/company-data). The company dual-listed on the Hong Kong Stock Exchange Main Board under ticker 02493.HK on April 28, 2026, following its 2022 Shanghai STAR Market IPO under 688062.SH, to accelerate ADC pipeline development and global commercialization. Its funding records show one round, a 2020-04 Series A of $278.5 million led by Shiyu Capital. ## Earlier Mabwell Clinical and Regulatory Milestones In September 2026, Mabwell presented Phase Ib/IIa results of its anti-ST2 antibody 9MW1911 in COPD patients at ERS 2026, showing 24% and 81% reductions in moderate-to-severe exacerbations at 600 mg and 900 mg doses, respectively, Gurufocus reported. In August 2026, Mabwell's wholly-owned subsidiary T-mab passed the Brazilian GMP inspection for its denosumab biosimilars 9MW0311 and 9MW0321, conducted by ANVISA, marking the company's second PIC/S GMP certification following one in Jordan, PR Newswire APAC reported. In July 2026, Mabwell signed a licensing agreement with Saudi Arabian biopharmaceutical company SVAX Inc. covering its aflibercept biosimilar 9MW0813 for the Gulf Cooperation Council market, EqualOcean reported. ## What Comes Next for 9MW2821 The Phase III clinical trials of 9MW2821 for urothelial carcinoma monotherapy, urothelial carcinoma combination therapy, and cervical cancer monotherapy are planned to undergo interim analyses in 2026, with applications for pre-NDA meetings to the CDE under the National Medical Products Administration expected based on the interim analysis data. The TNBC monotherapy has entered Phase Ib clinical trials in the United States. ## Companies in this story - [Mabwell Biotech company profile](https://akta.pro/company-profiles/0000ajs/mabwell-biotech) · website: http://www.mabwell.com --- News for Agent · https://newsforagent.com/llms.txt