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CHENGDU, China, February 4, 2026—Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) announced that a new indication application for its TROP2-directed ADC sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) (佳泰莱^®) has been approved by the National Medical Products Administration (NMPA) of China for treatment of adult patients with unresectable or metastatic HR+/HER2- (IHC 0, IHC 1+ or IHC 2+/ISH-) breast cancer (BC) who have received prior endocrine therapy (ET) and at least one line of chemotherapy in advanced setting. This approval for HR+/HER2- BC after at least one prior line of chemotherapy marks the fourth indication for sac-TMT approved for marketing in China.

The approval is based on the positive results from the Phase III OptiTROP-Breast02 study which was selected as a Late-Breaking Abstract (LBA) and presented as an oral report at the 2025 European Society for Medical Oncology (ESMO) Congress.

The OptiTROP-Breast02 study evaluated the efficacy and safety of sac-TMT monotherapy compared to investigator's choice of chemotherapy in patients with unresectable or metastatic HR+/HER2- BC. Of the patients enrolled in this Phase III study, 95.7% had visceral metastases, 75.9% had liver metastases; 52.9% were HER2-zero (IHC 0), while 47.1% were HER2-low (IHC 1+ or IHC 2+/ISH-). All patients had received prior CDK4/6 inhibitor and taxane therapy; 56.6% had received ≥2 lines of prior chemotherapy in the advanced or metastatic setting.

Results showed that sac-TMT demonstrated a statistically significant and clinically meaningful increase in progression-free survival (PFS) as assessed by the Blinded Independent Central Review (BICR) compared to chemotherapy (8.3 vs. 4.1 months; hazard ratios (HR), 0.35; 95% CI: 0.26-0.48; p<0.0001). Consistent PFS benefits were observed across all pre-specified subgroups, including HER2-zero and HER2-low, number of chemotherapy lines received in the advanced or metastatic setting, presence of baseline visceral and liver metastases and previous CDK4/6 inhibitor use. According to BICR-assessed PFS results, the hazard ratios in the HER2-zero and HER2-low  (IHC 1+ or IHC 2+/ISH-) subgroups were 0.39 (95% CI: 0.26-0.57) and 0.31 (95% CI: 0.20-0.48), respectively. A trend towards overall survival (OS) benefit and a significantly higher objective response rate (ORR) (41.5% vs. 24.1%) were also observed compared with chemotherapy. ^[1]

Currently, Phase III clinical studies of sac-TMT with or without pembrolizumab (KEYTRUDA^®[2]) for the treatment of chemotherapy-naïve HR+/HER2- BC who have received prior ET have been initiated globally (NCT06312176) and in China (NCT07071337).

About HR+/HER2- Breast Cancer

Breast cancer is one of the most common malignant tumors that seriously threaten women's health worldwide. In 2022, there were about 2,297,000 new cases of breast cancer and 666,000 deaths worldwide. Among them, HR+/HER2- breast cancer is the most common subtype, accounting for about 70% of all breast cancer cases, and advanced HR+/HER2- breast cancer has a poor prognosis. This subtype is typically sensitive to hormonal therapy, and therefore, endocrine therapy combined with a CDK4/6 inhibitor constitutes the standard treatment. However, for patients with HR+/HER2- advanced breast cancer whose disease progresses on endocrine therapy, chemotherapy is widely used in clinical while it is associated with low response rate (ORR approximately 14%-22.9%) and limited survival benefit (mPFS approximately 4.0-4.9 months).

About Sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as non-small cell lung cancer (NSCLC), breast cancer (BC), gastric cancer (GC), gynecological tumors, among others. Sac-TMT is developed with a novel linker to conjugate the payload, a belotecan-derivative topoisomerase I inhibitor with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, four indications for sac-TMT have been approved and marketed in China for: EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy; unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy; unresectable or metastatic HR+/HER2- (IHC 0, IHC 1+ or IHC 2+/ISH-) BC who have received prior ET and at least one line of chemotherapy in advanced setting. The first two indications listed above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinical benefits to a greater number of patients with BC and NSCLC. Additionally, sac-TMT has been granted six Breakthrough Therapy Designations (BTDs) by the NMPA.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD is evaluating16 ongoing Phase III global clinical studies of sac-TMT as a monotherapy or with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical, which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

Reference Sources：

[1] Fan Y, Li H, Wang H, et al. ESMO Congress 2025, LBA23.

[2] KEYTRUDA^® (pembrolizumab) is a registered trademark of Merck Sharp & Dohme LLC (MSD), a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

CHENGDU, China, Jan. 16, 2026 /PRNewswire/ -- From January 12 to 15, 2026, the 44th J.P. Morgan Healthcare Conference (JPMHC) was held in San Francisco, California, USA. Dr. Ge Michael, President and CEO of Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK), was invited to attend the conference and delivered a keynote speech on the morning of January 15 (local time) and presented the Company's latest achievements in drug R&D, commercialization, and globalization, and outlined its innovation strategy and future development plans.

Since initiating its innovation journey in 2012, Kelun-Biotech has rapidly emerged as a leader in China's innovative drug field, building differentiated technology platforms and robust R&D pipelines. Leveraging its global leading OptiDC™ platform for antibody-drug conjugates (ADCs) and novel drug conjugates (DCs), the Company continuously advances the differentiated development of ADCs and novel DCs, forming a gradient portfolio for treating multiple tumor types. Currently, Kelun-Biotech has two ADC products on market: sacituzumab tirumotecan (sac-TMT, 佳泰莱®) and trastuzumab botidotin (舒泰莱®), covering breast cancer and lung cancer indications. Additionally, nine uniquely designed ADC and novel DC drugs—including cutting-edge directions such as bispecific ADC and radiopharmaceutical conjugate (RDC) are in clinical stage. For high-incidence tumor types in China, such as breast cancer, lung cancer, and gastrointestinal tumors, the Company has initiated nine pivotal studies, while multiple Phase II clinical studies targeting gynecological tumors are progressing steadily. Furthermore, Kelun-Biotech has also developed several non-DC candidates and expanded indications into non-oncology areas.

Over the past year, Kelun-Biotech has presented multiple research findings at international academic conferences and published in authoritative journals: three were selected for oral presentations at the American Society of Clinical Oncology (ASCO) annual meeting, and three were selected as Late-Breaking Abstracts (LBA) for oral presentations at the European Society for Medical Oncology (ESMO) Congress. Among these, the results of the OptiTROP-Lung04 study of sac-TMT for treating EGFR-mutant Non-Small Cell Lung Cancer (NSCLC) after TKI therapy were presented at the Presidential Symposium session of ESMO and simultaneously published in The New England Journal of Medicine, highlighting its global academic and clinical value.

In terms of commercialization, Kelun-Biotech has formed a competitive initial product portfolio. Its core product, the TROP2-directed ADC sac-TMT, has been approved in China for three indications: second-line and above triple-negative breast cancer, second-line and third-line EGFR-mutated NSCLC. The HER2-directed ADC trastuzumab botidotin was approved last year for second-line and above HER2-positive breast cancer, becoming the first domestically developed HER2-directed ADC approved for this indication. Furthermore, the anti-EGFR monoclonal antibody Cetuximab N01 (达泰莱®) for RAS wild-type colorectal cancer and the anti-PD-L1 monoclonal antibody tagitanlimab (科泰莱®) for nasopharyngeal carcinoma have been launched. Another small-molecule RET inhibitor A400 is expected to be approved within the year, bringing the total number of commercialized products in China to five. Currently, three of the Company's commercialized products, covering five indications, have been included in the National Reimbursement Drug List (NRDL), further benefiting a broad population of cancer patients.

While strengthening its presence in the domestic market, Kelun-Biotech is actively expanding overseas. It has established collaborations with MSD, Ellipses, Windward Bio and Crescent Biopharma to maximize the value of its pipeline value and corporate worth. Among these, MSD is evaluating 16 global Phase III clinical studies of sac-TMT.

The breakthroughs in both clinical development and commercialization are driven by the Company's sustained investment in innovative R&D. With over a decade of accumulation in the ADC field, Kelun-Biotech's proprietary OptiDC™ platform enables differentiated design of drug candidates, which combines specific targets or targeting mechanisms with the most suitable payload-linker strategy to balance efficacy and safety. Additionally, the company is adopting a "multi-pronged" innovation strategy to continuously enhance platform capabilities. By exploring novel targets, new payloads, and diverse conjugation technologies, it is expanding the application boundaries across both oncology and non-oncology fields.

Looking ahead, Kelun-Biotech will consolidate its foundations in R&D, technologies, platforms, and operations by Ｅxecuting five key development strategies. Concurrently, the Company will elevate its globalization strategy, enhancing its capabilities in product development, registration, and commercialization in ex-China market, advancing on its path to becoming a world-class biopharmaceutical company.

Please refer to the "Investor Relations-Investor Calendar" page of the company's official website for the presentation materials. You can visit the website for further details.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/. 

The 44^th J.P. Morgan Healthcare Conference (JPMHC) will be held in San Francisco, California, USA, from January 12 to 15, 2026. Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (“Kelun-Biotech” or the “Company”, 6990.HK) has been invited to attend the conference and Dr. Michael Ge, President and CEO of Kelun-Biotech, will share the company’s latest business progresses as well as its innovation capabilities and strategies.

Presentation Time: Thursday, January 15, 2026 at 9:30 AM Pacific Standard Time
Presentation Venue: Westin St. Francis, San Francisco, USA

J.P. Morgan Annual Healthcare Conference is honored as a “benchmark for development and investment in the global healthcare area”. During the conference, Kelun-Biotech will join massive seasoned experts and industry leaders to discuss cutting-edge trends in biopharmaceutical innovation. Based on the ongoing transformation moment of the global pharmaceutical industry, the company will actively pursue mutually beneficial partnership opportunities on the international stage.

You can visit “Investor Relations - Investor Calendar” page of Kelun-Biotech’s official website for participation of live webcast of presentation session, and watch replay within 30 days after the conference.

About Kelun-Biotech

 Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, Jan. 5, 2026 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech" or the "Company", 6990.HK) announced that its Investigational New Drug (IND) application for SKB105 (also known as CR-003), an internally developed integrin beta-6 (ITGB6)-targeted antibody-drug conjugate (ADC), has been approved by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China for the treatment of advanced solid tumors.

In December 2025, Kelun-Biotech and Crescent Biopharma, Inc. ("Crescent") entered into a strategic collaboration for SKB105/CR-003 and SKB118 (a PD-1 x VEGF bispecific antibody, also known as CR-001). Under the collaboration, Kelun-Biotech granted Crescent exclusive rights to research, develop, manufacture and commercialize SKB105/CR-003 in the United States, Europe and all other markets outside of Greater China. In addition, Crescent granted Kelun-Biotech exclusive rights to research, develop, manufacture and commercialize SKB118/CR-001 in Greater China. The IND application for SKB118/CR-001 has been cleared by the U.S. Food and Drug Administration (FDA) with a global Phase I/II clinical trial for the treatment of advanced solid tumors is set to commence shortly. Kelun-Biotech plans to submit an IND application for SKB118/CR-001 to the Center for Drug Evaluation of the National Medical Products Administration of China in the near future.

About SKB105 (also known as CR-003)

SKB105 is a differentiated ADC targeting ITGB6 with a topoisomerase I inhibitor payload. ITGB6 is overexpressed in many solid tumors, but shows minimal to no expression in most normal tissues, thereby potentially reducing the risk of systemic toxicity and off-target effects. SKB105 incorporates proprietary Kthiol® irreversible conjugation technology, linking an anti-ITGB6 fully human Immunoglobulin G1 (IgG1) monoclonal antibody (mAb) to a clinically validated cleavable linker. This design aims to enhance stability and tumor-specific payload delivery while reducing adverse effects. In preclinical models, SKB105 demonstrated a favorable efficacy, safety, and pharmacokinetic (PK) profile.

About SKB118(also known as CR-001)

SKB118/CR-001 is a tetravalent bispecific antibody being developed for the treatment of solid tumors that combines two complementary, validated mechanisms in oncology via a blockade of PD-1 and VEGF. PD-1 checkpoint inhibition is aimed at restoring T cells' ability to recognize and destroy tumor cells, and blocking VEGF is intended for reducing blood supply to tumor cells and inhibiting tumor growth. In preclinical studies, SKB118/CR-001 demonstrated cooperative pharmacology with increased binding to PD-1 and signal blockade in the presence of VEGF as well as robust anti-tumor activity. SKB118/CR-001's anti-VEGF activity may also normalize the vasculature at the tumor site, which has the potential to improve the localization and effectiveness of combination therapies, particularly in conjunction with ADCs. 

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

CHENGDU, China, January 5, 2026 -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (“Kelun-Biotech” or the “Company,” 6990.HK) today announced that its TROP2-directed antibody-drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT, also known as SKB264/MK-2870) (佳泰莱^®) in combination with MSD’s anti-PD-1 monoclonal antibody pembrolizumab (KEYTRUDA^®[1]) was granted Breakthrough Therapy Designation (BTD) by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA) of China for the first-line treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) who have PD-L1 tumor proportion score (TPS)≥1% and are EGFR-negative and ALK-negative.

BTD is granted for treatment regimens that provide effective treatment or prevention for conditions with no currently available therapy, or that demonstrate significant clinical advantages over currently available treatments. For drugs included in the breakthrough therapy process, if relevant conditions are met, applications for conditional approval and priority review and approval can be submitted when applying for marketing authorization.

Previously, the company announced that results from the Phase III clinical trial of OptiTROP-Lung05, evaluating sac-TMT in combination with pembrolizumab as first-line treatment for PD-L1-positive NSCLC, demonstrated a statistically significant and clinically meaningful improvement in its primary endpoint of progression-free survival (PFS). A positive trend was also observed in overall survival (OS). OptiTROP-Lung05 is the first Phase III study of an immunotherapy and ADC combination to meet its primary endpoint in the first-line treatment of NSCLC. Granting of BTD for the first-line treatment of PD-L1-positive NSCLC indication offers pathways to expedite the review and potential approval process of sac-TMT for this indication.

To date, sac-TMT has received five BTDs for:

• locally advanced or metastatic triple-negative breast cancer (TNBC) in July 2022;

• locally advanced or metastatic EGFR-mutant NSCLC after progression on EGFR-TKI therapy in January 2023;

• locally advanced or metastatic hormone-receptor positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) breast cancer (BC) in patients who have previously received at least two lines of systemic chemotherapy in June 2023;

• first-line treatment of unresectable locally advanced, recurrent or metastatic PD-L1 negative TNBC in March 2024;

• In combination with anti-PD-L1 monoclonal antibody tagitanlimab for the first-line treatment of locally advanced or metastatic non-squamous NSCLC without actionable genomic alterations in June 2025.

About sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, BC, gastric cancer (GC), gynecological tumors, among others. Sac-TMT is developed with a novel linker to conjugate the payload, a belotecan-derivative topoisomerase I inhibitor with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, three indications for sac-TMT have been approved and marketed in China for: EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy; Unresectable locally advanced or metastatic TNBC who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting); EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy. The first two indications listed above have been included in China's National Reimbursement Drug List (NRDL). This inclusion is expected to bring clinical benefits to a greater number of cancer patients.

Sac-TMT is the world's first TROP2 ADC drug approved for marketing in lung cancer. In addition, the sNDA for sac-TMT for second-line and above treatment of HR+/HER2- BC was accepted by the Center for Drug Evaluation of the National Medical Products Administration, and was included in the priority review and approval process.

As of today, Kelun-Biotech has initiated 9 registrational clinical studies in China. MSD has initiated 15 ongoing Phase 3 global clinical studies of sac-TMT as a monotherapy or with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

[1] KEYTRUDA^® (pembrolizumab) is a registered trademark of Merck Sharp & Dohme LLC (MSD), a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

Companies to advance CR-001, a PD-1 x VEGF bispecific antibody, and SKB105, an integrin beta-6-directed antibody-drug conjugate (ADC), in global markets and China

Collaboration designed to accelerate and expand the development of synergistic combinations with CR-001 and ADCs, including SKB105

CR-001 and SKB105 on track to enter Phase 1/2 monotherapy clinical trials in Q1 2026 with combination studies to follow

CHENGDU, China and WALTHAM, Mass., Dec. 4, 2025 /PRNewswire/ -- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. ("Kelun-Biotech", 6990.HK), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs, and Crescent Biopharma, Inc. ("Crescent") (Nasdaq: CBIO), a biotechnology company dedicated to rapidly advancing the next wave of therapies for cancer patients, today announced that the companies have entered into a strategic partnership to develop and commercialize oncology therapeutics, including novel combinations.

The partnership involves Crescent's CR-001, a PD-1 x VEGF bispecific antibody, and Kelun-Biotech's SKB105, an integrin beta-6 (ITGB6)-directed antibody-drug conjugate (ADC) with a topoisomerase payload. Both candidates are being developed for the treatment of solid tumors and are expected to enter Phase 1/2 monotherapy clinical trials in the first quarter of 2026.

Under the terms of the collaboration, Crescent has granted Kelun-Biotech exclusive rights to research, develop, manufacture and commercialize CR-001 in Greater China (including mainland China, Hong Kong, Macau and Taiwan). In addition, Kelun-Biotech has granted Crescent exclusive rights to research, develop, manufacture and commercialize SKB105 in the United States, Europe and all other markets outside of Greater China. The partnership includes the development of these candidates as monotherapies, and also the evaluation of CR-001 in combination with SKB105.Both Crescent and Kelun-Biotech have the right to independently develop CR-001 in additional combinations, including combinations of CR-001 with proprietary ADC pipeline assets.

Dr. Michael Ge, chief Ｅxecutive officer of Kelun-Biotech, said, "We are pleased to have entered into a partnership with Crescent for two innovative assets, CR-001 and SKB105. This collaboration complements and strengthens our differentiated oncology pipeline by the addition of CR-001 and also enables us to advance the development of SKB105 in the global market, bolstering its potential commercial value and our global collaboration network. Our creative global partnership combines the capabilities of both companies to explore novel monotherapies and combination strategies for tumor treatments with SKB105 and CR-001. By leveraging China's abundant clinical resources and Ｅxecution efficiency, we aim to expedite clinical development while rigorously maintaining the highest global standards. We believe this partnership creates a powerful synergy to maximize the potential of these two drug candidates for the treatment of patients in both China and the rest of the world."

"We are thrilled to be partnering with Kelun-Biotech, an established leader in the development and commercialization of ADCs who shares our commitment to bringing next generation therapeutics that can improve outcomes for people living with cancer," said Joshua Brumm, chief Ｅxecutive officer of Crescent. "This collaboration expands our pipeline with the addition of SKB105, furthers our strategy of advancing multiple modalities across our portfolio, and accelerates our efforts to deliver synergistic combinations with CR-001, which has the potential to be a foundational backbone therapy. We look forward to working with Kelun-Biotech to drive innovative therapeutics with the potential to address multiple tumor types and transform cancer care."

Under the collaboration, Kelun-Biotech will receive an upfront payment of US$80 million from Crescent and is also eligible to receive additional milestones of up to US$1.25 billion, plus tiered middle single-digit to low double-digit royalties on net sales of SKB105. Kelun-Biotech is also eligible to receive additional payment from Crescent if Crescent undergoes a near-term change of control or enters into a sublicense agreement with a third party. Crescent will receive an upfront payment of US$20 million from Kelun-Biotech and is also eligible to receive additional milestones of up to US$30 million, plus tiered low to middle single digit royalties on net sales of CR-001.

About CR-001 (also known as SKB118)

CR-001 is a tetravalent bispecific antibody being developed for the treatment of solid tumors that combines two complementary, validated mechanisms in oncology via a blockade of PD-1 and VEGF. PD-1 checkpoint inhibition is aimed at restoring T cells' ability to recognize and destroy tumor cells, and blocking VEGF is intended for reducing blood supply to tumor cells and inhibiting tumor growth. In preclinical studies, CR-001 demonstrated cooperative pharmacology with increased binding to PD-1 and signal blockade in the presence of VEGF as well as robust anti-tumor activity. CR-001's anti-VEGF activity may also normalize the vasculature at the tumor site, which has the potential to improve the localization and effectiveness of combination therapies, such as the administration of CR-001 with antibody-drug conjugates (ADCs). A global Phase 1/2 trial of CR-001 in patients with solid tumors is anticipated to commence in the first quarter of 2026.

About SKB105 (also known as CR-003)

SKB105 is a differentiated ADC targeting integrin beta-6 (ITGB6) with a topoisomerase 1 inhibitor payload. ITGB6 is overexpressed in many solid tumors, but shows minimal to no expression in most normal tissues, thereby potentially reducing the risk of systemic toxicity and off-target effects. SKB105 consists of an anti-ITGB6 fully human IgG1 monoclonal antibody conjugated via a stable, clinically validated cleavable linker. The molecule incorporates proprietary Kthiol® irreversible conjugation technology, designed to enhance stability and tumor-specific payload delivery while reducing adverse effects. SKB105 demonstrated a favorable efficacy, safety, and pharmacokinetic (PK) profile in preclinical models. A Phase 1/2 clinical trial of SKB105 in patients with solid tumors is anticipated to commence in the first quarter of 2026.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. Kelun-Biotech focuses on major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. Kelun-Biotech is committed to becoming a leading global enterprise in the field of innovative drugs. At present, Kelun-Biotech has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. Kelun-Biotech has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://en.kelun-biotech.com/.

About Crescent Biopharma

Crescent Biopharma's vision is to build a world leading oncology company bringing the next wave of therapies for cancer patients. Crescent 's pipeline includes its lead program, a PD-1 x VEGF bispecific antibody, as well as novel antibody-drug conjugates (ADCs). By leveraging multiple modalities and established targets, Crescent aims to rapidly advance potentially transformative therapies either as single agents or as part of combination regimens to treat a range of solid tumors. For more information, visit www.crescentbiopharma.com and follow Crescent on LinkedIn and X.

• After a median follow-up of 18.9 months, the median PFS was 8.3 months in the sac-TMT group and 4.3 months in the chemotherapy group (hazard ratio (HR), 0.49; 95% confidence interval (CI), 0.39 to 0.62; two-sided P<0.0001).

• OS was significantly longer with sac-TMT than with chemotherapy (HR, 0.60; 95% CI, 0.44 to 0.82; two-sided P=0.001); 18-month OS rate was 65.8% and 48.0%, respectively. In the supplementary analysis, in which data were censored at the start date of subsequent ADC, the HR was 0.56 (95% CI, 0.41 to 0.77).

• Sac-TMT was associated with a higher incidence of stomatitis with most cases being mild and with grade 3 or higher cases reported in very few patients (4.8%; all were grade 3). Low incidence of ocular-surface toxic effects, no ILD or pneumonitis, and one infusion-related reaction (grade 2) was reported in the sac-TMT group.

On October 20, results from the Phase III registrational clinical study OptiTROP-Lung04—led by Professor Zhang Li's team from Sun Yat-sen University Cancer Center—were published in the New England Journal of Medicine (Impact Factor = 78.5). The study evaluated the efficacy and safety of the TROP2 antibody-drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT) monotherapy versus pemetrexed plus platinum chemotherapy for the treatment of patients with epidermal growth factor receptor (EGFR)-mutant locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) who have progressed failed after treatment with EGFR-tyrosine kinase inhibitor (TKI) therapy. The study was also selected as a Late-Breaking Abstract (LBA) at the 2025 European Society for Medical Oncology (ESMO) Congress and was presented as an oral report in the Presidential Symposium (Presentation # LBA5).  

OptiTROP-Lung04 is a randomized, open-label, multicenter Phase III study designed to evaluate the efficacy and safety of sac-TMT monotherapy versus pemetrexed plus platinum in patients with EGFR-mutated locally advanced or metastatic NSCLC who had progressed on prior EGFR-TKI therapy. Eligible patients were those with histologically and/or cytologically confirmed disease. The primary endpoint was Progression-Free Survival (PFS) assessed by a Blinded Independent Review Committee (BIRC) per RECIST v1.1, and the key secondary endpoint was overall survival (OS). Results showed that compared with platinum-based doublet chemotherapy, sac-TMT monotherapy demonstrated a statistically significant and clinically meaningful improvement in both PFS and OS. Consistent PFS and OS benefits were observed across all prespecified subgroups, including prior EGFR-TKI therapy, presence of liver or brain metastases, and EGFR mutation subtype.

Based on the positive results of the OptiTROP-Lung04 study, sac-TMT has been approved by the National Medical Products Administration (NMPA) in China for the treatment of adult patients with EGFR mutation-positive locally advanced or metastatic non-squamous NSCLC who have progressed after EGFR-TKI therapy. To date, sac-TMT monotherapy remains the only approved treatment option for advanced EGFR-mutant NSCLC patients who have progressed after prior TKI therapy, as well as those who have progressed after prior TKI and platinum-based chemotherapy (either concurrently or sequentially). This achievement provides comprehensive coverage for the entire population of TKI-resistant patients.

Dr. Michael Ge, Chief Ｅxecutive Officer of Kelun-Biotech, commented: “OptiTROP-Lung04 is a key study that propels sac-TMT from late-line to an earlier-line treatment-setting in lung cancer, achieving a significant improvement in overall survival. We are thrilled that the results have been published in The New England Journal of Medicine, allowing this important finding to be shared widely among medical professionals and providing a reference for future lung cancer research. Together with our partner MSD, we will continue to advance sac-TMT’s clinical development and regulatory approvals, covering broader lung cancer and other indications, with the goal of making sac-TMT a cornerstone therapy for the benefit of patients.”

Professor Shengxiang Ren from the Department of Oncology at Shanghai Pulmonary Hospital, Tongji University, stated: “The application of third-generation EGFR-TKIs has significantly improved the overall prognosis for patients with advanced EGFR-mutant NSCLC. However, drug resistance is almost inevitable. Traditional treatment after resistance involves platinum-based doublet chemotherapy, which offers limited overall benefit. In recent years, regimens of chemotherapy plus immune checkpoint inhibitors+anti-angiogenic agents, or EGFR/c-Met bsAb, or PD-1/VEGF bsAb, have been successively approved for this indication. However, all these approaches are chemotherapy-based, highlighting an urgent need to explore novel treatment regimens. The OptiTROP-Lung04 study confirms sac-TMT as the first treatment option as a monotherapy to deliver clear dual benefits in both PFS and OS following EGFR-TKI progression. The sequential application of sac-TMT prior to chemotherapy demonstrates strong competence, establishing itself as a new standard of care for patients with advanced EGFR-mutant lung cancer after TKI resistance.”

About Sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, breast cancer (BC), gastric cancer (GC), gynecological tumors, among others. Sac-TMT is developed with a novel linker to conjugate the payload, a belotecan-derivative topoisomerase I inhibitor with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc., Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (includes Mainland China, Hong Kong, Macau, and Taiwan).

To date, three indications for sac-TMT have been approved and marketed in China for the treatment of adult patients with unresectable locally advanced or metastatic triple negative breast cancer (TNBC) who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting), EGFR mutation-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy and EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy. Sac-TMT is the first TROP2 ADC drug approved for marketing in lung cancer globally. In addition, the new indication application for sac-TMT for the treatment of adult patients with unresectable locally advanced, metastatic hormone receptor positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) BC who have received prior endocrine therapy and other systemic treatments in the advanced or metastatic setting was accepted by the Center for Drug Evaluation of the NMPA, and was included in the priority review and approval process.

As of today, the Company has initiated 9 registrational clinical studies in China. MSD has initiated 15 ongoing Phase Ⅲ global clinical studies of sac-TMT as a monotherapy or with pembrolizumab1 or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. The company focuses on major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. The Company is committed to becoming a leading global enterprise in the field of innovative drugs. At present, the Company has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. The company has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC projects approved for marketing, and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://kelun-biotech.com/.

References:

1. Pembrolizumab (KEYTRUDA®) is a registered trademark of Merck Sharp & Dohme LLC (MSD), a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.

CHENGDU, China, Oct, 18 , 2025——Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the “Company”) announced that at the 2025 European Society for Medical Oncology (ESMO) Congress held in Berlin, Germany, Results from a Phase 3 study of the Company’s human epidermal growth factor receptor 2 (HER2)-directed ADC trastuzumab botidotin (also known as A166) trastuzumab botidotin versus trastuzumab emtansine (T-DM1) in HER2-positive unresectable or metastatic BC was presented as an oral report by Professor Xichun Hu from Fudan University Shanghai Cancer Center (Presentation # LBA24, Proffered paper session 1: Breast cancer, metastatic).

Trastuzumab botidotin is a HER2-targeted ADC composed of a cytotoxic drug (Duostatin-5, anti-microtubule agent) with site-specific conjugation to trastuzumab via a stable protease-cleavable valine-citrulline linker. The unique linker is stable in plasma and selectively cleaved by lysosomal cathepsin B that is up-regulated in cancer cells.

In this study, a total of 365 patients with HER2+ unresectable or metastatic BC who had received at least one prior anti-HER2 therapy were randomized (1:1) to receive trastuzumab botidotin or T-DM1. 53% of patients had received ≥2 lines of anti-HER2 therapy, 61% of patients had HER2 Immunohistochemistry (IHC) 3+, and 60% of patients had been treated with TKIs, particularly pyrotinib (56%). As of April 26, 2025, median follow-up was 14.9 months.

Median PFS was significantly longer in trastuzumab botidotin than in T-DM1 (11.1 months vs 4.4 months; HR: 0.39, 95% CI, 0.30-0.51, p<0.0001). PFS benefit with trastuzumab botidotin was consistently observed regardless of prior lines of anti-HER2 therapy (HR 0.36, 95% CI, 0.25-0.53, for 1 prior line; HR 0.39, 95% CI, 0.28-0.56, for ≥2 prior lines).

ORR by blinded independent central review (BICR) was 76.9% vs 53.0%.

A trend toward benefit in OS was observed in trastuzumab botidotin (HR 0.62; 95% CI, 0.38-1.03).

Grade ≥3 treatment emergent adverse events (TEAEs) occurred in 69.8% of patients in trastuzumab botidotin and 63.7% in T-DM1. The most common TEAEs associated with dose reduction were ocular AEs for trastuzumab botidotin, and were platelet count decreased for trastuzumab emtansine. Only two patients permanently discontinued trastuzumab botidotin due to TEAE. No on-treatment deaths were observed in trastuzumab botidotin, compared with 1.6% in T-DM1, all of which were considered unrelated to treatment.

As a conclusion, this second head-to-head trial comparing T-DM1 with other anti-HER2 regimens demonstrated that trastuzumab botidotin statistically improved PFS with an ORR of 76.9% vs 53.0%. PFS benefit with trastuzumab botidotin was consistently observed regardless of prior lines of anti-HER2 therapy. Ocular AEs were also manageable.

"Professor Xichun Hu, National Lead Principal Investigator from Fudan University Shanghai Cancer Center:“Trastuzumab botidotin effectively balances safety and efficacy through its unique molecular design, reducing the incidence of interstitial lung disease and hematologic toxicity. According to research data, trastuzumab botidotin demonstrated significant survival benefits in the pivotal Phase III trial, with an overall manageable safety profile, providing a new important treatment option for pretreated HER2+ BC patients. These positive results also offer robust evidence-based support for personalized treatment and updates to clinical practice guidelines.”

About Trastuzumab botidotin

Trastuzumab botidotin is a differentiated HER2 ADC to treat advanced HER2+ solid tumors. As an innovative HER2 ADC developed by the Company, it conjugates a novel, monomethyl auristatin F (MMAF) derivative (a highly cytotoxic tubulin inhibitor, Duo-5) via a stable, enzyme-cleavable linker to a HER2 monoclonal antibody with a DAR of 2. Trastuzumab botidotin specifically binds to HER2 on the surface of tumor cells and is internalized by tumor cells, releasing the toxin molecule Duo-5 inside the cell. Duo-5 induces tumor cell cycle arrest in the G2/M phase, leading to tumor cell apoptosis. After targeting HER2, trastuzumab botidotin can also inhibit the HER2 signaling pathway; it has antibody-dependent cell-mediated cytotoxicity (ADCC) activity.

Based on the results of a multi-center, randomized, open-label, controlled, Phase 3 KL166-III-06 study, trastuzumab botidotin was approved for marketing by the NMPA in for adult patients with unresectable or metastatic HER2 positive BC who have received one or more prior anti-HER2 therapy. At a pre-specified interim analysis, trastuzumab botidotin demonstrated a statistically significant and clinically meaningful improvement in the primary endpoint of PFS as assessed by the BICR compared with T-DM1[; the beneficial trend for OS of trastuzumab botidotin was also observed.

Currently, the Company has initiated an open, multi-center Phase 2 clinical study of trastuzumab botidotin in the treatment of HER2+ unresectable or metastatic BC that previously received a topoisomerase inhibitor ADC.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. The company focuses on major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. The Company is committed to becoming a leading global enterprise in the field of innovative drugs. At present, the Company has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 projects are in the NDA stage and more than 10 projects are in the clinical stage. The company has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 1 ADC project approved for marketing and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://kelun-biotech.com/.

CHENGDU, China, Oct, 19, 2025——Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (the “Company”) announced that at the 2025 European Society for Medical Oncology (ESMO) Congress held in Berlin, Germany, results from a Phase 3 OptiTROP-Lung04 trial of the Company’s trophoblast cell-surface antigen 2 (TROP2)-directed antibody-drug conjugate (ADC) sacituzumab tirumotecan (sac-TMT)  in EGFR-mutated non-small cell lung cancer (NSCLC) following progression on epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) was presented as an oral report by Professor Li Zhang from Sun Yat-sen University Cancer Center (Presentation # LBA5, Presidential Symposium II) and were simultaneously published in the New England Journal of Medicine (Impact Factor = 78.5).

In the OptiTROP-Lung04 trial, a total of 376 patients were randomized (1:1) to receive sac-TMT monotherapy or chemotherapy.

As at the data cut-off date July 06, 2025, the median follow-up is 18.9 months. the median Progression-Free Survival (PFS) was 8.3 months in the sac-TMT group and 4.3 months in the chemotherapy group. Sac-TMT significantly improved PFS over chemotherapy with 51% lower risk of disease progression or death (hazard ratio (HR) 0.49; 95% confidence interval (CI), 0.39-0.62; P<0.0001).

At the preplanned interim analysis of overall survival (OS), the OS was not reached (NR) in the sac-TMT group and 17.4 months in the chemotherapy group. sac-TMT significantly improved OS over chemotherapy with 40% lower risk of death (hazard ratio (HR) 0.6; 95% CI: 0.44-0.82; two-sided P=0.001). In the supplemental analysis, when censoring patients at the date of initiation of subsequent ADCs, sac-TMT significantly improved OS over chemotherapy with 44% lower risk of death (HR, 0.56; 95% CI, 0.41 - 0.77).

Sac-TMT significantly improved ORR as compared to chemotherapy (60.6% vs 43.1%)

A consistent PFS and OS benefit of sac-TMT over chemotherapy was observed across all predefined subgroups, including prior EGFR-TKI therapy, presence of liver or brain metastases, and EGFR mutation subtype.

The incidence of any grade treatment-related adverse events (TRAEs) and grade ≥3 TRAEs was similar between the two groups. The most common TRAEs for both sac-TMT and chemotherapy were hematologic toxicities. No TRAEs led to discontinuation or death, and no cases of interstitial lung disease/pneumonitis were reported in the sac-TMT group. Ocular surface toxicity: occurred in 9.6% of patients in the sac-TMT group, all of which were grade 1 - 2.

As a conclusion, sac-TMT demonstrates highly statistically significant and clinically meaningful improvements in PFS and OS compared to platinum-based chemotherapy and showed a manageable safety profile, with no unexpected safety signals identified. Several global phase 3 studies of sac-TMT monotherapy (NCT06305754, NCT06074588) and combination study with osimertinib in China (NCT06670196) in EGFR-mutant NSCLC are ongoing.

Professor Zhang Li, National Lead Principal Investigator from Sun Yat-sen University Cancer Center, commented: "Compared to platinum-based doublet chemotherapy, sac-TMT not only significantly prolonged PFS but also demonstrated a statistically significant and clinically meaningful improvement in OS within this patient population. This achievement marks a major breakthrough in global lung cancer treatment—sac-TMT, as a monotherapy, demonstrated statistically significant and clinically meaningful improvements in both PFS and OS in the Phase III trial for patients with EGFR-TKI-resistant NSCLC. This study provides highly valuable, new evidence-based guidance for lung cancer management worldwide and has the potential to reshape the therapeutic landscape for EGFR-TKI-resistant NSCLC "

 About sac-TMT

Sac-TMT, a core product of the Company, is a novel human TROP2 ADC in which the Company has proprietary intellectual property rights, targeting advanced solid tumors such as NSCLC, BC, GC, gynecological tumors, among others. Sac-TMT is developed with a novel linker to conjugate the payload, a belotecan-derivative topoisomerase I inhibitor with a drug-to-antibody-ratio (DAR) of 7.4. Sac-TMT specifically recognizes TROP2 on the surface of tumor cells by recombinant anti-TROP2 humanized monoclonal antibodies, which is then endocytosed by tumor cells and releases the payload KL610023 intracellularly. KL610023, as a topoisomerase I inhibitor, induces DNA damage to tumor cells, which in turn leads to cell-cycle arrest and apoptosis. In addition, it also releases KL610023 in the tumor microenvironment. Given that KL610023 is membrane permeable, it can enable a bystander effect, or in other words kill adjacent tumor cells.

In May 2022, the Company licensed the exclusive rights to MSD (the tradename of Merck & Co., Inc, Rahway, NJ, USA) to develop, use, manufacture and commercialize sac-TMT in all territories outside of Greater China (which includes Mainland China, Hong Kong, Macao and Taiwan).

To date, three indications for sac-TMT have been approved and marketed in China for the treatment of adult patients with unresectable locally advanced or metastatic triple negative breast cancer (TNBC) who have received at least two prior systemic therapies (at least one of them for advanced or metastatic setting), EGFR mutation-positive locally advanced or metastatic non-squamous NSCLC following progression on EGFR-TKI therapy and platinum-based chemotherapy and EGFR mutant-positive locally advanced or metastatic non-squamous NSCLC who progressed after treatment with EGFR-TKI therapy. Sac-TMT is the first TROP2 ADC drug approved for marketing in lung cancer globally. In addition, the new indication applications for sac-TMT for the treatment of adult patients with unresectable locally advanced, metastatic HR+/HER2- BC who have received prior endocrine therapy and other systemic treatments in the advanced or metastatic setting was accepted by the Center for Drug Evaluation (CDE) of the National Medical Products Administration (NMPA), and was included in the priority review and approval process.

As of today, the Company has initiated 9 registrational clinical studies in China. MSD has initiated 15 ongoing Phase 3 global clinical studies of sac-TMT as a monotherapy or with pembrolizumab or other anti-cancer agents for several types of cancer. These studies are sponsored and led by MSD.

About Kelun-Biotech

Kelun-Biotech (6990.HK) is a holding subsidiary of Kelun Pharmaceutical (002422.SZ), which focuses on the R&D, manufacturing, commercialization and global collaboration of innovative biological drugs and small molecule drugs. The company focuses on major disease areas such as solid tumors, autoimmune, inflammatory, and metabolic diseases, and in establishing a globalized drug development and industrialization platform to address the unmet medical needs in China and the rest of world. The Company is committed to becoming a leading global enterprise in the field of innovative drugs. At present, the Company has more than 30 ongoing key innovative drug projects, of which 4 projects have been approved for marketing, 1 project is in the NDA stage and more than 10 projects are in the clinical stage. The company has established one of the world's leading proprietary ADC and novel DC platforms, OptiDC™, and has 2 ADC project approved for marketing and multiple ADC and novel DC assets in clinical or preclinical research stage. For more information, please visit https://kelun-biotech.com/.