Antengene (Hangzhou) Biologics Co., Ltd.

Long-Term Follow-Up Data Signal Promising Progression-Free Survival (PFS) for Selinexor in the Maintenance Setting with Median PFS of 28.4 Months in the TP53 Wild-Type and 39.5 Months in the Proficient Mismatched Repair Status (pMMR) TP53 Wild-Type Exploratory Subgroups Q-TWiST, an Important Metric Assessing Both Quality and Quantity of Clinical Benefit, Suggests Improvement with Selinexor versus Placebo, which is Critical in the Maintenance Setting Company Highlights Additional Presentations in Endometrial Cancer and Myelofibrosis at ASCO 2024 NEWTON, Mass., June 1, 2024 /PRNewswire/ -- Karyopharm Therapeutics Inc. (Nasdaq: KPTI), a commercial-stage pharmaceutical company pioneering novel cancer therapies, today announced the presentation of updated exploratory subgroup analyses from the SIENDO study (NCT03555422), in patients with advanced or recurrent TP53 wild-type endometrial cancer at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting. The data were presented in a special ASCO plenary series rapid abstract update session on June 1 at 12:30pm CT and simultaneously published in the Gynecologic Oncology Journal. The primary analysis of the Phase 3 SIENDO study of selinexor maintenance therapy in advanced or recurrent endometrial cancer showed improvements in median PFS for the intent-to-treat (ITT) population but were not clinically meaningful. However, an exploratory analysis of a pre-specified subgroup of patients with TP53 wild-type endometrial cancer showed a promising efficacy signal. In the exploratory subgroup analysis, 113 patients with TP53 wild-type advanced/recurrent endometrial cancer were randomized to receive selinexor (n=77) vs placebo (n=36) as maintenance therapy after 1L platinum-based chemotherapy. As of the April 1, 2024 data cut-off date, and a median duration of follow-up of 36.9 months, selinexor-treated patients had a median PFS of 28.4 months compared to 5.2 months for patients receiving placebo. In selinexor-treated patients with TP53 wild-type/pMMR and TP53 wild-type/dMMR endometrial cancer, median PFS was 39.5 months and 13.1 months compared to 4.9 months and 3.7 months in those treated with placebo, respectively. Although immature, preliminary overall survival (OS) in the TP53 wild-type subgroup was promising with a hazard ratio of 0.65; median OS for selinexor has not been reached. The updated analyses also highlighted findings from a quality-adjusted time without symptoms or toxicity analysis (Q-TWiST) used to assess quality and toxicity-adjusted PFS. The findings showed the restricted mean Q-TWiST for selinexor to be 26 months compared to 15 months for placebo, resulting in a difference of nearly 11 months. "The approximately 40 months median PFS observed with selinexor in patients whose tumors are both TP53 wild-type and pMMR, coupled with the robust QTWiST analysis, suggests that selinexor may be an optimal maintenance therapy in endometrial cancer," said Reshma Rangwala, MD, PhD, Chief Medical Officer and Head of Research at Karyopharm. "Our ongoing Phase 3 trial will definitively assess these benefits and may lead to a new standard of care in the novel subgroup of patients defined by TP53 wild-type status." No new safety signals were identified as of the data cut-off date of April 1, 2024. The most common treatment-emergent adverse events (TEAEs) in selinexor treated TP53 wild-type patients were nausea (90%), vomiting (60%) and diarrhea (45%), the majority of which were grades 1-2. The most common reported grade 3-4 TEAEs included neutropenia (20%), nausea (13%), and thrombocytopenia (10%). TEAEs leading to discontinuations were reported in 17% of patients. "It is exciting to see the emerging data around progression free survival, as well as an encouraging trend in overall survival and the Q-TWiST metric in the TP53 wild-type subgroup analysis from the SIENDO study," said Vicky Makker, MD, Gynecologic Oncologist, Memorial Sloan Kettering Cancer Center. "The long-term follow-up data further reinforce how selinexor could benefit patients with endometrial cancer, including patients with mismatch repair-proficient disease, and add to the growing body of evidence supporting the potential role of selinexor as a maintenance treatment option for patients whose options are limited." A copy of the presentation from the "ASCO Plenary Series: Rapid Abstract Updates" special session can be accessed under "Publications and Presentations" in the Investor section of the Company's website, . Selinexor is being evaluated in a global, Phase 3, randomized, double-blind study, EC-042 (XPORT-EC-042; NCT05611931), as a maintenance therapy following systemic therapy in patients with TP53 wild-type advanced or recurrent endometrial cancer. Karyopharm expects to report data from this trial in the first half of 2025. The following Karyopharm abstracts will also be presented at ASCO: About the EC-042 Study EC-042 (XPORT-EC-042; NCT05611931) is a global, Phase 3, randomized, double-blind study evaluating selinexor as a maintenance therapy following systemic therapy in patients with TP53 wild-type advanced or recurrent endometrial cancer. The EC-042 study was initiated in November 2022 and is expected to enroll up to 220 patients who will be randomized 1:1 to receive either a 60 mg, once-weekly, administration of oral selinexor or placebo until disease progression. The primary endpoint of the study is progression free survival (PFS), as assessed by an investigator, with overall survival as a key secondary endpoint. Further, in connection with the EC-042 Study, Karyopharm entered into a global collaboration with Foundation Medicine, Inc. to develop FoundationOne®CDx, a tissue-based comprehensive genomic profiling test to identify and enroll patients whose tumors are TP53 wild-type. About the SIENDO Study Karyopharm's evaluation of selinexor to treat patients with TP53 wild-type advanced or recurrent endometrial cancer is supported by data from an exploratory subgroup analysis from its ongoing SIENDO Study, a European Network of Gynaecological Oncological Trial Groups (ENGOT)-led trial in collaboration with the Gynecologic Oncology Group (GOG) Foundation, Inc. The SIENDO Study is a multicenter, randomized, double-blinded Phase 3 study evaluating the efficacy and safety of oral selinexor versus placebo as a front-line maintenance therapy in patients with advanced or recurrent endometrial cancer following at least one prior platinum-based combination chemotherapy treatment (NCT03555422). Participants in this study with advanced or recurrent disease who had a partial response or a complete response after at least 12 weeks of taxane-platinum combination chemotherapy were randomized in a 2:1 manner to receive either maintenance therapy of 80 mg of selinexor or placebo taken once per week, until disease progression. The primary endpoint in the study was PFS from time of randomization until death or disease progression as assessed by an investigator, with the goal of the study demonstrating a HR of 0.6. In the first quarter of 2022, Karyopharm presented top-line data from the SIENDO study, including preliminary exploratory subgroup analyses. Selinexor-treated patients had a median PFS of 5.7 months compared to 3.8 months for patients on placebo in the full trial population, which was not clinically meaningful. There were no new safety signals identified, and a discontinuation rate of 10.5% due to adverse events (AEs). The most common treatment-emergent AEs in the SIENDO study of any grade were: nausea (84%), vomiting (52%), constipation (37%) and thrombocytopenia (37%). The most common grade 3 treatment-emergent AEs were nausea (10%), neutropenia (9%), thrombocytopenia (7%) and asthenia (6%). About Endometrial Cancer Endometrial cancer is the most common cancer of the female reproductive organs in the U.S., with approximately 67,880 new cases expected in 2024 leading to nearly 13,250 deaths.1 In 2022, there were approximately 124,874 new cases and 30,272 deaths in Europe from endometrial cancer, while on a global scale there were 420,368 new cases and approximately 97,723 deaths.2 Since 2000, the incidence of new cases and deaths from endometrial cancer have risen.3 Risk factors include obesity, Type 2 diabetes, high-fat diets, use of tamoxifen and oral estrogens, and delayed menopause.4 About XPOVIO® (selinexor) XPOVIO is a first-in-class, oral exportin 1 (XPO1) inhibitor and the first of Karyopharm's Selective Inhibitor of Nuclear Export (SINE) compounds approved for the treatment of cancer. XPOVIO functions by selectively binding to and inhibiting the nuclear export protein XPO1. XPOVIO is approved in the U.S. and marketed by Karyopharm in multiple oncology indications, including: (i) in combination with Velcade® (bortezomib) and dexamethasone (XVd) in adult patients with multiple myeloma who have received at least one prior therapy; (ii) in combination with dexamethasone in adult patients with relapsed or refractory multiple myeloma who have received at least four prior therapies and whose disease is refractory to at least two proteasome inhibitors, at least two immunomodulatory agents, and an anti-CD38 monoclonal antibody; and (iii) in adult patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), not otherwise specified, including DLBCL arising from follicular lymphoma, after at least two lines of systemic therapy. XPOVIO (also known as NEXPOVIO® in certain countries) has received regulatory approvals in various indications in a growing number of ex-U.S. territories and countries, including but not limited to the European Union, the United Kingdom, China, South Korea, Canada, Israel and Taiwan. XPOVIO and NEXPOVIO is marketed by Karyopharm's partners, Antengene, Menarini, Neopharm and FORUS, in China, South Korea, Singapore, Australia, Hong Kong, Germany, Austria, Israel and Canada. Please refer to the local Prescribing Information for full details. Selinexor is also being investigated in several other mid- and late-stage clinical trials across multiple high unmet need cancer indications, including in endometrial cancer and myelofibrosis. For more information about Karyopharm's products or clinical trials, please contact the Medical Information department at: Tel: +1 (888) 209-9326 Email: [email protected] SELECT IMPORTANT SAFETY INFORMATION Warnings and Precautions Thrombocytopenia: Monitor platelet counts throughout treatment. Manage with dose interruption and/or reduction and supportive care. Neutropenia: Monitor neutrophil counts throughout treatment. Manage with dose interruption and/or reduction and granulocyte colony‐stimulating factors. Gastrointestinal Toxicity: Nausea, vomiting, diarrhea, anorexia, and weight loss may occur. Provide antiemetic prophylaxis. Manage with dose interruption and/or reduction, antiemetics, and supportive care. Hyponatremia: Monitor serum sodium levels throughout treatment. Correct for concurrent hyperglycemia and high serum paraprotein levels. Manage with dose interruption, reduction, or discontinuation, and supportive care. Serious Infection: Monitor for infection and treat promptly. Neurological Toxicity: Advise patients to refrain from driving and engaging in hazardous occupations or activities until neurological toxicity resolves. Optimize hydration status and concomitant medications to avoid dizziness or mental status changes. Embryo‐Fetal Toxicity: Can cause fetal harm. Advise females of reproductive potential and males with a female partner of reproductive potential, of the potential risk to a fetus and use of effective contraception. Cataract: Cataracts may develop or progress. Treatment of cataracts usually requires surgical removal of the cataract. Adverse Reactions The most common adverse reactions (≥20%) in patients with multiple myeloma who receive XVd are fatigue, nausea, decreased appetite, diarrhea, peripheral neuropathy, upper respiratory tract infection, decreased weight, cataract and vomiting. Grade 3‐4 laboratory abnormalities (≥10%) are thrombocytopenia, lymphopenia, hypophosphatemia, anemia, hyponatremia and neutropenia. In the BOSTON trial, fatal adverse reactions occurred in 6% of patients within 30 days of last treatment. Serious adverse reactions occurred in 52% of patients. Treatment discontinuation rate due to adverse reactions was 19%. The most common adverse reactions (≥20%) in patients with multiple myeloma who receive Xd are thrombocytopenia, fatigue, nausea, anemia, decreased appetite, decreased weight, diarrhea, vomiting, hyponatremia, neutropenia, leukopenia, constipation, dyspnea and upper respiratory tract infection. In the STORM trial, fatal adverse reactions occurred in 9% of patients. Serious adverse reactions occurred in 58% of patients. Treatment discontinuation rate due to adverse reactions was 27%. The most common adverse reactions (incidence ≥20%) in patients with DLBCL, excluding laboratory abnormalities, are fatigue, nausea, diarrhea, appetite decrease, weight decrease, constipation, vomiting, and pyrexia. Grade 3‐4 laboratory abnormalities (≥15%) are thrombocytopenia, lymphopenia, neutropenia, anemia, and hyponatremia. In the SADAL trial, fatal adverse reactions occurred in 3.7% of patients within 30 days, and 5% of patients within 60 days of last treatment; the most frequent fatal adverse reactions was infection (4.5% of patients). Serious adverse reactions occurred in 46% of patients; the most frequent serious adverse reaction was infection (21% of patients). Discontinuation due to adverse reactions occurred in 17% of patients. Use In Specific Populations Lactation: Advise not to breastfeed. For additional product information, including full prescribing information, please visit . To report SUSPECTED ADVERSE REACTIONS, contact Karyopharm Therapeutics Inc. at 1‐888‐209‐9326 or FDA at 1‐800‐FDA‐1088 or . About Karyopharm Therapeutics Karyopharm Therapeutics Inc. (Nasdaq: KPTI) is a commercial-stage pharmaceutical company whose dedication to pioneering novel cancer therapies is fueled by a belief in the extraordinary strength and courage of patients with cancer. Since its founding, Karyopharm has been an industry leader in oral compounds that address nuclear export dysregulation, a fundamental mechanism of oncogenesis. Karyopharm's lead compound and first-in-class, oral exportin 1 (XPO1) inhibitor, XPOVIO® (selinexor), is approved in the U.S. and marketed by the Company in three oncology indications. It has also received regulatory approvals in various indications in a growing number of ex-U.S. territories and countries, including Europe and the United Kingdom (as NEXPOVIO®) and China. Karyopharm has a focused pipeline targeting indications in multiple high unmet need cancers, including in multiple myeloma, endometrial cancer, myelofibrosis, and diffuse large B-cell lymphoma (DLBCL). For more information about our people, science and pipeline, please visit , and follow us on Twitter at @Karyopharm and LinkedIn. Forward-Looking Statements This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Such forward-looking statements include those regarding the ability of selinexor to treat patients with endometrial cancer; and expectations related to the clinical development of selinexor and potential regulatory submissions of selinexor. Such statements are subject to numerous important factors, risks and uncertainties, many of which are beyond Karyopharm's control, that may cause actual events or results to differ materially from Karyopharm's current expectations. For example, there can be no guarantee that Karyopharm will successfully commercialize XPOVIO or that any of Karyopharm's drug candidates, including selinexor and eltanexor, will successfully complete necessary clinical development phases or that development of any of Karyopharm's drug candidates will continue. Further, there can be no guarantee that any positive developments in the development or commercialization of Karyopharm's drug candidate portfolio will result in stock price appreciation. Management's expectations and, therefore, any forward-looking statements in this press release could also be affected by risks and uncertainties relating to a number of other factors, including the following: the adoption of XPOVIO in the commercial marketplace, the timing and costs involved in commercializing XPOVIO or any of Karyopharm's drug candidates that receive regulatory approval; the ability to obtain and retain regulatory approval of XPOVIO or any of Karyopharm's drug candidates that receive regulatory approval; Karyopharm's results of clinical trials and preclinical studies, including subsequent analysis of existing data and new data received from ongoing and future studies; the content and timing of decisions made by the U.S. Food and Drug Administration and other regulatory authorities, investigational review boards at clinical trial sites and publication review bodies, including with respect to the need for additional clinical studies; the ability of Karyopharm or its third party collaborators or successors in interest to fully perform their respective obligations under the applicable agreement and the potential future financial implications of such agreement; Karyopharm's ability to enroll patients in its clinical trials; unplanned cash requirements and expenditures; development or regulatory approval of drug candidates by Karyopharm's competitors for products or product candidates in which Karyopharm is currently commercializing or developing; the direct or indirect impact of the COVID-19 pandemic or any future pandemic on Karyopharm's business, results of operations and financial condition; and Karyopharm's ability to obtain, maintain and enforce patent and other intellectual property protection for any of its products or product candidates. These and other risks are described under the caption "Risk Factors" in Karyopharm's Quarterly Report on Form 10-Q for the quarter ended March 31, 2024, which was filed with the Securities and Exchange Commission (SEC) on May 8, 2024, and in other filings that Karyopharm may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and, except as required by law, Karyopharm expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise. XPOVIO® and NEXPOVIO® are registered trademarks of Karyopharm Therapeutics Inc. Any other trademarks referred to in this release are the property of their respective owners. References 1American Cancer Society, About Endometrial Cancer: (accessed May 22, 2024) 2International Agency for Research on Cancer, World Health Organization. "Top 15 Cancer Sites) (accessed May 22, 2024) 3Seer Cancer Incidence Rate Estimates, National Cancer Institute. Bethesda, MD. (accessed May 22, 2024) 4American Cancer Society, Endometrial Cancer Risk Factors. (accessed May 22, 2024) SOURCE Karyopharm Therapeutics Inc.

Promising clinical activities and efficacies during dose escalations for four lead global rights programs targeting CD24, Claudin 18.2, CD73, and PD-L1/4-1BB Positive, differentiated cervical cancer data advancing mTORC1/2 inhibitor on registrational track for APAC markets RMB1.188 billion cash expected to support planned operations SHANGHAI and HONG KONG, March 22, 2024 /PRNewswire/ -- Antengene Corporation Limited ( "Antengene", SEHK: 6996.HK), a leading innovative, commercial-stage global biopharmaceutical company dedicated to discovering, developing and commercializing first-in-class and/or best-in-class medicines for cancer, today announced its full year results for the period ended December 31, 2023, and provided an update on the impressive progress of its clinical development pipeline over the last several months. "2023 has been a breakout year for Antengene, with excellent pipeline momentum across multiple first/best-in-class programs marked by encouraging clinical activities and efficacies during dose escalations for our four lead global-rights programs, namely ATG-031, ATG-022, ATG-037, and ATG-101 which are designed to target CD24, Claudin 18.2, CD73, and PD-L1/4-1BB. With respect to our APAC-rights programs, our second generation mTORC1/2 inhibitor ATG-008 has made steady progress towards registrational path for the indication of cervical cancer, complemented by the inclusion of XPOVIO® in the 2023 China National Reimbursement Drug List. Furthermore, we have entered into a partnership with Hansoh Pharma, a leading Chinese pharmaceutical company, for the commercialization of XPOVIO® in the Mainland of China," said Dr. Jay Mei, Antengene 's Founder, Chairman and C EO . "Looking into 2024 and beyond, we are confident that out four lead global rights programs will continue to deliver encouraging results and emerge as category leaders. Our current cash balance totaling RMB1.188 billion is expected to fund planned operations and product development. We look forward to report on our progress throughout the year, starting with the presentation of several abstracts at the American Association for Cancer Research Annual Meeting (AACR 2024)." 1. Momentous clinical development across four lead global-rights programs ATG-031 (anti-CD24 monoclonal antibody): Promising Activity at Starting Doses: ATG-031 is the first-in-class humanized anti-CD24 monoclonal antibody to enter the clinic for cancer in the U.S. ATG-031 acts by inhibiting the "don't eat me" signal while stimulating the "eat me" signal and enhances macrophage-mediated phagocytosis of cancer cells. Phase I "PERFORM" study: To date, a total of 5 late-stage cancer patients have been treated with ATG-031 in the Phase I dose escalation study. To date, no dose-limiting toxicities (DLTs) have been observed among the 5 patients. Tumor shrinkage based on CT scan was observed in one heavily pre-treated patient (7 prior lines of therapy). Key study sites include four major U.S. cancer centers: The University of Texas MD Anderson Cancer Center, the University of California San Francisco, the University of Colorado, and Yale University Cancer Center. Next ATG-031 Milestone: Completion of the dose escalation portion of the Phase I "PERFORM" Study in H1 2025. ATG-022 (Claudin 18.2 antibody-drug conjugate, "ADC"): Potential to Target Claudin 18.2 Low Expressors: ATG-022 is differentiated by its potential ability to be active across a range of Claudin 18.2 expression levels, including in low expressors. Antengene has also developed a companion diagnostic assay to support the clinical program. The ADC has been awarded two Orphan Drug Designations (ODD) by the U.S. Food and Drug Administration (FDA) for treatment of gastric and pancreatic cancers. Phase I "CLINCH" study: To date, 7 gastric cancer patients (without pre-screening patients' Claudin 18.2 expression levels) have been treated with ATG-022. Antengene has observed one complete response (CR) and one partial response (PR) in 2 patients with metastatic gastric cancer. In the 2.4 mg/kg dose cohort, one patient with extremely low expression of Claudin 18.2 achieved CR, while one patient from the 1.8 mg/kg dose cohort achieved PR. The study has already completed the dose escalation portion and initiated the dose expansion portion. Next ATG-022 Milestone: Clinical data readout of Phase I "CLINCH trial", including preliminary efficacy and safety in H2 2024. ATG-037 (CD73 small molecule inhibitor): Early Combination Activity Shown Potential in Reversing Prior PD-1 Resistance: Inhibiting CD73 is intended to stop the production of adenosine, a key immunosuppressive molecule in the tumor microenvironment. As a small molecule inhibitor of CD73, ATG-037 has demonstrated pre-clinically the ability to overcome the "hook effect" that can limit efficacy and is commonly seen in anti-CD73 antibodies. Antengene entered into a global clinical collaboration with MSD and is currently evaluating this molecule in combination with the anti-PD-1 therapy, KEYTRUDA® (pembrolizumab), in patients with locally advanced or metastatic solid tumors. Phase I "STAMINA" study: In the dose escalation segment of ATG-037 combined with pembrolizumab, Antengene has observed PRs in two patients with melanoma and one patient with non-small cell lung cancer (NSCLC), all of whom were refractory to prior treatment with checkpoint inhibitors (CPIs). To date, 23 patients have been enrolled and received a first tumor assessment. Next ATG-037 Milestone: Completion of Phase I dose escalation and proceed to dose expansion in H1 2024. ATG-101 (PD-L1/4-1BB bispecific antibody): Durable Responses at Low Doses with No Off-Target Hepatotoxicity Observed and Efficacy in Cold Tumors: ATG-101's differentiated approach to targeting PD-L1 resistant cancers incorporates the T-cell co-stimulatory receptor 4-1BB. The bispecific antibody utilizes high PD-L1 affinity and conditional 4-1BB activation, to reduce the risk of hepatotoxicity. Phase I "PROBE" study: Antengene has observed a PR in a patient with metastatic colon adenocarcinoma (microsatellite stability biomarker [MSS], liver metastasis, and three prior lines of therapy). In addition, SD has been observed in two patients for longer than 1 year. Next ATG-101 Milestone: Completion of Phase I dose escalation and proceed to dose expansion in H1 2025. Progressing Early programs: Antengene continues to advance IND candidate, ATG-042 ( MTAPnull-selective PRMT5 Inhibitor), and the proprietary AnTenGagerTM "2+1" T cell engager platform. 2. Steadily progressing mid/late-stage clinical programs continue to demonstrate clinical potentials ATG-008 (mTORC1/2 small molecule inhibitor): Positive, Robust Cervical Cancer Data -The mTOR complex regulates different cellular processes and is upregulated in multiple tumors. mTORC1 and mTORC2 have to be inhibited simultaneously to maximize efficacy and minimize the development of resistance. ATG-008 was designed to inhibit both. Phase II "TORCH-2" study: ATG-008 has demonstrated positive Phase II results in cervical cancer that position the program to have a competitive profile compared to other agents approved across different global markets. The Phase II "TORCH-2" study is currently enrolling both checkpoint inhibitor (CPI)-naïve and CPI-pre-treated patients. Based on the latest data review as of March 14th, 2024, out of the 31 CPI-naïve patients who received treatment (30 had at least one tumor assessment), the objective response rate (ORR) was observed to be 53.3%, the disease control rate (DCR) was 86.7%. Among the 30 patients with prior CPI treatment (26 patients had at least one tumor assessment), the ORR was 23.1%, with a DCR of 84.6%. Next ATG-008 Milestone: Confirm registrational pathway in cervical cancer with health authorities. 3. Solidifying presence in APAC markets through accelerating commercialization Antengene and Hansoh Pharma entered into a collaboration for the commercialization of XPOVIO® in the Mainland of China in August 2023. XPOVIO® has been added to the NRDL (2023 Version) as announced on December 14th, 2023. The updated NRDL, taking effect on January 1st, 2024, will significantly improve the accessibility of XPOVIO® in Mainland of China. As of December 2023, Antengene has successfully secured XPOVIO® regulatory approvals in seven markets: Mainland of China, Taiwan China, Hong Kong China, Macau China, Australia, South Korea, and Singapore. National reimbursement has been secured in 3 markets: Mainland of China (NRDL), Australia (Pharmaceutical Benefits Scheme), and Singapore (Cancer Drug List). In June 2023, the coverage of XPOVIO® by the Australian Pharmaceutical Benefits Scheme (PBS) was extended from Xd to include both XVd and Xd regimens. . 4. Strong cash and bank balance enabling continuous growth As of December 31, 2023, the company's cash resources of about RMB1.188 billion, coupled with careful spending to support the continuous growth, development, and operations of Antengene. To learn more about the annual financial results of 2023, please see the full announcement on the "Investor Relations" section of the website. About Antengene Antengene Corporation Limited ( "Antengene", SEHK: 6996.HK) is a leading commercial-stage R&D-driven global biopharmaceutical company focused on the discovery, development, manufacturing and commercialization of innovative first-in-class/best-in-class therapeutics for the treatment of hematologic malignancies and solid tumors, in realizing its vision of "Treating Patients Beyond Borders". Since 2017, Antengene has built a pipeline of 9 oncology assets at various stages going from clinical to commercial, including 6 with global rights, and 3 with rights for the APAC region. To date, Antengene has obtained 29 investigational new drug (IND) approvals in the U.S. and Asia, and submitted 11 new drug applications (NDAs) in multiple Asia Pacific markets, with the NDA for XPOVIO® (selinexor) already approved in Mainland of China, Taiwan China, Hong Kong China, Macau China, South Korea, Singapore and Australia. Forward-looking statements The forward-looking statements made in this article relate only to the events or information as of the date on which the statements are made in this article. Except as required by law, we undertake no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise, after the date on which the statements are made or to reflect the occurrence of unanticipated events. You should read this article completely and with the understanding that our actual future results or performance may be materially different from what we expect. In this article, statements of, or references to, our intentions or those of any of our Directors or our Company are made as of the date of this article. Any of these intentions may alter in light of future development. For a further discussion of these and other factors that could cause future results to differ materially from any forward-looking statement, please see the other risks and uncertainties described in the Company's Annual Report for the year ended December 31, 2023, and the documents subsequently submitted to the Hong Kong Stock Exchange. For more information, please contact: Investor Contacts: Donald Lung E-mail: [email protected] Mobile: +86 18420672158 PR Contacts: Peter Qian E-mail: [email protected] Mobile: +86 13062747000 SOURCE Antengene Corporation Limited

SHANGHAI and HONG KONG, March 20, 2024 /PRNewswire/ -- Antengene Corporation Limited ( "Antengene" SEHK: 6996.HK), a leading innovative, commercial-stage global biopharmaceutical company dedicated to discovering, developing and commercializing first-in-class and/or best-in-class therapeutics in hematology and oncology, today announced that it has initiated the dose expansion portion of the Phase II CLINCH study of ATG-022 (Claudin 18.2 antibody-drug conjugate[ADC]) in China and Australia. Prior to this, the CLINCH trial has already produced promising preliminary clinical results with partial response (PR) and compete response (CR) . The CLINCH trial, consists of a dose escalation portion and a dose expansion portion, is a multi-center, open-label Phase I/II study of ATG-022 monotherapy in patients with advanced or metastatic solid tumors. The primary objective of the study is to evaluate the safety and tolerability of ATG-022 and to determine important dosing parameters including maximum tolerated dose (MTD) and recommended Phase II dose (RP2D) of ATG-022 monotherapy. The secondary objective is to characterize the pharmacology and evaluate the preliminary efficacy of ATG-022. The dose expansion portion of the study will enroll patients with gastric cancer or other solid tumors. In May 2023, the U.S. Food and Drug Administration (FDA) consecutively granted two Orphan Drug Designations (ODDs) to ATG-022 for the treatment of pancreatic cancer and gastric cancer, separately. Dr. Amily Zhang, Antengene's Chief Medical Officer, said, "We are excited that the dose expansion portion of the Phase II study of ATG-022 in China and Australia. The Phase I/II CLINCH trial is supported by strong preclinical data and has already made encouraging early observations with one PR and CR in two patients with metastatic gastric cancer. With the trial entering its next critical phase, we will continue working closely with regulators and investigators to fully explore the clinical potential of ATG-022." About ATG-022 ATG-022 is an antibody-drug-conjugate targeting Claudin 18.2. Claudins are cell adhesion molecules normally expressed within the tight junctions between cells to form a barrier that regulates cell permeability. In cancer, Claudins are expressed at the cell surface due to changes in cell polarity. The Claudin 18.2 is often overexpressed in various primary malignant tumors including gastric, esophageal, cholangiocarcinoma and pancreatic cancers. Data from preclinical studies, including results from gastric cancer-patient derived xenograft models presented at the 2022 American Association for Cancer Research (2022 AACR), showed that ATG-022 binds to Claudin 18.2 with low nanomolar affinity and demonstrated potent in vitro and in vivo antitumor effects, including in vivo efficacy demonstrated in Claudin 18.2 low expression models. This could pave the way for broad clinical utility of ATG-022 in gastric cancer patients with a wide range of Claudin 18.2 expression levels. ATG-022 demonstrated an excellent safety profile in Good Laboratory Practice (GLP) toxicology studies. About Antengene Antengene Corporation Limited ( "Antengene", SEHK: 6996.HK) is a leading commercial-stage R&D-driven global biopharmaceutical company focused on the discovery, development, manufacturing and commercialization of innovative first-in-class/best-in-class therapeutics for the treatment of hematologic malignancies and solid tumors, in realizing its vision of "Treating Patients Beyond Borders". Since 2017, Antengene has built a pipeline of 9 oncology assets at various stages going from clinical to commercial, including 6 with global rights, and 3 with rights for the APAC region. To date, Antengene has obtained 29 investigational new drug (IND) approvals in the U.S. and Asia, and submitted 11 new drug applications (NDAs) in multiple Asia Pacific markets, with the NDA for XPOVIO® (selinexor) already approved in Mainland of China, Taiwan China, Hong Kong China, Macau China, South Korea, Singapore and Australia. Forward-looking statements The forward-looking statements made in this article relate only to the events or information as of the date on which the statements are made in this article. Except as required by law, we undertake no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise, after the date on which the statements are made or to reflect the occurrence of unanticipated events. You should read this article completely and with the understanding that our actual future results or performance may be materially different from what we expect. In this article, statements of, or references to, our intentions or those of any of our Directors or our Company are made as of the date of this article. Any of these intentions may alter in light of future development. For a further discussion of these and other factors that could cause future results to differ materially from any forward-looking statement, please see the other risks and uncertainties described in the Company's Annual Report for the year ended December 31, 2022, and the documents subsequently submitted to the Hong Kong Stock Exchange. For more information, please contact: Investor Contacts: Donald Lung E-mail: [email protected] Mobile: +86 18420672158 PR Contacts: Peter Qian E-mail: [email protected] Mobile: +86 13062747000 SOURCE Antengene Corporation Limited