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Ascentage Pharma (NASDAQ: AAPG) showcases four AACR 2026 preclinical studies

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Ascentage Pharma Group International filed a report describing its participation in the AACR 2026 Annual Meeting, where it is presenting four preclinical poster studies on combination cancer therapies. The work features three drug candidates: olverembatinib, APG-2449, and APG-5918 across hematologic malignancies and solid tumors.

The studies explore olverembatinib beyond its approved use in China for chronic myeloid leukemia, including endometrial carcinoma and mantle cell lymphoma, as well as APG-2449 in BRAF V600E-mutant tumors and APG-5918 in small-cell lung cancer. These preclinical data are intended to help guide ongoing and planned global registrational trials in multiple cancer indications.

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Preclinical studies presented 4 studies Poster presentations at AACR 2026 Annual Meeting
AACR 2026 dates April 17–22, 2026 American Association for Cancer Research Annual Meeting in San Diego
Olverembatinib Phase III trials 3 trials POLARIS-1, POLARIS-2 and POLARIS-3 global registrational studies
Lisaftoclax Phase III trials 4 trials GLORA, GLORA-2, GLORA-3 and GLORA-4 global registrational studies
First approved product Olverembatinib Approved in China for several CML indications and listed on NRDL
Second approved product Lisaftoclax Approved in China for CLL/SLL after at least one prior systemic therapy
BCR-ABL inhibitor medical
"olverembatinib (HQP1351), a novel BCR-ABL inhibitor"
FAK/ALK/ROS1 triple tyrosine kinase inhibitor medical
"APG-2449, a FAK/ALK/ROS1 triple tyrosine kinase inhibitor"
PRC2/EED inhibitor medical
"APG-5918, a PRC2/EED inhibitor"
A PRC2/EED inhibitor is a drug that blocks a key part (EED) of the PRC2 complex, a cellular “off switch” that keeps certain genes silent. By releasing that brake, these drugs can reawaken genes that suppress tumors or change cell behavior, so they’re being explored for cancers and other diseases. Investors watch them because clinical progress, safety and regulatory decisions can dramatically affect a biotech’s value and future revenue prospects.
global registrational Phase III trial medical
"Ascentage Pharma is currently conducting an FDA-cleared global registrational Phase III trial"
chronic myeloid leukemia (CML) medical
"approved in China for chronic myeloid leukemia (CML)"
Chronic myeloid leukemia (CML) is a type of blood cancer in which bone marrow cells produce an overabundance of immature white blood cells, often driven by a specific genetic change. It progresses more slowly than some cancers but can become serious without treatment. Investors watch CML closely because new drugs, trial results, approvals or long-term treatment costs can significantly affect pharmaceutical revenues and healthcare spending — think of it like a factory that begins making too many defective parts and needs a costly retooling.
small-cell lung cancer (SCLC) medical
"preclinical small-cell lung cancer (SCLC) models"

 

 

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

 

Form 6-K

 

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16

under the Securities Exchange Act of 1934

 

For the month of April 2026

 

Commission File Number: 001-42484

 

ASCENTAGE PHARMA GROUP INTERNATIONAL

(Translation of Registrant’s name into English)

 

68 Xinqing Road

Suzhou Industrial Park

Suzhou, Jiangsu

China

(Address of principal executive offices)

 

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

 

Form 20-F Form 40-F

 

 

 

 

 

 

EXPLANATORY NOTE

 

On April 19, 2026, Ascentage Pharma Group International issued a press releases entitled “Ascentage Pharma to Present Four Promising Preclinical Studies Demonstrating the Potential of Combination Therapies at American Association for Cancer Research (AACR) 2026 Annual Meeting”. A copy of the press release is furnished as Exhibit 99.1. On April 20, 2026, Ascentage Pharma Group International issued an announcement entitled “Ascentage Pharma Presents Four Promising Preclinical Studies Demonstrating the Potential of Combination Therapies at American Association for Cancer Research (AACR) 2026 Annual Meeting”. A copy of the announcement is furnished as Exhibit 99.2.

 

1

 

 

INDEX TO EXHIBITS

 

Exhibit    
Number   Exhibit Title
     
99.1   Press Release dated April 19, 2026
99.2   Announcement dated April 20, 2026

 

2

 

 

SIGNATURE

 

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

 

  ASCENTAGE PHARMA GROUP INTERNATIONAL
   
Date: April 20, 2026 /s/ Dajun Yang
  Name: Dajun Yang
  Title: Chief Executive Officer

 

3

Exhibit 99.1 

 

 

 

Ascentage Pharma to Present Four Promising Preclinical

 

Studies Demonstrating the Potential of Combination

 

Therapies at American Association for Cancer Research (AACR)

 

2026 Annual Meeting

 

ROCKVILLE, Md. and SUZHOU, China, April 19, 2026 — Ascentage Pharma Group International (NASDAQ: AAPG; HKEX: 6855), a global, commercial stage, integrated biopharmaceutical company engaged in the discovery, development and commercialization of novel, differentiated therapies to address unmet medical needs in cancer, announced that it will present four preclinical studies in poster format at the American Association for Cancer Research (AACR) 2026 Annual Meeting, held April 17 to 22, 2026 in San Diego, CA, USA.

 

These posters feature three of the Company’s drug candidates, olverembatinib (HQP1351), a novel BCR-ABL inhibitor; APG-2449, a FAK/ALK/ROS1 triple tyrosine kinase inhibitor; and APG-5918, a PRC2/EED inhibitor.

 

Yifan Zhai, M.D., Ph.D., Chief Medical Officer of Ascentage Pharma, said, “These preclinical findings reflect our continued commitment to advancing innovative therapies across multiple cancer types. The four studies demonstrate the breadth and versatility of our pipeline, exploring the therapeutic potential of our key assets in combination with other approved treatment options in both hematologic malignancies and solid tumors.

 

 

 

 

 

Notably, the research examines olverembatinib’s potential beyond its approved use in China for chronic myeloid leukemia (CML), exploring new applications in areas such as endometrial carcinoma and mantle cell lymphoma, including combination approaches with BTK inhibitors. In addition, our evaluation of APG-2449 in BRAF-mutant tumors, and APG-5918 in small-cell lung cancer, underscores our strategic focus on addressing resistance mechanisms and exploring combination strategies.

 

These preclinical investigations are designed to inform our clinical development strategies and complement our ongoing global registrational trials as we bring new treatment options to patients with significant unmet medical needs.”

 

Detailed data presented at AACR 2026 Annual Meeting are summarized below:

 

(Abstract #4583)

 

Multitarget kinase inhibitor Olverembatinib (HQP1351) is efficacious and synergizes with chemotherapy in preclinical models of endometrial carcinoma (EC)

 

Background:

 

EC is the most common gynecologic malignancy in developed countries, with an incidence that is steadily increasing globally. Patients with advanced-stage, high-risk non-endometrioid EC subtypes or recurrent disease have a poor prognosis and limited treatment options.

 

Olverembatinib is a tyrosine kinase inhibitor approved by the National Medical Products Administration (NMPA) of China for the treatment of patients with CML. It targets multiple kinases, including VEGFR1–3, FGFR1–4, Src family kinases, RAF, KIT, RET, and PDGFR.

 

Drug sensitivity screening of 883 human cancer cell lines using the PRISM (Profiling Relative Inhibition Simultaneously in Mixtures) platform showed that EC is one of the tumor types most sensitive to olverembatinib. This study further explored the antitumor effects of olverembatinib alone or in combination with standard-of-care chemotherapy in preclinical EC models.

 

2

 

 

 

Summary:

 

In a broad range of preclinical in vitro and in vivo EC models, olverembatinib was efficacious and synergized with chemotherapy agents to promote antitumor effects.

 

Mechanistically, olverembatinib combined with chemotherapy suppressed FGFR2, PI3K/AKT, and MEK/ERK signaling pathways, induced DNA damage, and resulted in enhanced cell apoptosis.

 

These findings support future clinical evaluation of Olverembatinib and its combination with other approved treatment options in EC.

 

(Abstract #5875)

 

Multikinase inhibitor Olverembatinib (HQP1351) is efficacious and synergizes with BTK inhibitor acalabrutinib in mantle cell lymphoma (MCL) preclinical models

 

Background:

 

MCL is a rare, aggressive type of non-Hodgkin lymphoma. Although BTK inhibitors have transformed MCL treatment, response to monotherapy is limited, and efforts are underway to develop combination therapies.

 

Olverembatinib, an investigational multikinase inhibitor (approved in China for CML), inhibits Src-family kinases (e.g., Lyn, Fyn, YES1) and BTK, which are essential for B-cell receptor (BCR) signaling and B-cell proliferation, differentiation, and activation.

 

Hypothesizing that dual inhibition of Lyn and BTK pathways could enhance antitumor effects, this study evaluated olverembatinib in combination with acalabrutinib in preclinical MCL models and explored potential mechanisms of action.

 

Summary:

 

Olverembatinib potently inhibited MCL cell proliferation both in vitro and in vivo and showed synergistic effects when combined with acalabrutinib. The combination significantly promoted apoptosis and induced G0/G1 cell cycle arrest.

 

Mechanistically, olverembatinib inhibited phosphorylation of Lyn and its downstream BTK, while the combination further downregulated NF-kB activity.

 

These data provide a scientific rationale for further clinical evaluation of this novel combination therapy in patients with MCL.

 

3

 

 

 

(Abstract #1858)

 

FAK inhibition by APG-2449 enhances the antitumor activity of MAPK pathway blockade in BRAF V600E-mutant tumor models

 

Background:

 

BRAF mutations occur in approximately 4% to 8% of all cancers, most frequently in colorectal cancer (CRC), melanoma, and non-small-cell lung cancer. The V600E mutation is the most common and functionally activating form, leading to constitutive activation of the mitogen activated protein kinase (MAPK) signaling cascade.

 

Combined BRAF and MAPK kinase (MEK) inhibition has shown substantial clinical benefit in BRAF V600Emutant melanoma and CRC. However, resistance frequently develops through feedback reactivation of extracellular signal-regulated kinase (ERK) or compensatory activation of the phosphoinositide-3 kinase (PI3K)-AKT signaling pathway.

 

Recent evidence indicates that focal adhesion kinase (FAK) signaling is also adaptively reactivated upon MAPK inhibition, contributing to therapeutic resistance.

 

This study evaluated the effects of APG-2449, a potent and selective multi-kinase inhibitor that also targets FAK, on the antitumor activities of the BRAF inhibitor dabrafenib and the MEK inhibitor trametinib in BRAF V600E-mutant CRC and melanoma preclinical models.

 

Summary:

 

The results showed selective sensitivity of BRAF V600E-mutant cancer cell lines to APG-2449.

 

APG-2449 suppresses compensatory signaling activation induced by MAPK pathway blockade and synergistically enhances the antitumor activity of dabrafenib + trametinib in preclinical models.

 

These results warrant clinical development of APG-2449 for patients with melanoma or CRC harboring the BRAF V600E mutation.

 

4

 

 

 

(Abstract #4500)

 

Embryonic ectoderm development (EED) inhibitor APG-5918 synergizes with topoisomerase I inhibitors in preclinical small-cell lung cancer (SCLC) models through epigenetic priming of chemosensitivity

 

Background:

 

Although SCLC initially responds to platinum-based chemotherapy, it rapidly develops resistance, resulting in a poor prognosis.

 

PRC2-mediated epigenetic silencing represses Schlafen 11 (SLFN11), a biomarker of sensitivity to DNA-damaging therapies, thereby contributing to treatment resistance.

 

EZH2, the catalytic subunit of PRC2, promotes chemoresistance in part through SLFN11 repression. EED, another core PRC2 component, stabilizes the complex and maintains its methyltransferase activity, making it an attractive therapeutic target in SCLC.

 

Topoisomerase I inhibitors, such as topotecan and irinotecan, are used in relapsed SCLC; however, their efficacy is limited when SLFN11 is epigenetically suppressed.

 

APG-5918 is a selective and investigational EED inhibitor that disrupts PRC2 function. This study evaluated the antitumor activity of APG-5918 in combination with topoisomerase I inhibitors in preclinical SCLC models.

 

Summary:

 

In preclinical SCLC models, combination treatment with APG-5918 and topoisomerase I inhibitors synergistically inhibited cell proliferation and induced apoptosis.

 

In vivo, APG-5918 combined with irinotecan demonstrated synergistic antitumor activity in the NCI-H446 SCLC cell-derived xenograft (CDX) model without significant body-weight loss, indicating favorable tolerability.

 

Mechanistically, APG-5918 reduced the repressive histone mark H3K27me3, indicating on-target inhibition of PRC2 activity. Consistent with this effect, APG-5918 treatment increased SLFN11 and p21 expression. Notably, treatment with topotecan or SN-38 increased H3K27me3 levels, whereas APG-5918 reduced this effect. Combination treatment further decreased expression of PRC2 core components, suppressed cell-cycle progression, and enhanced DNA damage and apoptotic signaling, supporting a synergistic proapoptotic effect.

 

The findings support clinical investigation of APG-5918 in combination with DNA-damaging agents as a promising therapeutic strategy for SCLC.

 

*Olverembatinib, APG-2449, and APG-5918 are currently under investigation and have not been approved by the U.S. FDA.

 

5

 

 

 

About Ascentage Pharma

 

Ascentage Pharma Group International (NASDAQ: AAPG; HKEX: 6855) (“Ascentage Pharma” or the “Company”) is a global, commercial stage, integrated biopharmaceutical company engaged in the discovery, development and commercialization of novel, differentiated therapies to address unmet medical needs in cancer. The Company has built a rich pipeline of innovative drug products and candidates that include inhibitors targeting key proteins in the apoptotic pathway, such as Bcl-2 and MDM2-p53, next-generation kinase inhibitors, and protein degraders.

 

The Company’s first approved product, Olverembatinib, is the first novel third-generation BCR-ABL1 inhibitor approved in China for the treatment of patients with CML in chronic phase (CML-CP) with T315I mutations, CML in accelerated phase (CML-AP) with T315I mutations, and CML-CP that is resistant or intolerant to first and second-generation TKIs. It is covered by the China National Reimbursement Drug List (NRDL). Ascentage Pharma is currently conducting an FDA-cleared global registrational Phase III trial, called POLARIS-2, of Olverembatinib for CML, as well as global registrational Phase III trials for patients with newly diagnosed Ph+ ALL, called POLARIS-1, and SDH-deficient GIST patients, called POLARIS-3.

 

The Company’s second approved product, Lisaftoclax, is a novel Bcl-2 inhibitor for the treatment of various hematologic malignancies. Lisaftoclax has been approved by China’s National Medical Products Administration (NMPA) for the treatment of adult patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) who have previously received at least one systemic therapy including Bruton’s tyrosine kinase (BTK) inhibitors. The Company is currently conducting four global registrational Phase III trials: the FDA-cleared GLORA study of Lisaftoclax in combination with BTK inhibitors in patients with CLL/SLL previously treated with BTK inhibitors for more than 12 months with suboptimal response; the GLORA-2 study in patients with newly diagnosed CLL/SLL; the GLORA-3 study in newly diagnosed, elderly and unfit patients with AML; and the FDA-cleared GLORA-4 study in patients with newly diagnosed higher risk MDS.

 

Leveraging its robust R&D capabilities, Ascentage Pharma has built a portfolio of global intellectual property rights and entered into global partnerships and other relationships with numerous leading biotechnology and pharmaceutical companies, such as Takeda, AstraZeneca, Merck, Pfizer, and Innovent, in addition to research and development relationships with leading research institutions, such as Dana-Farber Cancer Institute, Mayo Clinic, National Cancer Institute and the University of Michigan. For more information, visit https://ascentage.com/

 

6

 

 

 

Cautionary Note Regarding Forward-Looking Statements

 

This press release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements, other than statements of historical facts, contained in this press release may be forward-looking statements, including statements that express Ascentage Pharma’s opinions, expectations, beliefs, plans, objectives, assumptions or projections regarding future events or future results of operations or financial condition. These forward-looking statements are subject to a number of risks and uncertainties as discussed in Ascentage Pharma’s filings with the SEC, including those set forth in the sections titled “Risk factors” and “Cautionary note regarding forward-looking statements” in its Annual Report on Form 20-F for the year ended December 31, 2024, filed with the SEC on April 16, 2025, the sections headed “Forward-looking Statements” and “Risks Factors” in the prospectus of the Company for its Hong Kong initial public offering dated October 16, 2019, and other filings with the SEC and/or The Stock Exchange of Hong Kong Limited where the Company’s ordinary shares are listed it has made or it makes from time to time that may cause actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. The forward-looking statements contained in this presentation do not constitute profit forecast by the Company’s management.

 

As a result of these factors, you should not rely on these forward-looking statements as predictions of future events. The forward-looking statements contained in this press release are based on Ascentage Pharma’s current expectations and beliefs concerning future developments and their potential effects and speak only as of the date of such statements. Ascentage Pharma does not undertake any obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

 

Contact Information

 

Investor Relations:
Stella Yang
Ascentage Pharma
Stella.Yang@ascentage.com

+1 (301) 792-6286

 

Stephanie Carrington
ICR Healthcare
AscentageIR@icrhealthcare.com
+1 (646) 277-1282

 

Media Relations:
Sean Leous
ICR Healthcare
AscentagePR@icrhealthcare.com
+1 (646) 866-4012

 

 

7

 

 

Exhibit 99.2 

 

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this announcement, make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement.

 

 

ASCENTAGE PHARMA GROUP INTERNATIONAL

亞盛醫藥集團

(Incorporated in the Cayman Islands with limited liability)

(Stock Code: 6855)

 

VOLUNTARY ANNOUNCEMENT

 

ASCENTAGE PHARMA PRESENTS FOUR PROMISING PRECLINICAL STUDIES DEMONSTRATING THE POTENTIAL OF COMBINATION THERAPIES AT AMERICAN ASSOCIATION FOR CANCER RESEARCH (AACR) 2026 ANNUAL MEETING

 

Ascentage Pharma Group International (the “Company” or “Ascentage Pharma”) is pleased to announce that it will present four preclinical studies in poster format at the American Association for Cancer Research (AACR) 2026 Annual Meeting, held from April 17, 2026 to April 22, 2026, in San Diego, California, USA.

 

These posters feature three of the Company’s drug candidates, olverembatinib (HQP1351), a novel BCR-ABL inhibitor; APG-2449, a FAK/ALK/ROS1 triple tyrosine kinase inhibitor; and APG-5918, a PRC2/EED inhibitor.

 

Notably, the research examines olverembatinib’s potential beyond its approved use in China for chronic myeloid leukemia (CML), exploring new applications in areas such as endometrial carcinoma and mantle cell lymphoma, including combination approaches with BTK inhibitors. In addition, our evaluation of APG-2449 in BRAF-mutant tumors, and APG-5918 in small-cell lung cancer, underscores our strategic focus on addressing resistance mechanisms and exploring combination strategies.

 

These preclinical investigations are designed to inform the Company’s clinical development strategies and complement the Company’s ongoing global registrational trials as the Company brings new treatment options to patients with significant unmet medical needs.

 

 

 

Detailed data from Ascentage Pharma presented at the AACR 2026 Annual Meeting are summarized below:

 

Multitarget kinase inhibitor Olverembatinib (HQP1351) is efficacious and synergizes with chemotherapy in preclinical models of endometrial carcinoma (EC)

 

Abstract number: 4583

 

Background:

 

EC is the most common gynecologic malignancy in developed countries, with an incidence that is steadily increasing globally. Patients with advanced-stage, high-risk non-endometrioid EC subtypes or recurrent disease have a poor prognosis and limited treatment options.

 

Olverembatinib is a tyrosine kinase inhibitor approved by the National Medical Products Administration (NMPA) of China for the treatment of patients with CML. It targets multiple kinases, including VEGFR1-3, FGFR1-4, Src family kinases, RAF, KIT, RET, and PDGFR.

 

Drug sensitivity screening of 883 human cancer cell lines using the PRISM (Profiling Relative Inhibition Simultaneously in Mixtures) platform showed that EC is one of the tumor types most sensitive to olverembatinib. This study further explored the antitumor effects of olverembatinib alone or in combination with standard-of-care chemotherapy in preclinical EC models.

 

Summary:

 

In a broad range of preclinical in vitro and in vivo EC models, olverembatinib was efficacious and synergized with chemotherapy agents to promote antitumor effects.

 

Mechanistically, olverembatinib combined with chemotherapy suppressed FGFR2, PI3K/ AKT, and MEK/ERK signaling pathways, induced DNA damage, and resulted in enhanced cell apoptosis.

 

These findings support future clinical evaluation of Olverembatinib and its combination with other approved treatment options in EC.

 

Multikinase inhibitor Olverembatinib (HQP1351) is efficacious and synergizes with BTK inhibitor acalabrutinib in mantle cell lymphoma (MCL) preclinical models

 

Abstract number: 5875

 

Background:

 

MCL is a rare, aggressive type of non-Hodgkin lymphoma. Although BTK inhibitors have transformed MCL treatment, response to monotherapy is limited, and efforts are underway to develop combination therapies.

 

Olverembatinib, an investigational multikinase inhibitor (approved in China for CML), inhibits Src-family kinases (e.g., Lyn, Fyn, YES1) and BTK, which are essential for B-cell receptor (BCR) signaling and B-cell proliferation, differentiation, and activation.

 

2

 

 

Hypothesizing that dual inhibition of Lyn and BTK pathways could enhance antitumor effects, this study evaluated Olverembatinib in combination with acalabrutinib in preclinical MCL models and explored potential mechanisms of action.

 

Summary:

 

Olverembatinib potently inhibited MCL cell proliferation both in vitro and in vivo and showed synergistic effects when combined with acalabrutinib. The combination significantly promoted apoptosis and induced G0/G1 cell cycle arrest.

 

Mechanistically, olverembatinib inhibited phosphorylation of Lyn and its downstream BTK, while the combination further downregulated NF-kB activity.

 

These data provide a scientific rationale for further clinical evaluation of this novel combination therapy in patients with MCL.

 

FAK inhibition by APG-2449 enhances the antitumor activity of MAPK pathway blockade in BRAF V600E-mutant tumor models

 

Abstract number: 1858

 

Background:

 

BRAF mutations occur in approximately 4% to 8% of all cancers, most frequently in colorectal cancer (CRC), melanoma, and non-small-cell lung cancer. The V600E mutation is the most common and functionally activating form, leading to constitutive activation of the mitogen activated protein kinase (MAPK) signaling cascade.

 

Combined BRAF and MAPK kinase (MEK) inhibition has shown substantial clinical benefit in BRAF V600E-mutant melanoma and CRC. However, resistance frequently develops through feedback reactivation of extracellular signal-regulated kinase (ERK) or compensatory activation of the phosphoinositide-3 kinase (PI3K)-AKT signaling pathway.

 

Recent evidence indicates that focal adhesion kinase (FAK) signaling is also adaptively reactivated upon MAPK inhibition, contributing to therapeutic resistance.

 

This study evaluated the effects of APG-2449, a potent and selective multi-kinase inhibitor that also targets FAK, on the antitumor activities of the BRAF inhibitor dabrafenib and the MEK inhibitor trametinib in BRAF V600E-mutant CRC and melanoma preclinical models.

 

Summary:

 

The results showed selective sensitivity of BRAF V600E-mutant cancer cell lines to APG-2449.

 

APG-2449 suppresses compensatory signaling activation induced by MAPK pathway blockade and synergistically enhances the antitumor activity of dabrafenib + trametinib in preclinical models.

 

These results warrant clinical development of APG-2449 for patients with melanoma or CRC harboring the BRAF V600E mutation.

 

3

 

 

Embryonic ectoderm development (EED) inhibitor APG-5918 synergizes with topoisomerase I inhibitors in preclinical small-cell lung cancer (SCLC) models through epigenetic priming of chemosensitivity

 

Abstract number: 4500

 

Background:

 

Although SCLC initially responds to platinum-based chemotherapy, it rapidly develops resistance, resulting in a poor prognosis.

 

PRC2-mediated epigenetic silencing represses Schlafen 11 (SLFN11), a biomarker of sensitivity to DNA-damaging therapies, thereby contributing to treatment resistance.

 

EZH2, the catalytic subunit of PRC2, promotes chemoresistance in part through SLFN11 repression. EED, another core PRC2 component, stabilizes the complex and maintains its methyltransferase activity, making it an attractive therapeutic target in SCLC.

 

Topoisomerase I inhibitors, such as topotecan and irinotecan, are used in relapsed SCLC; however, their efficacy is limited when SLFN11 is epigenetically suppressed.

 

APG-5918 is a selective and investigational EED inhibitor that disrupts PRC2 function. This study evaluated the antitumor activity of APG-5918 in combination with topoisomerase I inhibitors in preclinical SCLC models.

 

Summary:

 

In preclinical SCLC models, combination treatment with APG-5918 and topoisomerase I inhibitors synergistically inhibited cell proliferation and induced apoptosis.

 

In vivo, APG-5918 combined with irinotecan demonstrated synergistic antitumor activity in the NCI-H446 SCLC cell-derived xenograft (CDX) model without significant body-weight loss, indicating favorable tolerability.

 

Mechanistically, APG-5918 reduced the repressive histone mark H3K27me3, indicating on-target inhibition of PRC2 activity. Consistent with this effect, APG-5918 treatment increased SLFN11 and p21 expression. Notably, treatment with topotecan or SN-38 increased H3K27me3 levels, whereas APG-5918 reduced this effect. Combination treatment further decreased expression of PRC2 core components, suppressed cell-cycle progression, and enhanced DNA damage and apoptotic signaling, supporting a synergistic proapoptotic effect.

 

The findings support clinical investigation of APG-5918 in combination with DNA-damaging agents as a promising therapeutic strategy for SCLC.

 

4

 

 

Cautionary Statement required by Rule 18A.05 of the Listing Rules: WE MAY NOT BE ABLE TO ULTIMATELY DEVELOP AND MARKET PELCITOCLAX (APG-5918) and APG-2449 SUCCESSFULLY.

 

By order of the Board
 Ascentage Pharma Group International
 Dr. Yang Dajun
 Chairman and Executive Director

 

Suzhou, People’s Republic of China, April 20, 2026

 

As at the date of this announcement, the Board comprises Dr. Yang Dajun as Chairman and executive Director, Dr. Wang Shaomeng and Dr. Lu Simon DazhongNote1 as non-executive Directors, and Mr. Ye Changqing, Mr. Ren Wei, Dr. David SidranskyNote2, Ms. Marina S. Bozilenko, Dr. Debra Yu and Dr. Marc E. Lippman, MD as independent non-executive Directors.

 

Notes:

 

1.Dr. Lu Simon Dazhong satisfy the independence requirements of the U.S. Securities and Exchange Commission and Nasdaq corporate governance requirements

 

2.Dr. David Sidransky is the Lead Independent Non-Executive Director of the Company.

 

 

 

 

FAQ

What does Ascentage Pharma (AAPG) disclose in this Form 6-K?

Ascentage Pharma reports that it is presenting four preclinical poster studies at the AACR 2026 Annual Meeting. These studies evaluate combination strategies using olverembatinib, APG-2449, and APG-5918 across several cancer types to inform future clinical development.

What cancer indications are covered in Ascentage Pharma’s four preclinical studies?

The four studies cover endometrial carcinoma, mantle cell lymphoma, BRAF V600E-mutant tumors, and small-cell lung cancer. They focus on synergy between Ascentage’s candidates and other treatments, such as chemotherapy, BTK inhibitors, MAPK pathway blockade, and topoisomerase I inhibitors.

Is olverembatinib already approved for any indication according to Ascentage Pharma?

Yes. Olverembatinib is described as the first novel third-generation BCR-ABL1 inhibitor approved in China for certain chronic myeloid leukemia settings. The new preclinical work examines additional uses beyond these approved CML indications, including in endometrial carcinoma and mantle cell lymphoma.

What late-stage trials does Ascentage Pharma mention in this disclosure?

Ascentage Pharma notes global registrational Phase III trials for olverembatinib in CML, newly diagnosed Ph+ ALL, and SDH-deficient GIST. It also references four Phase III GLORA studies of lisaftoclax in CLL/SLL, AML, and higher-risk MDS, complementing its preclinical research portfolio.

Are APG-2449 and APG-5918 approved therapies according to Ascentage Pharma?

No. The document states that APG-2449 and APG-5918 are under investigation and have not been approved by the U.S. FDA. A cautionary statement notes there is no assurance the company will ultimately develop and market these candidates successfully.

Filing Exhibits & Attachments

2 documents