UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington,D.C. 20549

Form6-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 August 2025

Commission File Number: 002-023311

ASCENTAGE PHARMA GROUP INTERNATIONAL

(Translation of Registrant’s name intoEnglish)

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 annualreports under cover of Form 20-F or Form 40-F.

Form 20-F ☒            Form40-F ☐

On August 7, 2025, AscentagePharma Group International issued a press release entitled, “Ascentage Pharma to Report 2025 Six Month Interim Results and ProvideCorporate Update on August 20, 2025”. A copy of the press release is furnished as Exhibit 99.1 to this Report.

INDEX TO EXHIBITS

SIGNATURE

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

Exhibit 99.1

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

Ascentage Pharma to Report 2025 Six Month Interim Results andProvide Corporate Update on August 20, 2025

Your publication date and time will appear here.| Source:ASCENTAGEPHARMA GROUP INTERNATIONAL

ROCKVILLE, Md. and SUZHOU, China, Aug. 07, 2025 (GLOBE NEWSWIRE) --Ascentage Pharma Group International (NASDAQ: AAPG; HKEX: 6855) (“Ascentage Pharma” or the “Company”),a global biopharmaceutical company dedicated to addressing unmet medical needs in cancers, announced today that it will release its sixmonths 2025 unaudited interim results and provide business updates at 7:00 pm Eastern Daylight Time (EDT) on August 20, 2025 / 7:00 amHong Kong Time (HKT) on August 21, 2025.

Analysts and investors are invited to join the investor webcast withQ&A, conducted by the Company’s management team.

Ascentage Pharma will host a Chinese (Mandarin) language investor webcastat 9:00 pm EDT on August 20, 2025 / 9:00 am HKT on August 21, 2025.  To access the Chinese language investor event or conferencecall, please register in advance here.

The English language investor webcast will be held at 8:00 am EDT /8:00 pm HKT on August 21, 2025. To access the English language webcast, please register in advance here. The webcastreplay for English language presentation will also be available on the News & Events page of the Ascentage Pharma website.

About Ascentage Pharma Group International

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

The Company’s first approved product, Olverembatinib, is thefirst novel third-generation BCR-ABL1 inhibitor approved in China for the treatment of patients with CML in chronic phase (CML-CP) withT315I mutations, CML in accelerated phase (CML-AP) with T315I mutations, and CML-CP that is resistant or intolerant to first and second-generationTKIs. It is covered by the China National Reimbursement Drug List (NRDL). Ascentage Pharma is currently conducting an FDA-cleared registrationalPhase III trial, called POLARIS-2, of Olverembatinib for CML, as well as registrational Phase III trials for patients with newly diagnosedPh+ ALL, called POLARIS-1, and SDH-deficient GIST patients, called POLARIS-3.

The Company’s second approved product, Lisaftoclax, is a novelBcl-2 inhibitor for the treatment of various hematologic malignancies. Lisaftoclax has been approved by China’s National MedicalProducts 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 currentlyconducting four global registrational Phase III trials: the FDA-cleared GLORA study of Lisaftoclax in combination with BTK inhibitorsin patients with CLL/SLL previously treated with BTK inhibitors for more than 12 months with suboptimal response; the GLORA-2 study inpatients with newly diagnosed CLL/SLL; the GLORA-3 study in newly diagnosed, elderly and unfit patients with AML; and the GLORA-4 studyin patients with newly diagnosed higher risk MDS.

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

Contacts

Investor Relations:

Hogan Wan, Head of IR and Strategy
Ascentage Pharma
Hogan.Wan@ascentage.com
+86 512 85557777

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

Media Relations:

Jon Yu
ICR Healthcare
AscentagePR@icrhealthcare.com
+1 (646) 677-1855