Ascentage Pharma's Clinical Portfolio Gains Recognition at ASH 2025 Conference with Multiple Study Presentations

Ascentage Pharma Group International Inc. (NASDAQ: AAPG; HKEX: 6855) will showcase clinical evidence from several investigational programs at the 67th American Society of Hematology Annual Meeting scheduled for December 6-9, 2025, in Orlando, Florida. The conference will feature presentations spanning three therapeutic candidates—olverembatinib, lisaftoclax, and APG-5918—reflecting the company’s expanding clinical pipeline in hematologic malignancies.

The biopharmaceutical company has achieved a milestone by securing eight consecutive years of ASH conference presentations for olverembatinib (HQP1351), Ascentage Pharma’s proprietary third-generation BCR-ABL inhibitor and the first such agent approved in China. The drug is currently being commercialized in the Chinese market through a partnership with Innovent Biologics.

Pivotal Data from Global Phase III Study in Newly Diagnosed Acute Lymphoblastic Leukemia

Among the highlighted presentations, Ascentage Pharma will release inaugural efficacy and safety findings from POLARIS-1, a globally-designed Phase III registrational trial evaluating olverembatinib combined with low-intensity chemotherapy in patients with newly diagnosed Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). This represents a significant milestone for the program.

According to data analyzed through July 18, 2025, the trial enrolled 53 efficacy-evaluable patients. Clinical outcomes demonstrated robust response rates, with 50 patients (94.3%) achieving complete remission (CR) or CR with incomplete hematologic recovery following induction therapy. The trial’s primary endpoint—minimal residual disease (MRD) negativity at BCR-ABL/ABL1 ≤0.01%—was met in 66.0% of patients overall, with 64.2% achieving MRD-negative CR status.

A notable subset analysis examined outcomes in patients harboring IKZF1plus mutations combined with BTG1 deletion, a genomic signature associated with increased chemotherapy resistance and relapse risk in B-ALL. Among 10 such patients in the study, 90% (9/10) achieved molecular response at the conclusion of induction therapy, suggesting potential clinical benefit in this high-risk population.

Tolerability remained favorable throughout the trial. The most frequently observed grade 3 or higher treatment-related adverse events included neutropenia (63.6%), thrombocytopenia (56.4%), leukopenia (54.5%), anemia (49.1%), pneumonia (30.9%), hypokalemia (20%), and hepatic function abnormalities (16.4%)—predominantly representing expected hematologic toxicity patterns.

Extended Follow-Up Data in TKI-Resistant Chronic Myeloid Leukemia

Ascentage Pharma will present updated efficacy and safety results from a randomized, controlled Phase II registrational study examining olverembatinib in chronic-phase CML (CML-CP) patients who had demonstrated resistance or intolerance to first- and second-generation tyrosine kinase inhibitors (TKIs). This update incorporates four years of patient follow-up data.

The trial enrolled 144 CML-CP patients total, including 105 without T315I mutations, randomized in a 2:1 ratio to either olverembatinib or investigator-selected best available therapy (BAT). The primary efficacy measure was event-free survival (EFS).

Olverembatinib demonstrated substantial clinical advantage. In the overall CML-CP population as of January 13, 2025, median EFS reached 21.22 months for olverembatinib-treated patients compared to 2.86 months in the BAT arm (P<0.001). Among the T315I-mutation-negative subset, median EFS was 11.96 months versus 3.14 months, respectively (P=0.0159).

Secondary efficacy parameters consistently favored olverembatinib across the entire cohort: complete hematologic response rates were 85% versus 34.8%; complete cytogenetic response rates were 37.5% versus 18.9%; major molecular response rates were 29.5% versus 8.1% for olverembatinib and BAT groups, respectively. Among patients without T315I mutations receiving olverembatinib, complete hematologic response, complete cytogenetic response, and major molecular response rates were 82.1%, 25.8%, and 16.1%, respectively.

Safety monitoring revealed hematologic toxicities as the primary adverse event category in both treatment arms, with both olverembatinib and BAT demonstrating favorable tolerability profiles throughout the extended follow-up period.

Second-Line Treatment Outcomes in Chronic Phase CML

Additional ASH presentation material will include efficacy and safety data from an open-label, single-arm Phase II study evaluating olverembatinib at 40 mg administered every other day in CML-CP patients who had progressed on or become intolerant to one prior TKI therapy (including imatinib, flumatinib, nilotinib, or dasatinib) and lacked T315I mutations.

As of July 24, 2025, the trial enrolled 47 CML-CP patients without T315I mutations. Among 39 efficacy-evaluable patients, complete cytogenetic response was achieved in 71.8% (28/39), while major molecular response occurred in 43.6% (17/39). Response deepening was observed with extended treatment duration, with complete cytogenetic response and major molecular response rates reaching 90.0% and 60.0% by cycle 21, and 89.5% and 57.9% by cycle 24, respectively.

A subset of 30 patients had received second-generation TKIs as first-line therapy; among these, 76.7% achieved complete cytogenetic response and 43.3% attained major molecular response. The nine patients previously treated with imatinib showed complete cytogenetic response and major molecular response rates of 55.6% (5/9) and 44.4% (4/9).

Treatment-related adverse events of any grade occurred in 42 patients (89.4%), with 21 (44.7%) experiencing grade 3 or higher toxicity and 6 (12.8%) experiencing serious adverse events. Grade 3+ hematologic toxicities included platelet count reduction (42.6%), neutropenia (25.5%), and anemia (8.5%). No deaths were reported during the study period, with median treatment duration of 16.0 cycles.

Broader Clinical Program Recognition

Beyond olverembatinib, Ascentage Pharma’s oral presentation on lisaftoclax (APG-2575), a BCL-2 inhibitor, will present registrational Phase 2 data in relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) patients who previously failed Bruton’s tyrosine kinase inhibitor therapy. A separate poster presentation will detail lisaftoclax combined with azacitidine in newly diagnosed or prior venetoclax-exposed myeloid malignancies.

Preclinical and clinical data on APG-5918, an EED inhibitor, will also be featured, examining mechanisms of overcoming immunomodulatory drug resistance in multiple myeloma models.

Clinical Development Momentum

Dr. Yifan Zhai, Chief Medical Officer at Ascentage Pharma, stated that eight consecutive years of ASH conference presentations reflects sustained recognition from the international hematology community. The company is advancing three global Phase III registrational trials for olverembatinib and continues to prioritize accelerated clinical development to expand treatment options for patients with hematologic malignancies.

The 67th ASH Annual Meeting represents one of the largest international forums for hematology research and will include both in-person and virtual participation opportunities. Additional abstracts featuring lisaftoclax will be addressed in supplementary materials provided by Ascentage Pharma concurrent with this announcement.

Note: Olverembatinib, lisaftoclax, and APG-5918 remain investigational agents not yet approved by the FDA in the United States.