Ascentage Pharma Presents Updated Clinical Data for Olverembatinib as Second-Line Therapy in CML-CP at ASCO 2026

Ascentage Pharma's Olverembatinib Shows Deepening Responses in CML-CP

Ascentage Pharma announced updated efficacy and safety data for olverembatinib as a second-line therapy in patients with chronic-phase chronic myeloid leukemia (CML-CP) at the 2026 ASCO Annual Meeting. The data, from a single-arm, multicenter, open-label study in China, showed that at cycle 24, patients achieved a complete cytogenetic response (CCyR) rate of 91.3% and a major molecular response (MMR) rate of 60.9%. Responses deepened over time, and olverembatinib maintained a stable and manageable safety profile with no new signals, further supporting its potential as a second-line treatment for CML-CP patients who failed first-line TKI therapy without the T315I mutation.

• Olverembatinib demonstrated significant and progressively deepening anti-tumor activity in CML-CP patients. At cycle 24, the complete cytogenetic response (CCyR) rate reached 91.3%, and the major molecular response (MMR) rate was 60.9%. These high response rates were also observed in patients previously treated with second-generation TKIs, indicating strong efficacy over longer treatment durations.
• The drug maintained a stable and manageable safety profile during long-term treatment, with no new safety signals identified. The overall incidence of treatment-related adverse events was 89.4%, predominantly low-grade events such as skin hyperpigmentation, hyperuricemia, and increased creatine phosphokinase. Any observed grade ≥3 hematologic toxicities were recoverable with supportive treatment.
• The updated, more mature and encouraging results further support olverembatinib's role as a promising second-line treatment option for patients with CML-CP who have failed first-line TKI therapy and do not harbor the T315I mutation. These findings provide stronger evidence for clinical practice and contribute to optimizing treatment pathways for CML patients.

Olverembatinib's Durable Efficacy and Safety in Second-Line CML-CP

Recent clinical studies in chronic-phase chronic myeloid leukemia (CML-CP) have provided important insights into treatment outcomes across multiple therapeutic approaches. These studies encompass both established and emerging interventions, offering valuable data on efficacy and safety profiles for various patient populations.

• ASC4FIRST Trial (2025-2026) evaluated asciminib versus investigator-selected TKIs in newly diagnosed CML-CP, demonstrating superior major molecular response (MMR) rates at week 96: 74.1% with asciminib versus 52.0% with comparator TKIs (treatment difference 22.4%; P<0.001), with favorable safety profile including lower discontinuation rates due to adverse events compared to second-generation TKIs

• Italian Multicenter Prospective Cohort Study (2025) analyzed 1,433 CML patients comparing frontline imatinib versus second-generation TKIs, showing faster molecular responses with second-generation TKIs within the first 6 months (subhazard ratio 1.31; 95% CI 1.15-1.50) but similar 5-year overall survival rates of 88% between treatment groups

• Generic TKI Study from North Eastern India (2026) prospectively evaluated 85 newly diagnosed CML-CP patients treated with generic tyrosine kinase inhibitors, achieving complete hematological response in 94.11% of patients with BCR-ABL levels falling to 0.1% by 12 months in 60% of cases, while demonstrating manageable toxicity profile with neutropenia in 8.2% and edema in 14.1% of patients

• UK Multi-disciplinary TFR Programme (2025) assessed treatment-free remission outcomes in 37 patients over median follow-up of 37 months, achieving overall success rate of 70.3% with all patients who failed treatment-free remission successfully regaining disease control upon medication restart

Addressing Unmet Needs in TKI-Resistant CML-CP

Despite significant advances with tyrosine kinase inhibitors (TKIs), several critical challenges continue to limit optimal outcomes in CML-CP treatment. These limitations span from biological resistance mechanisms to practical clinical and economic considerations that affect both patients and healthcare systems.

• TKI resistance and intolerance - A significant proportion of patients do not achieve optimal response or develop resistance to TKI treatment, with nearly one-fifth of patients experiencing intolerance or resistance to imatinib specifically

• ABL kinase domain mutations - Mutations in the ABL kinase domain are extensively implicated in TKI resistance pathogenesis, detected in approximately 31% of resistant patients, with the T315I mutation presenting particular challenges as second-generation TKIs remain ineffective against this variant

• Treatment-free remission failures - Leukemic stem cells often persist and expand in approximately half of patients attempting TKI discontinuation, with myelofibrosis presence at diagnosis serving as a significant predictor of treatment-free remission failure

• Non-optimal treatment patterns - Nearly 25% of patients experience non-optimal treatment due to early treatment modifications or poor adherence, resulting in 80% more inpatient admissions and $13,551 additional per-patient-per-year medical costs

• Disease eradication limitations - Current therapies are not curative despite dramatic outcome improvements, with resistance mechanisms and BCR-ABL1-independent leukemia stem cell persistence preventing complete disease elimination

• Quality of life and adherence challenges - Even low-grade chronic side effects adversely affect patient quality of life and treatment adherence, which is essential for successful outcomes, while prolonged survival increases demands for ongoing patient education and adverse event management

• Treatment selection complexity - No controlled studies guide second-line therapy decisions, requiring individualized approaches based on leukemic cell characterization, patient comorbidities, and TKI safety profiles, with cardiovascular complications occurring in 4-6% of patients depending on the specific TKI used

Olverembatinib's Expanding Pipeline Beyond CML-CP

Beyond its established use in chronic-phase chronic myeloid leukemia, olverembatinib has demonstrated activity across multiple hematologic malignancies, particularly those harboring BCR::ABL1 mutations including the challenging T315I resistance mutation. The drug has shown particular promise in Philadelphia chromosome-positive acute lymphoblastic leukemia and accelerated-phase CML, with studies encompassing both pediatric and adult populations.

Olverembatinib's Broadened Horizon in Second-Line CML-CP

Olverembatinib's latest data presentation at ASCO 2026 marks a pivotal moment for its potential role in chronic myeloid leukemia (CML). Historically, this third-generation tyrosine kinase inhibitor (TKI) has been lauded for its potent activity against the challenging T315I gatekeeper mutation, a known driver of resistance to many first- and second-generation TKIs. However, these new results, demonstrating a remarkable 91.3% complete cytogenetic response (CCyR) and 60.9% major molecular response (MMR) at cycle 24 in second-line CML-CP patients without the T315I mutation, significantly broaden its therapeutic horizon.

This robust efficacy, coupled with a stable and manageable safety profile, positions olverembatinib as a compelling option for a wider segment of patients who have failed initial TKI therapy. In a landscape where patients often face resistance or intolerance to existing treatments, a new, highly effective, and well-tolerated agent is crucial for improving long-term outcomes and quality of life. The CML treatment paradigm is dynamic, with several potent TKIs available, including other third-generation agents like ponatinib and asciminib. Olverembatinib's performance in this non-T315I population suggests it could carve out a significant niche, offering a differentiated profile.

However, strategic considerations must account for the study's design as a single-arm, open-label trial conducted in China. While promising, these results will need validation in broader, potentially randomized, international studies to fully establish its comparative efficacy and safety against current standards of care. Furthermore, while the safety profile is manageable, long-term data on specific adverse events and their impact on patient adherence will be vital. The competitive environment also means continuous innovation and differentiation will be key to sustained market success. Nevertheless, these data underscore olverembatinib's potential to become a cornerstone therapy for a broader range of CML patients.