Ascentage Pharma announced that the registrational Phase III study (HQP1351AG301, NCT06051409) of olverembatinib, Ascentage Pharma's lead drug candidate, combined with chemotherapy, versus imatinib combined with chemotherapy in treatment-naïve patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) has dosed its first patient. As a global best-in-class drug, olverembatinib holds the promise of becoming the first tyrosine kinase inhibitor (TKI) approved in China for the first-line treatment of Ph+ ALL This global multi-center, randomized-controlled, open-label, registrational Phase III study (HQP1351AG301) is designed to evaluate the efficacy and safety of olverembatinib combined with chemotherapy versus imatinib combined with chemotherapy in newly-diagnosed patients with Ph+ ALL. Accounting for 20%-30% of all ALL cases in adults, Ph+ ALL is commonly associated with a high relapse rate, short progression-free survival, and poor prognosis.

Prior to the introduction of TKIs, a class of targeted small molecule compounds, allogeneic hematopoietic stem cell transplantation (allo-HSCT) after achieving complete responses (CRs) from chemotherapy was widely adopted as a first-line treatment for patients with Ph+ ALL. However, the five-year overall survival (OS) was only less than 30% and more than 70% patients relapsed before the transplantation or simply lacked access to the surgical treatment. The clinical adoption of TKIs has resulted in a new clinical paradigm for patients with Ph+ ALL.

However, first and second-generation TKIs have known clinical limitations, including high relapse rates and disappointing long-term survival with a three to five-year OS rate of just about 50%. These limitations are primarily caused by low complete molecular responses (CMRs) and T315I kinase domain mutations, thus leaving substantial room for improvement in the treatment of Ph+ ALL. Currently, no TKI has been approved for the first-line treatment of Ph+ ALL in China and third-generation TKIs with more potent efficacy can potentially provide better prognosis to patients with Ph+ ALL by inducing a higher rate of CMRs and inhibiting the T315I mutation.

Ascentage Pharma's novel drug candidate, olverembatinib, is an orally-administered third-generation TKI and the first and only China-approved third-generation BCR-ABL inhibitor. Currently, olverembatinib is being jointly commercialized by Ascentage Pharma and Innovent Biologics. In November 2021, Olverembatinib was approved by the Center for Drug Evaluation (CDE) of the China National Medical Products Administration (NMPA) for the treatment of adult patients with TKI-resistant chronic-phase chronic myeloid leukemia (CML-CP) or accelerated-phase CML (CML-AP) harboring the T315I mutation.

Previously, olverembatinib received a recommendation from the Chinese Society of Clinical Oncology (CSCO) Guidelines for the Diagnosis and Treatment Hematologic Malignancies as a treatment option for patients with Ph+ ALL.