Olverembatinib combined with venetoclax and reduced-intensity chemotherapy for adult newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia: a single-center, single-arm, phase 2 trial.

Tyrosine kinase inhibitors (TKIs) combined with chemotherapy and immunotherapy evolved as the standard treatment for newly diagnosed (ND) Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph ALL). Nonetheless, the efficacy and safety of combining TKIs with BCL-2 inhibitors in ND Ph ALL have yet to be fully elucidated. Hence, we carried out a prospective clinical trial to explore the efficacy and safety of olverembatinib combined with venetoclax and reduced-intensity chemotherapy as frontline treatment in Ph ALL. From October 2022 to March 2024, a total of 79 patients with a median age of 42 years completed a minimum of three cycles of olverembatinib and venetoclax-based regimen. The primary end point of the study was the complete molecular response (CMR) rate at 3 months. Ultimately, the regimen achieved CMR of 62.0% at 3 months in the absence of intensive chemotherapy or immunotherapy. No deaths occurred during the induction phase. With a median follow-up of 12 months, the estimated 1-year overall survival (OS) and event-free survival (EFS) rates were 93.1% (95% CI 86.4-99.8) and 89.1% (95% CI 80.3-97.9), respectively. Transcriptomic data revealed a potential complementary mechanism between TKIs and venetoclax, thereby verifying the rationale for the combination of these two agents. In conclusion, our study provides an alternative treatment strategy for patients with ND Ph ALL, particularly for those who are unfit or unavailable for immunotherapy or intensive chemotherapy at the initial stage of treatment. Clinical trial registration: The study was registered at https://clinicaltrials.gov/ with the registration number of NCT05594784.