Design, preclinical evaluation, and multicenter phase 1 clinical study of HZ-A-018 for relapsed or refractory central nervous system lymphoma.

Effective therapy for relapsed or refractory central nervous system lymphoma (r/r CNSL) remains an unmet medical need. Meanwhile, developing antitumor drugs for CNS malignancies faces the dual challenge of achieving effective blood‒brain barrier (BBB) penetration and potent tumor cell killing. To address these challenges, a comprehensive predictive system was established to support decision-making during the discovery of HZ-A-018, a potent and BBB-permeable Bruton tyrosine kinase (BTK) inhibitor. This study further presents key preclinical results for HZ-A-018, as well as efficacy/safety data from a multicenter Phase 1 trial in r/r CNSL patients. HZ-A-018 demonstrated manageable safety, with only 19.2% of patients experienced grade 3 or higher adverse events according to the Common Terminology Criteria for Adverse Events version 5.0. Treatment with HZ-A-018 at the recommended phase II dose (RP2D) of 600 mg achieved an overall response rate (ORR) of 72.7% (95% CI, 39.0-94.0) and a 12-month survival rate of 90.5%. The Center for Drug Evaluation in China has authorized the initiation of this single-arm Phase II study as a pivotal registrational clinical trial for accelerated approval of HZ-A-018 for monotherapy in patients with r/r PCNSL. This trial has been registered under the identifiers ChiCTR2400091821 at www.chictr.org.cn and CTR20210181 at www.chinadrugtrials.org.cn.