TRLS-06. A Phase 1–2 clinical trial of EO1001 (APL-122), a novel irreversible pan-ErbB inhibitor with promising brain penetration

CNS metastases are a prominent driver of cancer morbidity and mortality, especially as targeted therapies have improved systemic outcomes. Mutations in the ErbB/HER kinase family are known oncodrivers in many cancers. Extensive cross-talk among ErbB/HER receptors suggests that inhibition of multiple family members may benefit treatment and limit drug resistance. There is a desperate need for new agents that are more tolerable and effective in treating CNS metastases. EO1001 (APL-122) is a first-in-class, oral, irreversible pan-ErbB inhibitor targeting ErbB1, ErbB2 and ErbB4 with promising CNS penetration in preclinical models. Preclinical data suggests a favorable pharmacokinetic and safety profile and activity against ErbB-driven cancers in patient-derived xenograft models. We report on a first-in-human Phase 1–2 clinical trial in progress. Adult participants with confirmed ErbB-positive cancer, including patients with CNS involvement, who have progressed after standard-of-care, with adequate bone marrow, renal and liver function are eligible. Materials and methods Escalation: One subject per dose cohort is enrolled in an accelerated dose-escalation design until drug-related toxicity (≥G2) is observed in the first cycle, after which dose escalation will revert to a 3 + 3 design to determine the maximum tolerated dose (MTD). Cycle 1: Patients receive a single oral dose of EO1001 on day 1; single-dose pharmacokinetics are measured. Beginning on day 8, EO1001 is administered once daily for 21 days; multi-dose pharmacokinetics are measured. Cycles 2–6: EO1001 is administered once daily in continuous 28-day cycles for up to 20 weeks. Expansion: EO1001 is administered once daily to 20 patients at the MTD in continuous 28-day cycles for up to 6 cycles to determine a recommended Phase 2 dose (RP2D) for further study. Toxicity is assessed based on NCI CTCAEv5 and tumor response is assessed by RECIST 1.1. CNS exposure is evaluated in patients via CSF collection with confirmed CNS disease involvement.