AbstractMutations causing errant ErbB activation are implicated in many cancers, including tumors correlated with high incidence of CNS metastasis. ErbB family member “crosstalk” is associated with rapid development acquired resistance to ErbB TKIs, particularly in advanced disease. The development of agents targeting multiple ErbB receptors has shown promise but has been limited by toxicity and poor brain penetration. EO1001 is a first-in-class, oral, brain penetrating, irreversible pan-ErbB inhibitor. Preclinical data suggests a favorable pharmacokinetic and safety profile and promising activity against ErbB-driven cancers in patient-derived xenograft models. EO1001 is being advanced into first-in-man studies under the Australia Clinical Trials Notification (CTN) scheme (ANZCTR Reg.#ACTRN12320000589343p). METHODS: Adult patients with confirmed ErbB-positive cancer, including patients with CNS involvement, who have progressed after standard of care therapy, with adequate bone marrow, renal and liver function are eligible. Toxicity is assessed by NCI CCTCAEv5 and tumor response is assessed by RECISTv1.1. CNS exposure is evaluated in in select patients with confirmed CNS disease involvement via CSF collection. An accelerated dose-escalation design is employed. One subject per dose cohort will be recruited until drug related toxicity (≥ G2) is observed, after which dose escalation will revert to a 3 + 3 design to determine the maximum tolerated dose (MTD). DOSE ESCALATION: Cycle 1: Patients will receive a single dose EO1001 on day 1 and single dose pharmacokinetics will be performed. Beginning on day 8, EO1001 will be administered once daily for 21 days; multi-dose pharmacokinetics will be performed. Cycles 2–6: Oral EO1001 will be administered once daily in continuous 28-day cycles for up to 20 weeks. MTD EXPANSION: Oral EO1001 will be administered once daily at the MTD in continuous 28-day cycles for up to 6 cycles (24 weeks). An update on the progress of this trial will be presented.