A Study of BPI-1178 in Patients With Advanced Solid Tumor and HR+/HER2- Breast Cancer

This is a study which consists of phase １study（dose-escalation study、dose-expansion study and PK trial） and phase 2a study. Phase 1 study will adopt the classical 3+3 dose escalation design, exploring the safety and tolerance of 6 dose cohorts (25mg, 75mg, 150mg, 250mg, 400mg and 500mg) in subjects with advanced solid tumor and determining the maximum tolerated dose of BPI-1178 for phase 2a study. Phase 2a is an open-label clinical study in subjects of HR+/HER2- breast cancer using 3+3 design, to evaluate the efficacy and safety of BPI-1178 in combination with endocrine therapy. Cohort A is BPI-1178 in combination with fulvestrant for advanced or recurrent HR+/HER2- breast cancer after failure or intolerance of non-fulvestrant first-line endocrine therapy. Cohort B is BPI-1178 in combination with letrozole for advanced or relapse more than 1 year after the end of adjuvant endocrine therapy as first-line treatment. Phase 1 and 2a consist of screening period (28 days before enrollment), treatment period and follow up period (every 3 months until death or the end of study). Phase 1 study: Subjects in each dose group will first receive a single dose. After a single dose for washout period, if the subject has no dose-limiting toxicity (DLT) related to the investigational product, the subject will enter the continuous dose cycle and receive continuous dose in a 28-day treatment cycle (single daily dose for 3 consecutive weeks/drug withdrawal for 1 week) .Once the maximum tolerated dose (MTD) is reached in phase 1, phase 2a study will explore the dose of BPI-1178 from MTD in combination with fulvestrant or letrozole. Phase 2a study: Subjects in Cohort A and Cohort B with intermittent dosing (3-week continuous dosing followed by 1-week rest) and continuous dosing (28-day continuous dosing) will be received in combination with fulvestrant or letrozole. Each 28-day is a complete treatment cycle during the concomitant-drug period. Dose limiting toxicity (DLT) will be recorded for the single dose period of 7 days and the multiple dose period up to 28 days in phase 1 study, as well as 28 days after the first dose of BPI-1178 in phase 2a. Efficacy will be evaluated by RECIST v1.1 and the Response Assessment in Neuro-Oncology Brain Metastases (RANO-BM) every 2 months. Adverse events will be monitored throughout the trial. Other exploration of pharmacokinetic information will be assessed throughout the trial.