This is a first-in-human (FIH), phase Ⅰ/Ⅱa, open-label, multicenter clinical study of HMPL-A251 monotherapy in adult participants with unresectable, advanced or metastatic HER2-expressing solid tumors.
Histologically confirmed unresectable advanced or metastatic disease.
Have at least one measurable lesion per RECIST v1.1;
Life expectancy ≥ 12 weeks;
Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0-1;
An established diagnosis of type I diabetes mellitus or uncontrolled type II diabetes mellitus.
Use of strong inhibitors of cytochrome P450 3A4 enzyme (CYP3A4), and inhibitors of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) within 5 elimination half-lives or 2 weeks (whichever is longer) before the first dose of study drug;
Toxicity from prior anti-tumor therapy has not recovered to Grade 1 or baseline prior to the first dose of study drug (except alopecia). Participants with chronic Grade 2 toxicities may be eligible after discussion between the investigator and Sponsor Medical Monitor (e.g., Grade 2 chemotherapy-induced neuropathy);
Baseline blood amylase or lipase exceeds the normal range and are judged by the investigators to be clinically significant;