This is a Phase I, open-label，dose-escalation trial in patients with relapsed or refractory multiple myeloma. There are two parts of the study: a dose-escalation part and a dose-expansion part. Dose escalation follows an accelerated design initially with 2 single subject cohorts (Cohorts 1-2) and switches to a classical 3+3 design (Cohorts 3-7). Dose-expansion means that at least 9 subjects (included subjects of the dose-escalation part) will be selected in 1 - 3 dose levels to focus on the pharmacokinetics (PK) / pharmacodynamic (PD) features and recommended dose for Phase II (RP2D). Additional purpose of the study is to find out whether the study drug has anti-tumor effects.
The main purpose of this Phase I study is to access the safety and tolerability of Y150 at different dose levels. It is hoped to find out the recommended dose for Phase II/III.