The study is comprised of a dose escalation part (Part I) exploring escalating doses of YH003 in combination with fixed dose toripalimab in subjects with advanced solid tumors (Part I), followed by an expansion part (Part II) with three expansion cohorts.~During Part I, dose escalation part of the study, a traditional 3+3 dose algorithm will be utilized to identify MTD(maximum tolerated dose) and/or RP2D (recommended phase 2 dose).~This dose escalation part will consist two phases, the run-in phase to explore safety and tolerability of YH003 as single agent and the combination phase to explore safety and tolerability of escalating doses of YH003 in combination with fixed dose Toripalimab.~The Phase II expansion part of this clinical trial will include three parallel cohorts(cohort 2A, 2B and 2C) of 20 subjects each treated with a dose around the RP2D of YH003 in combination with Toripalimab to assess the antitumor activity and safety/tolerability. One expansion cohort (2A) is YH003 and toripalimab in subjects with unresectable/metastatic melanoma, the other two expansion cohorts (2B and 2C) are YH003 and toripalimab with or without nab-paclitaxel + gemcitabine in unresectable/ metastatic pancreatic ductal adenocarcinoma.~Subjects will be monitored for safety, tolerability and efficacy throughout the study.
This is a phase I/II, multi-center, open-label study of YH003 in combination with Toripalimab (anti-PD-1 mAb). The study is comprised of a dose escalation part (Part I) exploring escalating doses of YH003 in combination with fixed dose toripalimab in subjects with advanced solid tumors (Part I), followed by an expansion part (Part II) with three expansion cohorts.