This study is an open-label, Phase 1 study to evaluate the safety, tolerability, PK, and pharmacodynamic profiles of AGEN1223 as a single-agent and in combination with balstilimab, as well as to assess the maximum tolerated dose and determine the RP2D of AGEN1223 as a single-agent and in combination with balstilimab in subjects with advanced solid tumors. This Phase 1 study will be conducted in an accelerated titration (for the first 2 single agent AGEN1223 dosing cohorts) and standard 3+3 dose escalation format. Study drug treatment will be administered on Day 1 of each 3-week cycle for up to 2 years or until any progressive disease (PD) or unacceptable toxicity is reported. The timing of the administration of doses may be adjusted for management of adverse events (AEs). The safe starting dose of AGEN1223 single-agent will be at the estimated minimally anticipated biological effect level.~The treatment phase is divided into 3-week cycles with associated evaluations and procedures that must be performed at specific time points. Tumor assessments will be conducted every 6 weeks (±7 days) from first dose until treatment discontinuation or disease progression. In subjects that discontinue treatment for reasons other than PD, imaging will continue until PD or initiation of a new therapy. If the subject discontinues treatment because of PD, imaging may be performed if clinically beneficial or if deemed necessary by the investigator until the initiation of new antineoplastic therapy. This must be approved by the Sponsor.~A Safety Monitoring Committee (SMC) will be established to assess safety and determine dose escalation.
This study is an open-label, Phase 1 study to evaluate the safety, tolerability, PK, and pharmacodynamic profiles of AGEN1223 as a single-agent and in combination with balstilimab, as well as to assess the maximum tolerated dose and determine the RP2D of AGEN1223 as a single-agent and in combination with balstilimab in subjects with advanced solid tumors.