This is a Phase 1/2, open-label, multi-center study whose primary Phase 1 stage objective is to determine the maximum tolerated dose (MTD) or recommended phase 2 dose (RP2D) of RSO-021 (thiostrepton), a naturally-occurring, sulfur-rich, cyclic oligopeptide antibiotic of the thiopeptide class, in patients with MPE from any solid tumor, including mesothelioma.~In the Phase 2 stage, once the RP2D has been identified, the antitumor activity of RSO-021 will be evaluated in two expansion cohorts in patients with MPE due to 1) non-mesothelioma solid tumors and 2) mesothelioma only tumors.
This is an open-label, non-randomized, multicenter, translational Phase 1/2 dose-escalation and expansion study designed to determine the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary anti-tumor activity of RSO-021 after intrapleural (IP) administration in patients with malignant pleural effusion (MPE) (non-mesothelioma) and MPE from mesothelioma.