Targeting a Tumor's Mitochondrial Weakness Shows Promise Against Mesothelioma

A Vermont team’s approach blocks mitochondrial enzyme PRX3 with thiostrepton (RSO-021) to leverage mesothelioma’s oxidative stress. In a UK phase 1 trial, delivering the drug directly into the chest achieved disease control in 67% of relapsed mesothelioma patients (15 participants), with a median ~4.2 months progression-free and longer overall survival than standard therapy; no treatment-related deaths at the 90 mg dose. The therapy may also stimulate immune responses and is being advanced toward second-generation, potentially oral, inhibitors, with phase 2 results expected to be presented later and broader applications to other cancers under exploration.