Multicenter phase 1 trial of MYC targeting by OMO-103 in metastatic solid malignancies

The oncogene MYC coordinates key transcriptional programs in tumor development and maintenance. OMO-103 is a MYC inhibiting miniprotein consisting of 91 amino acids. A multicenter phase 1 trial in Spain evaluated OMO-103 for advanced solid tumors. A classical 3 + 3 design was used for dose escalation of weekly intravenous, single-agent OMO-103 administration in 21-days cycles, encompassing six dose levels (DLs). Safety and tolerability were primary outcomes. A total of 22 patients were enrolled, with a median of 4 previous lines of treatment (range 2-12). OMO-103 treatment was maintained until disease progression. The most common adverse events were grade 1 infusion-related reactions, occurring in ten patients. One dose-limiting toxicity occurred at DL5. Among the 19 patients evaluable for response, 12 reached the predefined 9-week time point for assessment of drug antitumor activity, eight of those showing stable disease by computed tomography. One patients defined as stable disease by RECIST showed a 49% reduction in total tumor volume at best response. The authors conclude that among patients with metastatic solid malignancies, OMO-103 was safe and had promising activity.