Study ADI-PEG 20 Plus Pembrolizumab in Advanced Solid Cancers

This is an open-label, phase 1b trial of ADI-PEG 20 in combination with pembrolizumab in subjects with advanced cancers. Dose escalation will occur using a 3 + 3 + 3 design. The first subject in a dose escalation cohort must have had treatment with ADI-PEG 20 + pembrolizumab with a week of follow up) before the next 2 subjects are enrolled. Thus subjects 2 and 3 may be enrolled on day 8 if there is no dose limiting toxicity (DLT) in subject 1. No additional delay is required between treating subjects 4 to 6 or 7 to 9 in an expanded cohort. Before proceeding to the next cohort dose level, the first 3 eligible subjects in each cohort will have received at least 21 days of treatment (i.e. at least 2 of the expected 3 doses of ADI-PEG 20 + one dose of pembrolizumab).