Recombinant Human Arginase 1 (rhArg1) in Patients With Advanced Arginine Auxotrophic Solid Tumors

This is a phase 1, multiple sites, open label and non-randomized study to evaluate the safety of PEG-BCT-100. Patient enrollment and sample size will follow a classical 3 + 3 dose-escalation design. The study will enroll a maximum of 36 patients. Cohorts of 3 patients will receive an initial single dose of PEG-BCT-100 beginning at 0.5 mg/kg. Single dose safety parameters including hematology and chemistry laboratory profiles will be monitored for 3 weeks. Patients not demonstrating a dose-limiting toxicity (DLT) following the single dose may then receive two additional doses of PEG-BCT-100 at the same dose level on Day 22 and Day 29. After these 2 additional doses, patients will undergo a full tumor and safety assessment after Day 29. Patients whose cancer is stable or responding may then receive weekly doses of PEG-BCT- 100 until disease progression. Dose escalations are planned for the next cohorts of 3 patients, which will be enrolled after Day 22 of the previous cohort, assuming that no single dose DLTs were reported. Each cohort of 3 patients may begin weekly administration if there is no DLTs by Day 22, and if the previous and lower dose cohort has successfully passed Week 4 of the study (doses on Days 1, and 22 + one week). As of the beginning of 2018, an additional 22 patients will include only malignant melanoma patients. All newly enrolled patients will be enrolled at the dose level of Cohort Four (2.7 mg/kg) of PEG-BCT-100.