Dose-Escalation of MNPR-101-PCTA-177Lu in Solid Tumors

This Phase 1a study will enroll qualified participants from the MNPR-101-D001 imaging study. Patients will receive three equal doses of MNPR-101-PCTA-177Lu, dose-escalating in cohorts of two starting at Dose Level 1 (960 MBq).On Cycle 1 Day 1, Cycle 1 Day 15, and Cycle 2 Day 1, patients will receive a 20-minute intravenous infusion of MNPR-101-PCTA-177Lu consisting of an antibody with radioactivity ranging from 480-2240 MBq (Dose Levels 0-4).

This study employs a Time-to-Event Bayesian Optimal Interval Design (TITE-BOIN). Dosing of subsequent cohorts will escalate, stay, or de-escalate based on TITE-BOIN predetermined, fixed dose escalation / de-escalation rules.

Any hematologic event must be ≤ Grade 1 for dosing to occur, i.e., patients with an active ≥ Grade 2 hematologic event may not be dosed. Any patient experiencing a ≥ Grade 2 allergic reaction during or immediately following infusion will not receive further treatment. Patients experiencing a DLT, at least possibly related to MNPR-101-PCTA-177Lu and occurring within 6 weeks of C1D1, will not receive any further doses. C1D15 and C2D1 doses may be delayed for up to 14 days for specified adverse events.

All subjects will undergo SPECT imaging on Cycle 1 Day 8 and Cycle 2 Day 8. CT scans will occur on Cycle 1 Day 43, Cycle 2 Day 1, and Cycle 2 Day 43; a baseline CT scan must be provided. These will allow for the assessment of tumor SUVs, as well as the radiologic response rate by RECIST 1.1.

Patients will be followed for safety for 12 weeks following the last dose of MNPR-101-PCTA-177Lu.