Title
A Phase I, Open-Label, Escalation and Expansion Study to Evaluate Dosimetry, Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Clinical Activity of CEA-Pre-Targeted 212PB Therapy in Participants with Metastatic Colorectal Cancer

Description
A Phase I, Open-Label, Escalation and Expansion Study to Evaluate Dosimetry, Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Clinical Activity of CEA-Pre-Targeted 212Pb Therapy in Participants With Metastatic Colorectal Cancer

Objective
Primary:

Part 1:
- To select the appropriate SPLIT antibody (Ab) dose and interval to 212Pb-DOTAM administration

Part 1 to 2:
-To determine the organ/tissue and tumor dosimetry

Part 1 to 3:
-To determine the maximumtolerated 212Pb-DOTAM administered activity (MTA) and/or the recommended
Phase 2 activity (RP2A) of 212Pb-DOTAM and to assess its safety and tolerability

Treatment This study will evaluate the dosimetry, safety, efficacy, pharmacokinetics (PK), pharmacodynamics and immunogenicity of CEA-PRIT 2.0 in participants with metastatic microsatellite-stable (MSS) mCRC who are intolerant to or have progressed after having received available standard-of-care (SOC) therapies.

Key Eligibility Inclusion Criteria:
- Histologically confirmed adenocarcinoma originating from the colon or rectum
- Metastatic disease (Stage IV American Joint Committee on Cancer, Version 7)
- Confirmed MSS and/or proficient mismatch repair (MMR) status
- Experienced disease progression during or within 3 months following the last administration of systemic anti-cancer therapies for metastatic disease
- Presence of measurable disease according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1.
- Life expectancy estimated by the Investigator to be >=12 weeks
- Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0-1
- Adequate cardiovascular, hematological and renal function and laboratory parameters

Exclusion Criteria:
- Pregnant or breastfeeding or intending to become pregnant
- Participants with active central nervous system (CNS) metastases
- History of malignancy other than the one under investigation
- Any unresolved toxicities from prior therapy, i.e., radiotherapy, chemotherapy, targeted therapy or surgical procedure
- Major surgery or significant traumatic injury <4 weeks prior to the first CEA-PRIT 2.0 administration (excluding biopsies) or anticipation of the need for major surgery during study treatment
- Participants have a known confirmed positive test for HIV
- Positive hepatitis B surface antigen (HBsAg) test, and/or positive total hepatitis B core Ab (HBcAb) test at screening.
- Positive hepatitis C (HCV) Ab test result at screening
- Any anticancer treatment or any investigational agent within 4 weeks (or 5 times the half-life, whichever is shorter) prior to C1D1
- Prior treatment with a CEA-targeted agent or systemic radio therapy

Applicable Disease Sites
Colon and Rectum

Participating Institutions
UW Health Eastpark Medical Center; UW Health University Hospital