Novel mRNA-LNP-Based Intratumoral Immunotherapy in Patients With Advanced Malignant Solid Tumors (mRNA-LNP)

A Phase 1/2a Clinical Study to Evaluate the Safety Tolerability, Pharmacokinetics, and Preliminary Efficacy of a Novel mRNA-LNP PMC2129G12-Based Immunotherapy in Patients With Advanced Malignant Solid Tumors

PMC2129G12 is an investigational intratumorally administered messenger RNA-lipid nanoparticle (mRNA-LNP) immunotherapy designed to enable localized, transient expression of a humanized EpCAM-targeted CD3-engaging bispecific antibody together with the immunostimulatory cytokines to kill tumors by recruited immune T cells.

Study Overview

• Status: Not yet recruiting
• Conditions: Advanced Solid Tumor
• Intervention / Treatment: Genetic: mRNA-LNP

Detailed Description

This Phase 1/2a, open-label study is designed to evaluate the safety and tolerability of PMC2129G12 encoding humanized EpCAM-targeted CD3-engaging bispecific antibody together with the immunostimulatory cytokines administered by intratumoral injection in patients with EpCAM-positive advanced malignant solid tumors. Secondary and exploratory objectives include characterization of pharmacokinetics, pharmacodynamic immune effects, and preliminary antitumor activity. The study will provide critical information to support further clinical development of PMC2129G12 as a novel intratumoral immunotherapy for patients with advanced epithelial cancers.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 2; Phase 1

Contacts and Locations

• Study Contact: Name: Lijun Wu, MD; Phone Number: 5105293021; Email: john@intraabinc.com
• Study Contact Backup: Name: Lijun Lijun, MD; Phone Number: 5105293021; Email: john@intraabinc.com

Study Locations

• United States
  • California
    • Richmond, California, United States, 94806
      • IntraAb Inc.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age >18 years
• Histologically or cytologically confirmed advanced or metastatic solid tumor refractory to standard therapy
• EpCAM expression ≥2+ intensity in ≥50% of tumor cells by central IHC
• At least one measurable lesion per RECIST v1.1 (≥2 cm) that is anatomically accessible for intratumoral injection
• ECOG performance status 0-1
• Life expectancy ≥3 months
• Adequate hematologic, hepatic, renal, and coagulation function
• Willingness to use effective contraception

Exclusion Criteria:

• Prior EpCAM- or CD3-targeted therapy
• Active autoimmune disease requiring systemic therapy
• Uncontrolled infection or significant cardiovascular disease
• Active or symptomatic CNS metastases requiring immediate local therapy. Patients with treated, stable CNS metastases may be eligible.
• Ongoing ≥Grade 2 toxicity from prior anticancer therapy
• Known hypersensitivity to study drug components
• Pregnancy or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: all participants; mRNA-LNP	Genetic: mRNA-LNP; intratumoral mRNA-LNP administration

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of participants with treatment-emergent adverse events (TEAEs) assessed by CTCAE v5.	The number of participants experiencing treatment-emergent adverse events following intratumoral administration of PMC2129G12, graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.	From first dose through Day 28 (±3 days)
Number of participants with dose-limiting toxicities (DLTs)	The number of participants experiencing dose-limiting toxicities during the DLT evaluation period following intratumoral administration of PMC2129G12.	From first dose through Day 28 (±3 days)
Maximum tolerated dose (MTD) of PMC2129G12	Determination of the maximum tolerated dose (MTD) of PMC2129G12 administered by intratumoral injection based on the incidence of dose-limiting toxicities.	Up to approximately 28 days

Collaborators and Investigators

• Sponsor: IntraAb, Inc.
• Investigators: Study Chair: Lijun Wu, MD, IntraAb, Inc.

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2027
• Primary Completion (Estimated): January 1, 2030
• Study Completion (Estimated): January 1, 2031

Study Registration Dates

• First Submitted: April 27, 2026
• First Submitted That Met QC Criteria: May 7, 2026
• First Posted (Actual): May 14, 2026

Study Record Updates

• Last Update Posted (Actual): May 14, 2026
• Last Update Submitted That Met QC Criteria: May 7, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: PMC2129G12-001

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: Yes