A Trial to Find Safe and Active Doses for an Investigational Drug, CX-904, for Patients With Advanced Solid Tumors

A Phase 1/1b, Open-label, Dose-finding, First-in-human Study to Evaluate the Safety and Antitumor Activity of CX-904, an EGFR-targeted T-cell Engager in Advanced Solid Tumors (CTMX-904-101)

The purpose of this first-in-human study, CTMX-904-101, is to characterize the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and antitumor activity of CX-904 in adult subjects with metastatic or locally advanced unresectable solid tumors.

Study Overview

• Status: Recruiting
• Conditions: Solid Tumors
• Intervention / Treatment: Drug: CX-904

Detailed Description

This is a first-in-human study evaluating the safety, tolerability, and activity of CX-904, a conditionally activated T-cell bispecific to EGFR and CD3. The design includes single patient cohorts and a 3+3 design. Escalating dose increments will be determined in discussion with a Safety Review Committee.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Karen Deane; Phone Number: (650) 515-3185; Email: ClinicalTrials@CytomX.com

Study Locations

• United States
  • Tennessee
    • Nashville, Tennessee, United States, 37203
      • Recruiting
      • Sarah Cannon Research Institute, LLC
  • Texas
    • Houston, Texas, United States, 77030
      • Recruiting
      • MD Anderson Cancer Center
    • San Antonio, Texas, United States, 78229
      • Recruiting
      • South Texas Accelerated Research Therapeutics, LLC
  • Virginia
    • Fairfax, Virginia, United States, 22031
      • Recruiting
      • Virginia Cancer Specialist

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Histologically confirmed metastatic or locally advanced unresectable solid tumor. Must have received prior standard therapy.
• Measurable disease per RECIST 1.1
• Eastern Cooperative Oncology Group performance status of 0 or 1
• Adequate baseline laboratory values
• Patients of childbearing potential or those with partners of childbearing potential must agree to use a highly effective method of birth control from signing the ICF, and for a period of 30 days after the last dose of CX-904.
• Additional inclusion criteria may apply

Exclusion Criteria:

• History of malignancy that was active within the previous 2 years. Exceptions include localized cancers that are not related to the current cancer being treated, that are considered to have been cured, and in the opinion of the Investigator, present a low risk of recurrence
• Screening electrocardiogram demonstrating a mean QTcF value > 480 msec; a screening echocardiogram with left ventricular ejection fraction (LVEF) < 50%

• Serious concurrent illness including

  • History of or current active autoimmune diseases
  • History of myocarditis regardless of the cause
• Pregnant or breast feeding
• Additional exclusion criteria may apply

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: CX-904	Drug: CX-904; CX-904 is a T-cell engaging bispecific Probody® candidate against Epidermal Growth Factor Receptor (EGFR) and CD3.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patients Experiencing Dose-limiting Toxicity	The number of patients experiencing a dose-limiting toxicity (DLT) as defined in the protocol at any dose level during dose escalation.	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective Response Rate (ORR)	ORR is the proportion of patients in the efficacy-evaluable population with a best response of Complete Response (CR) or Partial Response (PR) based on Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 by Central Radiology Review (CRR).	30 months
Duration of Response (DOR)	The time from the first documentation of CR or PR (based on RECIST v1.1) that is subsequently confirmed to the first documentation of disease progression or death due to any cause on study, whichever occurs first.	30 months
Investigator-assessed Progression-Free Survival (PFS)	The time from the date of the first dose of study treatment until documentation of objective tumor progression based on RECIST v1.1 or until death due to any cause, whichever occurs first.	30 months
Disease Control Rate (DCR)	DCR is defined as the rate of confirmed CR, PR, and stable disease (SD) as per RECIST v1.1.	30 months
Overall Survival (OS)	The time from treatment initiation until death due to any cause.	30 months

Collaborators and Investigators

• Sponsor: CytomX Therapeutics
• Investigators: Study Director: Monika Vainorius, M.D., CytomX Therapeutics, Inc

Study record dates

Study Major Dates

• Study Start (Actual): February 22, 2022
• Primary Completion (Estimated): August 1, 2025
• Study Completion (Estimated): August 1, 2025

Study Registration Dates

• First Submitted: May 19, 2022
• First Submitted That Met QC Criteria: May 19, 2022
• First Posted (Actual): May 24, 2022

Study Record Updates

• Last Update Posted (Actual): April 12, 2024
• Last Update Submitted That Met QC Criteria: April 11, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms
• Other Study ID Numbers: CTMX-904-101

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No