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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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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)

Conditions
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Solid Tumors

Intervention / Treatment
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* Drug: CX-904


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Histologically confirmed metastatic or locally advanced unresectable solid tumor. Must have received prior standard therapy. Measurable disease per RECIST 1.1 Patients with brain metastases that are ≤ 1 cm, are symptomatic, and require treatment may be eligible after discussion with Medical Monitor. 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

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CX-904<br> | Drug: CX-904<br>* CX-904 is a T-cell engaging bispecific Probody® candidate against Epidermal Growth Factor Receptor (EGFR) and CD3.<br>|

What is the study measuring?
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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 |