A Phase 1 interventional study of CX-801 and pembrolizumab in Solid Tumor, Adult, sponsored by CytomX Therapeutics. Recruiting at 5 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-28.
Sponsored by CytomX Therapeutics · Phase 1, Interventional, and Treatment
The purpose of this first-in-human study, CTMX-801-101, is to characterize the safety, tolerability, and antitumor activity of CX-801 as monotherapy and in combination with pembrolizumab in adult participants with advanced solid tumors.
The study is comprised of 2 parts. Part 1 involves CX-801 dose escalation to identify the maximum tolerated dose (MTD) of CX-801 as monotherapy and as combination therapy (CX-801 combined with pembrolizumab). Part 2 (dose expansion) will further assess safety and tolerability as well as preliminarily assess antitumor activity of CX-801 combination therapy in indication-specific expansion cohorts.
CytomX Therapeutics is the lead sponsor of 9 studies on the registry; 2 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 3 (50%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Drug: CX-801
Drug: CX-801 · Drug: pembrolizumab
Investigational drug
Standard of Care Therapy
Also known as: KEYTRUDA®
Safety and tolerability of CX-801 as monotherapy and combination therapy
The number of participants experiencing a dose-limiting toxicity (DLT) as defined in the protocol, AEs (adverse events), and treatment-emergent adverse events (TEAEs) at any dose level
Time frame: 44 months
Determine the recommended Phase 2 dose (RP2D)
The number of participants experiencing a dose-limiting toxicity (DLT) as defined in the protocol, AEs (adverse events), and treatment-emergent adverse events (TEAEs) at any dose level
Time frame: 44 months
Objective response rate (ORR)
ORR defined as the proportion of participants who achieve a confirmed complete response (CR) or partial response (PR) based on Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 by Investigator assessment.
Time frame: 60 months
Duration of response (DOR)
DOR defined as the time from the first documentation of confirmed CR or PR (based on RECIST v1.1) to the first documentation of disease progression or death due to any cause on study, whichever occurs first.
Time frame: 60 months
Progression-free survival (PFS)
PFS defined as the time from the first dose of study intervention to the date of first documentation of objective tumor progression (based on RECIST v1.1) or death due to any cause, whichever occurs first.
Time frame: 60 months
Disease control rate (DCR)
DCR defined as the proportion of participants with confirmed CR, PR, or stable disease (SD) as per RECIST v1.1 by Investigator assessment.
Time frame: 60 months
Duration of disease control (DODC)
DODC defined as the time from the first documentation of confirmed CR, PR, or SD (based on RECIST v1.1) to the first documentation of disease progression or death due to any cause on study, whichever occurs first.
Time frame: 60 months
Overall survival (OS)
OS defined as the time from the first dose of study intervention to death due to any cause.
Time frame: 60 months
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CytomX Therapeutics