A Phase 1 interventional study of PF-08046033 in Non-Small-Cell Lung, Esophageal Cancer and Cutaneous Melanoma, sponsored by Pfizer. Recruiting at 20 sites in 5 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-06.
Sponsored by Pfizer · Phase 1, Interventional, and Treatment
This is an early-stage (Phase 1) clinical study testing a new study medicine called PF-08046033. The goal of the study is to understand how safe the medicine is, how well people tolerate it, how it behaves in the body, and whether it shows early signs of helping to treat cancer.
The study includes adult participants who have advanced cancers that cannot be removed by surgery or have spread to other parts of the body. These cancers include non-small cell lung cancer, esophageal squamous cell cancer, and melanoma.
The study has two parts:
In the first part, small groups of participants receive increasing doses of the study medicine. This helps researchers find a dose that is safe and suitable for further testing.
Once a suitable dose is identified, the second part enrolls more participants with specific cancer types to better understand the safety of the medicine and whether it shows signs of helping control the cancer.
Participants receive the study medicine through regular treatment cycles and are closely monitored for side effects and how their cancer responds. The information from this study will help researchers decide whether PF-08046033 should be studied further in later-stage clinical trials.
1,592 studies on the registry are indexed under Esophageal Neoplasms; 460 are open to participants now.
This study's planned enrollment of 250 is above the median of 58 across 1,170 interventional studies indexed under Esophageal Neoplasms.
Browse Esophageal Neoplasms studies →Pfizer is the lead sponsor of 3,244 studies on the registry; 139 are open to participants now.
Of its 582 completed or terminated interventional studies of FDA-regulated products, 381 (65%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Participants will receive PF-08046033 dose level 1 intravenously (IV).
Drug: PF-08046033
Participants will receive PF-08046033 dose level 2 IV.
Drug: PF-08046033
Participants will receive PF-08046033 dose level 3 IV.
Drug: PF-08046033
Participants will receive PF-08046033 dose level 4 IV.
Drug: PF-08046033
Participants will receive PF-08046033 dose level 5 IV.
Drug: PF-08046033
Participants will receive PF-08046033 dose level 6 IV.
Drug: PF-08046033
Participants will receive PF-08046033 dose level 7 IV.
Drug: PF-08046033
PF-08046033: Specified dose IV on specified days
Drug: PF-08046033
PF-08046033: Specified dose IV on specified days
Drug: PF-08046033
PF-08046033: Specified dose IV on specified days
Drug: PF-08046033
Powder for solution for infusion.
Type, incidence and severity of participants with adverse events (AEs)
Type, incidence, severity (as graded by National Cancer Institute Common Terminology Criteria for Adverse Events \[NCI CTCAE\] v 5.0), seriousness, and relatedness of adverse events (AEs).
Time frame: From the first day through 30-37 days after the last study treatment, up to approximately 1 year
Type, incidence, and severity of participants with laboratory abnormalities
Type, incidence, and severity (graded by NCI CTCAE version 5.0) of laboratory abnormalities
Time frame: From the first day through 30-37 days after the last study treatment, up to approximately 1 year
Number of participants with dose modifications
Frequency of dose modifications (eg, dose delay and treatment discontinuations) due to AEs
Time frame: From the first day through 30-37 days after the last study treatment, up to approximately 1 year
Incidence of dose-limiting toxicities (DLTs)
To identify the maximum tolerated dose (MTD) or maximum administered dose (MAD) of PF-08046033
Time frame: From the first day through 30-37 days after the last study treatment, up to approximately 1 year
Recommended dose and schedule of PF-08046033 for expansion (RDE)
RDE will be based on cumulative safety, preliminary antitumor activity and pharmacokinetics findings
Time frame: Up to 1 year
Objective response rate (ORR) using Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 as assessed by investigator
Objective response defined as Complete Response (CR) or Partial Response (PR) per RECIST v1.1, from the date of first dose until the date of the first documentation of PD, death, or start of new anticancer therapy, whichever occurs first.
Time frame: Up to 3 years
Duration of response (DOR) using RECIST v1.1 as assessed by investigator
DOR is defined as the time from first documentation of CR or PR to date of first documentation of PD or death due to any cause.
Time frame: Up to 3 years
Progression-free survival (PFS) using RECIST v1.1 as assessed by investigator
Progression-free survival is defined as the time from the date of randomization to the date of the first documentation of objective progressive disease (PD) assessed by investigator per RECIST 1.1, or death due to any cause, whichever occurs first.
Time frame: Up to 3 years
Overall survival (OS) using RECIST v1.1 as assessed by investigator
Overall survival defined as the time from the date of randomization to the date of death due to any cause.
Time frame: Up to 3 years
Pharmacokinetics (PK): Maximum Observed Concentration (Cmax) of PF-08046033
To characterize the PK of PF-08046033
Time frame: From Cycle 1 Day 1 (each cycle is 21 days) until End of Treatment, , Up to approximately 1 year
PK: Area under the concentration-time curve (AUC) of PF-08046033
To characterize the PK of PF-08046033
Time frame: From Cycle 1 Day 1 (each cycle is 21 days) until End of Treatment, Up to approximately 1 year
PK: Time to Maximum concentration (Tmax) of PF-08046033
To characterize the PK of PF-08046033
Time frame: From Cycle 1 Day 1 (each cycle is 21 days) until End of Treatment, Up to approximately 1 year
PK: Trough concentration (Ctrough) of PF-08046033
To characterize the PK of PF-08046033
Time frame: From Cycle 1 Day 1 (each cycle is 21 days) until End of Treatment, Up to approximately 1 year
PK: Terminal Elimination half-life (t1/2) of PF-08046033
Time frame: From Cycle 1 Day 1 (each cycle is 21 days) until End of Treatment, Up to approximately 1 year
Incidence of antidrug antibodies (ADAs)
To characterize the immunogenicity of PF-08046033
Time frame: From Cycle 1 Day 1 (each cycle is 21 days) until End of Treatment, Up to approximately 1 year
Percent change of immune cells and PD-L1 expression based on immunohistochemistry
To evaluate the pharmacodynamic effects of PF-08046033 in tumor tissue
Time frame: From Cycle 1 Day 1 (each cycle is 21 days) until End of Treatment, Up to approximately 1 year
Plan to share: No — Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Pfizer