A Phase 1 interventional study of PF-08052666 in Carcinoma, Non-Small-Cell Lung, Ovarian Neoplasms and Pancreatic Adenocarcinoma, sponsored by Seagen, a wholly owned subsidiary of Pfizer. Terminated at 19 sites in 2 countries. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-07.
Sponsored by Seagen, a wholly owned subsidiary of Pfizer · Phase 1, Interventional, and Treatment
This clinical trial is studying advanced solid tumors. Solid tumors are cancers that start in a part of your body like your lungs or liver instead of your blood. Once tumors have grown bigger in one place but haven't spread, they're called locally advanced. If your cancer has spread to other parts of your body, it's called metastatic. When a cancer has gotten so big it can't easily be removed or has spread to other parts of the body, it is called unresectable. These types of cancer are harder to treat.
Patients in this study must have cancer that has come back or did not get better with treatment. Patients must have a solid tumor cancer that can't be treated with standard of care drugs.
This clinical trial uses an experimental drug called PF-08052666/SGN-MesoC2. PF-08052666/SGN-MesoC2 is a type of antibody-drug conjugate (ADC). ADCs are designed to stick to cancer cells and kill them. They may also stick to some normal cells.
This study will have 3 parts. Part A and Part B of the study will find out how much PF-08052666/SGN-MesoC2 should be given to participants. Part C will use the information from Parts A and B to see if PF-08052666/SGN-MesoC2 is safe and if it works to treat solid tumor cancers.
6,488 studies on the registry are indexed under Carcinoma, Non-Small-Cell Lung; 1,632 are open to participants now.
This study's enrollment of 19 is below the median of 62 across 5,213 interventional studies indexed under Carcinoma, Non-Small-Cell Lung.
Browse Carcinoma, Non-Small-Cell Lung studies →Seagen, a wholly owned subsidiary of Pfizer is the lead sponsor of 30 studies on the registry; 5 are open to participants now.
Of its 11 completed or terminated interventional studies of FDA-regulated products, 3 (27%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
PF-08052666 monotherapy
Drug: PF-08052666
Given into the vein (IV; intravenously)
Also known as: HBM9033; SGN-MesoC2
Number of participants with adverse events (AEs)
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.
Time frame: Through 30-37 days after the last dose of study treatment, 48 Months
Number of participants with laboratory abnormalities
Time frame: Through 30-37 days after the last dose of study treatment, 48 Months
Number of participants with dose modifications
Frequency of dose modifications (eg, dose delay, treatment interruptions, dose reductions and treatment discontinuations) due to AEs
Time frame: Up to 4 months
Number of participants with dose-limiting toxicities (DLTs)
Incidence of dose-limiting toxicities (DLTs)
Time frame: Cycle 1 (21 days)
Objective response rate (ORR)
ORR is defined as the proportion of participants in the relevant analysis set with best response of complete response (CR) or partial response (PR) according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1.
Time frame: Approximately 1 year 4 months
Best response
The best timepoint response achieved for the subject during the protocol specified period according to RECIST V1.1.
Time frame: Approximately 1 year 4 months
Duration of response (DOR)
DOR is defined as the time interval from first occurrence of documented objective response to the time of progressive disease (PD) according to RECIST v1.1 or death from any cause, whichever comes first.
Time frame: Approximately 1 year 4 months
Disease control rate (DCR)
DCR is defined as the proportion of participants with best response of CR, PR or stable disease (SD) according to RECIST v1.1.
Time frame: Approximately 1 year 4 months
Progression-free survival (PFS)
PFS is defined as the time from first dosing to the first occurrence of PD according to RECIST v1.1 or death from any cause, whichever comes first.
Time frame: Approximately 1 year 4 months
Overall survival (OS)
Overall survival (OS) defined as the time from first dosing to death.
Time frame: Approximately 1 year 4 months
Pharmacokinetic (PK) parameter - Area under the serum concentration (AUC)
Time frame: Cycles 1, 2, and 3 (each cycle is up to 21 days)
Pharmacokinetic (PK) parameter - Maximum serum concentration (Cmax)
Time frame: Cycles 1, 2, and 3 (each cycle is up to 21 days)
Pharmacokinetic (PK) parameter - Time to reach maximum serum concentration (Tmax)
Time frame: Cycles 1, 2, and 3 (each cycle is up to 21 days)
Pharmacokinetic (PK) parameter - Half-life
Time frame: Cycles 1, 2, and 3 (each cycle is up to 21 days)
Number of participants with antidrug antibodies
Time frame: Cycles 1, 2, and 3 (each cycle is up to 21 days)
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.
This study is terminated, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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Carcinoma, Non-Small-Cell Lung→
Seagen, a wholly owned subsidiary of Pfizer