SGN-MesoC2 for Solid Tumors

Recruiting at 31 trial locations

Overseen By Seagen Pfizer CT.gov Call Center

Age: 18+

Sex: Any

Trial Phase: Phase 1

Sponsor: Seagen Inc.

Must not be taking: Anticancer drugs, Radiotherapy

Disqualifiers: HIV, Uncontrolled hypertension, Diabetes, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

365 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new drug, PF-08052666/SGN-MesoC2, to determine its effectiveness in treating certain hard-to-treat solid tumors, such as those in the lungs, pancreas, and ovaries. The drug is an antibody-drug conjugate (ADC), designed to target and kill cancer cells. The trial consists of three parts: the first two parts determine the appropriate dose, and the last part assesses the drug's safety and effectiveness. Suitable candidates for this trial have a solid tumor cancer that has not improved with standard treatments or has recurred. As a Phase 1 trial, this research focuses on understanding how the treatment works in people, offering participants the opportunity to be among the first to receive this new drug.

Will I have to stop taking my current medications?

The trial requires that you stop taking any systemic anticancer therapy or focal radiotherapy at least 4 weeks before starting the study drug, or 2 weeks if your disease has progressed on treatment. The protocol does not specify other medications, so it's best to discuss your current medications with the trial team.

Is there any evidence suggesting that PF-08052666/SGN-MesoC2 is likely to be safe for humans?

Research shows that PF-08052666/SGN-MesoC2, the experimental drug used in this trial, is being carefully studied for safety. This drug is an antibody-drug conjugate (ADC) that specifically targets cancer cells, aiming to destroy them, though it might also affect some normal cells.

There is no direct information from previous human trials about the safety of PF-08052666/SGN-MesoC2. However, it is in an early stage of clinical testing, where researchers focus on understanding its safety and tolerability. This stage is crucial for identifying any side effects and determining safe dosage levels.

Preclinical studies showed promising results, supporting further research. While this doesn't guarantee safety in humans, it provides a basis for ongoing trials. Participants in this study will help gather important information about the drug's safety in people with advanced solid tumors. ^{1 2 3 4 5}

Why do researchers think this study treatment might be promising?

Unlike the standard treatments for solid tumors, which typically include chemotherapy, radiation, and surgery, SGN-MesoC2 is unique because it specifically targets mesothelin, a protein often overexpressed in certain tumors, enabling a more precise attack on cancer cells. Researchers are excited about SGN-MesoC2 because its targeted approach could potentially minimize damage to healthy cells and reduce side effects compared to traditional therapies. Additionally, SGN-MesoC2 leverages an innovative antibody-drug conjugate technology that combines an antibody with a potent anti-cancer drug, enhancing its ability to deliver toxic agents directly to tumor cells. This cutting-edge mechanism of action could lead to more effective treatments for patients with mesothelin-expressing tumors.

What evidence suggests that this treatment might be an effective treatment for solid tumors?

Research shows that PF-08052666, also known as SGN-MesoC2, is an antibody-drug conjugate (ADC) that targets and destroys cancer cells. Early tests in the lab and on animals have shown promising results for this drug in treating advanced solid tumors. This suggests it might be effective against cancers that have grown large or spread, such as those in the lungs or liver. ADCs deliver a toxic drug directly to cancer cells, helping to protect healthy cells. Although human studies have provided limited information, early findings suggest that SGN-MesoC2 could be an important option for treating hard-to-treat cancers. Participants in this trial will receive PF-08052666 monotherapy to further evaluate its effectiveness and safety in humans. ^{1 3 6 7 8}

Who Is on the Research Team?

Pfizer CT.gov Call Center

Principal Investigator

Pfizer

Are You a Good Fit for This Trial?

This trial is for adults weighing at least 40 kg with certain advanced solid tumors, including ovarian cancer, NSCLC, pancreatic adenocarcinoma, colorectal cancer, and mesothelioma. Participants must have tried standard treatments without success or have no available standard options. They should be relatively active (ECOG score of 0 or 1) and have at least one measurable tumor lesion.

Inclusion Criteria

I have a tumor that can be measured using standard criteria.

I am fully active or can carry out light work.

My cancer is advanced, cannot be surgically removed, and has not responded to standard treatments.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Part A - Dose Finding

Determine the appropriate dose of PF-08052666/SGN-MesoC2 for participants

Up to 4 months

Part B - Dose Confirmation

Confirm the dose of PF-08052666/SGN-MesoC2 and assess safety

Up to 4 months

Part C - Efficacy Evaluation

Evaluate the safety and efficacy of PF-08052666/SGN-MesoC2 in treating solid tumor cancers

Approximately 1 year 4 months

Follow-up

Participants are monitored for safety and effectiveness after treatment

30-37 days after the last dose

What Are the Treatments Tested in This Trial?

Interventions

• SGN-MesoC2

Trial Overview SGN-MesoC2 is being tested in this study. It's an experimental antibody-drug conjugate designed to target and kill cancer cells while sparing normal ones. The trial has three parts: determining the right dose (Parts A & B) and assessing safety and effectiveness (Part C).

How Is the Trial Designed?

Group I: PF-08052666 Experimental Treatment 1 Intervention

PF-08052666 monotherapy

Who Is Running the Clinical Trial?

Seagen Inc.

Lead Sponsor

Trials

212

Recruited

73,800+

Founded

1997

Headquarters

Bothell, USA

Known For

Antibody-Drug Conjugates

Top Products

Adcetris (brentuximab vedotin), Tukysa (tucatinib), Padcev (enfortumab vedotin-ejfv), Tivdak (tisotumab vedotin-tftv)

Dr. Roger Dansey

Seagen Inc.

Chief Medical Officer since 2018

MD from University of Witwatersrand

David R. Epstein

Seagen Inc.

Chief Executive Officer since 2022

BSc in Pharmacy from Rutgers University, MBA from Columbia University

Seagen, a wholly owned subsidiary of Pfizer

Lead Sponsor

Trials

20

Recruited

4,900+

Published Research Related to This Trial

The Tmod™ system, which combines a novel MSLN-activated CAR with an HLA-A*02-gated inhibitory receptor, allows for targeted killing of MSLN-positive cancer cells while protecting normal cells, reducing the risk of inflammation associated with MSLN-directed therapies.

In preclinical models, the Tmod system demonstrated comparable sensitivity to traditional MSLN CAR-T cells but with significantly improved safety, as it effectively spares normal cells even in mixed populations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mesothelin-specific CAR-T cell therapy that incorporates an HLA-gated safety mechanism selectively kills tumor cells. Tokatlian, T., Asuelime, GE., Mock, JY., et al.[2022]

A comprehensive analysis of 15,050 tumors revealed that mesothelin (MSLN) is expressed in 54% of tumor types, with particularly high levels in ovarian carcinomas (up to 97%) and pancreatic adenocarcinomas (up to 81%), suggesting these cancers could benefit from targeted therapies against MSLN.

While high MSLN expression is associated with advanced tumor stages and metastasis in colorectal adenocarcinomas, it does not correlate with malignancy in several other cancer types, indicating that while MSLN-targeted therapies may be promising, its prognostic value is limited.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mesothelin Expression in Human Tumors: A Tissue Microarray Study on 12,679 Tumors. Weidemann, S., Gagelmann, P., Gorbokon, N., et al.[2021]

HPN536 is a novel trispecific T-cell-activating protein that effectively targets mesothelin-expressing tumor cells, activating T cells to kill these cancer cells, demonstrating strong potency in preclinical models.

In nonhuman primates, HPN536 was well tolerated and showed a favorable pharmacokinetic profile, supporting its potential for weekly dosing in humans, and it is currently undergoing phase I clinical trials for patients with mesothelin-expressing cancers.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Preclinical Characterization of HPN536, a Trispecific, T-Cell-Activating Protein Construct for the Treatment of Mesothelin-Expressing Solid Tumors. Molloy, ME., Austin, RJ., Lemon, BD., et al.[2022]

Mesothelin (MSLN) was found to be highly expressed in 91.67% of pancreatic ductal adenocarcinoma (PDAC) cases studied, indicating its potential as a diagnostic and therapeutic target for this aggressive cancer.

The study showed no MSLN expression in para-cancerous tissues, suggesting that MSLN could help differentiate between cancerous and non-cancerous tissues, although its expression did not correlate with other clinicopathological factors like tumor size or stage.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Overexpression of Mesothelin in Pancreatic Ductal Adenocarcinoma (PDAC). Le, K., Wang, J., Zhang, T., et al.[2023]

The study involved 11 patients with pancreatic and ovarian cancers, using (89)Zr-PET imaging to assess the uptake of the mesothelin-targeting antibody MMOT0530A, which showed significant tumor uptake and distribution patterns.

The results indicated that the uptake of the tracer correlated with mesothelin expression in tumors, suggesting that (89)Zr-MMOT0530A-PET imaging could help tailor antibody-based treatments for individual patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

ImmunoPET with Anti-Mesothelin Antibody in Patients with Pancreatic and Ovarian Cancer before Anti-Mesothelin Antibody-Drug Conjugate Treatment. Lamberts, LE., Menke-van der Houven van Oordt, CW., ter Weele, EJ., et al.[2021]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT06466187

NCT06466187 | A Study of SGN-MesoC2 in Advanced ... 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 ...

2. mayo.edu mayo.edu/research/clinical-trials/cls-20580117

A Study of PF-08052666/​SGN-MesoC2 in Advanced ... 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 ...

3. firstwordpharma.com firstwordpharma.com/story/5953380

Nona Biosciences' Partner Pfizer Presents Preclinical Data ... These promising preclinical results support the ongoing first-in-human phase 1 clinical trial of PF-08052666 in patients with advanced solid ...

4. trialfinder.panfoundation.org trialfinder.panfoundation.org/en-US/trial/listing/504915

A Study of SGN-MesoC2 in Advanced Solid Tumors 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 ...

5. prnewswire.com prnewswire.com/news-releases/nona-biosciences-partner-pfizer-presents-preclinical-data-on-top1i-based-adc-targeting-msln-at-aacr-annual-meeting-2025-302436930.html

Nona Biosciences' Partner Pfizer Presents Preclinical Data ... These promising preclinical results support the ongoing first-in-human phase 1 clinical trial of PF-08052666 in patients with advanced solid ...

6. trialx.com trialx.com/clinical-trials/listings/297075/a-study-of-sgn-mesoc2-in-advanced-solid-tumors/

A Study of SGN-MesoC2 in Advanced Solid Tumors This clinical trial uses an experimental drug called PF-08052666/SGN-MesoC2. ... SGN-MesoC2 is safe and if it works to treat solid tumor cancers.

7. nonabio.com nonabio.com/nona-biosciences-partner-pfizer-presents-preclinical-data-on-top1i-based-adc-targeting-msln-at-aacr-annual-meeting-2025/

Nona Biosciences' Partner Pfizer Presents Preclinical Data ... These promising preclinical results support the ongoing first-in-human phase 1 clinical trial of PF-08052666 in patients with advanced solid ...

8. clin.larvol.com clin.larvol.com/trial-detail/NCT06466187

A Study of SGN-MesoC2 in Advanced Solid Tumors A phase 1 study to evaluate the safety and tolerability of the antibody–drug conjugate (ADC) MesoC2 (PF-08052666) in patients with advanced solid tumors.