STRO-004 + Pembrolizumab for Metastatic Cancer

Recruiting at 6 trial locations

Overseen By Sutro Clinical Development

Age: 18+

Sex: Any

Trial Phase: Phase 1

Sponsor: Sutro Biopharma, Inc.

Disqualifiers: Eye disorders, Untreated brain metastases, others

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

Breakthrough Therapy This drug has been fast-tracked for approval by the FDA given its high promise

Compensation: Varies

Number of Visits: Unknown

200 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests the safety and early effectiveness of a new drug, STRO-004, both alone and in combination with pembrolizumab (an immunotherapy drug), for individuals with advanced cancers that have spread. Researchers aim to determine if these treatments can shrink tumors and identify the optimal dose for future studies. The trial consists of three parts: testing STRO-004 alone, determining the best dose, and combining it with pembrolizumab. It seeks participants with specific types of cancer, such as lung or colorectal cancer, who have not responded to other treatments. 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.

Do I have to stop taking my current medications for the trial?

The trial protocol does not specify if you need to stop taking your current medications, but it does mention that participants on anticoagulants must be on a stable dose. It's best to discuss your specific medications with the trial team.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

A previous study tested STRO-004 on animals, specifically monkeys, and it showed a good safety profile at doses up to 50 mg/kg, the highest dose tested. This indicates it was generally well-tolerated in these tests. However, these results come from early trials and animal studies, so effects in humans might differ.

Pembrolizumab is already approved for treating certain cancers and has a well-documented safety record. Various studies have shown that when used with chemotherapy, about 59.1% of patients experienced significant side effects. Although these side effects are serious, pembrolizumab's widespread use means its safety is well understood.

Researchers are testing the combination of STRO-004 and pembrolizumab to ensure they can be used safely together. Since this study is in its early stages, it focuses on finding the right dose and understanding how the combination affects people. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about STRO-004 combined with pembrolizumab for metastatic cancer because it represents a novel approach in cancer treatment. Unlike traditional therapies that primarily attack cancer cells directly, STRO-004 is an antibody-drug conjugate designed to deliver a potent cytotoxic agent specifically to the tumor, potentially improving precision and minimizing damage to healthy cells. Additionally, pembrolizumab, an immunotherapy, works by unleashing the immune system to recognize and fight cancer, and when used in combination with STRO-004, it may enhance the overall effectiveness against metastatic cancer. This dual approach offers a promising potential for better outcomes compared to existing treatments.

What evidence suggests that this trial's treatments could be effective for metastatic cancer?

Research has shown that STRO-004, which participants in this trial may receive as monotherapy, may help treat cancer that has spread to other parts of the body. In early animal tests, it reduced cancer in 39% of cases and controlled the disease in 72% of cases. This suggests STRO-004 might slow cancer growth in some situations.

Another group of participants in this trial will receive STRO-004 combined with pembrolizumab. Early studies suggest they work better together, especially against tumors with a specific protein called Tissue Factor. Pembrolizumab alone has been successful, with research showing that more than half of the patients lived much longer, sometimes up to six years. This combination could offer a strong new treatment option for people with advanced cancer. ^{1 5 6 7 8}

Are You a Good Fit for This Trial?

This trial is for adults with certain types of metastatic cancer that have not responded to previous treatments. Participants must have a type of cancer known to express Tissue Factor, such as stomach, endometrial, esophageal, colorectal, cervical, head and neck squamous cell carcinoma, lung, pancreatic or bladder cancer.

Inclusion Criteria

Measurable disease per RECIST 1.1

I can provide samples of my tumor for testing.

I am 18 years old or older.

Exclusion Criteria

I have an eye disorder.

Concurrent participation in another therapeutic treatment trial

I do not have serious eye, lung, heart, brain disorders, or other uncontrolled conditions.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment Part 1A

Dose escalation study of STRO-004 monotherapy in selected tumor types

Up to 12 months

Treatment Part 1B

Cohort expansion to further evaluate STRO-004 monotherapy dose and anti-tumor activity

Up to 12 months

Treatment Part 1C

Dose escalation of STRO-004 combined with pembrolizumab to determine tolerability and preliminary anti-tumor activity

Up to 12 months

Follow-up

Participants are monitored for safety and effectiveness after treatment

4-8 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Pembrolizumab
• STRO-004

Trial Overview The study tests STRO-004 alone or combined with Pembrolizumab in three parts: dose escalation (Part 1A), cohort expansion to determine the best dose (Part 1B), and evaluating tolerability and anti-tumor activity when both drugs are used together (Part 1C).

How Is the Trial Designed?

Group I: Part 1C STRO-004 in Combination with Pembrolizumab Experimental Treatment 2 Interventions

Group II: Part 1B STRO-004 Monotherapy Experimental Treatment 1 Intervention

Group III: Part 1A STRO-004 Monotherapy Experimental Treatment 1 Intervention

Who Is Running the Clinical Trial?

Sutro Biopharma, Inc.

Lead Sponsor

Trials

7

Recruited

1,100+

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT07227168?lastUpdPost=2020-10-10_

A Study of STRO-004 in Adults With Refractory/Recurrent ... This is a study to evaluate the safety and preliminary anti-tumor activity of STRO-004 in adults with metastatic cancer.

2. sutrobio.com sutrobio.com/wp-content/uploads/2025/07/STRO_July-2025-Corporate-Presentation_FINAL.pdf

STRO This presentation and the accompanying oral presentation contain “forward-looking” statements that are based on our management's beliefs and assumptions.

3. d1io3yog0oux5.cloudfront.net d1io3yog0oux5.cloudfront.net/_7ae0985d3246edbb7f632c156abe2a37/sutrobio/files/pages/sutrobio/db/986/post_event_details/15th-adc/STRO_Alice_Yam_World_ADC_2024_FINAL.pdf

Preclinical Safety and Activity of STRO-004, a Tissue Factor ... Combination treatment of STRO-004 + aPD1 results in enhanced efficacy in a TF- expressing syngeneic model. Combination treatment of STRO-004 + aPD1 ...

4. targetedonc.com targetedonc.com/view/fda-grants-fast-track-to-alnodesertib-combo-for-metastatic-colorectal-cancer

FDA Grants Fast Track to Alnodesertib Combo for ... The combination of alnodesertib and irinotecan shows promising efficacy in ATM-negative metastatic colorectal cancer, with a 45% objective ...

5. sutrobio.com sutrobio.com/wp-content/uploads/2025/04/2025-AACR-1572-STRO-004-preclinical-FINAL.pdf

Preclinical Activity and Safety of STRO-004, a Novel ADC ... STRO-004 induces an overall response rate of 39% and a disease control rate of 72% across PDX models of cervical cancer, NSCLC, esophageal cancer, and head and ...

6. urotoday.com urotoday.com/clinical-trials/bladder-cancer/164700-a-phase-1-open-label-study-to-evaluate-safety-pharmacokinetics-and-preliminary-anti-tumor-activity-of-stro-004-in-adults-with-refractory-recurrent-metastatic-solid-tumors.html?tags=14645

A Phase 1 Open-Label Study to Evaluate Safety ... A Phase 1 Open-Label Study to Evaluate Safety, Pharmacokinetics, and Preliminary Anti-Tumor Activity of STRO-004 in Adults With Refractory/Recurrent Metastatic ...

7. aacrjournals.org aacrjournals.org/cancerres/article/85/8_Supplement_1/1572/760999/Abstract-1572-Preclinical-activity-and-safety-of

Abstract 1572: Preclinical activity and safety of STRO-004, a ... Exploratory toxicology studies show that STRO-004 has a favorable safety profile in cynomolgous monkeys up to 50 mg/kg, the highest dose tested.

8. trial.medpath.com trial.medpath.com/clinical-trial/26721187c47f9f6d/nct07227168-strok-004-safety-pk-tumor-activity-solid-tumors

A Study of STRO-004 in Adults With Refractory/Recurrent ... This is a study to evaluate the safety and preliminary anti-tumor activity of STRO-004 in adults with metastatic cancer.