NCT07226999 · Pfizer
Symbiotic-Lung-04: A Study to Learn About the Study Medicine Called PF-08634404 in Combination With Chemotherapy in Adult Participants With Extensive-Stage Small Cell Lung Cancer
What this study is about
This study is being done to learn more about a new medicine called PF-08634404 and how well it works when given with chemotherapy to adults with extensive-stage small cell lung cancer (ES-SCLC), a fast-growing type of lung cancer that has spread widely in the body. To join the study, participants must meet the following conditions: * Be 18 years or older.
View original scientific description
This study is being done to learn more about a new medicine called PF-08634404 and how well it works when given with chemotherapy to adults with extensive-stage small cell lung cancer (ES-SCLC), a fast-growing type of lung cancer that has spread widely in the body. To join the study, participants must meet the following conditions: * Be 18 years or older. * Have extensive-stage small cell lung cancer confirmed by lab tests. * Have not received chemotherapy or radiation for this type of lung cancer. * Be in good physical condition and have healthy organs based on medical tests. The study has two parts: * In the first part, researchers will check how safe the study medicine is and how well people tolerate it when given with chemotherapy. * In the second part, they will compare study medicine plus chemotherapy to another approved treatment (atezolizumab plus chemotherapy) to see which works better. Participants will receive the treatment through IV infusions (medicine given directly into a vein). The treatment will be given in repeated time periods called cycles. Some participants will continue receiving the study medicine alone after the initial treatment.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Histologically or cytologically confirmed extensive-stage small cell lung cancer (ES-SCLC).
- Participants have not received systemic therapy (chemotherapy, radiotherapy, chemoradiation) for ES-SCLC.
- Treatment-free for at least 6 months since last chemo/radiotherapy, among those treated (with curative intent) with prior chemo/radiotherapy for limited-stage SCLC
- Have at least one measurable lesion as the targeted lesion based on RECIST V1.1.
- Eastern Cooperative Oncology Group performance status of 0 or 1.
- Adequate organ function
Exclusion criteria
- known active CNS lesions, including brainstem, meningeal, or spinal cord metastases or compression
- Leptomeningeal disease
- Clinically significant risk of hemorrhage or fistula
- history of another malignancy within 3 years
- active autoimmune diseases requiring systemic treatment within the past 2 years
Where
- Fayetteville, Arkansas
- Coral Springs, Florida
- Orange City, Florida
- Tamarac, Florida
- Cleveland, Ohio
- Beaumont, Texas
- Fredericksburg, Texas
- Houston, Texas
- Irving, Texas
- New Braunfels, Texas
- Pearland, Texas
- San Antonio, Texas
And 8 more locations — see the full list below.
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 8, 2026 · Source of record for eligibility and locations