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
A GLOBAL PHASE 2/3 INTERVENTIONAL STUDY OF PF-08634404 IN COMBINATION WITH CHEMOTHERAPY IN PARTICIPANTS WITH EXTENSIVE STAGE SMALL CELL LUNG CANCER
3 other identifiers
interventional
550
7 countries
32
Brief Summary
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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_2
Started Dec 2025
Longer than P75 for phase_2
32 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
November 7, 2025
CompletedFirst Posted
Study publicly available on registry
November 12, 2025
CompletedStudy Start
First participant enrolled
December 9, 2025
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 14, 2030
ExpectedStudy Completion
Last participant's last visit for all outcomes
March 11, 2034
April 20, 2026
April 1, 2026
4.5 years
November 7, 2025
April 17, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (3)
Phase 2: Confirmed Objective Response Rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 [RECIST 1.1] based on the investigator's assessment
Defined as the proportion of participants in whom a confirmed complete response (CR) or partial response (PR) is observed as best overall response. ORR using RECIST v1.1 as assessed by investigator.
Up to approximately 2 years after completion of study treatment of last study participant
Phase 2: Number of participants with treatment-emergent adverse events
Adverse Events (AEs) as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0), timing, seriousness, and relationship to study intervention.
Up to 90 days after the last dose of treatment
Phase 3: Overall Survival (OS)
OS is defined as the time from the date of randomization to the date of death due to any cause. OS is secondary outcome measure in Phase 2 portion of the study.
Up to approximately 2 years after completion of study treatment of last study participant
Secondary Outcomes (14)
Duration of Response (DOR) as assessed by Investigator based on RECIST v1.1
Up to approximately 2 years after completion of study treatment of last study participant
Progression Free Survival (PFS) as assessed by investigator based on RECIST v1.1
Up to approximately 2 years after completion of study treatment of last study participant
Number of participants with Laboratory abnormalities
Up to 90 days after the last dose of treatment
Phase 2: Number of Participants who Experience a Dose-Limiting Toxicity (DLT)
Up to 90 days after the last dose of treatment
Pharmacokinetics: Serum concentrations of PF-08634404
Up to 37 days after the last dose of treatment
- +9 more secondary outcomes
Study Arms (3)
Phase 2 Single arm
EXPERIMENTALParticipants will receive PF-08634404 in combination with chemotherapy
Phase 3 Experimental Arm
EXPERIMENTALParticipants will receive PF-08634404 in combination with chemotherapy
Phase3 Control Arm
ACTIVE COMPARATORParticipants will receive atezolizumab in combination with chemotherapy
Interventions
Injection for intravenous use
Eligibility Criteria
You may qualify if:
- 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
You may not qualify if:
- 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
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Pfizerlead
Study Sites (32)
Highlands Oncology Group
Fayetteville, Arkansas, 72703, United States
Highlands Oncology Group
Rogers, Arkansas, 72758, United States
Highlands Oncology Group
Springdale, Arkansas, 72762, United States
BRCR Coral Springs
Coral Springs, Florida, 33065, United States
BRCR Global - Coral Springs
Coral Springs, Florida, 33065, United States
Mid Florida Hematology and Oncology Center
Orange City, Florida, 32763, United States
BRCR Global - Tamarac
Tamarac, Florida, 33321, United States
Clario
Philadelphia, Pennsylvania, 19103, United States
Texas Oncology - Gulf Coast
Beaumont, Texas, 77702, United States
Texas Oncology - San Antonio
Fredericksburg, Texas, 78624, United States
Texas Oncology - Gulf Coast
Houston, Texas, 77024, United States
Texas Oncology - Gulf Coast
Houston, Texas, 77054, United States
Texas Oncology - San Antonio
New Braunfels, Texas, 78130, United States
Texas Oncology - Gulf Coast
Pearland, Texas, 77584, United States
Texas Oncology - San Antonio
San Antonio, Texas, 78217, United States
Texas Oncology - San Antonio
San Antonio, Texas, 78240, United States
Texas Oncology - San Antonio
San Antonio, Texas, 78258, United States
Texas Oncology - Gulf Coast
Sugar Land, Texas, 77479, United States
Texas Oncology - Gulf Coast
The Woodlands, Texas, 77380, United States
Texas Oncology - Gulf Coast
Webster, Texas, 77598, United States
Border Medical Oncology Research Unit
Albury, New South Wales, 2640, Australia
Hôpital Ambroise Paré
Boulogne-Billancourt, Île-de-France Region, 92100, France
Kansai Medical University Hospital
Hirakata, Osaka, 573-1191, Japan
Shizuoka Cancer Center
Nagaizumi-cho, Shizuoka, 411-8777, Japan
Doctor's Center Hematology & Oncology Group
Manati, 00674, Puerto Rico
Pan American Center for Oncology Trials, LLC - Mayaguez Office Mayaguez Medical Center
Mayagüez, 00680, Puerto Rico
Pan American Center for Oncology Trials, LLC
San Juan, 00909, Puerto Rico
Hospital Oncologico Dr. Isaac Gonzalez-Martinez
San Juan, 00935, Puerto Rico
Hospital Universitario 12 de Octubre
Madrid, Madrid, Comunidad de, 28041, Spain
National Cheng Kung University Hospital
Tainan, 704302, Taiwan
National Taiwan University Hospital
Taipei, 10002, Taiwan
Taipei Medical University Hospital
Taipei, 110, Taiwan
Related Links
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Officials
- STUDY DIRECTOR
Pfizer CT.gov Call Center
Pfizer
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 2
- Allocation
- RANDOMIZED
- Masking
- QUADRUPLE
- Who Masked
- PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
- Masking Details
- Phase 2 is open-label, whereas Phase 3 is double-blind, randomized design.
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- INDUSTRY
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
November 7, 2025
First Posted
November 12, 2025
Study Start
December 9, 2025
Primary Completion (Estimated)
June 14, 2030
Study Completion (Estimated)
March 11, 2034
Last Updated
April 20, 2026
Record last verified: 2026-04
Data Sharing
- IPD Sharing
- Will share
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.