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

Pfizer

Status and phase: Enrolling; Phase 3; Phase 2

Conditions: Small Cell Lung Cancer (SCLC)

Treatments: Drug: Chemotherapy; Drug: PF-08634404; Biological: Atezolizumab

Study type: Interventional

Funder types: Industry

Identifiers

NCT07226999

2025-523522-41-00 (EU Trial (CTIS) Number)

C6461004

Symbiotic-Lung-04 (Other Identifier)

Details and patient eligibility

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.
• 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.

Enrollment: 550 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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550 participants in 3 patient groups

Phase 2 Single arm

Experimental group

Description:

Participants will receive PF-08634404 in combination with chemotherapy

Treatment:

Drug: PF-08634404

Drug: Chemotherapy

Phase 3 Experimental Arm

Experimental group

Description:

Participants will receive PF-08634404 in combination with chemotherapy

Treatment:

Drug: PF-08634404

Drug: Chemotherapy

Phase3 Control Arm

Active Comparator group

Description:

Participants will receive atezolizumab in combination with chemotherapy

Treatment:

Biological: Atezolizumab

Drug: Chemotherapy