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.
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.
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
Parallel
PF-08634404
DrugConcentrate for solution for infusion
Atezolizumab
Biological/VaccineInjection for intravenous use
Chemotherapy
DrugInjection for intravenous use
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.
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.
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.
Duration of Response (DOR) as assessed by Investigator based on RECIST v1.1
DOR is defined as the time from the first documentation of objective response (CR or PR) to the date of first documentation of progressive disease (PD) or death due to any cause.
Progression Free Survival (PFS) as assessed by investigator based on RECIST v1.1
PFS is defined as the time from the date of randomization to the date of first documented disease progression, per RECIST v1.1, or death to any cause, whichever occurs first
Number of participants with Laboratory abnormalities
Laboratory abnormalities as characterized by type, frequency, severity (as graded by NCI CTCAE version 5.0), and timing.
Phase 2: Number of Participants who Experience a Dose-Limiting Toxicity (DLT)
DLT (any of the prespecified AEs that are attributable to study treatment(s), excluding toxicities clearly due to underlying disease or extraneous causes) rate estimated based on data from DLT-evaluable participants during the DLT evaluation period.