Symbiotic-Lung-14: A Study to Learn About the Study Medicine Called PF08634404 in Combination With Chemotherapy in Adult Participants With Transformed Small Cell Lung Cancer

NCT07476287 | Recruiting Phase 2 FDA Drug

• 2 other identifiers: C64610142025-524686-24-00
• Study Type: interventional
• Target: 40
• Locations: 5 countries
• Sites: 12

Brief Summary

This study is being done to learn more about a new medicine called PF-08634404. The study team wants to understand how well PF-08634404 works when given alone or with chemotherapy . Chemotherapy is a type of cancer treatment that uses medicines to destroy cancer cells or stop them from growing. The study is for adults with Transformed Small Cell Lung Cancer (T-SCLC ). T SCLC is a rare lung cancer that happens when one type of lung cancer changes into a more aggressive type after treatment stops working. To join the study, participants must meet the following conditions:

• Are aged 18 years or older
• Diagnosed with T-SCLC and have not received treatment for this type of lung cancer (a single cycle of chemotherapy may be permitted)
• Prior diagnosis of epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer treated with tyrosine kinase inhibitors (TKIs)
• Have healthy organs based on medical tests and are in good physical condition After joining the study, adults will be given chemotherapy in addition to the study medicine. After this combination treatment is finished, the study medicine will be continued alone. Adults will receive the treatment through IV infusions (medicine given directly into a vein). All treatments will be done at clinical study sites, where a trained medical team will monitor adults during and after each visit.

Conditions

Transformed Small Cell Lung Cancer; Small Cell Lung Cancer; Lung Neoplasms; Small Cell Cancer Of The Lung; Small Cell Lung Cancer ( SCLC ); Carcinoma, Small Cell Lung

Keywords

Transformed Small Cell Lung Cancer; Small Cell Lung Cancer

Outcome Measures

Primary Outcomes (2)

• Confirmed Objective Response Rate (ORR) as assessed by investigator based on Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1)

  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.

  From start of treatment until first documented CR or PR (approximately maximum up to 1 years)

• Number of Participants with Adverse Events (AEs)

  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

Secondary Outcomes (6)

• 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

• Overall Survival (OS)

  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

• Pharmacokinetics: Predose and postdose Serum concentrations of PF-08634404

  Up to 37 days after the last dose of treatment

Study Arms (1)

PF-08634404

EXPERIMENTAL

Participants will receive PF-08634404 in combination with chemotherapy intravenously, followed by maintenance therapy with PF-08634404.

Drug: PF-08634404; Drug: Chemotherapy

Interventions

PF-08634404 DRUG

Concentrate for solution for infusion

Also known as: SSGJ-707

PF-08634404

Chemotherapy DRUG

Injection for intravenous use

PF-08634404

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male or female participants aged ≥18 years at the time of informed consent.
• Histologically or cytologically confirmed T-SCLC. Participant must have had a prior diagnosis of NSCLC with EGFR mutation which transformed to SCLC following the treatment with TKI(s).
• Participants have not received systemic therapy for T-SCLC.
• Have at least one measurable lesion as the target lesion based on RECIST v1.1.
• Have sufficient tumor tissue from the diagnosis of transformed SCLC available.
• Eastern Cooperative Oncology Group performance status of 0 or 1.
• Have a minimum life expectancy of \>12 weeks.
• Clinical laboratory values at screening within acceptable limits, as defined in the protocol, including: 1) Hematology, 2) Liver function and 3) Renal function.

You may not qualify if:

• Participants are excluded from the study if any of the following criteria apply:
• Active or untreated CNS disease, including brain, brainstem, spinal cord, or meningeal metastases. Participants with definitively treated, clinically stable brain metastases may be eligible per protocol criteria. Participants with untreated asymptomatic brain metastases of longest diameter \<1 cm are permitted if all of the following criteria are met: absence of neurological symptoms, no need for corticosteroids, and brain metastasis has no evidence of edema or hemorrhagic features.
• Leptomeningeal disease
• Clinically significant risk of hemorrhage or fistula, including tumor necrosis/cavitation, invasion or compression of major blood vessels, airways, or critical organs, or risk of tracheoesophageal or pleuroesophageal fistula
• History of another malignancy (other than NSCLC) within 3 years prior to first dose, except for malignancies with negligible risk of metastasis or death (eg, adequately treated carcinoma in situ, nonmelanoma skin cancer)
• Unresolved toxicity from prior anti-tumor therapy that has not recovered to Grade ≤1 per NCI CTCAE v5.0 (except alopecia or irreversible toxicities deemed stable)
• History of allogeneic organ or hematopoietic stem cell transplantation
• Active autoimmune disease requiring systemic treatment within the past 2 years (Stable replacement therapy and selected low-risk autoimmune conditions are permitted per protocol)
• Interstitial lung disease (ILD), pneumonitis, or significant pulmonary disease, including:
• Prior or current non-infectious pneumonitis requiring systemic therapy
• DLCO \<50% predicted
• Severe asthma, COPD, pulmonary embolism, or autoimmune lung involvement
• Uncontrolled or clinically significant cardiovascular, cerebrovascular, metabolic, hepatic, or renal disease within 6 months prior to first dose
• Baseline QTcF \>480 msec
• Major surgery or severe trauma within 4 weeks prior to first dose, or planned major surgery during the study

Sponsors & Collaborators

• Pfizer: lead

Study Sites (12)

City of Hope National Medical Center

Duarte, California, 91010, United States

RECRUITING

City of Hope Lennar Foundation Cancer Center

Irvine, California, 92618, United States

RECRUITING

Hope and Healing Clinical Research

Hinsdale, Illinois, 60521, United States

RECRUITING

Hope and Healing Clinical Research

New Lenox, Illinois, 60451, United States

RECRUITING

Peking Union Medical College Hospital

Beijing, Beijing Municipality, 100730, China

NOT YET RECRUITING

Union Hospital Tongji Medical College Huazhong University of Science and Technology

Wuhan, Hubei, 430048, China

NOT YET RECRUITING

Shanghai Chest Hospital

Shanghai, Shanghai Municipality, 200030, China

NOT YET RECRUITING

Sheba Medical Center

Ramat Gan, HA Merkaz, 5265601, Israel

RECRUITING

Shaare Zedek Medical Center

Jerusalem, Jerusalem, 9103102, Israel

RECRUITING

Japanese Foundation for Cancer Research

Kotoku, Tokyo, 135-8550, Japan

RECRUITING

National Cheng Kung University Hospital

Tainan, 704302, Taiwan

NOT YET RECRUITING

National Taiwan University Hospital

Taipei, 100, Taiwan

NOT YET RECRUITING

Related Links

• To obtain contact information for a study center near you, click here.

MeSH Terms

Conditions

Small Cell Lung Carcinoma; Lung Neoplasms

Interventions

Drug Therapy

Condition Hierarchy (Ancestors)

Carcinoma, Bronchogenic; Bronchial Neoplasms; Respiratory Tract Neoplasms; Thoracic Neoplasms; Neoplasms by Site; Neoplasms; Lung Diseases; Respiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Therapeutics

Study Officials

• Pfizer CT.gov Call Center

  Pfizer

  STUDY DIRECTOR

Central Study Contacts

Pfizer CT.gov Call Center

CONTACT

1-800-718-1021; ClinicalTrials.gov_Inquiries@pfizer.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 13, 2026
• First Posted: March 17, 2026
• Study Start: May 15, 2026
• Primary Completion (Estimated): March 19, 2028
• Study Completion (Estimated): March 19, 2031
• Last Updated: June 4, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share

Locations

US (4); JP (1); CN (3); IL (2); TW (2)