A Phase 2 Study to Evaluate the Efficacy and Safety of Pembrolizumab plus Investigational Agents in Combination with Etoposide and Cisplatin or Carboplatin for the First-Line Treatment of Participants with Extensive-Stage Small Cell Lung Cancer (KEYNOTE-B99)

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

EU CTIS

Registry ID

CTIS2023-506538-56-00

Acronym

MK-3475-B99

Enrollment

Registered

2024-02-01

Start date

2021-08-12

Completion date

2025-06-20

Last updated

2025-06-17

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

First-line treatment of participants with extensive-stage small cell lung cancer

Brief summary

Objective Response Rate (ORR) as Assessed by Blinded Independent Central Review (BICR) per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1), Six-Month Progression-Free Survival (PFS) as Assessed by BICR per RECIST 1.1

Detailed description

Duration of Response (DOR) as Assessed by BICR per RECIST 1.1, PFS as Assessed by BICR per RECIST 1.1, Overall Survival (OS), Percent Change From Baseline in Tumor Size as Assessed by BICR, Number of Participants Who Experienced an Adverse Event (AE), Number of Participants Who Discontinued Study Treatment Due to an AE, Change From Baseline in the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) Global Health Status/Quality of Life Scale (Items 29 and 30) at Week 19

Interventions

DRUGLenvatinib

DRUGKEYTRUDA 25 mg/mL concentrate for solution for infusion

DRUGMK-4830

DRUGETOPOSIDE

DRUGCISPLATIN

DRUGboserolimab

DRUGCARBOPLATIN

Eligibility

Sex/Gender

All

Age

18 Years to No maximum

Design outcomes

Primary

Measure	Time frame
Objective Response Rate (ORR) as Assessed by Blinded Independent Central Review (BICR) per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1), Six-Month Progression-Free Survival (PFS) as Assessed by BICR per RECIST 1.1	—

Secondary

Measure	Time frame
Duration of Response (DOR) as Assessed by BICR per RECIST 1.1, PFS as Assessed by BICR per RECIST 1.1, Overall Survival (OS), Percent Change From Baseline in Tumor Size as Assessed by BICR, Number of Participants Who Experienced an Adverse Event (AE), Number of Participants Who Discontinued Study Treatment Due to an AE, Change From Baseline in the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) Global Health Status/Quality of Life Scale (Items 29 and 30) at Week 19	—

Measure

Time frame

—

Countries

Austria, Hungary, Italy, Poland, Spain

Outcome results

None listed

Source: EU CTIS · Data processed: Feb 4, 2026