Phase 3
N=1,060
Study of Chemoradiotherapy With or Without Pembrolizumab (MK-3475) For The Treatment of Locally Advanced Cervical Cancer (MK-3475-A18/KEYNOTE-A18/ENGOT-cx11/GOG-3047)
Uterine Cervical Neoplasms
Bottom Line
View on ClinicalTrials.gov: NCT04221945 ↗Enrolled (actual)
1,060
Serious AEs
31.0%
Results posted
Jan 2026
Primary outcome: Primary: Progression-Free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as Assessed by the Investigator — 47.6; 47.5 Months — p=0.0004
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 3
- Interventions
- Pembrolizumab (Biological); Placebo for pembrolizumab (Drug); Cisplatin (Drug); External Beam Radiotherapy (EBRT) (Radiation); Brachytherapy (Radiation)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- Female
- Sponsor
- Merck Sharp & Dohme LLC
- Primary completion
- Jan 2025
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Progression-Free Survival (PFS) Per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as Assessed by the Investigator |
47.6; 47.5 | 0.0004 sig |
| PRIMARY Overall Survival (OS) |
NA; NA | 0.0076 sig |
| SECONDARY PFS Per RECIST 1.1 as Assessed by Blinded Independent Central Review (BICR) |
48.9; NA | 0.0011 sig |
| SECONDARY PFS Per RECIST 1.1 at Month 24 as Assessed by the Investigator |
70.6; 59.7 | — |
| SECONDARY PFS Per RECIST 1.1 at Month 24 as Assessed by BICR |
76.0; 68.1 | — |
| SECONDARY Overall Survival (OS) at Month 36 |
81.8; 74.4 | — |
| SECONDARY Complete Response (CR) Rate Per RECIST 1.1 at Week 12 as Assessed by the Investigator |
36.9; 33.5 | 0.1307 |
| SECONDARY CR Rate Per RECIST 1.1 at Week 12 as Assessed by BICR |
42.9; 42.2 | 0.4082 |
| SECONDARY Objective Response Rate (ORR) Per RECIST 1.1 as Assessed by the Investigator |
87.3; 83.7 | 0.0496 sig |
| SECONDARY ORR Per RECIST 1.1 as Assessed by BICR |
90.5; 88.3 | 0.1244 |
| SECONDARY PFS Per RECIST 1.1 in Programmed Cell Death 1 Ligand 1 (PD-L1) Positive Participants as Assessed by the Investigator |
47.6; 47.5 | 0.0010 sig |
| SECONDARY PFS Per RECIST 1.1 in PD-L1 Positive Participants as Assessed by BICR |
48.9; NA | 0.0016 sig |
| SECONDARY OS in PD-L1 Positive Participants |
NA; NA | 0.0083 sig |
| SECONDARY PFS After Next-Line Treatment (PFS 2) Following Discontinuation of Study Treatment |
NA; NA | 0.0015 sig |
| SECONDARY Change From Baseline in European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) Global Health Status Score |
7.51; 7.44 | 0.9593 |
| SECONDARY Change From Baseline in European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) Physical Function Score |
2.74; 2.07 | 0.5145 |
| SECONDARY Change From Baseline in European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Symptom Specific Scale for Cervical Cancer (EORTC QLQ-CX24) Score |
-8.86; -9.60 | 0.2953 |
| SECONDARY Number of Participants Who Experience One or More Adverse Events (AEs) |
528; 526 | — |
| SECONDARY Number of Participants Who Discontinue Study Treatment Due to an AE |
112; 79 | — |
Summary
The purpose of this study is to evaluate the efficacy and safety of pembrolizumab plus concurrent chemoradiotherapy compared to placebo plus concurrent chemoradiotherapy in participants with locally advanced cervical cancer.
The primary hypotheses are that pembrolizumab plus concurrent chemoradiotherapy is superior to placebo plus concurrent chemoradiotherapy with respect to progression-free survival and overall survival.
Once the study objectives have been met or the study has ended, participants will be discontinued from this study and will be enrolled in an extension study to continue protocol-defined assessments and treatment.
Eligibility Criteria
Inclusion Criteria
- Has high-risk locally advanced cervical cancer (LACC): The International Federation of Gynecology and Obstetrics (FIGO) 2014 Stage IB2-IIB (with node-positive disease) or FIGO 2014 Stages III-IVA
- Has histologically-confirmed squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma of the cervix
- Has not previously received any definitive surgical, radiation, or systemic therapy for cervical cancer, including investigational agents, and is immunotherapy-naïve
- Female participants must not be pregnant or breastfeeding and agree to use highly effective contraception during the treatment period and for at least 120 days after the last dose of pembrolizumab or placebo and 180 days following the end of chemoradiotherapy and agrees not to donate eggs (ova, oocytes) to others or freeze/store for her own use for the purpose of reproduction during this period.
- Female participants must abstain from breastfeeding during the study intervention period and for at least 120 days after the last dose of pembrolizumab or placebo and 180 days following the end of chemoradiotherapy
- Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 within 7 days prior to the first dose of study treatment
- Has provided a tissue sample from a core incisional or excisional biopsy of a tumor lesion
- Has radiographically evaluable disease, either measurable or non-measurable per RECIST 1.1, as assessed by the local site investigator/radiology
- Has adequate organ function within 7 days prior to the start of study treatment.
Exclusion Criteria
- Has excluded subtypes of LACC
- Has FIGO 2014 Stage IVB disease
- Has undergone a previous hysterectomy defined as removal of the entire uterus or will have a hysterectomy as part of their initial cervical cancer therapy
- Has bilateral hydronephrosis, unless at least one side has been stented or resolved by positioning of nephrostomy or considered mild and not clinically significant in the opinion of the investigator
- Has anatomy or tumor geometry or any other reason or contraindication that cannot be treated with intracavitary brachytherapy or a combination of intracavitary and interstitial brachytherapy
- Has received a live vaccine within 30 days prior to the first dose of study treatment
- Has received treatment with systemic immunostimulatory agents, colony stimulating factors, interferons, interleukins and vaccine combinations within 6 weeks or 5 half-lives of the drug, whichever is shorter, prior to Cycle 1, Day 1
- Has received prior therapy with an anti-programmed cell death receptor 1 (PD-1), anti-programmed cell death receptor ligand 1 (PD-L1), or anti-programmed cell death receptor ligand 2 (PD-L2) agent or with an agent directed to another stimulatory or co-inhibitory T-cell receptor (eg, cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), OX-40, CD137)
- Has received prior systemic anticancer therapy including investigational agents within 4 weeks prior to randomization
- Is currently participating in or has participated in a study of an investigational agent or has used an investigational device within 4 weeks prior to randomization
- Has any contraindication to the use of cisplatin
- Has a diagnosis of immunodeficiency or is receiving chronic systemic steroid therapy (in dosing exceeding 10 mg daily of prednisone equivalent) or any other form of immunosuppressive therapy within 7 days prior to the first dose of study treatment
- Has a known additional malignancy that is progressing or has required active treatment within the past 3 years
- Has severe hypersensitivity to pembrolizumab and/or any of its excipients
- Has an active autoimmune disease that has required systemic treatment in past 2 years
- Has a history of (non-infectious) pneumonitis/interstitial lung disease that required steroids or has current pneumonitis/interstitial lung disease
- Has an active infection requiring systemic therapy
- Has a known history of Human Immunode
Data sourced from ClinicalTrials.gov (NCT04221945). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.