NCT06556563 · NovoCure GmbH
EF-41/KEYNOTE D58: Phase 3 Study of Optune Concomitant With Temozolomide Plus Pembrolizumab in Newly Diagnosed Glioblastoma
(EF-41)
What this study is about
This is a conducted at multiple hospitals, two-treatment group$1, randomly assigned, where neither patients nor doctors know which treatment is given, compared against an inactive treatment study of Optune® (Tumor Treating Fields at 200 kHz) together with maintenance Temozolomide (TMZ) chemotherapy agent and pembrolizumab compared to Optune® together with maintenance TMZ and placebo in newly diagnosed Glioblastoma (GBM) patients. The primary objective of the study is to evaluate the how long patients live (OS).
View original scientific description
This is a multicenter, two-arm, randomized, double-blind, placebo-controlled study of Optune® (Tumor Treating Fields at 200 kHz) together with maintenance Temozolomide (TMZ) chemotherapy agent and pembrolizumab compared to Optune® together with maintenance TMZ and placebo in newly diagnosed Glioblastoma (GBM) patients. The primary objective of the study is to evaluate the Overall Survival (OS).
Interventions
DEVICE
Optune® device
Optune® device delivering TTFields therapy at 200 kHz.
DRUG
Temozolomide
Temozolomide per approved labeling.
DRUG
Pembrolizumab
Pembrolizumab dose throughout this study is 200 mg IV Q3W for a maximum of 35 cycles.
DRUG
Placebo
Placebo (saline solution) dose throughout this study is 200 mg IV Q3W for a maximum of 35 cycles.
Primary outcome measures
Overall survival
Time frame: 24 months
Overall survival (OS) is defined as the time from randomization to death due to any cause
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- The participant (or legally acceptable representative) has provided documented informed consent for the study. 2. Be ≥ 18 years of age on day of providing informed consent. 3. Participant with new diagnosis of GBM according to World Health Organization (WHO) 2021 Classification. 4. Recovered from maximal debulking surgery (gross total resection, partial resection and biopsy-only patients are all acceptable), Gliadel wafers placement at the time of surgical resection is not allowed. 5. Have completed standard adjuvant chemoradiotherapy of radiotherapy (RT) according to local practice (56-64 Gy), and concomitant TMZ chemotherapy. 6. Amenable to treatment with Optune concomitant with maintenance TMZ (150-200 mg/m\^2 daily x 5, Q28 days). 7. Have an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 1 assessed within 7 days before randomization. 8. Stable or decreasing dose of corticosteroids (dexamethasone ≤ 2mg or equivalent) for the last 7 days
Where
- Phoenix, Arizona
- Los Angeles, California
- Newport Beach, California
- Palo Alto, California
- San Francisco, California
- Gainesville, Florida
- Jacksonville, Florida
- Miami, Florida
- Tampa, Florida
- Chicago, Illinois
- Lexington, Kentucky
- Baltimore, Maryland
And 18 more locations — see the full list below.
Collaborators
Merck Sharp & Dohme LLC
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced May 1, 2026 · Source of record for eligibility and locations