The KEYNOTE trial (also known as the “EF-41 trial”) 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).

Tumor Treating Fields (TTFields) are low-intensity wave-like electric fields, tuned to interfere with the division process of cancer cells.

TTFields are delivered to the region of the tumor using the Optune® medical device. The Optune® System is a portable, light-weight, battery operated device designed to deliver TTFields to glioblastoma (GBM) tumors.

Patients receiving TTFields need to wear four adhesive patches called “transducer arrays” on their scalp, which deliver the fields non-invasively to the location of the GBM tumor. The system is intended for continuous use by patients.

TTFields have been approved by the FDA for treatment of adult patients with recurrent and newly diagnosed GBM. What makes the TRIDENT study different is that is testing the use of Optune® together with radiation therapy (RT) and temozolomide (TMZ) in newly diagnosed patients.


*Watch TTField Videos from our 2025 Caring For the Caregiver Event below:

The KEYNOTE study is 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).

If you want to take part in the KEYNOTE trial, please contact one of the participating centers as soon as possible. Consult your treating physician if you have questions about your medical condition and if a clinical trial is right for you.