Novocure's brain cancer treatment fails to meet late-stage trial goal

Novocure said on Thursday that early use of its non-invasive cancer therapy did not significantly improve overall survival in patients with newly diagnosed brain tumors in a late-stage study.

The company's shares were down 16.1% at $14.98 in premarket trading.

The trial was designed to test the safety and effectiveness of Tumor Treating Fields (TTFields) therapy given together with chemoradiation in newly diagnosed glioblastoma patients, compared with starting TTFields after chemoradiation is finished.

Novocure's Optune Gio TTFields device is already approved to treat glioblastoma in combination with chemotherapy.

The treatment uses low-energy electrical fields to kill cancer cells. It is delivered through electrode pads connected to a wearable and portable device and placed on the skin near the tumor.

The device sends mild electrical currents that target cancer cells while sparing most nearby healthy cells and is typically worn for most of the day, allowing patients to continue daily activities.

In the trial, patients who began TTFields therapy at the start of chemoradiation had a median overall survival of 17.7 months, compared with 17.5 months in the maintenance group, the company said.

Although the study did not meet the main goal, the results "demonstrated promising signals that earlier initiation of TTFields treatment may improve outcomes for selected patients," said Wenyin Shi, professor of radiation oncology, Thomas Jefferson University, in a statement.

Novocure's approved TTFields therapy devices also include Optune Lua for a type of lung cancer and Optune Pax for pancreatic cancer.

(Reporting by Sneha S K in Bengaluru; Editing by Tasim Zahid and Sahal Muhammed)

Copyright Reuters or USA Today Network via Reuters Connect

This story was originally published June 18, 2026 at 5:20 AM.