Phase 3 Trial of Tumor-Treating Fields for NSCLC Impresses at Interim Analysis

Interim analysis of the phase 3 LUNAR trial led to a data monitoring committee recommendation to reduce the trial sample size due to strongly positive results gathered from the current patient population treated with tumor-treating fields.

Results from a prespecified interim update to the phase 3 LUNAR trial (NCT02973789) of tumor-treating fields (TTFields) by the NovoTTF-100L system in patients with stage IV non–small cell lung cancer (NSCLC) after progression on or after platinum-base chemotherapy concluded with a favorable recommendation to continue, reported Novocure who is responsible for the therapy.

The interim analysis included data taken from 210 patients with a data monitoring committee (DMC) recommendation to reduce the sample size to approximately 276 patients. Continued accrual and randomization of 534 patients, which was formerly set at the target enrollment for the study, was deemed to be unnecessary or possibly unethical given the available data. Of note, there was no evidence of increased systemic toxicity when patients were treated with TTFields.

“We are very pleased with the DMC recommendations, which we believe support the potential for TTFields to make a significant difference in treatment outcomes for patients with non–small cell lung cancer, whether used together with immune checkpoint inhibitors or docetaxel,” William Doyle, Novocure’s Executive Chairman, said in a press release. “The accelerated interim analysis with an encouraging outcome adds to the accumulating evidence of tumor treating fields’ broad potential across a range of hard-to-treat cancers.”

The prospective, randomized controlled phase 3 trial randomized patients with squamous or nonsquamous histology who progressed on frontline platinum-based chemotherapy to received immune checkpoint blockade or docetaxel with or without TTFields. The primary end point for the trial is overall survival in the TTFields groups versus those treated with systemic therapy alone. Secondary end points include progression-free survival in the efficacy set, OS in patients receiving docetaxel with or without TTFields, OS for immunotherapy with or without TTFields, quality-of-life measures, and safety.

“The completion of the LUNAR interim analysis is an important milestone for Novocure,” Asaf Danziger, Novocure’s CEO, said in press release. “Pending regulatory approval, the recommended protocol adjustments could accelerate trial completion by more than a year. We look forward to sharing final data from the LUNAR trial as quickly as possible.”

Treatment in the TTFields arm of the current trial requires that patients wear 4 electrically insulated electrode arrays on the chest and that they maintain regular daily routine with the therapy. The electric fields delivered by the electrodes have demonstrated an anti-mitotic effect and is mainly intended for use in conjunction with standard-of-care therapies, such as radiation and/or systemic therapy agents.

“Combination therapy is a cornerstone of cancer care, and we believe using TTFields together with other cancer treatments, including immunotherapies, may lead to better outcomes for some patients,” Doyle said. “We are very encouraged that, consistent with our expectations, the DMC concluded that TTFields exhibited no systemic toxicity. We will continue to develop TTFields as a limited toxicity backbone therapy upon which other standard-of-care and emerging cancer treatments can be added.”

The NovoTTF-100L system was approved in May 2019 as the first device indicated for use with standard 2-drug chemotherapy for the treatment of patients with unresectable, malignant pleural mesothelioma.2 Premarket approval to another TTFields system, Optune, from Novocure was approved in 2011 for patients with glioblastoma multiforme.3


1. Novocure Announces Update on Phase 3 Pivotal LUNAR Trial of Tumor Treating Fields in Non-Small Cell Lung Cancer. News release. Novocure. April 13, 2021. Accessed April 14, 2021.

2. NovoTTF – 100L System – H180002. FDA. May 28, 2019. Accessed April 14, 2021.

3. Summary of Safety and Effectiveness Data (SSED) – Tumor Treating Fields (Optune). FDA. October 15, 2015. Accessed April 14, 2021.