Last month, the U.S. Food & Drug Administration (FDA) approved the NovoTTF-100L system, a new first-line therapy for treating malignant pleural mesothelioma. This is the first treatment for mesothelioma to receive approval in over 15 years. NovoTTF-100L uses Tumor Treating Fields, a type of therapy that emits electric currents to disrupt cancer cell division and tumor growth.

NovoTTF-100L was created by Novocure and approved under the FDA’s Humanitarian Device Exemption eight months after Novocure released results from the STELLAR phase 2 clinical trial. The STELLAR trial was carried out at cancer centers across Europe and included 80 patients with unresectable, previously untreated malignant pleural mesothelioma. Results in the trial showed that patients treated with NovoTTF-100L survived six months longer, on average, than patients receiving only chemotherapy. There were  no reported major side effects or system toxicities, although 46 percent of patients noted skin irritation from using the device, but only 4 percent reported grade 3 skin irritation.

Ninety-seven percent of patients saw a clinical benefit from using the system, including either a partial response or stable disease. The median overall survival for patients with epithelioid mesothelioma – the most common cell type – was 21.2 months. Patients with sarcomatoid or biphasic cell types survived 12.1 months on average. Patients in the Tumor Treating Fields group saw a progression-free survival of 7.6 months, compared to 5.7 months for the chemotherapy group only.

The FDA approved the Tumor Treating Fields delivery system for use in combination with pemetrexed and platinum-based chemotherapy for unresectable, locally advanced or metastatic malignant pleural mesothelioma. NovoTTF-100L uses low-intensity alternating electric fields, which are calibrated to interfere with the division of cancer cells. For mesothelioma patients, the currents are delivered noninvasively to the upper torso and the system is intended for home use.

This is an important breakthrough for mesothelioma patients, as only 10 to 20 percent of patients qualify for tumor reduction surgery, according to Asbestos.com. In 2011, the FDA approved Optune, another Tumor Treating Fields device, for the treatment of glioblastomas.