A phase I/II trial of Tumor Treating Fields (TTFields) therapy in combination with pemetrexed for advanced non-small cell lung cancer

Background Low intensity, intermediate frequency, alternating electric fields (Tumor Treating Fields; TTFields) exhibit anti-mitotic activity in cancer cells. Promising preclinical data have led to a single arm phase I/II trial in NSCLC patients. Methods Forty-two inoperable stage IIIB (with pleural effusion) and IV NSCLC patients who had had tumor progression received pemetrexed 500mg/m2 iv q3w together with daily TTFields therapy until disease progression. The primary endpoint was time to “in-field” progression. Results Median age for all patients was 63 years, 76% had stage IV disease, 78% had adenocarcinoma and 17% had performance status of 2. The median time to in-field progression was 28 weeks and the median time to systemic progression was 22 weeks. Six patients (14.6%) had a partial remission (PR) and 20 had stable disease (SD) (48.8%). Median overall survival was 13.8 months and 1 year survival rate was 57%. There were no TTFields-related serious adverse events. Conclusions The combination of TTFields and pemetrexed as a second line therapy for NSCLC is safe and potentially more effective than pemetrexed alone. TTFields improved disease control within the treatment field and a phase III study is planned to further investigate its role as a novel treatment in NSCLC.