Clinical Value of TTFields Treatment in Mesothelioma Using ASCO and ESMO Frameworks

Abstract

The potential effectiveness and safety of TTFields in addition to pemetrexed and cisplatin or carboplatin in malignant pleural mesothelioma (MPM) was recently shown by the analysis of the phase II single arm EF-23 STELLAR trial. To account for the need of physicians and policymakers to objectively and comparably capture the clinical value of new cancer treatments the American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO) have both developed assessment frameworks. We quantified the clinical value of the TTFields treatment in MPM by applying ASCO and ESMO frameworks to the comparison of the STELLAR data to historical controls. The EF-23 STELLAR Trial (n=80) demonstrated that adding TTFields to pemetrexed and cisplatin or carboplatin for malignant pleural mesothelioma patients resulted in overall survival of 18.2 months (95% CI 12.1-25.8) and progression free survival of 7.6 months (95% CI 6.7-8.6). The ESMO Magnitude of Clinical Benefit Scale (MCBS) and the ASCO Net Health Benefit (NHB) frameworks were applied to the EF-23 trial data using a historical control as comparator. The application of the ASCO framework to the EF-23 data resulted in a NHB score of 52. This result was at the higher end of the score range of novel cancer treatments and compares well to the results for nivolumab in advanced non-squamous NSCLC and advanced squamous NSCLC as reference points. Applying the ESMO framework resulted in MCBS scores of A/5 (adjuvant/advanced) which would be the first score reported for MPM. The MCBS scores of A/5 are the highest scores achievable in the ESMO framework, and higher than the ESMO MCBS scores reported in the literature for NSCLC treatments. Despite differences in their respective concepts, both the ASCO and ESMO frameworks suggest that adding TTFields to Pemetrexed and Cisplatin or Carboplatin in malignant pleural mesothelioma patients provides a significant clinical benefit. The high scores underline the fact that treatment with TTFields may extend progression free and overall survival without additional systemic toxicities.