Malignant pleural mesothelioma (MPM) is an aggressive cancer characterised by modest sensitivity to systemic chemotherapy. The standard treatment remains platinum-based chemotherapy with pemetrexed. Recently, the addition of an antiangiogenic drug, bevacizumab, to first-line chemotherapy has been shown to improve overall survival. All the patients, unfortunately, will progress, and currently, there is no standard treatment approved in second-line. Recently, the results of the NGR015 phase III randomised with NGR-hTNF plus chemotherapy versus placebo in addition to physician's choice second-line chemotherapy for MPM have been published. Despite encouraging data achieved in previous phase I and phase II studies, the NGR-hTNF drug failed to meet the primary endpoint of the study, although a signal of activity was observed in the group of patients who had a shorter treatment failure interval from the first-line treatment. Hereby, we start from this recent trial to highlight once more the importance of thoroughly investigating possible predictive factors during the early drug development phase to allow more efficient phase III trial design, thus avoiding the possibility of potentially effective molecules like NGR-hTNF, continuing to be wasted.