Towards new methods for the determination of dose limiting toxicities and the assessment of the recommended dose for further studies of molecularly targeted agents--dose-Limiting Toxicity and Toxicity Assessment Recommendation Group for Early Trials of Targeted therapies, an European Organisation for Research and Treatment of Cancer-led study.

INTRODUCTION: Traditional dose-limiting toxicity (DLT) definition, which uses grade (G) 3-4 toxicity data from cycle 1 (C1) only, may not be appropriate for molecularly targeted agents (MTAs) of prolonged administration, for which late or lower grade toxicities also deserve attention. PATIENTS AND METHODS: In collaboration with pharmaceutical companies and academia, an European Organisation for Research and Treatment of Cancer (EORTC)-led initiative, Dose-Limiting Toxicity and Toxicity Assessment Recommendation Group for Early Trials of Targeted therapies (DLT-TARGETT), collected data from completed phase 1 trials evaluating MTAs as monotherapy. All toxicities at least possibly related to the study drugs that occurred during C1-6, their type, grade (CTCAEv3.0), and duration as well as patients' relative dose-intensity (RDI), were recorded. RESULTS: The 54 eligible trials enrolled 2084 evaluable adult patients with solid tumours between 1999 and 2013, and evaluated small molecules (40), antibodies (seven), recombinant peptides (five) and antisense oligodeoxynucleotides (two). A maximum tolerated dose was set in 43 trials. Fifteen percent of the patients received <75% of the intended RDI in C1, but only 9.1% of them presented protocol-defined DLTs. After C1, 16-19% of patients received <75% of the intended RDI. A similar proportion of G ⩾ 3 toxicities was recorded in C1 and after C1 (936 and 1087 toxicities, respectively), with the first G⩾3 toxicity occurring after C1 in 18.6% of patients. CONCLUSION: Although protocol-defined DLT period is traditionally limited to C1, almost 20% of patients present significant reductions in RDI at any time in phase 1 trials of MTAs. Recommended phase 2 dose assessment should incorporate all available information from any cycle (notably lower grade toxicities leading to such RDI decrease), and be based on achieving >75% RDI.

Prospective validation of a prognostic score to improve patient selection for oncology phase I trials.

PURPOSE: With the aim of improving patient selection for phase I trials, we previously performed a retrospective analysis of 212 phase I oncology patients where we were able to develop a prognostic score predicting overall survival (OS). This prospective study was performed to test the validity of the prognostic score. PATIENTS AND METHODS: On the basis of our retrospective multivariate analysis, three factors were associated with poor survival (albumin < 35 g/L, lactate dehydrogenase [LDH] > upper limit of normal [ULN], and > two sites of metastases). We integrated these into a prognostic score ranging from 0 to 3 and analyzed this score in a prospectively selected cohort of 78 patients enrolled onto phase I trials. RESULTS: All patients had progressive disease before study entry. The median age was 56 years (range, 18 to 79 years). After a median follow-up time of 27.3 weeks, patients with a prognostic score of 0 to 1 (n = 43) had superior OS (33.0 weeks; 95% CI, 24 to 42 weeks) compared with patients with a score of 2 to 3 (n = 35; 15.7 weeks; 95% CI, 11 to 21 weeks). Our multivariate analysis confirmed that our prognostic score was an independent marker for OS, with a hazard ratio of 1.4 (95% CI, 1.02 to 1.9; P = .036). CONCLUSION: This is the first prospective analysis confirming that a prognostic score based on objective markers, including albumin less than 35 g/L, LDH more than ULN, and more than two sites of metastasis, is a helpful tool in the process of patient selection for phase I trial entry.