PDF file - 309K, Supplemental table 1 - Drugs included in the analysis and their respective phase I trials. Supplemental table 2 - Drugs included in the analysis and their respective schedule and later trial leading to FDA approval. Supplemental table 3 - Agents and Phase I trials characteristics. Supplemental table 4 - Univariate analysis of the probability of adopting the RP2D plus or minus 20% according to phase I trials characteristics. Supplemental Figure 1 - Flow diagram of search results. Supplemental figure 2 - Analysis of the probability of adopting the RP2D in relation to continuous variables.
ARTICLE ABSTRACT
Phase I trials use a small number of patients to define a maximum tolerated dose (MTD) and the safety of new agents. We compared data from phase I and registration trials to determine whether early trials predicted later safety and final dose. We searched the U.S. Food and Drug Administration (FDA) website for drugs approved in nonpediatric cancers (January 1990–October 2012). The recommended phase II dose (R2PD) and toxicities from phase I were compared with doses and safety in later trials. In 62 of 85 (73%) matched trials, the dose from the later trial was within 20% of the RP2D. In a multivariable analysis, phase I trials of targeted agents were less predictive of the final approved dose (OR, 0.2 for adopting ± 20% of the RP2D for targeted vs. other classes; P = 0.025). Of the 530 clinically relevant toxicities in later trials, 70% (n = 374) were described in phase I. A significant relationship (P = 0.0032) between increasing the number of patients in phase I (up to 60) and the ability to describe future clinically relevant toxicities was observed. Among 28,505 patients in later trials, the death rate that was related to drug was 1.41%. In conclusion, dosing based on phase I trials was associated with a low toxicity-related death rate in later trials. The ability to predict relevant toxicities correlates with the number of patients on the initial phase I trial. The final dose approved was within 20% of the RP2D in 73% of assessed trials. Clin Cancer Res; 20(2); 281–8. ©2013 AACR.
