Management of Increasing Complexity of Phase I Trials: A Retrospective Analysis from the Niguarda Cancer Center Phase I Unit

In the last decade, significant advancements in oncology clinical trials have led to the introduction of novel study designs, endpoints, and the integration of predictive biomarkers and molecular tumour profiling for patient selection. In parallel, increased quality standards and regulatory changes in phase I cancer trials have resulted in a substantial rise in study-related procedures, which require dedicated professionals to effectively manage all these tasks. To better understand the factors contributing to this complexity, we analyzed data from 36 phase I trials conducted at Niguarda Cancer Center between 2016 and 2023, focusing on solid tumors in adult patients. Of the 36 studies, 31 (86.1%) were designed with a dose-escalation phase followed by an expansion phase. While the majority of studies were biomarker-driven (n = 31, 86.1%), only 12 (33.3%) included an embedded molecular pre-screening. On average, each trial involved 3.7 ± 2.1 Investigational Medicinal Products (IMPs), with a mean of 6.9 ± 4.7 planned cohorts per study. Regarding protocol-related procedures, 17 studies (47.2%) incorporated an intensive pharmacokinetic (PK) program (≥ 6 PK samples within 24 h), and 7 (19.4%) included an intensive ECGs (≥ 4 ECGs in 24 h). Additionally, 16 studies (44.4%) required at least one mandatory tumor biopsy. When comparing data across 4 biennia from 2016 to 2023, we observed an increase in the average number of IMPs (1.5 ± 0.58 in 2016/17; 4.43 ± 2.10 in 2022/23) and the average number of cohorts per trial (4.00 ± 1.15 in 2016/17; 8.21 ± 6.20 in 2022/23). In conclusion, this study highlights the growing complexity of phase I trials, driven by factors such as an increased number of IMPs, cohorts, tumor histologies, and study procedures like PK, ECG, and tumor biopsies. These factors should be considered when planning resource allocation and developing strategies for workforce training. Clinical centers must ensure adequate resources, specialized personnel, and efficient organizational strategies to handle the expanding procedural demands of phase I trials.