Phase I clinical trials aim to find the highest dose of a novel drug that may be administrated safely without having serious adverse effects. Model-based designs have recently become popular in dose-finding procedures. Our objective is to provide an overview of phase I clinical trials in oncology.

A retrospective analysis of phase I clinical trials in oncology was performed by using the PubMed database between January 1, 2020, and December 31, 2022. We extracted all papers with the inclusion of trials in oncology and kept only those in which dose escalation or/ and dose expansion were conducted. We also compared the study parameters, design parameters, and patient parameters between industry-sponsored studies and academia-sponsored research.

Among the 1450 papers retrieved, 256 trials described phase I clinical trials in oncology. Overall, 71.1% of trials were done with a single study cohort, 56.64% of trials collected a group of at least 20 study volunteers, 55.1% were sponsored by industry, and 99.2% of trials had less than 10 patients who experienced DLTs.

The traditional 3 + 3 (73.85%) was still the most prevailing method for the dose-escalation approach. More than 50% of the trials did not reach MTDs. Industry-sponsored study enrolled more patients in dose-escalation trials with benefits of continental cooperation. Compared to previous findings, the usage of model-based design increased to about 10%, and the percentage of traditional 3 + 3 design decreased to 74%.

Phase I traditional 3 + 3 designs perform well, but there is still room for development in novel model-based dose-escalation designs in clinical practice.

Caregivers of adult phase 1 oncology trial patients experience high levels of distress and face barriers to in-person supportive care. The Phase 1 Caregiver LifeLine (P1CaLL) pilot study assessed the feasibility, acceptability, and general impact of an individual telephone-based cognitive behavioral stress-management (CBSM) intervention for caregivers of phase I oncology trial patients.

The pilot study involved 4 weekly adapted CBSM sessions followed by participant randomization to 4 weekly cognitive behavioral therapy sessions or metta-meditation sessions. A mixed-methods design used quantitative data from 23 caregivers and qualitative data from 5 caregivers to examine the feasibility and acceptability outcomes. Feasibility was determined using recruitment, retention, and assessment completion rates. Acceptability was assessed with self-reported satisfaction with program content and participation barriers. Baseline to post-intervention changes in caregiver distress and other psychosocial outcomes were assessed for the 8-session intervention.

The enrollment rate was 45.3%, which demonstrated limited feasibility based on an a priori criterion enrollment rate of 50%. Participants completed an average of 4.9 sessions, with 9/25 (36%) completing all sessions and an 84% assessment completion rate. Intervention acceptability was high, and participants found the sessions helpful in managing stress related to the phase 1 oncology trial patient experience. Participants showed reductions in worry and isolation and stress.

The P1CaLL study demonstrated adequate acceptability and limited feasibility and provided data on the general impact of the intervention on caregiver distress and other psychosocial outcomes. Caregivers of phase 1 oncology trial patients would benefit from supportive care services; a telephone-based intervention may have more utilization and thus make a larger impact.