OBJECTIVE: This study aims to calculate the global warming potential, in carbon dioxide (CO DESIGN: The study design involved a retrospective analysis of completed clinical trials. SETTING: Select set of seven clinical trials conducted between 2018 and 2023 and sponsored by Johnson & Johnson Innovative Medicine: TMC114FD1HTX1002, 77242113PSO2001, 42756493BLC2002, 54767414MMY3012, VAC18193RSV3006, R092670PSY3016 and 28431754DIA4032 PARTICIPANTS: While participants and the public were involved in all seven trials, the life cycle assessments (LCAs) were performed as an independent retrospective analysis after the clinical trials were completed. As a retrospective analysis, we leveraged clinical trial documentation and interviews with the sponsor trial staff and trial site staff. None of the participating trial subjects were involved specifically in the LCA analysis, nor was any personal identifying information from the trial subjects collected or shared.The underlying clinical trials were performed in accordance with the Declaration of Helsinki and Guidelines for Good Pharmacoepidemiology Practice. All participating investigators were required to obtain full governing board approval for conducting research involving humans. Sponsor approval and continuing review were obtained through the appropriate Institutional Review Board/Ethics Committee (IRB) and Health Authority channels. For academic investigative sites that did not receive authorisation to use the central IRB, full board approval was obtained from their respective governing IRBs, and documentation of approval was submitted to Johnson & Johnson Innovative Medicine, LLC, before the site's participation and initiation of any trial procedures. All registry participants provided written informed consent and authorisation before participating. PRIMARY OUTCOME MEASURE: Primary outcome measure CO RESULTS: The TMC114FD1HTX1002 phase 1 trial was the smallest trial both in terms of number of patients (39) and sites (1) and had the smallest emissions at 17 648 kgCO CONCLUSIONS: Based on our LCAs of seven clinical trials spanning all four phases of development and multiple disease areas, there are five activities that drive no less than 79% of the average clinical trial's GHG footprint. These are drug product manufacture, packaging, and distribution
patient travel
on-site monitoring visit travel
the collection, transport and processing of laboratory samples
and sponsor staff commuting between their homes and the office. Understanding the activities that drive GHG emissions in clinical trials can both guide trial designers in avoiding or minimising reliance on these activities when designing new trials and guide trial sponsors in taking targeted actions to reduce GHG emissions from these activities where their use cannot be avoided. TRIAL REGISTRATION NUMBER: TMC114FD1HTX1002 (ClinicalTrials.gov: NCT04208061), 77242113PSO2001 (ClinicalTrials.gov: NCT05364554), 42756493BLC2002 (ClinicalTrials.gov: NCT03473743), 54767414MMY3012 (ClinicalTrials.gov: NCT03277105), VAC18193RSV3006 (ClinicalTrials.gov: NCT05070546), R092670PSY3016 (ClinicalTrials.gov: NCT04072575) and 28431754DIA4032 (ClinicalTrials.gov: NCT04288778).