Clinical trials with cannabis medicines-guidance for ethics committees, governance officers and researchers to streamline ethics applications and ensuring patient safety: considerations from the Australian experience.

With cannabis medicines now obtaining legal status in many international jurisdictions (generally on the authorisation of a medical professional), a rapid increase in consumer demand for access to cannabis as a therapeutic option in the treatment and management of a range of indications is being noted. Despite this accessibility, knowledge on optimal use is lacking. Further drug development and clinical trials at regulatory standards are necessary both if a better understanding of the efficacy of cannabis medicines, optimal product formulation and indication-specific dosing is needed and to ensure the broader quality and safety of cannabis medicines in the clinical setting.To enable this, clinical, academic and public calls for the undertaking of rigorous clinical trials to establish an evidence base for the therapeutic use of cannabis medicines have been made internationally. While this commitment to undertake human studies with cannabis medicines is welcomed, it has highlighted unique challenges, notably in the review stages of ethics and governance. This often results in lengthy delays to approval by Human Research Ethics Committees (herein 'HREC', Australia's nomenclature for Institutional Review Boards) and trial commencement. A principal concern in these cases is that in contrast to clinical trials using other more conventional pharmaceutical products, trials of cannabis medicines in humans often involve the use of an investigational product prior to some (or any) of the preclinical and pharmaceutical safety issues being established. This paucity of data around product safety, potential drug interactions, continuity of supply, shelf life and product storage results in apprehension by HRECs and governance bodies to endorse trials using cannabis medicines.This manuscript draws from the experiences of Australian researchers and staff involved in clinical trials of cannabis medicines to describe some of the common difficulties that may be faced in the HREC approval process. It also presents practical advice aimed to assist researchers, HRECs and governance officers navigate this complex terrain. While the authors' experiences are situated within the Australian setting, many of the barriers described are applicable within the international context and thus, the solutions that have been proposed are typically adaptive for use within other jurisdictions.