The Linked Clinical Trials initiative (LCT) for Parkinson's disease

The Linked Clinical Trials (LCT) initiative is a drug repurposing programme specifically aimed at identifying drugs that can slow the progression of Parkinson's disease (PD). Tom Isaacs was one of the key people behind the idea of LCT in 2011. He ensured it became a priority of The Cure Parkinson's Trust (CPT), a philanthropic funding body based in the UK which Tom had co‐founded 7 years earlier. During the latter 6 years of his life, Tom Isaacs was heavily involved in the LCT initiative and held the programme dear to his heart. This article describes the genesis of LCT and how the LCT scientific committee evaluates candidate drugs. From 2012, this committee has met annually to prioritise drugs suitable for repurposing in PD. This article does not catalogue every clinical trial within the LCT programme, but describes the 10 clinical trials that emerged either directly, or as an offspring from discussions, at the first meeting of the LCT scientific committee. Some, but not all, are funded by CPT, and all 10 trials are now either completed or ongoing. These trials use drugs developed to address one of the four therapeutic targets: glucagon‐like peptide 1 receptor, iron, and c‐abl tyrosine kinase. We conclude the LCT programme has already sparked a large number of promising clinical trials aimed at slowing PD progression. In doing so, it is a major legacy of Tom Isaacs, carrying the torch he once lit and conveying a sense of urgency for new and life‐transforming therapies for people with PD. This diagram briefly describes how the Linked Clinical Trials (LCT) program selects compounds to move forward to clinical trials with the aim of achieving disease modification in Parkinson’s disease. The numbers indicate the total numbers of compounds evaluated at each step during 2012‐2018. The LCT scientific committee carefully considers a range of important pre‐clinical, pharmaceutical, biochemical and clinical criteria, and some of these imperatives are illustrated in the bulleted lists.