765 trials with potential cancer drugs
Brussels - The Anticancer Fund, renowned for its expertise in drug repurposing, has found out how many existing non-cancer drugs with potential anticancer effects are currently involved in clinical trials. Which potential drugs are being tested? Where are the repurposing trials taking place? We went through more than 3000 trials to find the answers to these questions. This lead to the creation of a database, the ReDO_Trials_DB.
There is growing interest in the use of existing non-cancer drugs as potential cancer treatments - a strategy known as drug repurposing. The Anticancer Fund, which is a leading voice in this area, had already created the ReDO_DB, or the Repurposing Drugs in Oncology Database, a list of non-cancer drugs with published evidence of anticancer effects. Now it has also undertaken the first analysis of current clinical trial activity in oncological drug repurposing. Making use of the ReDO_DB, the Anticancer Fund team has constructed a unique database of active clinical trials exploring the therapeutic use of these drugs in cancer.
The first release of the database includes data from 765 trials, representing around 5% of active cancer trials globally.
ReDO_Trials_DB lists all active clinical trials which include one or more repurposing candidates in a treatment arm. Trials which are using repurposing candidates for new uses not related to their anticancer effects, for example to treat symptoms or reduce side-effects from other treatments, are not included even though they are still repurposing trials. This focus on new cancer treatments is completely in line with the Anticancer Fund's patient-centric approach.
Initial results from this analysis show that 151 (44%) of the drugs in the ReDO_DB are included in active clinical trials. While almost 15% of trials are at a late stage (Phase 3 or 4), over 17% of trials are still at Phase 1.
'One of the arguments in favour of repurposing is that as these are already licensed drugs early phase trials can be skipped, but until now we've not had the data to accurately gauge this - the trials database gives us greater insight into where the oncology community is actually going with repurposing', comments Pan Pantziarka, Director of Drug Repurposing at the Anticancer Fund.
'Metformin is irrationally popular'
The database also shows that the most popular drugs currently explored are: metformin, celecoxib, hydroxychloroquine, aspirin (acetylsalicylic acid) and vitamin C (ascorbic acid). Metformin, for example, is included in 124 clinical trials (16% of the total number of trials in the database).
'It’s a complex situation to analyse but I think we are observing a form of herd behaviour or 'Matthew effect', with the most popular drugs becoming irrationally popular. While there is a strong rationale for testing these drugs in a selection of cancer types, our data suggest some degree of shaky extrapolation and, with a high number of trials, a risk of false positive results which could artificially maintain enthusiasm for these drugs', explains Gauthier Bouche, Director Clinical Research of the Anticancer Fund.
Philanthropic funding is essential
The data also shows that fewer than 6% of the trials have commercial sponsorship - underlining the importance of academic, government and philanthropic funding of repurposing trials, like ours.
While the database answers some questions it also raises more - for example, how many of the trials will complete and deliver results? Will repurposing trials increase in number, and will it also become a higher proportion of oncology trials overall? It is intended that the database will be maintained and updated regularly, providing an online resource to researchers and clinicians and also helping to answer these additional questions.