In the mid-2010s, a spate of start-ups hoping to transform the laborious process of finding new drugs launched with big promises. Artificial intelligence would dramatically reduce the time it took to discover new medicines and cut the average of $2bn it takes to develop a drug. 

The emerging businesses attracted the attention of Big Pharma companies such as Bristol Myers Squibb and Sanofi, which signed deals worth billions of dollars pending the drugs’ eventual approval. Press releases boasted of “breakthrough productivity gains” and “groundbreaking research collaborations”.

But now, sceptics are asking: where are the drugs? It has been longer than the average 10 years that it takes to discover and develop a medicine, yet there are few AI-discovered candidates in late-stage clinical trials, and not one has been approved. Despite pledging to cut the industry’s high failure rate, many of the companies’ initial studies flopped.