Keytruda®: the best-selling drug that nearly wasn’t

A new generation of cancer treatment

In 2007, we entered a collaboration with Organon – ultimately acquired by Merck – to translate innovative drug targets into potent and selective therapeutic antibody candidates that could be progressed into pre-clinical and clinical studies.

When our collaborators at Organon first discovered PD109.A, the molecule that would lead to Keytruda_^®, there was much scepticism around immuno-oncology – fuelled by years of failed attempts to harness the immune system against cancer.

Despite this uncertainty, we saw great promise in Organon’s discovery and decided to pursue it. Together, we humanised their mouse antibody, transforming it into pembrolizumab – a highly potent, selective molecule that targets the human PD1 checkpoint inhibitor – later marketed as Keytruda^®.

Keytruda^® entered the market in 2014, with the exact same sequence as the molecule that left our laboratory 6 years earlier. Its emergence marked a turning point in the way we treat some types of cancer and, by 2023, Keytruda^® became the world’s top-selling drug, having treated its millionth patient.

We remain committed to backing projects with the potential to change lives, even those that may otherwise be overlooked due to their complexity or high-risk nature. We fund the entirety of our humanisation projects, taking on the financial risk so our partners don’t have to – helping promising antibody projects like Organon’s PD109. A move one step closer to the clinic.