20 Years of Medicinal Chemistry – Always Look at the Bright Side (of Life)

This paper summarizes a personal perspective on key learnings from projects the author was involved in over the last 20 years. For example, the discovery of macitentan, the most successful molecule to date from this personal collection, marketed by J&J for the treatment of pulmonary arterial hypertension (PAH). [1] Then the discovery of ACT-462206, a dual orexin receptor antagonist for the treatment of insomnia disorder with a serendipitously short story from the screening hit to the drug [2] followed by the identification of daridorexant, another dual orexin receptor antagonist. Daridorexant successfully passed first pivotal phase 3 clinical trial in April 2020 for the treatment of insomnia disorder [3] ("Good things come to those who wait"). Finally, ACT-451840, an antimalarial drug with a novel mechanism of action, identified in the perfect collaboration between academia and industry. The compound is in phase 2 clinical development. [4] In addition, the importance of the screening compound collection is briefly discussed, as a key asset for drug discovery. The measures Idorsia implemented to obtain valuable hits from high-throughput screening (HTS) campaigns are elaborated. [5] Drug discovery is a multi-disciplinary business with unlimited exciting challenges asking for excessive optimism when tackling them in a playful manner.