Figure 1:

Modern PDD strikes a balance between planned discovery and serendipity. Approved drugs are listed based on the original phenotypic assay which first connected the compound series or the drug itself to the disease. Notably, while all discoveries from cellular screens represented the outcome of planned efforts, it was unexpected clinical side effects in patients which led to compound repurposing. References: ivacaftor,^6,7 , daclatasvir,⁸ risdiplam,⁹ trametinib,¹⁰ lacosamide,¹¹ memantine,¹² minoxidil,^13,14 ezetimibe,¹⁵ amantadine,¹⁶ sildenafil.¹⁷