Plasmodium Falciparum Chemical Space

What is IC₅₀?

The IC₅₀ score is the concentration of a drug required to inhibit 50% of a target’s biological activity, measured in molarity (µM or nM). It provides a quantitative measure of drug potency.

How is it measured?

Through dose–response experiments: a compound is applied at varying concentrations to a culture of the target, and the resulting growth or metabolic activity is quantified (e.g., via fluorescence). The IC₅₀ is the midpoint of the resulting sigmoidal curve.

Why is IC₅₀ important?

• Standard pharmacology metric—widely used in ChEMBL
• Enables cross-study comparability
• More abundant than rarer endpoints (IC₉₀, EC₉₀), giving more data
• Consistent reporting yields stable signals for ML models
• Primary screening output in malaria drug-discovery pipelines