What is the purpose of screening compounds in disease-relevant assays during hit identification?

• A. To identify hits from screening many compounds in disease-relevant assays.
• B. To determine the maximum tolerated dose in humans.
• C. To confirm the identity of biological targets.
• D. To assess market viability of a compound.

Answer: (A)

Screening compounds in disease-relevant assays during hit identification aims to find molecules that produce a desired effect in a biological setting that mirrors the disease. By testing large libraries against an assay that reflects disease biology, you identify “hits”—compounds that show meaningful activity on the target or pathway in a context that matters for disease. This boosts the chances that these hits will be active in more complex biological systems and not just in generic test conditions, making them good starting points for optimization.

Other options aren’t the goal of this step: determining the maximum tolerated dose is a toxicology/dose-finding task done later; confirming the identity of biological targets is target deconvolution; and assessing market viability is a business consideration. The screening in disease-relevant assays specifically serves to uncover initial lead compounds with real therapeutic potential.