Minibinder
A small protein designed from scratch to latch tightly onto a specific target protein, which is how many modern medicines work.
Most drugs work by sticking to something. A minibinder is a small protein built deliberately to stick to one chosen target protein and nothing else, so it can block that target, switch it on, or carry something to it. Designing one from scratch rather than copying an existing molecule is called de novo design, and it has historically taken a protein engineer weeks or months per target, with a lot of computation and a lot of failed candidates.
Two numbers describe how well a campaign went. The hit rate is what fraction of the designs actually bind when tested in a lab, and 10 to 15 percent has been typical. Affinity is how tightly a binder holds on, which matters because a strong binder works at a lower dose with fewer side effects. Anthropic’s August 2026 campaign with Claude reported hit rates of 22 to 35 percent across 15 targets, which is why the result drew attention. Designing a binder is still only the first step toward an actual drug.