AARWRArrowhead Pharmaceuticals, Inc.

Arrowhead switches off individual genes in the liver and other organs — the same principle as RNA interference drugs.

The drug does not block an already-made protein but stops the cell from synthesising it. The company developed a way to deliver such molecules to a specific organ, and that is its main asset: the technology applies to a whole range of diseases rather than to one.

Its development model is not to bring everything to market itself but to license programmes to large pharmaceutical companies, receiving milestone payments and future royalties. That reduces the need for capital while limiting the share of success. Its own programmes address inherited metabolic disorders and cardiovascular risk. Risks: trial outcomes and the funding runway. The company pays no dividend.