Rather than trying to make ever smaller molecules that retain activity against complex targets, Coferon Inc. is using a bioorthogonal linker technology to deliver two halves of a therapeutic that self-assemble on the target after gaining entry into a cell. The company was set to announce the close of a $12 million series B round on Monday this week.

Targeting intracellular protein-protein interactions requires walking a fine line - a therapeutic needs to be small enough to enter the cell but large enough to modulate the interface between two bulky proteins.