LondonCondensates degraded an oncogenic KRAS mutation while sparing normal copies.
Antibody-loaded condensates using liquid-liquid phase separation eliminated the variant and suppressed tumor growth in animals without harming healthy cells, a study found.
The platform may reach intracellular proteins conventional degrader drugs cannot target.
Sources: Nature
THE UNDRUGGABLE PROBLEM
Roughly 85% of human proteins lack the deep, well-shaped binding pockets that small-molecule drugs need. KRAS — mutated in a quarter of all human cancers — was the canonical undruggable target for four decades. Its surface is smooth.
THE THREE EXISTING MODALITIES
Drug discovery has historically had three shapes: small molecules (block an active site), biologics like antibodies (bind a surface, usually outside the cell), and gene/RNA therapies (stop the protein being made). Each fails on different terrain.
WHY DEGRADATION CHANGES THE GAME
A traditional inhibitor must occupy the active site continuously — one molecule per protein, around the clock. A degrader only needs to touch the target briefly to mark it for destruction, then moves on to the next. Catalytic, not stoichiometric. This is the core insight behind PROTACs and now condensates.
WHAT A CONDENSATE IS
Inside every cell, certain proteins spontaneously demix from the cytosol into liquid droplets — the way oil separates from vinegar. These biomolecular condensates concentrate specific molecules hundreds of times above the surrounding fluid without any membrane. The nucleolus is the textbook example; cells use them to run reactions that need crowding.
THE SELECTIVITY TRICK
A single amino acid change between mutant and wild-type KRAS is enough for an antibody to discriminate. Loading that antibody into a condensate concentrates both the binder and its target in the same droplet — pulling mutant KRAS out of circulation while normal copies, never recruited, keep doing their jobs. The droplet acts as a programmable sorting compartment.
THE FOURTH MODALITY
If the platform generalizes, drug discovery gains an entire new shape: any intracellular protein with a selective binder becomes a potential target, regardless of pocket geometry. The bottleneck shifts from chemistry (finding a molecule that fits) to biology (finding a binder that discriminates) — a problem antibody engineering has been solving for decades.