On August 26, 2026, the FDA approved Rasonque (daraxonrasib) for adults with metastatic pancreatic adenocarcinoma—a landmark development for targeting the RAS signaling pathway. On August 26, 2026, the FDA approved Rasonque (daraxonrasib) for adults with metastatic pancreatic adenocarcinoma—a landmark development for targeting the RAS signaling pathway. Clinical results showed an unprecedented ~2× improvement in overall survival.
What makes daraxonrasib particularly fascinating is its mechanism. Rather than simply searching for a conventional binding pocket on RAS, daraxonrasib uses a fundamentally different binding strategy. The molecule binds cyclophilin A, a cellular chaperone, and this drug–cyclophilin complex creates a new composite surface that can engage active RAS. The resulting three-part complex blocks RAS interactions with downstream effectors and suppresses RAS signaling.
The deeper design principle is fascinating:
Instead of only looking for a druggable pocket, we can potentially create a new druggable surface.
Small molecules could be designed to engineer new protein–protein interactions inside cells, bringing a disease-driving protein together with a cellular partner to generate a therapeutic effect.
This opens a much broader vision for drug discovery.
Many disease-driving proteins have historically been considered “undruggable” because they lack suitable binding pockets for conventional small molecules. But if we can engineer new protein surfaces—or, more precisely, create new composite interfaces and induce productive protein–protein interactions—the universe of potentially druggable proteins could expand dramatically.
And that could ultimately expand the range of diseases and cancers that can be treated.
This is chemical biology at its most powerful: a small molecule is no longer simply an inhibitor. It becomes an architect of a new molecular interaction.
Rather than asking only:
“Where is the pocket?”
we can begin asking:
“What new interaction can we engineer?”
That shift could fundamentally change how we think about drugging previously “undruggable” proteins.
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