Level2 has invested in Ditto Bio, drug discovery in reverse

Ticks and worms are better at controlling the human immune system than any drug we have built. Ditto Bio decided to learn from them.

Viruses, ticks and worms survive by quieting our immune response, evolving proteins that do it with a precision no lab has matched. Ditto Bio, part of Y Combinator’s W26 batch, built an AI platform that reads their genomes, finds those proteins, and turns them into therapies for people whose immune systems attack their own bodies.

It inverts how drug discovery usually works. Most drugs start from molecules that have never been inside a human, part of why 90% fail in trials. Ditto starts from molecules already proven in humans.

We backed the founders. Adair Borges, Dennis Sun and Emily Weiss, all three PhDs, built together for three years at Arcadia Science before starting Ditto. They already know how each other works when the data is ambiguous and the pressure is on. For a decade-long climb, that matters as much as the science.

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