Most bispecific antibody programs don’t fail because of weak biology. They fail later, when molecules that look promising in early assays run into issues with pharmacokinetics, developability, or manufacturability.
These are not edge cases. They are predictable failure modes. And yet, they are often addressed too late.
Cantai Therapeutics approached this differently. Built as a discovery-focused company in autoimmune disease, the team started with validated targets, but made an early decision to design for clinical success, not just biological activity.
Instead of optimizing for potency first and solving problems downstream, they defined target product profiles from the outset, engineering molecules to meet both biological and development requirements from day one.
That shift changes how decisions get made. Affinity, format, and binding behavior are no longer optimized in isolation. They are designed together, against a clear set of constraints tied to how the molecule needs to perform in vivo.
To execute, Cantai partnered with Alloy Therapeutics as an integrated discovery engine.
“We knew from the start we didn’t want to build a lab. We wanted a partner who could help us move quickly and build the right product, and Alloy was the perfect fit,” explained Geeta Vemuri, Managing Partner at Agent Capital and CEO of Cantai.
Rather than operating through a traditional CRO model, the teams worked as a single system, combining transgenic platforms, computational design, and experimental validation in tightly coordinated cycles.
“It felt like the Alloy team was an extension of our R&D team,” said Ross Leimberg, COO & Founder, Cantai Therapeutics.
The result was not just a set of potent bispecific antibodies, but molecules designed to translate, balancing target engagement, pharmacokinetics, and developability within a single architecture.
“You can’t treat bispecifics as two independent antibodies fused together. If you do, you miss critical failure modes in vivo,” Mike Schmidt, CSO, Alloy Therapeutics.
This is the direction complex biologics are moving.
Not faster iteration on the same model, but a shift toward designing out risk from the beginning.
We’ll be sharing more from the Cantai program in the next weeks, including the full case study and recorded conversations with the team.
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Download our case study to learn how Mediar Therapeutics and Alloy Therapeutics advanced antibody programs from concept to clinic ahead of schedule.