Veteran biologics leader brings more than 25 years of drug discovery experience and a track record of pipeline-scale impact at Roche
SAN MATEO, Calif.--(BUSINESS WIRE)--BigHat Biosciences, an AI-driven platform and therapeutics company, announced today the appointment of Stefan Weigand, PhD, as Chief Scientific Officer. Stefan joins from Roche, where he was Head of Large Molecule Research, overseeing a global team of approximately 350 scientists and the company's biologics, conjugates, and gene therapy pipeline from discovery through Phase I. Weigand's appointment comes as BigHat advances its AI-integrated drug design platform across multiple therapeutic programs. The company's closed-loop approach combines generative protein design with high-throughput experimental cycles, using Bayesian optimization to tune biologics across many competing design parameters at once.
Under Stefan's leadership at Roche, the biologics research organization doubled its output, reaching a steady-state delivery of five to six biologics entering first-in-human trials annually. Biologics grew to represent roughly half of Roche's discovery and early development pipeline. His team established several of the company's signature therapeutic platforms, including BrainShuttle™, CrossMab™, and T-cell bispecifics, and enabled more than 60 molecules to advance into clinical development, contributing to several marketed products.
At BigHat, Weigand will lead the scientific strategy across the company’s integrated platform, internal pipeline, and partner collaborations. Central to that work is Milliner™, BigHat’s data generation engine: generating the right experimental data at scale, leveraging that data to build more predictive models, and applying reinforcement learning to translate those models into the next round of designs, compounding with each cycle. Stefan’s experience leading large-scale biologics research across modalities and disease areas gives him a clear view of where today's biologics fall short and where AI-driven design can close the gap, ultimately delivering the most impact for patients.
"Biologics have delivered dozens of life-saving medicines, but the field needs to move faster and optimize for more dimensions simultaneously," said Stefan. "BigHat's platform, combining state-of-the-art AI and ML with rapid build-and-test cycles, makes that possible. Shaping the future of this platform alongside the team that built it is what drew me in."
"Stefan has spent over 25 years doing exactly the kind of work we exist to accelerate: taking complex biologics from first principles to clinical proof," said Peyton Greenside, CEO of BigHat Biosciences. "His experience growing research organizations, scaling novel technology platforms, and delivering therapeutics that reach patients makes him the right person to lead our science at this stage of the company."
About BigHat Biosciences
BigHat Biosciences is an AI-drive platform and therapeutics company combining a closed-loop, high-throughput wet lab with machine learning to design complex protein therapeutics. The company’s integrated platform pairs the Milliner™ automated lab with an agentic data and modeling layer to engineer novel biologics that overcome the hardest problems in antibody and complex protein engineering. BigHat is headquartered in San Mateo, CA. For more information, visit [www.bighatbio.com].
Contacts
Mimi Shilling, BigHat Biosciences | mshilling@bighatbio.com
