- $47.5 million Series A financing led by Samsara Biocapital and Lightstone Ventures to advance PsiThera’s growing pipeline, starting with multiple clinically validated TNF superfamily preclinical programs
- Biotech veteran Eric Shaff appointed CEO and joins established leadership team, including Woody Sherman, Ph.D., Founder and Chief Innovation Officer, and Camil Sayegh, Ph.D., Chief Scientific Officer
- PsiThera’s scientific approach and QUAISAR™ platform, integrating molecular dynamics with artificial intelligence, is anchored in understanding and predicting the dynamic basis of biological function and drug action that conventional static methods can miss
WATERTOWN, Mass., Dec. 10, 2025 (GLOBE NEWSWIRE) -- PsiThera, a biotech company harnessing biologically relevant protein states and computational intelligence to create oral drugs for diseases long-constrained by injectable-only approaches, announced today that it has closed a $47.5 million Series A financing and appointed Eric Shaff as Chief Executive Officer. The equity round was led by Samsara Biocapital and Lightstone Ventures with participation from other top-tier investors, including Roivant, YK Bioventures, Eurofarma Ventures, and others. PsiThera, formerly called Psivant Therapeutics, originated as a Roivant spinout and now operates as a fully independent company.
“PsiThera has integrated predictive computational power, biophysics, mechanistic biology, and drug hunter expertise into a continuous feedback loop. The company is designed to bring the best computational tools to bear on the rate-limiting problems for difficult small molecule targets,” said Eric Shaff, Chief Executive Officer. “The four-month advancement of our lead program from identification of a novel chemical scaffold hit to lead optimization illustrates how efficiently our discovery engine operates and its potential to accelerate bringing new therapeutics to patients. With the support of our investors and deep expertise across the team, PsiThera will further scale our approach and expand the boundaries of what oral medicines can deliver, addressing high-value targets in a novel manner.”
The company’s QUAISAR™ computational intelligence platform — originating from Dr. Sherman’s founding role at Silicon Therapeutics and refined over years at Roivant Discovery — leverages quantum chemistry, molecular dynamics, machine learning, and supercomputing to model how proteins and drugs behave in biological environments. PsiThera’s discovery ecosystem unites world-class experts in structural biophysics, mechanistic biology, and computational modeling to optimize oral drugs for clinically validated targets long-considered accessible only to biologics.
The company is rapidly advancing a pipeline of novel therapeutics designed to modulate high-value targets, with initial programs focused on the Tumor Necrosis Factor (TNF) superfamily. PsiThera’s platform enabled rapid cycle times, moving from hit identification to lead optimization in four months, underscoring its ability to translate complex physics and AI insights into actionable design decisions.
“PsiThera exists at the nexus of advanced capabilities directed at creating real products and where biotech needs to go next,” said Christina Isacson, Ph.D., Partner, Lightstone Ventures, and Chair of PsiThera’s Board of Directors. “The company’s computational excellence, scientific rigor, closed-loop integration, target selection strategy, and top-tier team position PsiThera to rapidly deliver differentiated therapeutic breakthroughs with the potential to meaningfully impact patient lives.”
Woody Sherman, Ph.D., Founder and Chief Innovation Officer, adds: “Traditional drug discovery approaches have significant limitations when it comes to challenging targets where molecular motion plays a pivotal role. The fusion of our proprietary predictive computational models and human feedback from drug hunters with deep domain expertise accelerates the discovery of new drugs with optimized properties and the potential for superior efficacy.”
In addition to Eric Shaff (CEO) and Woody Sherman, Ph.D. (CIO), PsiThera’s leadership team includes Camil Sayegh, Ph.D., Chief Scientific Officer, and Jean-Christophe Harmange, Pharm.D., Ph.D., SVP, Drug Discovery, and Kal Lapan, Ph.D., VP, Head of Operations. Mr. Shaff recently joined PsiThera after a decade with Seres Therapeutics, having served as CEO and led Seres’ approval of VOWST™, a Breakthrough Designated clinical program and the first oral FDA-approved microbiome therapeutic. The original visionary of PsiThera’s QUAISAR™ platform, Dr. Sherman, is also the Executive Committee Chairperson of the OpenFold Consortium. Dr. Sayegh brings more than 20 years of cross-sector experience in biopharma and has contributed to the discovery and development of several clinical assets, including ZILBRYSQ®.
PsiThera’s Board of Directors includes Chair Christina Isacson, Ph.D.; Eric Shaff; Srini Akkaraju, M.D., Ph.D., Founder and Managing General Partner, Samsara Biocapital; James P. Edwards, Ph.D., Venture Partner, Samsara Biocapital; and Alex Gasner, Executive Vice President, Roivant Health.
PsiThera’s Scientific Advisory Board includes Todd Martinez, Ph.D., Professor, Stanford University; James Rush, Ph.D., CEO, Spica Therapeutics; H. Martin Seidel, Ph.D., CEO, IFM Therapeutics; Peter Tummino, Ph.D., President, R&D, Nimbus Therapeutics; and Harald Wajant, Ph.D., Professor, University Hospital of Würzburg.
About PsiThera
PsiThera is a biotechnology company harnessing biologically relevant protein states and computational intelligence to create oral drugs for immune and inflammatory diseases — therapeutic areas long reliant on injectables. Integrating biophysics, computational modeling, and mechanistic biology enables PsiThera’s expert drug hunters to discover new therapeutic opportunities and optimized drugs. The company’s rapidly advancing pipeline focuses on high-value targets, starting with the Tumor Necrosis Factor (TNF) superfamily. For more information, please visit www.psithera.com or follow us on LinkedIn.
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