At Principia Biopharma, a Sanofi company, we are focused on bringing transformative therapies to patients with serious immune-mediated diseases by changing the way small molecules are developed.

Our mission is to make best-in-class medicines to address unmet medical needs by changing the way small molecule drugs are designed. We are a late-stage biopharmaceutical company developing next-generation therapies — immuno-modulators — that have the potential to transform the treatment of underserved patients who have immune-mediated diseases.

We design novel therapies using our proprietary and unique Tailored Covalency® platform. We have developed both reversible covalent and irreversible covalent small molecule drugs that bind very specifically to targets in the body that are central to immune disorders.


Our pioneering approach to achieving molecular connections, or bonds, is unique and a breakthrough in small molecule drug discovery.

Based on medicinal chemistry that is both insightful and elegant, Tailored Covalency enables us to better select where and how binding takes place. Our goal is to optimize these bonds so that our drug candidates remain bound to their desired target, potentially minimizing side effects while achieving high clinical benefit. Quite simply, bonding matters.

We have consistently and efficiently succeeded in designing drug candidates for clinically relevant targets. So far, we have produced three new clinical drug candidates from our scientific platform, resulting in five clinical development programs. Our strategy is to continue advancing the development of our proprietary drug candidates and, when appropriate, use collaborations and partnerships as strategic tools to maximize the value of those assets.

Our Science is Powered by Tailored Covalency…Radical Thinking

We believe that innovation is more than a catch phrase, it is a mindset and requires radical thinking to challenge the status quo. We looked to revolutionize conventional small molecule drug discovery by utilizing our proprietary technology and know-how to generate new therapies to address immune mediated diseases. In doing so we have been able to create drugs that combine the dosing convenience of an oral small molecule drug with the specificity typically achieved with antibody therapy.

In September of 2020, Principia Biopharma was acquired by Sanofi, joining forces with the mutual goal of expanding and accelerating the potential benefits of therapies for patients with immune-mediated diseases. Read the press release finalizing the deal.

Driven by a Shared Passion