In our fortuitous introduction to Prellis Biologics in January of 2021, we were inspired by the vision of the biotherapeutics company—employing sophisticated laser and holographic printing techniques, along with biologics workflows, to rapidly advance healthcare.

Melanie Mattheu impressed us as a CEO who thinks big. A PhD-trained immunologist and biophysicist, Melanie founded her company with the mission to build transplantable organs, such as livers and kidneys, for the good of humanity.

It was an exciting vision in the field of bioconvergence—where biology meets deep tech—but we were left with the burning question: Was this a viable application of their revolutionary innovation?

We gravitated to evaluating Prellis’ technology as a platform for innovation, considering which of its budding applications could have the greatest impact on public health and best position it for success.

Constructing a Human Immune System

We learned that Prellis could construct lymph node organoids with implanted immune cells from donors to mimic the human immune response in a dish. Put simply, they could build an Externalized Human Immune System (EXIS)!  

With their EXIS platform, Prellis could generate libraries of novel therapeutic antibodies. The antibodies exhibiting unique functional properties—such as a high affinity for binding—could be selected as drug candidates for hard-to-cure diseases like the Marburg virus, different cancers, and more. Enabling meaningful improvement in clinical outcomes, the platform could become the gold standard in drug discovery for the pharmaceutical industry. The potential was limitless.

If Prellis can fundamentally alter the drug discovery process for the pharmaceutical industry, it would save lives and turn out to be a home run investment.

Driving Speed and Value in the Pharmaceutical Industry

It often takes at least 10 years for drugs to complete the journey from discovery to the marketplace, at a cost of at least $1 billion and up to $3 billion per drug. But only a small fraction of drugs entering clinical trials end up meeting clinical endpoints and securing FDA approval to end up in the pharmacy.

Established approaches to antibody drug discovery have a range of drawbacks. Pharmaceutical companies maintain large animal rooms to harvest antibodies from rodents or other animals, resulting in a slow process and drug candidates that carry genetic artifacts that may result in undesired effects in patients. Using genetically modified mice has similar drawbacks and even higher costs. Discovering drug candidates from natural antibodies harvested from already-infected patients (also known as serum) is typically impractical. 

From our conversations with potential pharmaceutical customers and experts, it became clear that the industry could use a better drug discovery platform.

What's Happened Since Prellis' Series B Round?

Prellis exceeded its milestones since our initial investment, when we co-led its Series B. It streamlined focus, de-emphasizing other promising applications to ensure its laser focus on antibody drug discovery. Most importantly, it signed collaboration and licensing deals with pharma majors, Bristol Myers and Sanofi.

Based on that record, Prellis attracted its incoming CEO, Michael Nohaile, who will help drive the company in its next stage of growth. This progress also encouraged Celesta to lead Prellis' Series C fundraise, along with Avidity Partners, with participation from early investors Khosla Ventures and SOSV just announced today.

On behalf of the Celesta team, we are thrilled to support Prellis on its important journey.