Guillaume Pfefer is a Flagship Pioneering CEO-Partner and serves as Chief Executive Officer of Senda Biosciences. [Credit: Senda Biosciences, Inc.]
Senda Biosciences—a company enabling cell-type specific targeting of medicines in vivo—has announced the completion of a $123-million series C financing, a major step towards its goal of becoming a clinical-stage company.

Based in Cambridge, Massachusetts, Senda was founded on the idea of reprogramming and engineering any human cell in vivo. Part of this solution lies in the modality of information molecules. According to Guillaume Pfefer, PhD, CEO of Senda and a Partner at Flagship Pioneering, nucleic acids like mRNA are part of a natural code within cells, which can be designed to reprogram or modify the function of cells.

But the problem isn’t designing the information modalities to have cells execute specific functions, as major steps have been taken in recent years to reprogram cells in vivo—see the COVID-19 mRNA vaccine. The major limiting factor has been getting the programming medicines delivered only to the right cells at the right time.

“If you look at the mRNA field, today there are basically just two approved medicines,” Pfefer told GEN Edge. “Even though there are thousands of different ways to reprogram cells, the process is limited by the delivery methods, which often do not reach specific cells or tissues beyond the liver.”

Nature-made nanoparticles

Pfefer says that Senda is taking a humble approach by leveraging millions of years natural evolution to address this problem, rather than trying to do so synthetically, which people have been trying to solve for over 20 years. Senda identifies how cells from different evolutionary kingdoms communicate with human cells by investigating the trillions of non-human cells that come along for the ride with each person.

“We host trillions of non-human cells—more or less 400 trillion—coming from plants, archaea, fungi, and bacteria, and we have only 40 trillion human cells,” Pfefer said. “And there is constant communication between these cells. Plant, bacteria, archaea, and fungi send molecules to our cells with a natural language to be harnessed in the way that evolution created.”

By investigating cross-kingdom communication, Senda has revealed that these non-human cells target specific human cell types using nanometer-sized particles with specific chemical “mailing” codes. “We’re not synthesizing or looking at nature for inspiration,” Pfefer said. “We extract natural nanoparticles from plants, archaea, fungi, and bacteria and strip away any protein and nucleic acid, leaving us with this chemical code that we reprogram by removing or adding classes of individual molecules found in nature to enhance, expand, and drive very specific performance for therapeutic effect.”

Studying these four kingdoms of life, Senda has already found that different species in each kingdom have natural nanoparticles that give them the unique ability to target specific human cells safely and repeatedly. “From 50,000 identified molecules, we now have a chemical alphabet address code that we are learning to program with,” Pfefer said. “There is a lot to understand from this natural language and a lot of power that we are already harnessing.”

Senda now has the ability to program nanoparticles that can be directed to particular human cells used at safe and repeatable doses, allowing them to embark on the second very important part of their approach, which is the programming modalities, such as mRNA. “But mRNA is just one of several information molecules we at Senda are exploring,” Pfefer continued. “The portfolio is not confined to mRNA; that’s just the data we’ve generated so far. We can go beyond mRNA, such as gene editors, but we need to start somewhere.”

Commencing clinical translation

Senda says it has been able to use these nanoparticles to reach cells and tissues previously unreachable and pair them with different information modalities. At this stage, Senda’s platform has worked in small animal to non-human primates; that is, they’ve been able to reach cells throughout the body and skip past the liver, which is where much of mRNA delivery gets tied up.

The company is at the early stage of testing several tissue types, including the lung, pancreas, and brain. This foundational work has led to the launch of several programs around different clinical indications, including immuno-oncology with mRNA as well as infectious disease and metabolic disease. “Senda is creating medicines that reprogram cell types implicated in diseases in a way that cannot be attained today,” Pfefer said. “But we’re going to have to pick where we want to focus on driving the largest possible impact and fastest value creation out of this extraordinary platform.”

All of this work has led to the successful acquisition of funds announced by the company. Flagship Pioneering, which founded Senda, participated along with new investors, including the Samsung Life Science Fund, Qatar Investment Authority (QIA), Bluwave Capital, and Stage 1 Ventures. Also participating in the financing are current investors, including Alexandria Venture Investments, Longevity Vision Fund, Mayo Clinic, Partners Investment, and the State of Michigan Retirement System. This round of financing brings Senda’s total funding raised to date to $266 million.

As typically done at Flagship, Senda will continue to invest in the platform. “It’s not a one-off to run against the first product you can grab out of a platform,” Pfefer said. “We balance investment to nourish and continue to build a platform for us, and, increasingly, we want to use machine learning to help contribute to developing programmable medicines.”

Senda will also be setting up the platform to be translated into INDs and launching the company, founded in October 2020, to the clinical stage. “Moving Senda to a clinical-stage company and turning the utility of this platform into a programmed solution for patients is the plan,” Pfefer said. “I’m very excited to be able to bring several million dollars from existing and new investors to validate and advance something that is of value and certainly very unique at this point of time for the industry.”