Tessera Therapeutics Announces R&D Collaboration with Cystic Fibrosis Foundation as Part of a Portfolio of Complementary Technologies Advanced by Flagship’s Pioneering Medicines to Treat Cystic Fibrosis

Tessera’s Gene Writing^TM Technology is Designed to Simultaneously Correct Multiple Genetic Mutations as well as to Write Genes in Their Entirety

CAMBRIDGE, Mass.--(BUSINESS WIRE)--#GeneWriting--Tessera Therapeutics today announced a treatment-focused collaboration with the Cystic Fibrosis Foundation using Tessera’s Gene Writing technology to rewrite the genetic codes that cause cystic fibrosis. The Gene Writers are part of a portfolio of technologies that Pioneering Medicines has assembled to treat cystic fibrosis as part of a broader collaboration with the Cystic Fibrosis Foundation.

Gene Writers make precise single nucleotide changes, small insertions and deletions, and can replace entire genes in a programmable way to correct the genetic code driving disease. Cystic fibrosis is an inherited genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that cause persistent and worsening lung congestion and infections that limit a person’s ability to breathe. It affects approximately 70 thousand people globally. While major advances have been made over the past decade that have led to more therapeutic options for individuals living with cystic fibrosis, a curative approach is still lacking. Furthermore, current treatments are ineffective for about 10% of individuals living with cystic fibrosis.

“We’re excited to work with the Cystic Fibrosis Foundation, the world’s leader in supporting breakthrough technologies for cystic fibrosis,” said Geoffrey von Maltzahn, Ph.D, Co-Founder and CEO of Tessera, and General Partner at Flagship Pioneering. “The Cystic Fibrosis Foundation’s extensive network of scientists, companies, and clinicians knowledgeable about cystic fibrosis will help accelerate screening and development of our cystic fibrosis-targeting Gene Writers. We hope our collaboration leads to treatments and cures for cystic fibrosis.”

The agreement involves multiple Gene Writers in Tessera’s portfolio of candidates and applies them to cystic fibrosis. This includes the ability to make true corrections of specific mutations, such as the F508-del mutation, which drives roughly 70% of CF cases, as well as other nonsense mutations, and to introduce a functional full-length copy of the CFTR gene at its endogenous locus. Tessera and Pioneering Medicines—an initiative that brings together complementary technologies from Flagship Pioneering’s portfolio of companies—will advance the technology through preclinical development and prepare it for first-in-human proof of concept studies.

“The collaboration of Pioneering Medicines and the Cystic Fibrosis Foundation will support development of Gene Writers designed to give people living with cystic fibrosis functional CFTR genes, with the goal of restoring normal, healthy lung function,” said Paul Biondi, President, Pioneering Medicines and Executive Partner, Flagship Pioneering. “Gene Writers have the potential to revolutionize the treatment of cystic fibrosis and to deliver multiple new medicines that introduce a full length CFTR sequence, or to make true corrections of pathogenic alleles in the CFTR sequence.”

About Tessera’s Gene Writers

Tessera’s Gene Writers are based on nature’s genome architects, Mobile Genetic Elements (MGEs)—the most abundant class of genes across the tree of life, representing approximately half of the human genome. Tessera has evaluated tens of thousands of natural and synthetic MGEs to create candidate Gene Writers with the ability to write therapeutic messages into the human genome. These candidates are run through Tessera’s research engine to optimize them for efficiency, specificity, and fidelity—essentially compressing eons of evolution into a few months.

Tessera’s lead Gene Writers for the collaboration with the Cystic Fibrosis Foundation use target-primed reverse transcription (TPRT), which evolved in a class of MGEs known as retrotransposons. TPRT uses three steps to make an alteration: DNA-binding, DNA-nicking (without double strand breaks to DNA), and reverse transcription. Gene Writing requires a DNA sequence match at all three steps, reducing the likelihood of off-target editing. Tessera’s Gene Writers are delivered as therapeutic compositions comprised of RNA molecules within lipid nanoparticles, offering the potential for scalable, re-dosable genetic medicines with the ability to make the full spectrum of small and large edits to genome, from single or multi-base pair corrections, insertions, deletions, to writing entire genes.

About Tessera Therapeutics

Tessera Therapeutics is pioneering Gene Writing, a new biotechnology designed to offer scientists and clinicians the ability to write therapeutic messages into the human genome, thereby curing diseases at their source. Gene Writing allows the correction of single nucleotides, the deletion or insertion of short sequences of DNA, and the writing of entire genes into the genome, offering the potential for a new category of genetic medicines with broad applications both in vivo and ex vivo. Tessera Therapeutics was founded by Flagship Pioneering, a life sciences innovation enterprise that conceives, resources, and develops first-in-category companies to transform human health and sustainability. For more information about Tessera, please visit www.tesseratherapeutics.com.

About Pioneering Medicines

Pioneering Medicines is a strategic initiative within Flagship Pioneering dedicated to conceiving and developing a broad portfolio of life-changing treatments by leveraging and expanding the use of Flagship’s innovations. By harnessing the power of Flagship's multiple scientific platforms, Pioneering Medicines will create and advance novel medicines with the platform companies to accelerate the extension of their portfolios into novel areas and show that the platform can be applied more broadly, thereby delivering benefits to more patients and platforms, sooner.

About Flagship Pioneering

Flagship Pioneering conceives, creates, resources, and develops first-in-category bioplatform companies to transform human health and sustainability. Since its launch in 2000, the firm has, through its Flagship Labs unit, applied its unique hypothesis-driven innovation process to originate and foster more than 100 scientific ventures, resulting in more than $200 billion in aggregate value. To date, Flagship has deployed over $2.5 billion in capital toward the founding and growth of its pioneering companies alongside more than $19 billion of follow-on investments from other institutions. The current Flagship ecosystem comprises 42 transformative companies, including Axcella Health (NASDAQ: AXLA), Codiak BioSciences (NASDAQ: CDAK) Denali Therapeutics (NASDAQ: DNLI), Evelo Biosciences (NASDAQ: EVLO), Foghorn Therapeutics (NASDAQ: FHTX), Indigo Ag, Kaleido Biosciences (NASDAQ: KLDO), Moderna (NASDAQ: MRNA), Omega Therapeutics (NASDAQ: OMGA), Rubius Therapeutics (NASDAQ: RUBY), Sana Biotechnology (NASDAQ: SANA), Seres Therapeutics (NASDAQ: MCRB), and Sigilon Therapeutics (NASDAQ: SGTX).

Allison (Ally) Simon, ally.andrew@salutemcomms.com

TesseraTeam@salutemcomms.com