Typewriter Therapeutics Emerges from Stealth with $56 Million Series A Financing to pursue in vivo CAR T medicines

– Typewriter's site-specific, non-viral technology uses only LNP-delivered RNA to insert whole genes into the genome, to create safer, re-dosable, durable genetic medicines –

– Matthew Stanton, PhD, and Leanne Peiser, DPhil, appointed CEO and CSO, respectively; former Pfizer CSO Mikael Dolsten, MD, PhD, joins Typewriter board as independent director and the Fred Hutch's Stanley R. Riddell, MD, joins Typewriter Scientific Advisory Board –

CAMBRIDGE, Mass. and TOKYO, Sept. 2, 2026 /PRNewswire/ -- Typewriter Therapeutics, Inc., a biotech company developing safe, durable and re-dosable genetic medicines with curative impact for patients with cancer, autoimmune diseases, and severe genetic diseases, today emerged from stealth with $56 million in Series A financing led by AN Venture Partners and RA Capital Management with participation from ANRI, Gemseki, and SBI US Gateway Fund. In addition, Typewriter announced the appointments of Matthew Stanton, PhD, as Chief Executive Officer, Leanne Peiser, DPhil, as Chief Scientific Officer, and Mikael Dolsten, MD, PhD, as a member of the company's board of directors.

Typewriter's Target-Primed Reverse Transcription (TPRT) technology platform is built on the R2 retrotransposon, a natural gene-insertion system discovered by the company's academic co-founders. Typewriter's two-part, all-RNA therapy comprises a payload mRNA to make the R2 protein and a second RNA containing the therapeutic gene flanked by sequences to recruit the R2 protein. Inside the cell, the two assemble into an active complex that inserts the gene into the specific target site by TPRT. The R2 machinery then degrades along with the mRNA, leaving only the inserted gene at its intended location.

Typewriter's initial focus will be on two high-value indications with life-changing potential to patients: in vivo CAR T and genetic liver diseases. The company's first NHP studies are planned for late 2026.

"By inserting a durable, functioning gene into a safe-harbor site in T cells using lipid nanoparticle-delivered RNA, our technology is designed to create safer, re-dosable genetic medicines that are accessible to many more patients than current cumbersome and complex CAR T approaches," said Matthew Stanton, PhD, Chief Executive Officer and Board Director of Typewriter Therapeutics. "This financing enables us to build on the proof-of-concept we have established in humanized mouse models and establish our first in vivo CAR T development candidate."

Prior to Typewriter, Matthew Stanton was a Venture Partner at Raven, RA Capital's healthcare incubator. Before Raven, he spent seven years at Generation Bio, first as Chief Technology Officer and for the past five years as Chief Scientific Officer. Prior to Generation, he was Vice President and Head of Chemistry at Moderna Therapeutics, where his team identified proprietary lipid nanoparticles for vaccine development and helped to bring the first mRNA vaccines into clinical development.

Newly appointed CSO Leanne Peiser brings to Typewriter more than 20 years of R&D leadership across biotech and pharma, with deep expertise in immunology, immunotherapy, and cellular therapy, including autologous, allogeneic, and in vivo CAR T for oncology and autoimmune diseases. Most recently, as Executive Director of Translational Research, Cellular Therapy at Bristol Myers Squibb (BMS), she served as a senior scientific lead for their CAR T portfolio across multiple indications.

"The mRNA vaccines proved to the world that RNA delivered by a lipid nanoparticle can become a medicine at global scale. Typewriter takes that breakthrough a decisive step further –using only RNA not to express a transient protein, but to write a durable therapeutic gene into a precise, safe location in the genome, without a virus," said Mikael Dolsten, MD, PhD, independent board director at Typewriter Therapeutics and former Chief Scientific Officer and President of Worldwide Research & Development at Pfizer. "I am especially excited by what this means for in vivo CAR T. Engineering a patient's own T cells in vivo with an LNP-delivered RNA medicine could combine simpler administration with durable CAR expression and the ability to re-dose, potentially making cell therapy safer and accessible to far more patients than today's complex manufacturing allows. It is a privilege to join the board and help bring this platform to patients with cancer, autoimmune, and genetic diseases."

Typewriter is led by an experienced management team, including:

• Matthew Stanton, PhD, Chief Executive Officer
• Leanne Peiser, DPhil, Chief Scientific Officer
• Jun Zhou, PhD, Founder and Vice President, Discovery and Global Operations
• Ari Friedland, PhD, Vice President, Research
• Mayu Yoshikawa, PhD, President, Typewriter Japan

In addition to Matthew Stanton and Mikael Dolsten, Typewriter's board of directors includes board chair Ken Horne, Managing Partner, AN Venture Partners and Laura Tadvalkar, PhD, Managing Director at RA Capital.

Typewriter also announced that Stanley R. Riddell, MD, has joined as a member of its Scientific Advisory Board. Dr. Riddell is a member of the Translational Science and Therapeutics Division at Fred Hutchinson Cancer Center and Professor of Medicine at the University of Washington. He was the principal investigator on the first human trial of adoptively transferred therapeutic T cells, and his laboratory's CAR T work was licensed to Juno Therapeutics, which he co-founded and which is now part of Bristol Myers Squibb.

About Typewriter Therapeutics

Typewriter Therapeutics is a start-up company that focuses on developing and commercializing RNA-based gene therapies for patients suffering from cancer, autoimmune, and severe genetic disorders. Typewriter's cutting-edge platform technology enables the targeted insertion of whole therapeutic genes to create safer, durable, and re-dosable medicines. Founded in February 2022, the company builds on the research of Professor Emeritus Haruhiko Fujiwara of the University of Tokyo on transposons. With research facilities in Tokyo and Cambridge, USA, Typewriter is committed to bringing Japan-originated technology to the global stage. For more information, visit www.typewritertx.com.

SOURCE Typewriter Therapeutics, Inc.