Alltrna Expands Leadership Team with Appointments of Chief Scientific Officer and Chief Technology Officer

CAMBRIDGE, Mass., August 15, 2023 – Alltrna, a Flagship Pioneering company unlocking transfer RNA (tRNA) biology and pioneering tRNA therapeutics to regulate the protein universe and resolve disease, today announced that it has appointed Chris Henderson, Ph.D., as Chief Scientific Officer and promoted William (Will) Kiesman, Ph.D., to Chief Technology Officer. Dr. Henderson was formerly Senior Vice President, Head of Research at Biogen, and Dr. Kiesman was Senior Vice President, CMC and Medicinal Chemistry at Alltrna.

“We are excited to strengthen our C-suite as Alltrna advances its first drug candidates towards the clinic for a first indication in Stop Codon Disease,” said Michelle C. Werner, CEO of Alltrna and CEO-Partner at Flagship Pioneering. “Chris’ deep scientific expertise and experience advancing programs into the clinic across a wide range of disease areas will be invaluable. Will has significantly advanced our internal medicinal chemistry programs and developed a flexible manufacturing strategy to scale and deliver engineered tRNAs. I look forward to working with both of them and the rest of our talented executive team as we continue building our platform to transform tRNA biology into powerful programmable medicines.”

“I am impressed with the platform Alltrna has built to turn tRNA’s sophisticated biology into programmable medicines with powerful potential therapeutic properties, including the ability to achieve broad readthrough in vivo of premature termination codons and restore full-length functional protein production,” said Dr. Henderson. “I look forward to applying my expertise in preclinical and early clinical development and working with the team and clinicians to advance new tRNA medicines to treat Stop Codon Disease, which encompasses thousands of rare and common human diseases driven by premature termination codon mutations.”

Dr. Chris Henderson

As SVP, Head of Research at Biogen, Dr. Henderson led a team responsible for preclinical programs and target validation across the company’s core disease areas of neurodegenerative diseases, multiple sclerosis and immunology, neuromuscular and muscle diseases, ophthalmology, and genetic and neurodevelopmental disorders. Prior to this, he held multiple roles of increasing responsibility at Biogen including Vice President of Neuromuscular and Movement Disorders Research and Early Development, where he worked with a team of clinicians and scientists to take programs from early research to clinical proof of concept. Prior to moving to the U.S., Dr. Henderson was Co-Founder and Chair of the Scientific Advisory Board of Trophos, which leveraged its proprietary screening platform to generate olesoxime for spinal muscular atrophy. Prior to his roles in industry, Dr. Henderson co-founded the Center for Motor Neuron Biology and Disease and was the Director of the Columbia Stem Cell Initiative at Columbia University. While at Columbia, he became Director and now serves as Chief Advisor of Target ALS Foundation. Dr. Henderson has more than 90 scientific research publications and been an editor and reviewer for top-tier scientific journals. He received his B.A. and Ph.D. from University of Cambridge and was a postdoctoral fellow at the Pasteur Institute.

Dr. Will Kiesman

Dr. Kiesman has more than two decades of experience in the design, development, and manufacturing of small molecule and oligonucleotide therapeutics. At Alltrna, Will has led the build of the company’s internal medicinal and computational chemistry capabilities, driven the design and construction of critical lab infrastructure, and assembled an end-to-end tRNA process development and manufacturing team. Prior to joining Alltrna, he served as the Vice President and Head of Oligonucleotide and Small Molecule Development at Biogen. During his 24 years with the company, he was responsible for a wide range of activities from medicinal chemistry research and automated parallel synthesis to building both the chemical development and the end-to-end oligonucleotide development and manufacturing teams. Dr. Kiesman and his teams have supported dozens of small molecule and oligonucleotide clinical programs and played pivotal roles in the successful worldwide regulatory CMC approvals of Tecfidera® (dimethyl fumarate) in multiple sclerosis and Spinraza® (nusinersen) for spinal muscular atrophy. He is co-author on more than 40 publications and patents and has contributed to five book chapters. Dr. Kiesman earned his B.S. and Ph.D. in chemistry from the University of Connecticut and was a postdoctoral fellow at Duke University.

About Alltrna

Alltrna unlocks tRNA biology to correct disease. The company’s platform incorporates AI/ML tools to learn the tRNA language and deliver diverse programmable molecules with broad therapeutic potential. Alltrna has an unprecedented opportunity to advance a single tRNA medicine to unify treatment across a wide range of diseases with the same underlying genetic mutation. Alltrna was founded in 2018 by Flagship Pioneering.

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 $90 billion in aggregate value. To date, Flagship has deployed over $3.4 billion in capital toward the founding and growth of its pioneering companies alongside more than $26 billion of follow-on investments from other institutions. The current Flagship ecosystem comprises 45 transformative companies, including Denali Therapeutics (NASDAQ: DNLI), Foghorn Therapeutics (NASDAQ: FHTX), Generate Biomedicines, Inari, Indigo Agriculture, Moderna (NASDAQ: MRNA), Omega Therapeutics (NASDAQ: OMGA), Sana Biotechnology (NASDAQ: SANA), Seres Therapeutics (NASDAQ: MCRB) and Tessera Therapeutics.

Media Contacts for Alltrna

Jessica Yingling, Ph.D., Little Dog Communications Inc.,, +1.858.344.8091

Josephine Zorbo, Ph.D., Flagship Pioneering,