We’re on a mission to end genetic disease.

in 2016 when our cofounders Shakked Halperin and David Schaffer along with their colleagues at UC Berkeley developed the first CRISPR-guided DNA polymerization technology that can target changes in genomes without making double stranded breaks. With the assembly of a world-class team of scientists and invention of a suite of secondary tools that make the technology applicable to therapeutic precision genome editing, Rewrite Therapeutics was born.


Shakked Halperin PhD

Co-founder & CEO

Shakked came to UC Berkeley for his PhD in Bioengineering as a National Science Foundation Graduate Research Fellow where he built on the then-nascent CRISPR discovery to invent CRISPR-guided DNA polymerases, a technology that can make targeted changes in genomes without generating toxic double stranded breaks. After spending a year as an Entrepreneurial Fellow at the Innovative Genomics Institute, Shakked developed technologies to improve the precision, efficiency, versatility, and deliverability of CRISPR-guided DNA polymerases enabling applications to therapeutic precision genome editing.

Before coming to Berkeley, Shakked received an MPhil in Pathology from the University of Cambridge as a Gates Cambridge Scholar and a BS in Bioengineering from the University of Missouri, Columbia. Shakked also spent a year working with a youth group in an Ethiopian community, researching material science at Tsinghua University in Beijing, leading a civil engineering projects in Honduras, and was the first engineer at two biotech start-ups, Magbiosense and Intershunt technologies. Outside of lab, Dr Halperin enjoys painting and traveling.

Samir Malhotra

Head of Operations

Samir  has deep experience driving innovation at the intersection of operations and corporate development. At IQVIA, Samir helped clients to develop and execute innovative strategies to achieve their organizational objectives. Samir has worked across multiple geographies with large pharma, start-ups, non-profits, and financial firms to drive over $5B in investments. His tenure culminated in supporting the development of a cell and gene therapy practice, where he engaged with industry leaders to advance the commercialization and adoption of next-generation technologies.

At Jazz Pharmaceuticals, Samir led a digital transformation across R&D by providing systems-driven insights to transform portfolio management and inform organizational strategy. Samir built and scaled operational processes to support immense company growth and the acquisition of GW Pharmaceuticals.

As a leader, Samir prides himself on his execution, being a team player, and ability to manage multiple variables, projects, and personalities. Samir holds a BA in Human Biology with Honors from Stanford University.

Denis Bronnikov PhD, MBA

Head of Business Development

Denis Bronikov has been leading business development and strategic activities across a number of pharmaceutical, diagnostics, and life sciences companies, including Roche, Novartis, CareDx, and Berkeley Lights. Over the last 10 years, Denis has led dozens of strategic partnering projects spanning key business development functions such as strategy and execution, and search and evaluation. He has deep experience executing pre- and post-transactional activities, such as due diligence, term sheet and contract negotiation, and alliance management. His contributions have resulted in a number of successful M&A transactions with VC- or angel-backed entities being acquired by big pharma companies.

Denis has experience working in the US, Switzerland, Canada, Finland, Russia, and many emerging markets. Denis completed his undergraduate studies with honors in Chemistry and Molecular Biology at the Moscow State University in Russia. He received a PhD in Human Genetics from David Geffen School of Medicine at the University of California Los Angeles in California. Denis also holds an MBA from the Institute of Management Development in Switzerland.

Scientific Advisory Board

Prof. David Schaffer PhD

Co-founder & SAB Chair

David Schaffer, a pioneer in the field of gene therapy, is our co-founder and advised our CEO, Shakked Halperin, throughout the development of the Rewriter™ platform. David has served as a Professor of Chemical and Biomolecular Engineering, Bioengineering, Molecular and Cell Biology, and the Helen Wills Neuroscience Institute at the U.C. Berkeley since 1999 and has served as the Director of the Berkeley Stem Cell Center since 2011. 

David has co-founded 5 biotech startups, including the now-public 4DMT, authored over 235 peer-reviewed publications, invented three AAV vectors that are in eight clinical trials, and has served on the board of directors of uniQure. He received a BS in Chemical Engineering from Stanford University in 1993 and earned his PhD in Chemical Engineering from the Massachusetts Institute of Technology in 1998.

Patrick Hsu PhD

Genome Editing Advisor

Patrick Hsu is an Assistant Professor at the University of California, Berkeley. His work aims to understand and manipulate the genetic circuits that control brain and immune cell function for the next generation of gene and cell therapies.

At the Broad Institute and Harvard University, he contributed pioneering studies on CRISPR-Cas9 for genome editing in human cells within the lab of CRISPR trailblazer Feng Zhang. As a group leader at Editas Medicine, Patrick also previously directed preclinical discovery projects to translate these tools for treating human genetic disorders.

Patrick began his independent group as a Salk-Helmsley Faculty Fellow at the Salk Institute from 2015-2019 before joining UC Berkeley as a faculty member in the Department of Bioengineering. He has been recognized in Forbes' 30 Under 30, the NIH Early Independence Award, the MIT Technology Review's Innovators Under 35, Berkeley Engineering's Deb Faculty Fellowship, the Rainwater Prize for Innovative Early-Career Scientist, and the Rose Hill Innovators Program.

Patrick is a co-founder of Spotlight Therapeutics, a GV-funded biotechnology startup that is developing platforms for non-viral genome editing. He is an inventor on 100+ patents and patents pending and has published 20+ high-impact papers in journals such as Cell, Nature, and Science.

investors & partnering foundations