Exsilio Therapeutics

Exsilio Therapeutics, formerly known as Averna Therapeutics, is a biotechnology firm developing genomic medicines to treat a wide range of conditions, including genetic diseases, cancer, and autoimmune disorders. The company was founded in 2022 and emerged from stealth in June 2024 with an $82 million Series A financing round. The funding was co-led by Novartis Venture Fund and Delos Capital, with participation from OrbiMed, Insight Partners, J.P. Morgan Life Sciences Private Capital, and CRISPR Therapeutics, among others. OrbiMed also provided the initial seed funding.

The company is led by interim CEO and Chairman Dr. Tal Zaks, the former chief medical officer of Moderna. His leadership, particularly his experience with mRNA technology during the COVID-19 pandemic, has drawn significant interest to the company. In January 2025, the company appointed Dr. Thomas M. Barnes, former CEO of Orna Therapeutics, as its new Chief Executive Officer, with Dr. Zaks continuing as the executive chairman of the board.

Exsilio's proprietary technology platform utilizes naturally occurring, programmable genetic elements encoded in messenger RNA (mRNA) to insert new, whole genes into a cell's genome. These genes are precisely integrated into genomic "safe harbor" sites, which are regions that can accommodate new genetic material without disrupting normal cell function. This process is guided by a combination of predictive in-silico modeling and wet lab experimentation. The medicines are delivered via lipid nanoparticles (LNPs), a clinically validated non-viral delivery method that is efficient, scalable, and cost-effective. A key advantage of this LNP-based approach is the ability to redose and titrate the treatment, allowing for a curative intent rather than just transient effects, a significant distinction from many existing gene therapies.

The business model focuses on leveraging its platform to develop a pipeline of therapeutic candidates. The initial Series A funding is intended to advance the platform and identify a lead candidate by generating sufficient in vivo data. By using mRNA and LNP technology, Exsilio aims to create cost-efficiencies in manufacturing compared to traditional biologics and viral-vector gene therapies. The company's strategy is to address a broad spectrum of diseases, treating conditions irrespective of the specific patient mutation by inserting whole, functional genes.

Keywords: genomic medicines, mRNA therapeutics, lipid nanoparticles, LNP delivery, gene insertion, redosable therapies, safe harbor sites, non-viral gene delivery, programmable genetic elements, genetic diseases, autoimmune disorders, oncology, Tal Zaks, in-silico modeling, biotechnology, Series A, Novartis Venture Fund, CRISPR Therapeutics, curative intent