TACIT THERAPEUTICS
Founded 2021 · 13 employees on LinkedIn · 4 known investors
Tacit develops RNA repair technology called Splicing-Directed Repair, which uses naturally-occurring biological systems to fix genetic mutations as an alternative to conventional gene editing. The company aims to build a platform for treating a range of genetic diseases.
Also known as Tacit · Tacit Tx
Investors · 4
Also in the syndicate · 1
Company profile
researched Aug 2026Tacit Therapeutics is a San Francisco, California biotechnology company developing a class of genetic medicines based on RNA trans-splicing. Its platform, marketed as Splicing-Directed Repair, repurposes the cell's native splicing machinery — spliceosome-mediated RNA trans-splicing — to replace mutant segments of pre-mRNA with therapeutic sequences, producing corrected transcripts while preserving native gene regulation and leaving genomic DNA unaltered. Because the approach operates at the RNA level and does not introduce foreign enzymes, the company positions it as non-immunogenic and as avoiding the risk of unintended genomic edits associated with DNA editors and conventional viral-vector gene therapy.
The company's stated initial focus is inherited neurological diseases, with planned expansion into additional therapeutic areas, targeting large and complex gene-mediated conditions that have been difficult to address with existing gene therapy or RNA modalities. Its capabilities combine RNA biology, synthetic biology, gene therapy expertise, computation and AI-driven design, and high-throughput screening and automation to engineer programmable trans-splicing therapeutics selected for specificity and efficiency. Leadership includes co-founder and CEO David Nelles, PhD, with Gene Liau, PhD as Chief Scientific Advisor and Beatriz Osuna, PhD as Head of Platform, alongside a scientific staff of RNA and synthetic biologists.
Founding story
Tacit was assembled around the observation that human cells continuously patch together genetic sequences through splicing, and the question of whether that process could be redirected to patch and repair mutated genes. Co-founder and CEO David Nelles previously pioneered the use of CRISPR/Cas9 to target RNA in human cells during graduate school and co-founded Locanabio, which raised a $100 million Series B in 2020; he conceived Tacit, his second company, while stranded in Europe during the COVID-19 pandemic, and the venture was based out of JLABS.
Business model
Therapeutics developer building a programmable RNA trans-splicing platform and an internal pipeline of candidate medicines, funded by venture capital.
Traction
Emerged from stealth in March 2026 concurrent with the close of its Series A financing, with total capital raised of $19 million, and stated plans to move lead inherited neurological disease programs toward IND-enabling studies.
Latest developments
On 9 March 2026, Tacit announced its Series A financing, led by KdT Ventures with participation from Civilization Ventures and Michigan Capital Network plus other new and existing investors, bringing total capital raised to $19 million and funding advancement of lead neurological programs toward IND-enabling studies and expansion into additional therapeutic areas. The launch was covered in an exclusive feature by Endpoints News the same day.
▸Full profile — market position, technology, go-to-market, geography, history
Market position
Positions itself as an RNA trans-splicing company offering an alternative to conventional viral-vector gene therapy and DNA editing approaches, targeting diseases where those modalities have not succeeded.
Claims the first broadly applicable and non-immunogenic method to repair mutations: correction occurs at the RNA level without introducing foreign enzymes or permanently altering the genome, preserving native gene regulation and reducing immunogenicity and off-target genomic editing risk, while enabling mutation-agnostic correction across large segments of a transcript.
Technology
Spliceosome-mediated RNA trans-splicing, branded Splicing-Directed Repair, which replaces mutant segments of pre-mRNA with therapeutic sequences to generate corrected transcripts. The company states the approach can correct mutations across large segments of target RNAs, is inherently cell-state and cell-type specific, is fully nucleic-acid mediated, and avoids promoters, protein editors and permanent DNA changes. Engineering relies on high-throughput screening, laboratory automation, computation and AI-driven design.
Go-to-market
Patients with inherited neurological diseases and other genetic disorders not adequately addressed by existing gene therapy or RNA approaches.
Geography
Headquartered in San Francisco, California, with open positions listed at a South San Francisco location.
History
The company was formed to pursue redirection of cellular splicing for gene repair, operated in stealth while assembling a team of RNA biologists, synthetic biologists and gene therapy experts, and publicly launched on 9 March 2026 with the announcement of its Series A financing.
Compiled by commissioned research from 8 cited public sources — announcements, filings, and press listed under research sources below.
Key figures
latest reportedCompany-reported or press-reported figures, each dated to when it was claimed — not independently audited.
Timeline · 1
launches, deals, and filingsTacit Therapeutics announced the closing of its Series A financing, bringing total capital raised to $19 million. The round was led by KdT Ventures with participation from Civilization Ventures, Michigan Capital Network, and other new and existing investors. Proceeds are earmarked for advancing lead inherited neurological disease programs toward IND-enabling studies and expanding into additional therapeutic areas.
$19M source ↗
Dated company events from announcements, filings, and press; legal rows summarize public dockets and regulator releases.
▸Research sources · 8
primary sources listed
- TACIT THERAPEUTICStacittx.com · web
8 public sources were cited for this profile; the first-party ones are listed here.
Frequently asked questions
- What does TACIT THERAPEUTICS do?
- San Francisco biotech developing spliceosome-mediated RNA trans-splicing medicines to repair mutated RNA transcripts.
- Who are TACIT THERAPEUTICS's investors?
- TACIT THERAPEUTICS's investors include Eisai Innovation, Inc., Mitsui Global Investment, KdT Ventures.