Tome Biosciences
The business, the turning points, and the decisions behind them.
01 / WHAT IT BUILT
What the company did
Tome Biosciences was a Massachusetts gene-editing startup led by CEO Rahul Kakkar, built on research licensed from MIT. Its programmable genomic integration (PGI) platform used proprietary enzymes to insert large DNA fragments — some stretching beyond 30 kilobases — anywhere in the genome without introducing double-stranded breaks, sidestepping a core limitation of CRISPR. Its lead program, integrase-PGI, targeted phenylketonuria alongside diseases of the immune system, liver and heart. The company launched in December 2023 with $213 million in Series A and Series B funding from Andreessen Horowitz, Arch Venture Partners and Polaris Partners.
02 / Tome Biosciences FAILURE REASONS
Failure reasons
Tome ran out of runway when it could not raise a Series C: investor sentiment had shifted sharply against preclinical gene-editing companies, and despite what the CEO called clear scientific progress, no new funding or partner materialized. With cash running low, the company scaled back to a skeleton operation and laid off 131 employees — essentially its entire staff — in November 2024, while seeking a buyer for its pipeline or platform.
03 / EVENT HISTORY
Events in the structured record
- Launch
Tome Biosciences launches in December 2023 with $213 million in Series A and Series B funding to advance its programmable genomic integration platform.
- Wind-down
After failing to raise a Series C, Tome lays off 131 employees — nearly all of its headcount — between November 1 and 14, 2024 under a Massachusetts WARN filing, operating at reduced capacity while exploring a sale or strategic options.
04 / CONTEMPORARY REBUILD ASSESSMENT
Difficulty of rebuilding this project today
Material for this section is being gathered and checked. It will appear here once ready.
Overall assessment: Not completed
05 / CAUSAL CHAIN
How the factors connect
- 01
Having failed to secure Series C funding, Tome filed a Massachusetts WARN notice covering 131 employees — essentially its entire staff — with layoffs effective November 1–14, 2024.
- 02
The company said it was operating at reduced capacity while in confidential talks with at least three parties interested in its pipeline or platform, but no rescue financing or acquisition was announced.