secwatch.observer — SEC 8-K summary
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Issuer:     Lexeo Therapeutics, Inc. (LXEO)
CIK:        0001907108
Form:       8-K
Filed at:   2026-09-29T20:20:33+00:00
Accession:  0001193125-26-407555
Event type: m_and_a
Sentiment:  neutral
Materiality: 0.60
Item codes: 2.01, 3.02, 9.01
LLM model:  deepseek-v4.1-flash:cloud@v2

Lexeo completes acquisition of Mantle Therapeutics for $5.3M cash and $3M stock plus contingent payments
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- Lexeo completed the Mantle Therapeutics acquisition on September 29, 2026, through the merger of Magma Merger Sub Inc. into Mantle.
- Upfront consideration was $5.3 million in cash and $3.0 million in Lexeo common stock, issued under Section 4(a)(2)/Regulation D exemption.
- Contingent payments include a $1.0 million additional cash payment and up to $12.0 million in milestone payments over 12 years tied to development and regulatory milestones.
- Mantle restricted stock vested and was cancelled, and Mantle SAFEs and convertible promissory notes were cancelled for applicable consideration or payoff.

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/1907108/000119312526407555/0001193125-26-407555-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/1907108/000119312526407555/lxeo-20260929.htm
  HTML page:      https://secwatch.observer/filing/0001193125-26-407555

License: Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer