secwatch.observer — SEC 8-K summary
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Issuer:     Atrium Therapeutics, Inc. (RNA)
CIK:        0002093101
Form:       8-K
Filed at:   2026-02-26T23:59:59+00:00
Accession:  0001193125-26-077105
Event type: other_material
Sentiment:  neutral
Materiality: 0.75
Item codes: 7.01, 9.01
LLM model:  deepseek-v4-flash:cloud@v2

Atrium Therapeutics completes spin-off from Avidity; 15.5M shares distributed, trading begins Feb 27 under RNA
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- Avidity distributed 15,514,966 Atrium shares at a ratio of 1 share per 10 Avidity shares; holds no equity interest after.
- Atrium shares expected to begin trading on Nasdaq under symbol RNA on February 27, 2026.
- Registration statement declared effective and spin-off consummated on February 26, 2026.
- Novartis acquisition of Avidity expected to close on February 27, 2026, subject to conditions.
- Atrium focused on early-stage precision cardiology programs ATR-1086 (phospholamban) and ATR-1072 (PRKAG2 syndrome).

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/2093101/000119312526077105/0001193125-26-077105-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/2093101/000119312526077105/d14901d8k.htm
  HTML page:      https://secwatch.observer/filing/0001193125-26-077105

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