Keros Therapeutics, Inc. filings document a clinical-stage biopharmaceutical issuer developing therapeutics that modulate transforming growth factor-beta family signaling. Its 8-K reports cover financial results, Regulation FD corporate presentations, clinical-program announcements, collaboration disclosures, and board composition changes, while exchange registration disclosures identify Nasdaq-listed common stock and preferred share purchase rights.
The company’s proxy materials describe stockholder voting matters, board and committee governance, director compensation, and executive compensation. They also disclose portfolio strategy, including prioritization of rinvatercept, discontinued internal development activities for cibotercept, and related governance oversight of the company’s research and development focus.
ADAR1 Capital Management and related entities report beneficial ownership of 5,389,264 shares (13.27%) of Keros Therapeutics (KROS). The Schedule 13D/A (Amendment No.4) states ADAR1 issued an August 21, 2025 press release and open letter criticizing the Board's refusal to engage on strategy, capital allocation and Board refreshment and said it will seek to elect new directors at the next annual meeting if the Board continues to refuse engagement. The filing notes no transactions in the past 60 days, the reporting persons no longer hold previously reported long and short put positions, and the ownership percentage is based on 40,615,414 shares outstanding as of July 31, 2025.
Keros Therapeutics reported that the U.S. Food and Drug Administration granted Orphan Drug designation to its investigational therapy KER-065 for treating Duchenne muscular dystrophy. This special status is reserved for drugs targeting rare, serious conditions and can provide regulatory and economic incentives to support development. The company disclosed this update through a press release, which is attached as an exhibit and incorporated by reference.
Keros Therapeutics insider Lorena Raquel Lerner, identified as the company’s Chief Science Officer, reports beneficial ownership of 35,000 restricted stock units and employee stock options covering 41,379 underlying shares. The RSUs vest in three tranches (33% on Feb 17, 2026; 34% on Aug 15, 2026; 33% on Feb 16, 2027). Listed options have exercise prices of $43.99, $54.38 and $56.18 with multi-year vesting schedules.
Esther Cho, SVP and General Counsel of Keros Therapeutics, Inc. (KROS), reported initial beneficial ownership on Form 3 for an event dated 08/06/2025. She directly holds 44,000 shares (RSUs) and beneficially owns employee stock options exercisable into 165,968 common shares across five option grants with exercise prices ranging from $29.02 to $70.93.
ADAR1 Capital Management LLC and related entities reported significant trading activity in Keros Therapeutics (KROS) securities on June 20, 2025. The transactions involved both direct stock sales and put option exercises:
- ADAR1 Partners LP disposed of 1,500 shares of common stock: - 100 shares at $60 per share - 1,400 shares at $70 per share
- Spearhead Insurance Solutions IDF LLC disposed of 200 shares at $70 per share
- Related put options were exercised, corresponding to the stock dispositions: - One $60 strike put option for 100 shares - Sixteen $70 strike put options for 1,600 shares total
Following these transactions, ADAR1 Partners LP maintains beneficial ownership of 4,391,237 shares, while Spearhead Insurance Solutions holds 743,358 shares. All reporting persons are considered 10% owners of Keros Therapeutics, with Daniel Schneeberger serving as the manager of the related entities.