Welcome to our dedicated page for Kronos Bio SEC filings (Ticker: KRON), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Kronos Bio Inc. filings document the company's transition from a Nasdaq-listed biopharmaceutical issuer to a deregistered public-company record. The filings include material-event reporting on completion of a tender offer by Concentra Biosciences, capital-structure and common-stock disclosures, and formal corporate-status records.
The filing record also includes Form 25 documentation for removal of Kronos Bio common stock from Nasdaq listing and registration, and Form 15 certification covering termination or suspension of Exchange Act reporting obligations. These disclosures provide the formal record of the company's listing status, holder-of-record status, governance authorization, and securities-registration changes.
Form 4 snapshot: Kronos Bio (KRON) director Elena Ridloff reported the disposal of her remaining equity on 20 Jun 2025 following the closing of the company’s merger with Concentra Biosciences. She tendered 25,296 common shares, each exchanged for $0.57 in cash plus one contingent value right (CVR), matching the terms of the tender offer that closed on 18 Jun 2025. All of Ridloff’s outstanding stock options—covering 136,200 shares with strike prices between $0.95 and $24.18—were automatically cancelled because every exercise price exceeded the $0.57 cash component, so no additional consideration was received. After these transactions she holds zero shares or options, and Kronos Bio is now a wholly owned subsidiary of Concentra Biosciences.
Key event: Form 4 discloses that director David M. Tanen has disposed of 100 % of his equity position in Kronos Bio (KRON) on 20 June 2025.
The disposition covers 887,408 common shares (363,428 held directly and 523,980 held through a revocable trust and family members) at the previously announced tender-offer cash price of $0.57 per share plus one non-transferable contingent value right (CVR) per share. All positions are now reported as zero.
Simultaneously, 227,100 stock options with exercise prices ranging from $0.95 to $24.18 were cancelled pursuant to the merger terms. Options with strike prices below $0.57 became fully vested and entitled the holder to a cash-out equal to the intrinsic value (cash amount minus exercise price) plus one CVR per underlying share; options that were at or above $0.57 received no consideration.
The transactions were executed in accordance with the Agreement and Plan of Merger dated 1 May 2025 among Kronos Bio, Concentra Biosciences, and Merger Sub IV. Concentra completed the tender offer on 18 June 2025 and immediately merged with Kronos Bio, which now operates as a wholly owned subsidiary of Concentra. At the effective time, all outstanding Kronos Bio shares (other than excluded shares) were cancelled and converted into the right to receive the offer price.
Following these actions, Mr. Tanen is no longer a beneficial owner of Kronos Bio securities, and Section 16 insider reporting obligations for this issuer will cease unless he acquires new positions.
Form 4 filing overview for Kronos Bio, Inc. (KRON)
The filing details the disposition of four tranches of stock options held by director Roshawn A. Blunt on 20 June 2025. The options, with exercise prices of $17.10, $3.53, $1.48 and $0.95, were cancelled or exchanged in connection with the closing of Kronos Bio’s merger with Concentra Biosciences LLC.
- Merger consideration for common shareholders: $0.57 per share in cash plus one contingent value right (CVR).
- Pursuant to the merger agreement, all unexercised options became fully vested immediately prior to the effective time.
- If an option’s exercise price was higher than the $0.57 cash amount, it was cancelled for no consideration; otherwise, the holder received the cash spread plus one CVR per underlying share.
- All four option grants had exercise prices above $0.57, resulting in no economic value to the reporting person. Post-transaction, Blunt reports zero derivative securities beneficially owned.
- The tender offer and subsequent merger were completed on 18 June 2025; the Form 4 documents changes dated 20 June 2025.
Because the merger converts Kronos Bio into a wholly-owned subsidiary of Concentra, this filing also serves as notice that the director is no longer subject to Section 16 reporting.
Kronos Bio, Inc. (KRON) – Form 4 insider transaction
Director Joshua A. Kazam reported the disposition of his entire equity position in connection with the closing of Kronos Bio’s merger with Concentra Biosciences (effective 20 June 2025).
- Common shares: 94,481 shares tendered at $0.57 per share + one contingent value right (CVR), the consideration outlined in the May 1, 2025 merger agreement.
- Stock options: 123,600 options with strike prices ranging from $0.95-$24.18 were cancelled/disposed; all strikes exceeded the $0.57 cash offer, so they were out-of-the-money and received no cash but one CVR per underlying share.
- Following the transactions, the reporting person shows zero direct or indirect ownership in KRON.
The filing confirms the tender-offer closing and subsequent merger that takes Kronos Bio private as a wholly owned subsidiary of Concentra Biosciences. Public shareholders have already received the same $0.57 + CVR consideration. Trading in KRON is expected to cease once post-merger formalities finish.