Enzon Pharmaceuticals, Inc.

Symbol
ENZN on OTC
Entity
Company
Business address
20 Commerce Drive, Suite 135, 07016 Cranford, NJ
Phone
732-980-4500
State of incorporation
DE
Fiscal year end
December 31
Category
Non-accelerated filer
Smaller reporting company
Former names
ENZON PHARMACEUTICAL INC (to 12/10/2002), ENZON INC (to 12/9/2002)
All SEC filings
View on sec.gov
Get insider transactions for this issuer
Enzon Pharmaceuticals, Inc. has filed 1,441 SEC EDGAR filings since 3/3/1995

Latest Filings

Form type Document Filing Description Filing date Reporting date File number(s)
SCHEDULE 13D/A Open Document Open Filing Oct 24, 2025 005-35587
425 Open Document Open Filing 425 Oct 24, 2025 000-12957
8-K Open Document | Data Open Filing FORM 8-K Oct 24, 2025 Oct 24, 2025 000-12957
8-A12G/A Open Document Open Filing 8-A12G/A Sep 30, 2025 000-12957
8-K Open Document | Data Open Filing FORM 8-K Sep 30, 2025 Sep 30, 2025 000-12957
8-A12G/A Open Document Open Filing 8-A12G/A Aug 14, 2025 000-12957
10-Q Open Document | Data Open Filing 10-Q Aug 14, 2025 Jun 30, 2025 000-12957
SCHEDULE 13D/A Open Document Open Filing Jun 23, 2025 005-35587
425 Open Document | Data Open Filing 425 Jun 23, 2025 000-12957
8-K Open Document | Data Open Filing FORM 8-K Jun 23, 2025 Jun 20, 2025 000-12957
10-Q Open Document | Data Open Filing 10-Q May 9, 2025 Mar 31, 2025 000-12957
10-K/A Open Document | Data Open Filing 10-K/A Apr 28, 2025 Dec 31, 2024 000-12957
8-A12G/A Open Document Open Filing 8-A12G/A Apr 1, 2025 000-12957
8-K Open Document | Data Open Filing FORM 8-K Apr 1, 2025 Mar 31, 2025 000-12957
10-K Open Document | Data Open Filing 10-K Feb 21, 2025 Dec 31, 2024 000-12957
3 Open Document Open Filing OWNERSHIP DOCUMENT Jan 10, 2025 Jan 7, 2025
8-K Open Document | Data Open Filing FORM 8-K Jan 10, 2025 Jan 7, 2025 000-12957
8-K Open Document | Data Open Filing FORM 8-K Dec 27, 2024 Dec 18, 2024 000-12957
SCHEDULE 13D/A Open Document Open Filing Dec 19, 2024 005-35587
10-Q Open Document | Data Open Filing 10-Q Nov 5, 2024 Sep 30, 2024 000-12957
8-K Open Document | Data Open Filing FORM 8-K Oct 1, 2024 Sep 26, 2024 000-12957
SC 13D/A Open Document Open Filing SC 13D/A Aug 19, 2024 005-35587
ARS Open Document Open Filing ARS Aug 8, 2024 Dec 31, 2023 000-12957
DEFA14A Open Document Open Filing DEFA14A Aug 8, 2024 000-12957
DEF 14A Open Document Open Filing DEF 14A Aug 8, 2024 Sep 26, 2024 000-12957
10-Q Open Document | Data Open Filing 10-Q Aug 8, 2024 Jun 30, 2024 000-12957
PRE 14A Open Document Open Filing PRE 14A Jul 29, 2024 Sep 26, 2024 000-12957
8-K/A Open Document | Data Open Filing FORM 8-K/A Jul 11, 2024 Jul 2, 2024 000-12957
8-K Open Document | Data Open Filing FORM 8-K Jul 2, 2024 Jul 2, 2024 000-12957
8-K Open Document | Data Open Filing FORM 8-K Jun 14, 2024 Jun 10, 2024 000-12957
8-A12G/A Open Document Open Filing 8-A12G/A May 22, 2024 000-12957
8-K Open Document | Data Open Filing FORM 8-K May 22, 2024 May 16, 2024 000-12957
10-Q Open Document | Data Open Filing 10-Q May 10, 2024 Mar 31, 2024 000-12957
10-K/A Open Document | Data Open Filing FORM 10-K/A Apr 26, 2024 Dec 31, 2023 000-12957
10-K Open Document | Data Open Filing 10-K Mar 20, 2024 Dec 31, 2023 000-12957
8-K Open Document | Data Open Filing FORM 8-K Jan 5, 2024 Dec 31, 2023 000-12957
10-Q Open Document | Data Open Filing 10-Q Nov 9, 2023 Sep 30, 2023 000-12957
10-Q Open Document | Data Open Filing 10-Q Aug 7, 2023 Jun 30, 2023 000-12957
4 Open Document Open Filing OWNERSHIP DOCUMENT Jun 16, 2023 Jun 14, 2023
8-K Open Document | Data Open Filing FORM 8-K Jun 14, 2023 Jun 8, 2023 000-12957
10-Q Open Document | Data Open Filing 10-Q May 5, 2023 Mar 31, 2023 000-12957
ARS Open Document Open Filing ARS Apr 20, 2023 Dec 31, 2022 000-12957
DEFA14A Open Document Open Filing DEFA14A Apr 20, 2023 000-12957
DEF 14A Open Document Open Filing DEF 14A Apr 20, 2023 Jun 8, 2023 000-12957
10-K Open Document | Data Open Filing 10-K Feb 16, 2023 Dec 31, 2022 000-12957
8-K Open Document | Data Open Filing FORM 8-K Jan 6, 2023 Dec 31, 2022 000-12957
10-Q Open Document | Data Open Filing 10-Q Nov 9, 2022 Sep 30, 2022 000-12957
10-Q Open Document | Data Open Filing 10-Q Aug 4, 2022 Jun 30, 2022 000-12957
3 Open Document Open Filing FORM 3 Jun 21, 2022 Jun 9, 2022
8-K Open Document | Data Open Filing FORM 8-K Jun 15, 2022 Jun 9, 2022 000-12957
10-Q Open Document | Data Open Filing 10-Q Apr 26, 2022 Mar 31, 2022 000-12957
DEFA14A Open Document Open Filing DEFA14A Apr 22, 2022 000-12957
DEF 14A Open Document Open Filing DEF 14A Apr 22, 2022 Jun 9, 2022 000-12957
10-K Open Document | Data Open Filing 10-K Feb 25, 2022 Dec 31, 2021 000-12957
10-Q Open Document | Data Open Filing FORM 10-Q Nov 5, 2021 Sep 30, 2021 000-12957
4 Open Document Open Filing OWNERSHIP DOCUMENT Aug 17, 2021 Aug 13, 2021
10-Q Open Document | Data Open Filing FORM 10-Q Aug 5, 2021 Jun 30, 2021 000-12957
8-A12G/A Open Document Open Filing 8-A12G/A Jun 8, 2021 000-12957
8-K Open Document Open Filing FORM 8-K Jun 8, 2021 Jun 2, 2021 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q May 4, 2021 Mar 31, 2021 001-36435
DEFA14A Open Document Open Filing DEFA14A Apr 14, 2021 001-36435
DEF 14A Open Document Open Filing DEF 14A Apr 14, 2021 Jun 2, 2021 001-36435
PRE 14A Open Document Open Filing PRE 14A Apr 2, 2021 Jun 2, 2021 001-36435
10-K Open Document | Data Open Filing FORM 10-K Feb 23, 2021 Dec 31, 2020 001-36435
8-K Open Document Open Filing FORM 8-K Jan 4, 2021 Dec 30, 2020 001-36435
8-K Open Document Open Filing FORM 8-K Dec 21, 2020 Dec 18, 2020 001-36435
424B3 Open Document Open Filing 424B3 Nov 24, 2020 333-250031
EFFECT Open Document Open Filing Nov 23, 2020 333-250031
4 Open Document Open Filing OWNERSHIP DOCUMENT Nov 18, 2020 Nov 16, 2020
CORRESP Open Document Open Filing Nov 18, 2020
4 Open Document Open Filing OWNERSHIP DOCUMENT Nov 17, 2020 Nov 13, 2020
UPLOAD Open Document Open Filing Nov 17, 2020
S-1 Open Document Open Filing FORM S-1 Nov 12, 2020 333-250031
10-Q Open Document | Data Open Filing FORM 10-Q Nov 9, 2020 Sep 30, 2020 001-36435
DEFA14A Open Document Open Filing DEFA14A Nov 3, 2020 001-36435
DEF 14A Open Document Open Filing DEF 14A Nov 3, 2020 Dec 18, 2020 001-36435
4 Open Document Open Filing FORM 4 Oct 14, 2020 Oct 9, 2020
SC 13D/A Open Document Open Filing Oct 14, 2020 005-35587
8-K Open Document Open Filing FORM 8-K Oct 14, 2020 Oct 9, 2020 001-36435
8-K Open Document Open Filing FORM 8-K Sep 23, 2020 Sep 21, 2020 001-36435
424B3 Open Document Open Filing 424B3 Sep 23, 2020 333-248528
EFFECT Open Document Open Filing Sep 21, 2020 333-248528
SC 13D/A Open Document Open Filing AMENDMENT NO. 2 TO THE SCHEDULE 13D Sep 17, 2020 005-35587
CORRESP Open Document Open Filing Sep 17, 2020
8-K Open Document Open Filing FORM 8-K Sep 15, 2020 Sep 15, 2020 001-36435
S-1/A Open Document Open Filing S-1/A Sep 15, 2020 333-248528
UPLOAD Open Document Open Filing Sep 8, 2020
8-K Open Document Open Filing FORM 8-K Sep 2, 2020 Sep 2, 2020 001-36435
SC 13D/A Open Document Open Filing Sep 1, 2020 005-35587
8-K Open Document Open Filing FORM 8-K Sep 1, 2020 Sep 1, 2020 001-36435
S-1 Open Document Open Filing FORM S-1 Sep 1, 2020 333-248528
8-K Open Document Open Filing FORM 8-K Aug 31, 2020 Aug 31, 2020 001-36435
4 Open Document Open Filing OWNERSHIP DOCUMENT Aug 26, 2020 Aug 24, 2020
3 Open Document Open Filing FORM 3 Aug 18, 2020 Aug 4, 2020
8-K Open Document Open Filing FORM 8-K Aug 14, 2020 Aug 14, 2020 001-36435
8-A12G Open Document Open Filing 8-A12G Aug 14, 2020 000-12957
3 Open Document Open Filing FORM 3 Aug 14, 2020 Aug 4, 2020
SC 13D/A Open Document Open Filing Aug 7, 2020 005-35587
8-K Open Document Open Filing FORM 8-K Aug 7, 2020 Aug 4, 2020 001-36435
4 Open Document Open Filing OWNERSHIP DOCUMENT Aug 6, 2020 Aug 5, 2020
3 Open Document Open Filing OWNERSHIP DOCUMENT Aug 6, 2020 Aug 3, 2020
SC 13D/A Open Document Open Filing AMENDMENT NO. 1 TO THE SCHEDULE 13D Aug 5, 2020 005-35587
10-Q Open Document | Data Open Filing FORM 10-Q Jul 29, 2020 Jun 30, 2020 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q Apr 30, 2020 Mar 31, 2020 001-36435
10-K/A Open Document Open Filing FORM 10-K/A Apr 24, 2020 Dec 31, 2019 001-36435
SC 13D Open Document Open Filing THE SCHEDULE 13D Apr 16, 2020 005-35587
4/A Open Document Open Filing OWNERSHIP DOCUMENT Mar 31, 2020 Mar 13, 2020
3 Open Document Open Filing OWNERSHIP DOCUMENT Mar 31, 2020 Mar 18, 2020
4 Open Document Open Filing Mar 27, 2020 Mar 13, 2020
SC 13G/A Open Document Open Filing AMENDMENT NO. 3 TO THE SCHEDULE 13G Mar 27, 2020 005-35587
10-K Open Document | Data Open Filing FORM 10-K Feb 19, 2020 Dec 31, 2019 001-36435
SC 13G/A Open Document Open Filing SC 13G/A Jan 22, 2020 005-35587
SC 13G/A Open Document Open Filing SC 13G/A Jan 16, 2020 005-35587
10-Q Open Document | Data Open Filing FORM 10-Q Nov 6, 2019 Sep 30, 2019 001-36435
8-K Open Document Open Filing 8-K Aug 22, 2019 Aug 22, 2019 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q Aug 7, 2019 Jun 30, 2019 001-36435
DEFA14A Open Document Open Filing DEFA14A Jul 12, 2019 001-36435
DEF 14A Open Document Open Filing DEF 14A Jul 12, 2019 Aug 22, 2019 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q May 8, 2019 Mar 31, 2019 001-36435
10-K/A Open Document Open Filing 10-K/A Apr 25, 2019 Dec 31, 2018 001-36435
10-K Open Document | Data Open Filing FORM 10-K Feb 21, 2019 Dec 31, 2018 001-36435
4 Open Document Open Filing OWNERSHIP DOCUMENT Feb 14, 2019 Feb 11, 2019
SC 13G/A Open Document Open Filing AMENDMENT NO. 2 TO THE SCHEDULE 13G Feb 14, 2019 005-35587
8-K Open Document Open Filing FORM 8-K Feb 1, 2019 Jan 30, 2019 001-36435
SC 13G/A Open Document Open Filing SC 13G/A Jan 31, 2019 005-35587
4 Open Document Open Filing OWNERSHIP DOCUMENT Jan 9, 2019 Apr 13, 2018
4 Open Document Open Filing OWNERSHIP DOCUMENT Jan 9, 2019 Apr 13, 2018
SC 13G/A Open Document Open Filing SC 13G/A Jan 3, 2019 005-35587
10-Q Open Document | Data Open Filing 10-Q Nov 7, 2018 Sep 30, 2018 001-36435
8-K Open Document Open Filing FORM 8-K Aug 13, 2018 Aug 9, 2018 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q Aug 10, 2018 Jun 30, 2018 001-36435
DEFA14A Open Document Open Filing DEFA14A Jun 29, 2018 001-36435
DEF 14A Open Document Open Filing DEFINITIVE PROXY STATEMENT Jun 29, 2018 Aug 9, 2018 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q May 10, 2018 Mar 31, 2018 001-36435
10-K/A Open Document Open Filing 10-K/A Apr 25, 2018 Dec 31, 2017 001-36435
3 Open Document Open Filing OWNERSHIP DOCUMENT Apr 13, 2018 Apr 4, 2018
SC 13G/A Open Document Open Filing AMENDMENT NO. 1 TO SCHEDULE 13G Apr 13, 2018 005-35587
10-K Open Document | Data Open Filing 10-K Mar 21, 2018 Dec 31, 2017 001-36435
15-12G Open Document Open Filing 15-12G Feb 13, 2018 000-12957
SC 13G Open Document Open Filing SCHEDULE 13G Feb 9, 2018 005-35587
SC 13G Open Document Open Filing SC 13G Jan 22, 2018 005-35587
10-Q Open Document | Data Open Filing FORM 10-Q Nov 9, 2017 Sep 30, 2017 001-36435
8-K Open Document Open Filing FORM 8-K Aug 10, 2017 Aug 10, 2017 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q Aug 10, 2017 Jun 30, 2017 001-36435
8-K Open Document Open Filing FORM 8-K Jun 30, 2017 Jun 26, 2017 001-36435
SC 13G Open Document Open Filing THE SCHEDULE 13G May 24, 2017 005-35587
DEFA14A Open Document Open Filing DEFA14A May 12, 2017 001-36435
DEF 14A Open Document Open Filing DEF 14A May 12, 2017 Jun 28, 2017 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q May 11, 2017 Mar 31, 2017 001-36435
10-K/A Open Document Open Filing FORM 10-K/A Apr 28, 2017 Dec 31, 2016 001-36435
10-K Open Document | Data Open Filing 10-K Mar 24, 2017 Dec 31, 2016 001-36435
SC 13G/A Open Document Open Filing 13G/A Feb 14, 2017 005-35587
SC 13D/A Open Document Open Filing Dec 8, 2016 005-35587
8-K Open Document Open Filing FORM 8-K Dec 8, 2016 Dec 8, 2016 001-36435
4 Open Document Open Filing FORM 4 Nov 29, 2016 Nov 28, 2016
SC 13D/A Open Document Open Filing Nov 29, 2016 005-35587
8-K Open Document Open Filing FORM 8-K Nov 14, 2016 Nov 14, 2016 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q Nov 10, 2016 Sep 30, 2016 001-36435
8-K Open Document Open Filing FORM 8-K Oct 26, 2016 Oct 25, 2016 001-36435
10-Q Open Document | Data Open Filing 10-Q Aug 10, 2016 Jun 30, 2016 001-36435
8-K Open Document Open Filing FORM 8-K Aug 9, 2016 Aug 9, 2016 001-36435
8-K Open Document Open Filing FORM 8-K Jul 5, 2016 Jun 29, 2016 001-36435
25-NSE Open Document | Data Open Filing Jun 10, 2016 000-12957
SC 13G/A Open Document Open Filing Jun 9, 2016 005-35587
8-K Open Document Open Filing FORM 8-K May 16, 2016 May 11, 2016 001-36435
DEFA14A Open Document Open Filing DEFA14A May 13, 2016 001-36435
DEF 14A Open Document Open Filing DEF 14A May 13, 2016 Jun 29, 2016 001-36435
10-Q Open Document | Data Open Filing 10-Q May 9, 2016 Mar 31, 2016 001-36435
10-K/A Open Document Open Filing FORM 10-K/A Apr 28, 2016 Dec 31, 2015 001-36435
3 Open Document Open Filing OWNERSHIP DOCUMENT Apr 5, 2016 Mar 31, 2016
10-K Open Document | Data Open Filing FORM 10-K Mar 21, 2016 Dec 31, 2015 001-36435
8-K Open Document Open Filing FORM 8-K Mar 21, 2016 Mar 18, 2016 001-36435
8-K Open Document Open Filing FORM 8-K Feb 23, 2016 Feb 22, 2016 001-36435
SC 13G/A Open Document Open Filing Feb 12, 2016 005-35587
SC 13G Open Document Open Filing ENZON PHARMACEUTICALS, INC. Feb 12, 2016 005-35587
8-K Open Document Open Filing FORM 8-K Feb 9, 2016 Feb 2, 2016 001-36435
DEFA14A Open Document Open Filing FORM 8-K Feb 9, 2016 001-36435
SC 13G/A Open Document Open Filing Jan 26, 2016 005-35587
8-K Open Document Open Filing FORM 8-K Dec 7, 2015 Dec 4, 2015 001-36435
8-K Open Document Open Filing 8-K Dec 3, 2015 Dec 2, 2015 001-36435
8-K Open Document Open Filing CURRENT REPORT Nov 12, 2015 Nov 11, 2015 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q Nov 6, 2015 Sep 30, 2015 001-36435
8-K Open Document Open Filing 8-K Sep 15, 2015 Sep 11, 2015 001-36435
10-Q Open Document | Data Open Filing 10-Q Aug 7, 2015 Jun 30, 2015 001-36435
8-K Open Document Open Filing FORM 8-K Jul 8, 2015 Jul 6, 2015 001-36435
8-K Open Document Open Filing FORM 8-K Jul 2, 2015 Jun 30, 2015 001-36435
ARS Open Document Open Filing AUTO-GENERATED PAPER DOCUMENT May 19, 2015 Dec 31, 2014 001-36435
DEFA14A Open Document Open Filing DEFA14A May 15, 2015 001-36435
DEF 14A Open Document Open Filing DEF 14A May 15, 2015 Jun 30, 2015 001-36435
10-Q Open Document | Data Open Filing FORM 10-Q May 13, 2015 Mar 31, 2015 001-36435
PRE 14A Open Document Open Filing FORM PRE 14A Apr 28, 2015 Apr 28, 2015 001-36435
10-K/A Open Document Open Filing FORM 10-K/A Apr 24, 2015 Dec 31, 2014 001-36435
10-K Open Document | Data Open Filing 10-K Mar 5, 2015 Dec 31, 2014 001-36435
SC 13G/A Open Document Open Filing Feb 6, 2015 005-35587
SC 13G/A Open Document Open Filing Jan 22, 2015 005-35587
8-K Open Document Open Filing 8-K Dec 10, 2014 Dec 8, 2014 001-36435
8-K Open Document Open Filing FORM 8-K Dec 5, 2014 Dec 4, 2014 001-36435
4 Open Document Open Filing FORM 4 Nov 28, 2014 Nov 28, 2012
10-Q Open Document | Data Open Filing 10-Q Nov 6, 2014 Sep 30, 2014 001-36435
10-Q Open Document | Data Open Filing 10-Q Aug 8, 2014 Jun 30, 2014 001-36435
8-K Open Document Open Filing CURRENT REPORT Jul 16, 2014 Jun 25, 2014 001-36435
8-K Open Document Open Filing FORM 8-K Jun 12, 2014 Jun 10, 2014 001-36435
8-K Open Document Open Filing 8-K May 30, 2014 May 28, 2014 001-36435
8-K Open Document Open Filing 8-K May 19, 2014 May 19, 2014 001-36435
DEFA14A Open Document Open Filing 8-K May 19, 2014 001-36435
8-K Open Document Open Filing 8-K May 9, 2014 May 8, 2014 001-36435
10-Q Open Document | Data Open Filing 10-Q May 9, 2014 Mar 31, 2014 001-36435
8-A12B Open Document Open Filing 8-A12B May 1, 2014 001-36435
8-K Open Document Open Filing FORM 8-K May 1, 2014 Apr 30, 2014 000-12957
ARS Open Document Open Filing AUTO-GENERATED PAPER DOCUMENT Apr 18, 2014 Dec 31, 2013 001-36435
DEFA14A Open Document Open Filing DEFA14A Apr 16, 2014 000-12957
DEF 14A Open Document Open Filing DEF 14A Apr 16, 2014 May 28, 2014 000-12957
SC 13G/A Open Document Open Filing ENZN13GAMEND6 Apr 9, 2014 005-35587
8-K Open Document Open Filing 8-K Mar 25, 2014 Mar 19, 2014 000-12957
10-K Open Document | Data Open Filing 10-K Mar 14, 2014 Dec 31, 2013 000-12957
SC 13G Open Document Open Filing SC 13G Mar 13, 2014 005-35587
SC 13G/A Open Document Open Filing Feb 12, 2014 005-35587
SC 13G/A Open Document Open Filing Jan 10, 2014 005-35587
SC 13G/A Open Document Open Filing ENZN13GAMEND5.PDML Jan 9, 2014 005-35587