Disc Medicine, Inc. Form 4 Filings

Disc Medicine, Inc. (IRON) reported that funds affiliated with director Kevin Bitterman sold an aggregate of 54,496 shares of Common Stock in open‑market transactions from September 1–3, 2026 at weighted average prices around $80 per share, pursuant to a Rule 10b5-1 trading plan adopted on July 30, 2026.

The shares were sold indirectly through Atlas Venture Opportunity Fund I, L.P., Atlas Venture Opportunity Fund II, L.P., and Atlas Venture Fund XII, L.P.; Bitterman is a member of entities that serve as their general partners and disclaims beneficial ownership of the securities held by these funds except to the extent of his pecuniary interest, if any.

Disc Medicine, Inc. (IRON) reported that Chief Operating Officer Jonathan Yen-Wen Yu exercised stock options and sold the resulting common shares under a pre-arranged Rule 10b5-1 trading plan. On August 24, 2026, he exercised options for 300 shares of common stock at an exercise price of $13.50 per share and sold 300 shares at a weighted average price of $82.5333 per share, with sale prices ranging from $82.50 to $82.60. On August 25, 2026, he exercised options for an additional 8,796 shares at $13.50 per share and sold 8,796 shares at a weighted average price of $83.1164 per share, with sale prices ranging from $82.57 to $83.47. The options exercised were from a grant vesting in 48 equal monthly installments after December 29, 2022, and all reported trades were effected pursuant to a Rule 10b5-1 trading plan adopted on March 17, 2026.

Disc Medicine, Inc. (IRON) CEO and director John D. Quisel reported an option exercise and related share sales. On August 17, 2026, he exercised a stock option for 33,000 shares of common stock at an exercise price of $13.50 per share, reducing that option position to rights over 91,586 shares, with the option expiring on December 28, 2032. The same day, he sold an aggregate of 33,000 common shares in three open-market transactions at weighted average prices of $78.1061, $79.1952, and $79.8420 per share, each over stated price ranges. All transactions were effected pursuant to a Rule 10b5-1 trading plan adopted on March 12, 2026.

Disc Medicine, Inc. Chief Operating Officer Yu Jonathan Yen-Wen exercised stock options for 804 shares of common stock at an exercise price of $13.50 per share and sold 804 shares of common stock at a weighted average price of $82.6425 per share, with individual sale prices ranging from $82.54 to $82.83. The transactions were made pursuant to a Rule 10b5-1 trading plan adopted on March 17, 2026. Following the option exercise, he held 22,943 option shares tied to this grant, which vests in 48 equal monthly installments after December 29, 2022 and expires on December 28, 2032.

Disc Medicine, Inc. Chief Legal Officer Rahul Khara exercised 5,000 stock options for common stock at an exercise price of $14.69 per share and acquired 5,000 shares, then sold 5,000 common shares at $80.00 per share on August 6, 2026. Following the exercise, 49,804 option shares tied to this award remained outstanding. All reported transactions were effected under a Rule 10b5-1 trading plan adopted on March 19, 2026.

Disc Medicine, Inc. Chief Executive Officer and director John D. Quisel reported option-related trades on July 13, 2026. He exercised stock options for 33,000 shares of common stock at strike prices of $13.50 and $9.86, and sold 33,000 shares in open-market transactions at weighted-average prices of $76.0520, $74.9469 and $74.2729, with individual trades ranging from $73.62 to $76.29. These sales were made under a Rule 10b5-1 trading plan adopted on March 12, 2026. Following the transactions, he holds 226,064 common shares directly and retains stock options covering 124,586 and 15,791 underlying shares.

Disc Medicine, Inc. Chief Operating Officer Jonathan Yen-Wen Yu reported an option exercise and related stock sale. On July 7, 2026, he exercised stock options for 100 shares of common stock at $13.50 per share and sold 100 shares of common stock at an average price of $82.50 per share under a pre-arranged Rule 10b5-1 trading plan. Following these transactions, he holds 54,324 shares of common stock directly and 23,747 stock options exercisable for common shares, with the option grant vesting in 48 equal monthly installments after December 29, 2022.

Disc Medicine, Inc. Chief Legal Officer Rahul Khara exercised stock options and sold common shares in a pre-planned set of transactions. He exercised options for 2,500 shares of common stock at $14.69 per share and sold 2,500 shares at $75.00 per share. After these trades, he directly holds 52,173 common shares. The transactions were executed under a Rule 10b5-1 trading plan adopted on March 19, 2026, indicating they were pre-arranged rather than timed discretionarily.

Disc Medicine Chief Operating Officer Jonathan Yu reported a small, pre-planned insider transaction in Disc Medicine, Inc. common stock. On June 26, 2026, he exercised stock options to acquire 300 shares of common stock at $13.50 per share, then sold 300 shares of common stock at an average price of $72.50 per share in an open-market transaction.

The filing notes these trades were executed under a previously adopted Rule 10b5-1 trading plan, indicating they were scheduled in advance rather than timed discretionarily. A related footnote explains that the option grant vests in 48 equal monthly installments starting from December 29, 2022, contingent on Yu’s continued service.

Disc Medicine, Inc. Chief Operating Officer Jonathan Yu Yen-Wen executed an options-related trade involving company stock. He exercised stock options to acquire 9,700 shares of common stock at $13.50 per share, then sold 9,700 shares in an open-market transaction at a weighted average price of $72.6593 per share.

The transactions were carried out under a pre-arranged Rule 10b5-1 trading plan adopted on March 17, 2026. Following these trades, he directly holds 54,324 shares of common stock and 24,147 stock options that are scheduled to vest monthly through December 29, 2026 and expire on December 28, 2032.

Disc Medicine Chief Legal Officer Rahul Khara reported an exercise-and-sell transaction in company common stock. On June 18, 2026, he exercised stock options to acquire 7,500 shares at an exercise price of $14.69 per share, then sold 7,500 shares in open-market trades at weighted average prices between about $69.35 and $71.81. The filing states these sales were made under a pre-arranged Rule 10b5-1 trading plan. Following the transactions, he directly holds 52,173 shares of Disc Medicine common stock.

Disc Medicine, Inc.’s CEO John D. Quisel reported mixed insider activity in Common Stock. On June 18, 2026, he sold a total of 34,000 shares in open-market transactions at weighted average prices within ranges from $69.35 to $71.85 per share under a pre-arranged Rule 10b5-1 trading plan. On the same date, he exercised a stock option to acquire 34,000 shares of Common Stock at an exercise price of $9.86 per share. After these transactions, he directly holds 226,064 shares of Common Stock and 41,375 stock options remain outstanding, indicating a sizable continuing equity stake.

Disc Medicine director William Richard White received a grant of stock options for 6,212 shares of common stock. The options have an exercise price of $70.79 per share and expire on June 17, 2036. They vest at the earlier of the company’s 2027 annual stockholder meeting or one year from the grant date, subject to his continued service.

Disc Medicine, Inc. director Liam Ratcliffe received a grant of stock options covering 6,212 shares of common stock. The options have an exercise price of $70.79 per share and expire on June 17, 2036.

These options vest on the earlier of the company’s 2027 annual stockholder meeting or the one-year anniversary of the grant date, as long as he continues to serve through that vesting date. Following this grant, he holds 6,212 stock options directly, reflecting a compensation-related award rather than an open-market trade.

Disc Medicine, Inc. director Donald William Nicholson received a grant of stock options, giving him the right to buy 6,212 shares of common stock at an exercise price of $70.79 per share. These options expire on June 17, 2036 and vest upon the earlier of the company’s 2027 annual stockholder meeting or the one-year anniversary of the grant date, as long as he continues serving through that vesting date. Following this grant, he holds stock options covering 6,212 shares directly.

Disc Medicine, Inc. director Georges Gemayel received a grant of stock options covering 6,212 shares of common stock. The options have an exercise price of $70.79 per share and expire on June 17, 2036, bringing his reported derivative holdings to 6,212 options.

The options vest on the earlier of the company’s 2027 annual stockholder meeting or the one-year anniversary of the grant date, as long as he continues to serve as a director on the vesting date.

Disc Medicine director Mark Chin received a new stock option grant. On the reported date, he was awarded options covering 6,212 shares of Disc Medicine common stock at an exercise price of $70.79 per share, expiring on June 17, 2036.

The options were granted as compensation and carry no upfront purchase cost, with a grant price of $0.00. According to the terms, the underlying shares vest on the earlier of the company’s 2027 annual shareholder meeting or the one-year anniversary of the grant date, provided he continues serving as a director.

Disc Medicine, Inc. director Kevin Bitterman received a grant of stock options covering 6,212 shares of common stock. The options have an exercise price of $70.79 per share and expire on June 17, 2036.

The options vest on the earlier of the company’s 2027 annual stockholders’ meeting or the one-year anniversary of the grant date, subject to his continued service. Footnotes state that proceeds from any sale of shares issued upon exercise will be transferred to Atlas Venture Life Science Advisors, LLC, and Bitterman disclaims ownership of the securities except for any pecuniary interest.

Disc Medicine director Nadim Ahmed received a grant of stock options, giving him the right to buy 5,176 shares of common stock. The options have an exercise price of $70.79 per share and expire on June 17, 2036.

These options vest on the earlier of the company’s 2027 annual stockholders’ meeting or the one-year anniversary of the grant date, contingent on his continued board service. After this grant, Ahmed holds options covering 5,176 shares directly.

Disc Medicine, Inc. Chief Operating Officer Yu Jonathan Yen-Wen reported option exercises and related share sales. On June 16, 2026, he exercised stock options for a total of 18,612 shares of common stock at an exercise price of $9.86 per share and sold 18,612 shares in open-market transactions. The sales occurred at weighted average prices of about $68.76 and $69.92 per share, within ranges from $68.37 to $70.19. The filing states these trades were executed under a pre-arranged Rule 10b5-1 trading plan, indicating they were scheduled in advance rather than timed discretionarily.

Disc Medicine, Inc. Chief Medical Officer William Jacob Savage reported open-market sales of company stock. On April 13, 2026, he sold 3,531 shares of common stock at a weighted-average price of $66.1209 per share and a further 2,200 shares at $66.8073 per share, totaling 5,731 shares sold.

The filing states these transactions were executed under a pre-arranged Rule 10b5-1 trading plan adopted on October 2, 2025. After the sales, he continued to hold 79,480 shares of Disc Medicine common stock directly.

Disc Medicine, Inc. Chief Financial Officer Jean M. Franchi reported open-market sales of company common stock. On April 14, 2026, the CFO sold 6,257 shares at a weighted average price of $69.2399 per share. On April 13, 2026, the CFO sold an additional 400 shares at $69.00 per share. These transactions were executed under a Rule 10b5-1 trading plan adopted on September 25, 2025. Following the reported sales, the CFO directly holds 64,333 shares of Disc Medicine common stock.

Disc Medicine, Inc. Chief Medical Officer William Jacob Savage reported two open-market sales of common stock. On March 2, he sold 4,392 shares at a weighted average price of $65.5218 per share, and 2,986 shares at a weighted average price of $66.4090 per share, totaling 7,378 shares sold. These transactions were executed under a pre-arranged Rule 10b5-1 trading plan adopted on October 2, 2025. After the sales, he continued to hold 85,211 shares directly.

Disc Medicine, Inc. Chief Financial Officer Jean M. Franchi reported an open-market sale of 353 shares of common stock at a weighted average price of $69.0569 per share. After this Rule 10b5-1 plan trade, she directly holds 70,990 shares. The shares were sold in multiple transactions between $69.00 and $69.36.

Disc Medicine, Inc. Chief Financial Officer Jean M. Franchi reported open-market sales of a total of 11,156 shares of common stock on February 17–18, 2026. The transactions were executed at weighted average prices of $62.8600, $65.0097, and $65.8889 per share, with footnotes noting sale price ranges between $64.47 and $66.38.

According to the disclosure, one of these transactions was a "sell to cover" sale used to satisfy tax withholding obligations related to previously vested restricted stock units, and did not represent a discretionary trade. All transactions were carried out under a pre-arranged Rule 10b5-1 trading plan adopted on September 25, 2025. After these sales, Franchi directly owned 71,343 shares of Disc Medicine common stock.

Disc Medicine, Inc. Chief Legal Officer Rahul Khara reported an open-market sale of 2,853 shares of common stock at an average price of $62.86 per share on February 17, 2026. According to the filing, this was a mandatory “sell to cover” transaction to satisfy tax withholding on vesting restricted stock units, not a discretionary sale. After this transaction, Khara directly owned 52,173 shares of Disc Medicine common stock.

Disc Medicine, Inc. Chief Commercial Officer Pamela Stephenson reported an open-market sale of 5,531 shares of common stock at $62.86 per share. According to the filing, the sale was solely to cover tax withholding on vesting restricted stock units. She now holds 80,998 shares directly.

Disc Medicine, Inc. Chief Medical Officer William Jacob Savage reported an open-market sale of 3,256 shares of common stock at $62.86 per share. According to the footnote, this was a non-discretionary “sell to cover” transaction to satisfy tax withholding obligations from vesting restricted stock units. After the sale, he directly owned 92,589 shares.

Disc Medicine, Inc. Chief Operating Officer Yu Jonathan Yen-Wen reported an open-market sale of 3,231 shares of common stock at $62.86 per share. After the transaction, he directly owns 54,324 shares. According to the footnote, the sale was solely to cover tax withholding on vesting restricted stock units and was not a discretionary trade.

Disc Medicine, Inc. Chief Executive Officer John D. Quisel reported an open‑market sale of 13,264 shares of common stock at $62.86 per share. According to the filing, this was a "sell to cover" transaction to satisfy tax withholding obligations from vesting restricted stock units and was not a discretionary trade. After the sale, Quisel directly owned 226,064 shares of Disc Medicine common stock.

Disc Medicine's Chief Legal Officer, Rahul Khara, reported new equity awards in the company’s stock. On February 10, 2026, he acquired 17,000 shares of Common Stock as restricted stock units granted at $0 cost. These RSUs vest in four annual 25% installments starting February 15, 2027, contingent on continued service.

He was also granted a stock option for 25,500 shares of Common Stock at an exercise price of $74.75 per share, vesting in 48 equal monthly installments beginning March 10, 2026. Following these awards, he directly owned 55,026 Common shares and 25,500 option shares.

Disc Medicine’s Chief Commercial Officer Pamela Stephenson reported equity awards that increase her direct ownership stake. On February 10, 2026, she acquired 17,000 shares of common stock as restricted stock units at a grant price of $0, bringing her directly held common shares to 86,529.

She also received a stock option for 25,500 shares with an exercise price of $74.75 per share. The RSUs vest in four annual 25% installments starting February 15, 2027, and the option vests in 48 equal monthly installments starting March 10, 2026, in each case subject to continued service.

Disc Medicine’s Chief Medical Officer William Jacob Savage reported new equity awards in the company’s stock. On February 10, 2026, he acquired 17,000 shares of Common Stock in the form of restricted stock units, bringing his direct Common Stock holdings to 95,845 shares.

He was also granted a stock option for 25,500 shares of Common Stock at an exercise price of $74.75 per share, all held directly. The option vests in 48 equal monthly installments beginning March 10, 2026, while the RSUs vest in four annual 25% installments starting February 15, 2027, in each case subject to his continued service.

Disc Medicine Chief Operating Officer Yu Jonathan Yen-Wen reported equity awards in the form of restricted stock units and stock options. He acquired 17,000 shares of Common Stock as RSUs at $0 per share, bringing his direct Common Stock holdings to 57,555 shares.

He was also granted a stock option for 25,500 shares with an exercise price of $74.75 per share, with 25,500 derivative securities owned directly after the grant. The RSUs vest in four annual 25% installments starting February 15, 2027, and the option vests in 48 equal monthly installments starting March 10, 2026, in each case subject to his continued service.

Disc Medicine Chief Financial Officer Jean M. Franchi reported equity compensation awards from the company. On February 10, 2026, Franchi acquired 19,000 restricted stock units, each representing one share of common stock, for no cash cost. Following this grant, Franchi directly holds 82,499 shares of common stock. The filing also shows a grant of a stock option for 25,500 shares at an exercise price of $74.75 per share, with 25,500 options held directly after the transaction. The RSUs vest in four annual 25% installments beginning February 15, 2027, and the option vests in 48 equal monthly installments starting March 10, 2026, in each case subject to continued service.

Disc Medicine, Inc. chief executive officer and director John D. Quisel reported equity awards consisting of restricted stock units and stock options. On February 10, 2026, he received 55,200 shares of common stock in the form of RSUs at a grant price of $0, bringing his directly held common shares to 239,328.

On the same date, he was granted a stock option for 82,800 shares of common stock at an exercise price of $74.75 per share, expiring on February 9, 2036. The RSUs vest in four equal 25% annual installments starting February 15, 2027, while the option vests in 48 equal monthly installments beginning March 10, 2026, in each case subject to his continued service.

Disc Medicine, Inc.'s Chief Legal Officer, Rahul Khara, reported an option exercise and share sale in company stock. On January 20, 2026, he exercised a stock option for 1,000 shares of common stock at an exercise price of $13.5 per share, converting derivative securities into common shares. On the same day, he sold 1,000 shares of common stock at a price of $69.74 per share, leaving him with 37,793 shares of common stock held directly and 21,270 stock options remaining.

The filing states that these transactions were carried out under a Rule 10b5-1 trading plan adopted on September 23, 2025, which is a pre-arranged plan designed to allow insiders to trade shares according to preset instructions. The underlying option shares vest in 48 equal monthly installments following December 29, 2022, conditioned on his continued service.

Disc Medicine, Inc. director reported several small sales of the company’s common stock on 12/17/2025. The transactions involved indirect holdings through Atlas Venture-managed funds. One fund sold 393 shares, leaving 349,210 shares beneficially owned following the sale. A second fund sold 213 shares, with 337,485 shares remaining, and a third fund sold 148 shares, with 14,013 shares remaining.

The weighted average sale price reported for these trades was $91.47 per share, with individual trades executed between $91.2501 and $91.52. The director reports these positions as indirectly owned through Atlas Venture Opportunity Fund I, Atlas Venture Opportunity Fund II, and Atlas Venture Fund XII and disclaims beneficial ownership beyond any pecuniary interest.

A director of Disc Medicine, Inc. reported multiple December 2025 transactions in the company’s common stock. The filing lists several sales coded 'S' on 12/12, 12/15, and 12/16/2025 at weighted average prices including $92.05, $92.58, $93.8, $91.18, $92.01, $91.87, and $91.24 per share.

On 12/15/2025 the director exercised a fully vested stock option for 7,000 shares at an exercise price of $13.5 per share and sold those 7,000 shares the same day at a weighted average price of $91.87 per share. After the 12/16/2025 sales, the director reports indirect beneficial ownership of 349,603 Disc Medicine shares through Atlas Venture Opportunity Fund I, 337,698 shares through Atlas Venture Opportunity Fund II, and 14,161 shares through Atlas Venture Fund XII, while disclaiming beneficial ownership beyond any pecuniary interest.

Disc Medicine, Inc. reported that a company officer serving as Chief Medical Officer sold shares of common stock on 12/15/2025 in open-market transactions executed under a Rule 10b5-1 trading plan adopted on June 26, 2025.

The sales included 3,642 shares at a weighted average price of $90.6037 (with trades between $90.02 and $90.97), 9,151 shares at a weighted average price of $91.4353 (with trades between $91.03 and $91.99), and 300 shares at $92.23.

After these transactions, the reporting person directly beneficially owned 75,702 shares of Disc Medicine common stock.

Disc Medicine, Inc.’s chief executive officer and director reported a series of equity transactions on December 11, 2025. On that date, the insider exercised stock options to acquire 40,000 shares of common stock at a price of $9.86 per share, then sold 40,000 common shares in multiple market trades at weighted average prices detailed in the footnotes.

The activity was carried out under a Rule 10b5-1 trading plan adopted on February 13, 2025. After these transactions, the insider directly beneficially owned 171,828 shares of Disc Medicine common stock and held 75,375 stock options that remain beneficially owned following the reported exercise.

Disc Medicine, Inc. (IRON) reported an insider transaction by its Chief Operating Officer on 11/11/2025. The officer exercised a stock option for 30,000 shares at $2.65 and executed pre‑planned sales under a Rule 10b5‑1 trading plan adopted on July 22, 2025.

The sales occurred in four tranches: 8,015 shares at a weighted average price of $83.1453, 4,585 shares at $83.9877, 9,360 shares at $85.3301, and 8,040 shares at $85.9129. Following these transactions, the officer beneficially owned 40,555 shares directly. The option carried an exercise price of $2.65 and is shown as fully vested, with an expiration of 08/10/2030; 7,941 derivative securities remained beneficially owned after the transactions.

Disc Medicine (IRON): insider sale disclosed. AI DMI LLC, identified as a director and 10% owner, reported selling 744,047 shares of Disc Medicine common stock on October 22, 2025 at $80.47 per share. The sale was executed as part of an underwritten secondary offering.

Following this transaction, the reporting persons show beneficial ownership of 2,814,379 shares held directly. The filing notes Access Industries affiliates and Len Blavatnik may be deemed beneficial owners through control relationships, with each disclaiming beneficial ownership except to the extent of any pecuniary interest.

Disc Medicine (IRON) director reported open‑market sales of common stock on 10/15/2025–10/17/2025. Transactions were executed in multiple tranches at weighted‑average prices, including ranges from $76.75–$77.60 and up to $92.15.

Following the sales, indirect holdings reported were 442,036 shares held by Atlas Venture Opportunity Fund I, LP; 385,549 shares held by Atlas Venture Opportunity Fund II, LP; and 51,000 shares held by Atlas Venture Fund XII, L.P. The reporting person is a member of the respective general partners and disclaims beneficial ownership beyond any pecuniary interest.

Director Kevin Bitterman reported a series of open-market sales of Disc Medicine, Inc. common stock executed on 10/07/2025 and 10/08/2025. The filings show 90,000 shares sold across multiple transactions at weighted average prices ranging roughly from $68.00 to $72.62, reducing his reported indirect beneficial holdings to 500,621 shares held through affiliated Atlas Venture funds. The sales are disclosed under Section 16 and were signed by an attorney-in-fact on 10/09/2025. The report identifies the holdings as indirect via Atlas Venture entities and includes footnotes describing the fund ownership structure and weighted-average price ranges for each tranche sold.

Georges Gemayel, a director of Disc Medicine, Inc. (ticker: IRON), was granted a stock option to purchase 1,000 shares of common stock on 09/16/2025 at an exercise price of $60.34 per share. The option is exercisable subject to vesting that occurs on the earlier of the company’s 2026 annual meeting or the one-year anniversary of the grant date, and it expires on 09/15/2035. The filing reports the option as a direct holding and shows 1,000 underlying shares following the transaction.

This Form 4 was submitted by an attorney-in-fact and signed on behalf of the reporting person on 09/18/2025. No other transactions or cash sales are disclosed in the filing.