Organization	3 Months Ended
Mar. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	1. Organization Pulmatrix, Inc. (“Pulmatrix” or the “Company”) was incorporated in 2013 as a Delaware corporation. The Company is a biopharmaceutical company that has focused on the development of a novel inhaled therapeutic products intended to prevent and treat migraine and respiratory diseases with important unmet medical needs using its patented iSPERSE™ technology. The Company’s proprietary dry powder delivery platform, iSPERSE™, is engineered to deliver small, dense particles with highly efficient dispersibility and delivery to the airways, which can be used with an array of dry powder inhaler technologies and can be formulated with a variety of drug substances. Agreement and Plan of Merger and Reorganization On November 13, 2024, Pulmatrix and Cullgen Inc., a Delaware corporation (“Cullgen”) entered into an Agreement and Plan of Merger and Reorganization, as amended by Amendment No. 1 thereto on April 7, 2025 (the “Merger Agreement”), pursuant to which, among other matters, PCL Merger Sub, Inc., a direct wholly owned subsidiary of Pulmatrix (“Merger Sub”), will merge with and into Cullgen, with Cullgen surviving as a wholly owned subsidiary of Pulmatrix, and the surviving corporation of the merger (the “Merger”). Pursuant to the Merger Agreement, prior to the closing of the Merger (the “Closing”), Pulmatrix may declare a cash dividend to the pre-Merger Pulmatrix stockholders equal in the aggregate to Pulmatrix’s reasonable, good faith approximation of the amount by which Pulmatrix’s net cash (as determined pursuant to the Merger Agreement) will exceed $2.5 million, subject to certain adjustments and limitations (such excess amount, the “Cash Dividend”). Subject to the terms and conditions of the Merger Agreement, at the Closing, (a) each then-outstanding share of Cullgen common stock other than dissenting shares, will be converted into the right to receive a number of shares of Pulmatrix common stock calculated in accordance with the Merger Agreement (the “Exchange Ratio”), (b) each then-outstanding share of Cullgen preferred stock, other than dissenting shares, will be converted into the right to receive a number of shares of Pulmatrix common stock equal to the number of shares of Cullgen common stock issuable upon conversion of each share of Cullgen preferred stock multiplied by the Exchange Ratio and (c) each then-outstanding option to purchase Cullgen common stock, whether vested or unvested, will be assumed by Pulmatrix, subject to adjustment to reflect the Exchange Ratio as set forth in the Merger Agreement. In connection with the Merger: (i) each share of Pulmatrix common stock that is issued and outstanding at the Effective Time (as defined below) of the Merger will remain issued and outstanding and such shares, subject to the proposed Pulmatrix reverse stock split, will be unaffected by the Merger; (ii) each option to acquire shares of Pulmatrix common stock outstanding but then not vested or exercisable shall be accelerated in full; (iii) each option to acquire shares of Pulmatrix common stock with an exercise price per share greater than $10.00 per share shall be cancelled for no consideration; (iv) each option to acquire shares of Pulmatrix common stock with an exercise price less than or equal to the Pulmatrix Closing Price (as defined herein) will be converted into the right to receive the number of shares underlying such Pulmatrix option, reduced as set forth in the Merger Agreement; (v) each option to acquire shares of Pulmatrix common stock with an exercise price greater than the volume weighted average closing trading price of a share of Parent Common Stock on Nasdaq for the five (5) consecutive trading days ending three (3) trading days immediately prior to the Closing Date as reported by Bloomberg L.P. (the “Pulmatrix Closing Price”), but less than $10.00 per share, will remain outstanding; and (vi) each warrant to acquire shares of Pulmatrix common stock that is outstanding and unexercised immediately prior to the Effective Time of the Merger shall survive the Closing and remain outstanding in accordance with its terms; provided that the holders of any such warrants which remain outstanding following closing may elect to require Pulmatrix to pay such holders cash in exchange for the termination of the remaining unexercised portion of such warrants if contemplated by the terms of such warrants. Under the Exchange Ratio formula in the Merger Agreement, upon the Closing, on a pro forma basis and based upon the number of shares of Pulmatrix common stock expected to be issued in the Merger, pre-Merger Cullgen stockholders will own approximately 96.4% of the combined company and pre-Merger Pulmatrix stockholders will own approximately 3.6% of the combined company on a fully-diluted basis (excluding out-of-the-money options and warrants and any shares reserved for future grants under Pulmatrix’s equity incentive plans). Under certain circumstances further described in the Merger Agreement, the ownership percentages may be adjusted upward or downward based on Pulmatrix’s net cash at the Closing. The Exchange Ratio assumes (i) a valuation for Pulmatrix of $10.5 million (comprised of $8 million in enterprise value and $2.5 million in cash) and (ii) a valuation for Cullgen of $280.0 million. The Exchange Ratio is also based on the relative capitalization of each of Pulmatrix and Cullgen, for which, for the purposes of calculating the Exchange Ratio, the shares of Pulmatrix common stock underlying Pulmatrix’s in-the-money stock options outstanding immediately prior to the time of the Closing (the “Effective Time”), as adjusted to take into account the Cash Dividend will be deemed outstanding, and all shares of Cullgen common stock underlying outstanding Cullgen’s stock options will be deemed outstanding, subject to certain exceptions as set forth in the Merger Agreement. The closing of the Merger is subject to approval by Pulmatrix stockholders and Cullgen stockholders, as well as other customary closing conditions, including the effectiveness of a registration statement filed with the SEC (defined below) in connection with the transaction, Nasdaq’s approval of the listing of the shares of Pulmatrix common stock to be issued in connection with the Merger, and approval from the China Security Regulatory Commission. If the Merger is completed, the business of Cullgen will continue as the business of the combined company. The Merger Agreement contains certain termination rights of each of Pulmatrix and Cullgen. Upon termination of the Merger Agreement under specified circumstances, Pulmatrix may be required to pay Cullgen a termination fee of $420,000, and in certain other circumstances, Cullgen may be required to pay Pulmatrix a termination fee of either $2,800,000 or $8,400,000. At the Effective Time, the board of directors of Pulmatrix is expected to consist of six members, one of which will be a director of Pulmatrix, as designated by Cullgen, and the remainder of which will be designated by Cullgen. Concurrent with the Merger, the Company will seek to monetize its intellectual property, including iSPERSE™ and its clinical assets (the “Asset Sale”). If Pulmatrix is unable to sell its historical assets and operations, Pulmatrix may not have enough net cash to be able to declare the Cash Dividend. The Company’s future operations are highly dependent on the success of the Merger and there can be no assurances that the Merger will be successfully consummated. There can be no assurance that the strategic review process or any transaction relating to a specific asset, including the Merger and any Asset Sale, will result in the Company pursuing such a transaction, or that any transactions, if pursued, will be completed on terms favorable to Pulmatrix and its stockholders in the existing Pulmatrix entity or any possible entity that results from a combination of entities. If the strategic review process is unsuccessful, and if the Merger is not consummated, the Company’s board of directors may decide to pursue a dissolution and liquidation.

Organization

3 Months Ended

Mar. 31, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

1. Organization

Pulmatrix, Inc. (“Pulmatrix” or the “Company”) was incorporated in 2013 as a Delaware corporation. The Company is a biopharmaceutical company that has focused on the development of a novel inhaled therapeutic products intended to prevent and treat migraine and respiratory diseases with important unmet medical needs using its patented iSPERSE™ technology. The Company’s proprietary dry powder delivery platform, iSPERSE™, is engineered to deliver small, dense particles with highly efficient dispersibility and delivery to the airways, which can be used with an array of dry powder inhaler technologies and can be formulated with a variety of drug substances.

Agreement and Plan of Merger and Reorganization

On November 13, 2024, Pulmatrix and Cullgen Inc., a Delaware corporation (“Cullgen”) entered into an Agreement and Plan of Merger and Reorganization, as amended by Amendment No. 1 thereto on April 7, 2025 (the “Merger Agreement”), pursuant to which, among other matters, PCL Merger Sub, Inc., a direct wholly owned subsidiary of Pulmatrix (“Merger Sub”), will merge with and into Cullgen, with Cullgen surviving as a wholly owned subsidiary of Pulmatrix, and the surviving corporation of the merger (the “Merger”).

Pursuant to the Merger Agreement, prior to the closing of the Merger (the “Closing”), Pulmatrix may declare a cash dividend to the pre-Merger Pulmatrix stockholders equal in the aggregate to Pulmatrix’s reasonable, good faith approximation of the amount by which Pulmatrix’s net cash (as determined pursuant to the Merger Agreement) will exceed $2.5 million, subject to certain adjustments and limitations (such excess amount, the “Cash Dividend”).

Subject to the terms and conditions of the Merger Agreement, at the Closing, (a) each then-outstanding share of Cullgen common stock other than dissenting shares, will be converted into the right to receive a number of shares of Pulmatrix common stock calculated in accordance with the Merger Agreement (the “Exchange Ratio”), (b) each then-outstanding share of Cullgen preferred stock, other than dissenting shares, will be converted into the right to receive a number of shares of Pulmatrix common stock equal to the number of shares of Cullgen common stock issuable upon conversion of each share of Cullgen preferred stock multiplied by the Exchange Ratio and (c) each then-outstanding option to purchase Cullgen common stock, whether vested or unvested, will be assumed by Pulmatrix, subject to adjustment to reflect the Exchange Ratio as set forth in the Merger Agreement.

In connection with the Merger: (i) each share of Pulmatrix common stock that is issued and outstanding at the Effective Time (as defined below) of the Merger will remain issued and outstanding and such shares, subject to the proposed Pulmatrix reverse stock split, will be unaffected by the Merger; (ii) each option to acquire shares of Pulmatrix common stock outstanding but then not vested or exercisable shall be accelerated in full; (iii) each option to acquire shares of Pulmatrix common stock with an exercise price per share greater than $10.00 per share shall be cancelled for no consideration; (iv) each option to acquire shares of Pulmatrix common stock with an exercise price less than or equal to the Pulmatrix Closing Price (as defined herein) will be converted into the right to receive the number of shares underlying such Pulmatrix option, reduced as set forth in the Merger Agreement; (v) each option to acquire shares of Pulmatrix common stock with an exercise price greater than the volume weighted average closing trading price of a share of Parent Common Stock on Nasdaq for the five (5) consecutive trading days ending three (3) trading days immediately prior to the Closing Date as reported by Bloomberg L.P. (the “Pulmatrix Closing Price”), but less than $10.00 per share, will remain outstanding; and (vi) each warrant to acquire shares of Pulmatrix common stock that is outstanding and unexercised immediately prior to the Effective Time of the Merger shall survive the Closing and remain outstanding in accordance with its terms; provided that the holders of any such warrants which remain outstanding following closing may elect to require Pulmatrix to pay such holders cash in exchange for the termination of the remaining unexercised portion of such warrants if contemplated by the terms of such warrants.

Under the Exchange Ratio formula in the Merger Agreement, upon the Closing, on a pro forma basis and based upon the number of shares of Pulmatrix common stock expected to be issued in the Merger, pre-Merger Cullgen stockholders will own approximately 96.4% of the combined company and pre-Merger Pulmatrix stockholders will own approximately 3.6% of the combined company on a fully-diluted basis (excluding out-of-the-money options and warrants and any shares reserved for future grants under Pulmatrix’s equity incentive plans). Under certain circumstances further described in the Merger Agreement, the ownership percentages may be adjusted upward or downward based on Pulmatrix’s net cash at the Closing.

The Exchange Ratio assumes (i) a valuation for Pulmatrix of $10.5 million (comprised of $8 million in enterprise value and $2.5 million in cash) and (ii) a valuation for Cullgen of $280.0 million. The Exchange Ratio is also based on the relative capitalization of each of Pulmatrix and Cullgen, for which, for the purposes of calculating the Exchange Ratio, the shares of Pulmatrix common stock underlying Pulmatrix’s in-the-money stock options outstanding immediately prior to the time of the Closing (the “Effective Time”), as adjusted to take into account the Cash Dividend will be deemed outstanding, and all shares of Cullgen common stock underlying outstanding Cullgen’s stock options will be deemed outstanding, subject to certain exceptions as set forth in the Merger Agreement.

The closing of the Merger is subject to approval by Pulmatrix stockholders and Cullgen stockholders, as well as other customary closing conditions, including the effectiveness of a registration statement filed with the SEC (defined below) in connection with the transaction, Nasdaq’s approval of the listing of the shares of Pulmatrix common stock to be issued in connection with the Merger, and approval from the China Security Regulatory Commission. If the Merger is completed, the business of Cullgen will continue as the business of the combined company.

The Merger Agreement contains certain termination rights of each of Pulmatrix and Cullgen. Upon termination of the Merger Agreement under specified circumstances, Pulmatrix may be required to pay Cullgen a termination fee of $420,000, and in certain other circumstances, Cullgen may be required to pay Pulmatrix a termination fee of either $2,800,000 or $8,400,000. At the Effective Time, the board of directors of Pulmatrix is expected to consist of six members, one of which will be a director of Pulmatrix, as designated by Cullgen, and the remainder of which will be designated by Cullgen.

Concurrent with the Merger, the Company will seek to monetize its intellectual property, including iSPERSE™ and its clinical assets (the “Asset Sale”). If Pulmatrix is unable to sell its historical assets and operations, Pulmatrix may not have enough net cash to be able to declare the Cash Dividend.

The Company’s future operations are highly dependent on the success of the Merger and there can be no assurances that the Merger will be successfully consummated. There can be no assurance that the strategic review process or any transaction relating to a specific asset, including the Merger and any Asset Sale, will result in the Company pursuing such a transaction, or that any transactions, if pursued, will be completed on terms favorable to Pulmatrix and its stockholders in the existing Pulmatrix entity or any possible entity that results from a combination of entities. If the strategic review process is unsuccessful, and if the Merger is not consummated, the Company’s board of directors may decide to pursue a dissolution and liquidation.