Pulmatrix Announces Termination of Prior Planned Merger and Continues Pursuit of Alternative Merger Opportunities
Rhea-AI Summary
Pulmatrix (Nasdaq: PULM) announced that on February 28, 2026 Cullgen notified Pulmatrix it was terminating the previously agreed Merger Agreement, which remained subject to China Securities Regulatory Commission approval. Pulmatrix said it is pursuing alternative merger opportunities while continuing development of its inhaled clinical assets and iSPERSE™ technology.
The company highlighted IND acceptance for PUR3100, Phase 1 data, ongoing PUR1800 development, and a Phase 3 pathway for PUR1900 with partner Cipla.
Positive
- Cullgen terminated Merger Agreement on Feb 28, 2026
- IND acceptance for PUR3100 Phase 2 study
- Cipla received approval to proceed to Phase 3 in India
- Patent portfolio: ~149 granted, 48 pending applications
Negative
- Merger closing condition unmet: no CSRC approval
- Termination may delay expected transaction-driven financing or strategic plans
News Market Reaction – PULM
On the day this news was published, PULM declined 36.79%, reflecting a significant negative market reaction. Argus tracked a trough of -32.2% from its starting point during tracking. Our momentum scanner triggered 25 alerts that day, indicating elevated trading interest and price volatility. This price movement removed approximately $6M from the company's valuation, bringing the market cap to $11M at that time. Trading volume was exceptionally heavy at 19.4x the daily average, suggesting significant selling pressure.
Data tracked by StockTitan Argus on the day of publication.
Key Figures
Market Reality Check
Peers on Argus
PULM is up 2.75% while key biotech peers like EVAX (-2.17%), LSTA (-7.24%), and MTVA (-2.58%) are down, indicating a stock-specific reaction to the merger termination news.
Previous Acquisition Reports
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Dec 18 | Merger waiver / alternatives | Positive | -8.2% | Cullgen and Pulmatrix waived No Solicitation to explore alternative deals. |
| Nov 13 | Cullgen merger announced | Positive | +73.7% | Announced Cullgen merger creating Nasdaq-listed degrader-focused company. |
Acquisition/merger headlines have produced mixed reactions: a strong gain on the initial Cullgen merger announcement and a notable decline when both parties opened the door to alternatives.
Over the past 18 months, Pulmatrix’s major strategic narrative has centered on its proposed merger with Cullgen. The initial merger announcement on Nov 13, 2024 led to a 73.66% gain, while the Dec 18, 2025 waiver to explore alternatives coincided with an -8.15% move. Today’s termination of that merger and continued pursuit of alternative transactions fits within this ongoing effort to reposition the company and monetize its iSPERSE™ platform and clinical assets.
Historical Comparison
Past acquisition headlines for PULM produced an average move of 32.75%, ranging from a sharp gain on the initial Cullgen deal to a notable drop when alternatives were opened.
Same-tag history shows a progression from announcing the Cullgen merger to waiving No Solicitation to pursue alternatives, culminating in Cullgen’s termination and Pulmatrix seeking new merger partners.
Market Pulse Summary
The stock dropped -36.8% in the session following this news. A negative reaction despite the company’s continued pursuit of strategic alternatives would fit past patterns where merger-related uncertainty weighed on PULM, such as the -8.15% move after the No Solicitation waiver. The end of the Cullgen deal leaves value in the iSPERSE™ portfolio and programs like PUR3100 and PUR1900 dependent on finding new partners or structures, which could keep downside risk elevated if alternatives disappoint.
Key Terms
china securities regulatory commission regulatory
form s-4 regulatory
investigational new drug regulatory
narrow spectrum kinase inhibitor medical
idiopathic pulmonary fibrosis medical
central drug standard control organization regulatory
royalties financial
AI-generated analysis. Not financial advice.
Cullgen had been seeking approval for a merger with Pulmatrix from the China Securities Regulatory Commission and on February 28, 2026, notified Pulmatrix that Cullgen was terminating the Merger Agreement
- Pulmatrix advances existing discussions on alternative merger opportunities -
Peter Ludlum, Interim Chief Executive Officer of Pulmatrix, commented, "Due to the significant delays at the Chinese Regulatory Authority (CSRC) in 2025, we initiated a process earlier this year to identify an alternative reverse merger opportunity for the Company, and we are encouraged by both the interest we've had to date as well as the recent increase in transaction activity within our industry."
Prior Proposed Merger with Cullgen
As previously reported, on November 13, 2024, the Company entered into an agreement and plan of merger with Cullgen, as amended by Amendment No. 1 thereto on April 7, 2025 (the "Merger Agreement" and the transactions contemplated thereunder, collectively, the "Merger").
Additional information about the Merger Agreement and the previously proposed Merger was previously disclosed in a registration statement on Form S-4 (File No. 333-284993) initially filed with the Securities and Exchange Commission (the "SEC") on February 14, 2025, as amended on April 17, 2025, and May 7, 2025, and declared effective on May 9, 2025.
On June 16, 2025, the Company held a special meeting in lieu of the annual meeting of Pulmatrix stockholders, at which meeting the Company's stockholders approved the Merger and related proposals. The closing of the Merger was subject to certain closing conditions, including approval from the China Security Regulatory Commission which had not been obtained at the time of Cullgen's termination.
Pulmatrix Clinical Assets and Proprietary iSPERSE™ Technology
iSPERSE™ Technology
- iSPERSE™, also licensed to MannKind Corporation and Cipla Technologies for certain fields of use, utilizes particles that are engineered with a small, dense and dispersible profile to exceed the performance of traditional dry powder particles as the iSPERSE™ particles have the dispersibility advantages of porous engineered particles. Pulmatrix believes this results in superior drug delivery compared to traditional oral and injectable forms of treatment for certain diseases.
- As of December 31, 2025, Pulmatrix's patent portfolio related to iSPERSE™ included approximately 149 granted patents, 18 of which are
U.S. -granted patents, plus approximately 48 pending patent applications in theU.S. and other jurisdictions.
PUR3100
- PUR3100, a Phase 2-ready asset, is an orally inhaled dihydroergotamine ("DHE") engineered with Pulmatrix's iSPERSE™ dry powder inhalation technology for the treatment of acute migraine has a Food and Drug Administration acceptance of an Investigational New Drug ("IND") application for PUR3100 and receipt of a "study may proceed" letter to proceed with a Phase 2 study. The IND includes a Phase 2 clinical protocol where safety and preliminary efficacy of PUR3100 will be investigated in patients with acute migraine.
- The Phase 2 IND builds on the Phase 1 trial results of PUR3100, which were published in 2024 in the peer-reviewed publication, Headache: The Journal of Head and Face Pain. The study showed that PUR3100 achieved peak exposures in the targeted therapeutic range and time to maximum concentration occurred at five minutes after dosing at all dosing levels. The PUR3100 dose groups also showed a lower incidence of nausea and no vomiting compared to observations of nausea and vomiting in the intravenously ("IV") administered DHE dose group.
PUR1800
- PUR1800 is a Narrow Spectrum Kinase Inhibitor ("NSKI"), engineered with our iSPERSE™ technology, for the treatment of acute exacerbations in chronic obstructive pulmonary disease ("AECOPD"). In 2023, Pulmatrix presented complete results from a Phase 1b study of PUR1800 for AECOPD, indicating PUR1800 was well-tolerated with no observed safety signals. The topline data, along with the results from chronic toxicology studies, support the continued development of PUR1800 for the treatment of AECOPD and other inflammatory respiratory diseases.
- In 2024, Pulmatrix published an abstract titled "Ex vivo evaluation of the potential for Narrow Spectrum Kinase inhibitors as a treatment for Idiopathic Pulmonary Fibrosis".
PUR1900
- PUR1900, approved to proceed to a Phase 3 in
India conducted by our partner Cipla, is the Company's inhaled iSPERSE™ formulation of the antifungal drug itraconazole being investigated for various indications. The Company and its partner, Cipla, wound down a Phase 2b trial that the Company was operating in 2024. Cipla has continued clinical development outsidethe United States , and in 2025 completed their Phase 2 study inIndia and have been approved byIndia's Central Drug Standard Control Organization to proceed with a Phase 3 clinical trial. - Pulmatrix will receive
2% royalties on any potential future net sales by Cipla outsidethe United States should Cipla successfully market PUR1900 outsidethe United States . Withinthe United States , the Company and Cipla share the rights 50/50 and will seek to monetize PUR1900 for indications where an orally inhaled antifungal may provide a therapeutic benefit or fulfill an unmet medical need.
About Pulmatrix, Inc.
Pulmatrix is a biopharmaceutical company that has focused on the development of 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 product pipeline includes treatments for central nervous system ("CNS") disorders such as acute migraine and serious lung diseases such as Chronic Obstructive Pulmonary Disease ("COPD") and allergic bronchopulmonary aspergillosis ("ABPA"). Pulmatrix's product candidates are based on its proprietary engineered dry powder delivery platform, iSPERSE™, which seeks to improve therapeutic delivery to the lungs by optimizing pharmacokinetics and reducing systemic side effects to improve patient outcomes.
For more on the Company's inhaled product candidates please visit:
https://www.pulmatrix.com/pipeline.html.
Forward-Looking Statements
Certain statements in this press release that are forward-looking and not statements of historical fact are forward-looking statements within the meaning of the federal securities laws. Such forward-looking statements include, but are not limited to, statements of historical fact and may be identified by words such as "anticipates," "assumes," "believes," "can," "could," "estimates," "expects," "forecasts," "guides," "intends," "is confident that," "may," "plans," "seeks," "projects," "targets," and "would," and their opposites and similar expressions are intended to identify forward-looking statements. Such forward-looking statements are based on the beliefs of management as well as assumptions made by and information currently available to management. Actual results could differ materially from those contemplated by the forward-looking statements as a result of certain factors, including, but not limited to, the consummation of any other potential reverse merger transaction in the future, among others; the Company's ability to divest its clinical assets on terms favorable to the Company, or at all, the Company's ability to maintain compliance with the listing standards of the Nasdaq Capital Market; the Company's ability to conduct its business and raise capital in the future when needed; delays in planned clinical trials; the ability to establish that potential products are efficacious or safe in preclinical or clinical trials; the ability to establish or maintain collaborations on the development of therapeutic candidates; the ability to obtain appropriate or necessary governmental approvals to market potential products; the ability to obtain future funding for developmental products and working capital and to obtain such funding on commercially reasonable terms; the Company's ability to manufacture product candidates on a commercial scale or in collaborations with third parties; changes in the size and nature of competitors; the ability to retain key executives and scientists; the ability to secure and enforce legal rights related to the Company's products, including patent protection. A discussion of these and other factors, including risks and uncertainties with respect to the Company, including the proposed Merger with Cullgen, is set forth in the Company's filings with the Securities and Exchange Commission, including its most recent Annual Report on Form 10-K, as may be supplemented or amended by the Company's Quarterly Reports on Form 10-Q and Current Reports on Form 8-K. The Company disclaims any intention or obligation to revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.
Investor Contact:
Chuck Padala
Managing Director
LifeSci Advisors
646-627-8390
chuck@lifesciadvisors.com
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SOURCE Pulmatrix Inc.
FAQ
Why did Cullgen terminate the merger with Pulmatrix (PULM) on Feb 28, 2026?
What is Pulmatrix's next step after the Cullgen merger termination for PULM shareholders?
What is the development status of PUR3100 mentioned by Pulmatrix (PULM)?
How does Pulmatrix's iSPERSE™ intellectual property support PULM's pipeline?
What is the status of PUR1900 development with partner Cipla for PULM?
Did Pulmatrix stockholders approve the Cullgen merger (PULM) before termination?
