Pulmatrix and Cullgen Mutually Waive No-Solicitation Clause While Awaiting Chinese Regulatory Approval for Merger
核心洞察
Pulmatrix and Cullgen (搜索) have mutually agreed to waive the "No Solicitation" clause in their November 2024 merger agreement to explore alternative transactions while continuing to seek approval from China's Securities Regulatory Commission.
The merger has already received approval from Pulmatrix stockholders in June 2025 and SEC effectiveness for the Form S-4 filing in May 2025, but still awaits final regulatory clearance from Chinese authorities.
Pulmatrix maintains a robust pipeline of inhaled therapeutics using its proprietary iSPERSE technology, including PUR3100 for acute migraine treatment which is Phase 2-ready with FDA approval.
Pulmatrix Inc. and Cullgen (搜索) Inc. announced on December 18, 2025, that they have mutually agreed to waive the "No Solicitation" clause in their merger agreement to permit each party to explore alternative transactions while continuing to work toward regulatory approval from the China Securities Regulatory Commission (CSRC).
The decision comes as the companies await final approval for their merger, which was initially agreed upon in November 2024. Peter Ludlum, Interim Chief Executive Officer of Pulmatrix, stated that while their Form S-4 filing was declared effective in May 2025 and stockholders approved the merger in June 2025, CSRC approval remains pending.
Merger Timeline and Current Status
The merger agreement was signed on November 13, 2024, and subsequently amended on April 7, 2025. Pulmatrix stockholders approved the merger and related proposals at a special meeting held on June 16, 2025. The closing of the merger remains subject to certain conditions, including Nasdaq's approval for listing shares and the crucial CSRC approval.
If completed, Cullgen (搜索)'s business will continue as the business of the combined company. The waiver allows both companies to explore opportunistic transactions that may benefit their respective operations while maintaining their commitment to the original merger plan.
Financial Position and Operational Outlook
Pulmatrix reported total cash and cash equivalents of $4.8 million as of September 30, 2025. The company anticipates this cash position, combined with current operational efficiencies and prioritized spending, will be sufficient to fund operations into at least the fourth quarter of 2026.
Clinical Pipeline and iSPERSE Technology Platform
Pulmatrix's proprietary iSPERSE technology represents a significant advancement in dry powder inhalation delivery. The engineered particles feature a small, dense and dispersible profile designed to exceed the performance of traditional dry powder particles while maintaining the dispersibility advantages of porous engineered particles. This technology aims to provide superior drug delivery compared to traditional oral and injectable forms of treatment for certain diseases.
The company's patent portfolio related to iSPERSE technology includes approximately 146 granted patents as of September 30, 2025, with 18 U.S.-granted patents, plus approximately 50 pending patent applications in the U.S. and other jurisdictions.
PUR3100: Phase 2-Ready Migraine Treatment
PUR3100, an orally inhaled dihydroergotamine (DHE) engineered with the iSPERSE technology, represents Pulmatrix's most advanced clinical asset for acute migraine treatment. The FDA has accepted the Investigational New Drug (IND) application for PUR3100 and issued a "study may proceed" letter for a Phase 2 study investigating safety and preliminary efficacy in patients with acute migraine.
Phase 1 trial results, published in 2024 in Headache: The Journal of Head and Face Pain, demonstrated that PUR3100 achieved peak exposures in the targeted therapeutic range with time to maximum concentration occurring at five minutes after dosing at all dosing levels. Notably, the PUR3100 dose groups showed a lower incidence of nausea and no vomiting compared to observations in the intravenously administered DHE dose group.
PUR1800: Respiratory Disease Treatment
PUR1800 is a Narrow Spectrum Kinase Inhibitor (NSKI) engineered with iSPERSE technology for treating acute exacerbations in chronic obstructive pulmonary disease (AECOPD). Complete results from a Phase 1b study presented in 2023 indicated PUR1800 was well-tolerated with no observed safety signals. The topline data, combined with chronic toxicology study results, support continued development for AECOPD and other inflammatory respiratory diseases.
In 2024, Pulmatrix published research exploring the potential application of Narrow Spectrum Kinase inhibitors for Idiopathic Pulmonary Fibrosis treatment.
PUR1900: Antifungal Development Partnership
PUR1900, an inhaled iSPERSE formulation of the antifungal drug itraconazole, is being developed through a partnership with Cipla. While Pulmatrix wound down a Phase 2b trial in 2024, Cipla continued clinical development outside the United States. In 2025, Cipla completed their Phase 2 study in India and received approval from India's Central Drug Standard Control Organization to proceed with a Phase 3 clinical trial.
Under the partnership agreement, Pulmatrix will receive 2% royalties on potential future net sales by Cipla outside the United States. Within the United States, both companies will seek to monetize PUR1900 for indications where an orally inhaled antifungal may provide therapeutic benefit or fulfill unmet medical needs.
Strategic Focus on Unmet Medical Needs
Pulmatrix positions itself as a biopharmaceutical company focused on developing novel inhaled therapeutic products for migraine prevention and treatment, as well as respiratory diseases with important unmet medical needs. The company's product pipeline addresses central nervous system disorders such as acute migraine and serious lung diseases including chronic obstructive pulmonary disease and allergic bronchopulmonary aspergillosis.
The iSPERSE platform seeks to improve therapeutic delivery to the lungs by optimizing pharmacokinetics and reducing systemic side effects to improve patient outcomes, representing a potentially significant advancement in inhalation therapy delivery systems.