Pulmatrix, Inc. filed a Form 425 on November 9, 2026, disclosing that merger partner Eos SENOLYTIX, Inc. will present pre-clinical data on its lead compound PTC-2105 at the 19th Sarcopenia, Cachexia and Wasting Disorders International Conference on December 11, 2026, in Washington, D.C.

Key Highlights

  • Upgraded presentation: Eos SENOLYTIX's submission was upgraded from a poster to a plenary presentation in the Rapid Fire Abstract Session on December 11, 2026, at 9:35 am ET.
  • PTC-2105 monotherapy lean-mass finding: In aged, high-fat-fed mice, PTC-2105 monotherapy reversed terminal lean-mass trajectory from decline to net gain (+0.005 g/wk versus -0.002 g/wk for saline), according to the filing.
  • Semaglutide comparison: The filing states semaglutide alone produced the steepest terminal lean-mass decline (-0.055 g/wk) and was associated with shorter survival (p=0.038), while PTC-2105 monotherapy avoided this decline (+0.009 g/wk).
  • Co-administration result: Co-administration of PTC-2105 with semaglutide at 10 and 25 mg/kg (once weekly) reduced late-life lean-mass loss relative to semaglutide alone (+0.126 and -0.011 g/wk versus -0.055 g/wk), according to the filing.
  • Merger status: The proposed merger between Pulmatrix (NASDAQ:PULM) and Eos SENOLYTIX is anticipated to close in the fourth quarter of 2026, subject to Nasdaq listing approval and customary closing conditions.
  • Stockholder approval obtained: Pulmatrix stockholders approved all merger-related proposals at a special meeting held on October 26, 2026, the filing disclosed.
  • Post-merger ticker: If the merger is completed, the combined company's common stock is expected to trade on Nasdaq under the ticker symbol "MTXL," pending Nasdaq listing approval.

Eos SENOLYTIX Pre-Clinical PTC-2105 Findings and Merger Progress Disclosed

According to the Form 425 filed by Pulmatrix, Inc. on November 9, 2026, Eos SENOLYTIX plans to present pre-clinical study data on PTC-2105, its lead MitoXcel geropeptide candidate, at the 19th Sarcopenia, Cachexia and Wasting Disorders International Conference in Washington, D.C. The presentation, originally scheduled as a poster, was upgraded to a plenary in the Rapid Fire Abstract Session. Kevin Slawin, MD, Founder and CEO of Eos SENOLYTIX, is listed as the plenary presenter, with Daniel Jasinski, Ph.D., Vice President of Research, serving as poster presenter at a concurrent session.

The filing reports three key data points from pre-clinical studies in aged mice. First, PTC-2105 monotherapy reversed the terminal lean-mass trajectory in aged, high-fat-fed mice from decline to net gain. Second, in a separate high-fat cohort, semaglutide alone was associated with the steepest lean-mass decline and shorter survival (p=0.038), while PTC-2105 monotherapy avoided that decline. Third, co-administration of PTC-2105 with semaglutide at two dose levels produced improvements relative to semaglutide alone. The filing explicitly states: "All data described in this release come from preclinical studies in mice. PTC-2105 is an investigational compound that has not been tested for lifespan in humans and has not been approved by the U.S. Food and Drug Administration or any other regulatory authority for any indication. Results in mice may not translate to humans."

The filing also provides an update on the pending merger between Pulmatrix and Eos SENOLYTIX. Pulmatrix's stockholders approved the merger proposals at a special meeting on October 26, 2026. The registration statement on Form S-4 (File No. 333-297342) was declared effective by the SEC on September 25, 2026. Merger-associated financings are described as expected to support advancement of the combined company's pipeline through key clinical milestones. The communication contains forward-looking statements, which the filing notes are subject to its cautionary language.

What Was Disclosed

Pulmatrix filed a Form 425 disclosing Eos SENOLYTIX's upcoming December 11, 2026, conference presentation of pre-clinical PTC-2105 data, including lean-mass and survival findings in aged mice, and providing a merger status update including stockholder approval obtained on October 26, 2026.