Tonix Pharmaceuticals Holding Corp. 8-K

What Happened
Tonix Pharmaceuticals Holding Corp. (TNXP) filed an 8-K on June 29, 2026, announcing that the first participant has been enrolled in HORIZON, a potentially pivotal Phase 2 study evaluating TNX-102 SL 5.6 mg as a first-line monotherapy in adults with major depressive disorder (MDD). The company attached a press release about the enrollment as Exhibit 99.01 to the filing.

Key Details

• Filing date: June 29, 2026 (Form 8-K).
• Study: HORIZON — potentially pivotal Phase 2 trial.
• Product candidate: TNX-102 SL, dose 5.6 mg, being tested as a first-line monotherapy.
• Milestone: First participant enrolled (company announcement / press release filed as Exhibit 99.01).

Why It Matters
Enrollment of the first participant is an early but concrete clinical development milestone that starts the patient recruitment phase of a trial the company describes as potentially pivotal. For investors, this confirms TNXP is advancing its TNX-102 SL program in major depressive disorder on the timeline communicated by management; subsequent enrollment progress, safety updates, and trial readouts will be the key events to watch. The 8-K does not disclose financial results or timelines for data readout.