Nexalis Clears Safety Hurdles to Dose Final Cohort in Fast-Acting Anxiety Trial

By John Zadeh -

Nexalis receives green light to dose final cohort in IRX-616a anxiety trial

Nexalis Therapeutics (ASX: NX1) has received approval to advance to Cohort 3, the final dosing cohort in its Phase 1 clinical trial of IRX-616a, an inhaled cannabidiol (CBD) formulation designed for rapid treatment of acute panic and anxiety episodes. The independent Safety Review Committee (SRC) made the recommendation following successful evaluation of safety, tolerability and supporting clinical data from Cohort 2.

The randomised, double-blind, placebo-controlled trial is being conducted at CMAX Adelaide and remains on track with the last participant expected to be dosed by the end of June 2026. Progressing through dose cohorts without safety holds demonstrates the drug candidate is performing within acceptable parameters, reducing clinical risk as the company approaches data readout.

What is IRX-616a and why does rapid onset matter?

IRX-616a is an inhaled cannabidiol (CBD) formulation designed to deliver rapid treatment for acute panic and anxiety episodes. The Phase 1 trial is focused on defining the drug’s pharmacokinetics (PK), safety and tolerability profile. Phase 1 trials represent the first stage of clinical testing in humans and establish whether a new drug is safe to use before efficacy testing begins in later trial phases.

Panic disorder is characterised by recurrent, unexpected panic attacks, persistent concern about future episodes, and significant functional impairment. Panic attacks require immediate intervention, yet current oral medications can have delayed onset of action. An inhaled formulation aims to deliver CBD directly to the lungs for faster absorption into the bloodstream, addressing this delayed onset limitation.

The Total Addressable Market (TAM) for anxiety disorders and depression treatments is estimated at US$13.3 billion by 2027.

How the Phase 1 trial is structured

The trial design includes the following characteristics:

  • Randomised, double-blind, placebo-controlled study
  • Conducted in healthy volunteers
  • Three dose cohorts with independent safety review between each cohort
  • Trial site: CMAX Adelaide
  • Study will inform future clinical development in acute anxiety-related indications

Management commentary

CEO Darryl Davies

“We are very encouraged by the outcome of the latest Safety Review Committee assessment and pleased to be advancing into dosing of the final cohort of subjects in the study. Reaching Cohort 3 marks an important milestone as we continue to build clinical evidence supporting IRX-616a and our rapid-onset inhaled delivery platform.”

Nexalis pipeline and funding position

Beyond IRX-616a, Nexalis has secured a funding partner with a facility of up to $52.3 million to accelerate development across three clinical programmes. This funding reduces near-term capital raising risk and allows NX1 to advance multiple clinical programmes in parallel.

The company is developing:

  1. IRX-211 for Breakthrough Cancer Pain (BTcP)
  2. IRX-616a for Panic Disorder (PD)
  3. SRX-25 for Treatment-Resistant Depression (TRD)

Nexalis is pursuing US FDA approval via the 505(b)(2) regulatory pathway, which provides a more rapid and cost-effective route to market for drugs with established active ingredients.

Key milestones and timeline

Milestone Status Expected Timing
Cohort 1 dosing Complete
Cohort 2 SRC review Complete
Cohort 3 (final) dosing Underway Q4 FY26
Last participant dosed Pending End June 2026

NX1 has stated it will announce further updates from the trial as material milestones are achieved. Data readout from the completed Phase 1 trial will inform the design and regulatory pathway for future clinical development in acute anxiety-related indications.

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Frequently Asked Questions

What is the Nexalis IRX-616a Phase 1 Trial testing?

The Nexalis IRX-616a Phase 1 Trial is testing an inhaled cannabidiol (CBD) formulation designed for rapid treatment of acute panic and anxiety episodes, with the Phase 1 study focused on defining the drug's safety, tolerability, and pharmacokinetic profile in healthy volunteers.

What does advancing to Cohort 3 mean for NX1 investors?

Advancing to Cohort 3 means the independent Safety Review Committee has cleared IRX-616a at the previous dose level without safety holds, reducing clinical risk and bringing Nexalis one step closer to a full Phase 1 data readout that will inform future efficacy trials.

When will the Nexalis IRX-616a Phase 1 Trial be completed?

Nexalis expects the last participant in the Phase 1 trial to be dosed by the end of June 2026, with the trial site being CMAX Adelaide.

What is the 505(b)(2) regulatory pathway that Nexalis is using?

The 505(b)(2) pathway is a US FDA approval route that allows companies to rely partly on existing safety and efficacy data for drugs with established active ingredients, providing a faster and more cost-effective path to market compared to a full new drug application.

How large is the market opportunity for IRX-616a?

The Total Addressable Market for anxiety disorders and depression treatments is estimated at US$13.3 billion by 2027, providing a substantial commercial opportunity if IRX-616a successfully progresses through clinical development and gains regulatory approval.

John Zadeh
By John Zadeh
Founder & CEO
John Zadeh is a investor and media entrepreneur with over a decade in financial markets. As Founder and CEO of StockWire X and Discovery Alert, Australia's largest mining news site, he's built an independent financial publishing group serving investors across the globe.
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