Nexalis Therapeutics Completes Phase 1 Panic Drug Trial With Zero Safety Events

By Josua Ferreira -

Nexalis Therapeutics completes dosing in Phase 1 IRX-616a panic disorder trial

Nexalis Therapeutics (ASX: NX1) has completed dosing of all patients in its Phase 1 clinical trial of IRX-616a, its inhaled cannabidiol (CBD) formulation targeting acute panic and anxiety episodes. The Last Patient Last Dose (LPLD) milestone marks the conclusion of the dosing phase of the first-in-human study, a randomised, double-blind, placebo-controlled trial conducted at CMAX Adelaide across three sequential dose cohorts in healthy volunteers.

Critically, zero Serious Adverse Events (SAEs) were reported across the entire study. The company has now initiated Phase 2 planning and regulatory preparation activities, signalling forward momentum with no gap between phases.

CEO Darryl Davies

“Completing dosing in our Phase 1 IRX-616a study is a significant achievement for Nexalis and an important step in advancing our rapid-onset therapeutic platform. We are particularly encouraged by the absence of any SAEs observed during the study and delighted with the early insights emerging from the pharmacokinetic profile of IRX-616a. These outcomes continue to strengthen our confidence in the program as we commence preparations for Phase 2 development.”

Why IRX-616a targets a clear gap in panic disorder treatment

Panic Disorder is a mental health condition characterised by recurring, unexpected panic attacks, which are sudden episodes of intense fear accompanied by physical symptoms such as a racing heart, shortness of breath, and dizziness. Current treatment options primarily consist of daily oral medications, such as antidepressants or benzodiazepines, which are not designed to address the acute, rapid-onset nature of a panic episode as it occurs.

Critically, as stated in the announcement, there are currently no FDA-approved drugs delivered via inhalation designed to treat Panic Disorder. This represents a meaningful gap in the treatment landscape.

Inhalation as a delivery route is strategically significant for rapid-onset conditions. When a drug is inhaled, it is absorbed directly through the lungs into the bloodstream, producing a much faster therapeutic effect than swallowed tablets, which must pass through the digestive system first. For a condition like a panic attack, where timing is central to effective treatment, this pharmacological speed advantage is material.

IRX-616a is formulated using cannabidiol (CBD), a non-intoxicating compound derived from the cannabis plant. The formulation is differentiated by its inhaled delivery mechanism, designed to match the acute, episodic nature of panic attacks rather than providing background daily suppression.

IRX-616a sits within a broader three-asset pipeline, backed by a funding facility of up to $52.3 million secured to advance all three programmes:

  • IRX-616a — Panic Disorder
  • IRX-211 — Breakthrough Cancer Pain
  • SRX-25 — Treatment-Resistant Depression

The company’s overarching regulatory strategy targets US FDA approval via the 505(b)(2) pathway, a route designed to be more cost-effective and faster than a standard new drug application by leveraging existing safety and efficacy data.

Phase 1 outcomes and what comes next for IRX-616a

Key outcomes from the Phase 1 study

The Phase 1 trial was a randomised, double-blind, placebo-controlled study conducted at CMAX Adelaide, assessing safety, tolerability, and pharmacokinetic parameters across three sequential dose cohorts in healthy volunteers. The most significant outcome from the dosing phase is the clean safety record: zero SAEs were reported across the entirety of the study.

This result carries particular weight ahead of Phase 2 advancement, as first-in-human studies carry inherent execution risk and a clean safety profile provides a stronger foundation for regulatory discussions. Management has described the pharmacokinetic data as providing “early insights,” and it is important to note that final data analysis is still underway. Database lock and final statistical analysis have now commenced.

Study Design Trial Site Cohorts Safety Outcome Current Status
Randomised, double-blind, placebo-controlled CMAX Adelaide 3 sequential dose cohorts 0 SAEs reported Database lock underway

The road to Phase 2 — next milestones

The company has outlined four confirmed next steps in sequence, drawn directly from the announcement:

  1. Completion of database lock and statistical analysis
  2. Review of final safety and pharmacokinetic data
  3. Release of topline Phase 1 results
  4. Advancement into Phase 2 clinical development in the target patient population

A key distinction in Step 4 is the move from healthy volunteers to the target patient population, people living with Panic Disorder. This is a meaningful clinical progression, as data generated in real patients carries significantly more weight for regulatory submissions than data from healthy individuals.

Importantly, Phase 2 planning and regulatory preparation activities have already been initiated, indicating no delay between phases. NX1 has confirmed it will issue further updates as material milestones are achieved.

Investment thesis — why this milestone strengthens the NX1 case

The completion of the LPLD milestone with zero SAEs materially de-risks the IRX-616a programme. The dosing phase of a first-in-human study carries genuine execution risk, and its clean conclusion removes a significant clinical hurdle on the path to Phase 2.

From a capital perspective, the $52.3 million funding facility secured to advance all three pipeline programmes means that near-term development timelines are not constrained by capital availability. This provides a degree of visibility over the company’s ability to execute across IRX-616a, IRX-211, and SRX-25 concurrently.

The 505(b)(2) regulatory strategy is also worth noting for investors assessing time-to-market potential. This pathway allows NX1 to rely, in part, on previously established safety and efficacy data, potentially compressing both the cost and timeline of achieving FDA approval relative to a full new drug application.

The next material news event investors should monitor is the release of topline Phase 1 data, which will follow the completion of database lock and final statistical analysis. Until that data is released, the absence of SAEs represents the primary clinical signal available. Investors should note that no conclusions can yet be drawn regarding efficacy.

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Frequently Asked Questions

What is the IRX-616a Phase 1 trial and what has Nexalis Therapeutics achieved?

The IRX-616a Phase 1 trial is a randomised, double-blind, placebo-controlled first-in-human study of Nexalis Therapeutics' inhaled cannabidiol formulation for acute panic disorder, conducted at CMAX Adelaide across three dose cohorts. Nexalis has completed dosing of all patients, reaching the Last Patient Last Dose milestone with zero Serious Adverse Events reported.

Why is inhaled CBD considered a novel approach for treating panic disorder?

There are currently no FDA-approved drugs delivered via inhalation designed to treat Panic Disorder, meaning IRX-616a targets an unmet medical need. Inhaled delivery allows the drug to be absorbed directly through the lungs into the bloodstream, producing a faster therapeutic effect than oral medications — a critical advantage for treating the acute, rapid-onset nature of panic attacks.

What are the next milestones for Nexalis Therapeutics following the Phase 1 LPLD milestone?

Following completion of dosing, Nexalis will complete database lock and statistical analysis, review final safety and pharmacokinetic data, release topline Phase 1 results, and then advance into Phase 2 clinical development in patients with Panic Disorder. Phase 2 planning and regulatory preparation have already commenced.

What is the 505(b)(2) regulatory pathway and why is Nexalis using it?

The 505(b)(2) pathway is an FDA approval route that allows drug developers to rely in part on previously established safety and efficacy data rather than conducting entirely new studies, making it potentially faster and less costly than a standard new drug application. Nexalis is targeting this pathway across its pipeline to reduce the time and cost required to achieve FDA approval.

How is Nexalis Therapeutics funded to advance its clinical pipeline?

Nexalis has secured a funding facility of up to $52.3 million to advance all three programmes in its pipeline — IRX-616a for Panic Disorder, IRX-211 for Breakthrough Cancer Pain, and SRX-25 for Treatment-Resistant Depression — providing capital visibility across near-term development activities.

Josua Ferreira
By Josua Ferreira
Partnership Director
Josua Ferreira holds a Bachelor of Commerce in Marketing and Advertising and brings a background in publication, business development, and ASX market storytelling. He has worked with listed companies across the resource sector and broader market, combining sharp commercial instincts with a genuine commitment to keeping investors informed.
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