Cohort 1 complete as RLS-2202 Phase 1a trial advances toward safety review
Patrys Limited (ASX: PAB) has confirmed that all four participants in Cohort 1 have completed dosing and the required follow-up period in the Phase 1a clinical trial of RLS-2202 in healthy volunteers. The study is designed to evaluate safety, tolerability and pharmacokinetics, and generate the data required to inform dose selection and the next stage of clinical development.
The available Cohort 1 data will now be compiled and reviewed by the Safety Review Committee (SRC), which is scheduled to meet in October 2026. The SRC will review the data and make a recommendation regarding the dose for Cohort 2 (n=12 participants) and whether any modifications to the dosing regimen or study conduct are required.
Patrys has explicitly cautioned that no decision regarding progression to Cohort 2 has yet been made, and the formal SRC review remains outstanding.
Dr Samantha South, CEO, Patrys Limited
“We are pleased that Cohort 1 is now complete and would like to thank the participants and clinical teams involved. The available Cohort 1 data will now be reviewed by the Safety Review Committee and we look forward to providing a further update following the SRC meeting.”
When big ASX news breaks, our subscribers know first
Understanding Phase 1a trials — what this milestone means for investors
A Phase 1a trial is the earliest stage of human clinical testing. Its primary purpose is to assess safety and tolerability in a small number of participants, rather than to measure whether the therapy works in patients.
The RLS-2202 Phase 1a uses an IV:oral crossover design across two cohorts and two periods. This means participants receive the therapy via both intravenous and oral routes, allowing researchers to compare how the body absorbs and processes RLS-2202 under each method. This crossover structure generates pharmacokinetic data that directly informs dose selection for subsequent, larger cohorts.
The SRC is an independent committee that reviews accumulating safety data before the trial advances. Its independence is important: it protects participants and provides scientific oversight that gives the program credibility with regulators and the broader clinical community.
The trial is being conducted at CMAX, Adelaide, under the oversight of Alithia Life Sciences, with HREC approval and TGA acknowledgement, signalling appropriate governance is in place.
Key trial parameters at a glance:
- Trial type: Phase 1a, two-cohort, IV:oral crossover design
- Total participants: 16 (Cohort 1: n=4; Cohort 2: n=12)
- Site: CMAX, Adelaide
- Oversight: Alithia Life Sciences
- Regulatory: HREC-approved; TGA-acknowledged
For investors, Cohort 1 completion represents a derisking step. The SRC review is a gating event; a green light to Cohort 2 would represent the next meaningful value inflection point for the program.
Trial design and what RLS-2202 is targeting
Patrys is a clinical-stage company developing an injectable therapy for delirium, alongside a deoxymab platform targeting immune-mediated inflammatory diseases.
The RLS-2202 program entered the Patrys pipeline through the Reliis acquisition completed in January 2026, which added the injectable quetiapine reformulation alongside two new directors bringing clinical trial execution and capital markets expertise to the company.
Delirium is an acute neurological condition that remains significantly underserved, with limited approved pharmacological treatment options. The company’s Phase 1a study is generating the foundational data set — covering safety, tolerability, and pharmacokinetics — that is required before the therapy can advance to further stages of clinical development.
Cohort 1, with four healthy volunteer participants now fully assessed, provides the initial human data from which the SRC will frame its recommendations for the larger Cohort 2.
Key milestones ahead for RLS-2202
The upcoming milestone sequence for the RLS-2202 Phase 1a study, as outlined by Patrys, is detailed below.
| Milestone | Timing | Detail |
|---|---|---|
| SRC meets to review Cohort 1 data | October 2026 | Reviews safety, tolerability and pharmacokinetic data; recommends Cohort 2 dose and any protocol modifications |
| Cohort 2 dosing commences | Q4 CY2026 | Subject to satisfactory SRC review and quality control release of Cohort 2 clinical material |
| Final participant dosing (Cohort 2) | Q4 CY2026 | Completion of all 12 Cohort 2 participants targeted |
It is important to note that Patrys has explicitly stated no decision on progression to Cohort 2 has yet been made, and the SRC outcome cannot be assumed. The company has indicated it intends to provide further updates as key clinical milestones are achieved and data from the study become available.
Investment thesis — why this phase matters
Cohort 1 completion marks a measurable step forward for the RLS-2202 program: all four participants have finished their planned clinical assessments, and the data set is now being prepared for independent review. The company has not released any clinical data, and the SRC review remains outstanding; the safety and tolerability profile of Cohort 1 has not been characterised publicly at this stage.
The October 2026 SRC meeting represents the next near-term catalyst. Should the committee recommend progression, Cohort 2 (n=12) would substantially expand the data set and move the program meaningfully closer to Phase 1b/2 readiness.
With both the commencement and completion of Cohort 2 dosing targeted for Q4 CY2026, the timeline offers the potential for further clinical updates before the year’s end, subject to the SRC’s recommendations and the successful quality control release of Cohort 2 clinical material.
For investors wanting the complete picture on how the trial is structured and what has already been de-risked on the manufacturing side, our full explainer on the RLS-2202 Phase 1a trial design and Cohort 2 manufacturing status details the bridging study rationale, the GMP production timeline, and the three programme functions the Phase 1a data is expected to serve.
Don’t Miss the Next ASX Healthcare Catalyst
Big News Blast delivers FREE breaking ASX healthcare news and in-depth analysis directly to your inbox within minutes of release. Join 20,000+ investors who stay ahead of clinical milestones, trial updates, and market-moving announcements the moment they drop. Click the “Free Alerts” button at Big News Blast to make sure you never miss the next key catalyst.