Loberamisal for Acute Ischaemic Stroke (LAIS): a multicentre, randomised, double-blind, parallel, placebo-controlled phase III clinical trial

Abstract

Background and objectives

Loberamisal, a novel agent that dissociates the post-synaptic density protein 95/neuronal nitric oxide synthase complex and potentiates the α2-containing γ-aminobutyric acid type A receptors, is a potential neuroprotectant that is effective in preclinical studies for acute ischaemic stroke. This trial aims to demonstrate the efficacy and safety of intravenous loberamisal in patients with acute ischaemic stroke (AIS) within 48 hours of onset.

Methods and design

The LAIS (Loberamisal for Acute Ischaemic Stroke) trial is a multicentre, prospective, randomised, double-blind, placebo-controlled phase 3 trial. A total of 998 eligible patients will be randomly assigned to receive either loberamisal or placebo in a 1:1 ratio.

Outcomes

The primary efficacy outcome is proportion of individuals achieving an excellent functional outcome, defined as modified Rankin Scale (mRS) 0–1 at 90 days. Secondary efficacy outcomes include favourable functional outcome (defined as an mRS score of 0 in patients with a baseline NIHSS score of 4 to 7; an mRS score of 0 to 1 in patients with a baseline NIHSS score of 8 to 14; and an mRS score of 0 to 2 in patients with a baseline NIHSS score of 15 to 25), distribution of mRS at 90 days, patients with ≥4 points reduction in National Institutes of Health Stroke Scale score from baseline at 10 days and 30 days, and Barthel Index ≥95 at 90 days. Safety outcomes were adverse events. Exploratory outcomes include the incidence of depressive and anxiety symptoms at 90 days.

Discussion

The LAIS trial will evaluate the potential of loberamisal as a novel neuroprotectant in acute ischaemic stroke.

Trial registration number

NCT06517173.

WHAT IS ALREADY KNOWN ON THIS TOPIC

• The clinical translation of multitarget neuroprotective strategies remains challenging; however, loberamisal, a dual-target small molecule, has shown promising safety and efficacy in acute ischaemic stroke (AIS) patients.

WHAT THIS STUDY ADDS

• This study will provide confirmatory evidence supporting the efficacy and safety of loberamisal in the treatment of AIS.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

• By validating a multitarget neuroprotective agent, this study may promote innovation in therapeutic strategies and accelerate the clinical translation of novel treatments for ischaemic stroke.

Introduction

Despite the established efficacy of reperfusion therapies in restoring cerebral blood flow following acute ischaemic stroke,^1–3 the translational development of neuroprotective agents with additional effects remains an unmet clinical challenge in cerebrovascular therapeutics.⁴ Postsynaptic density protein 95 (PSD-95) has emerged as a compelling therapeutic target for neuroprotection in ischaemic stroke. Nerinetide, a novel neuroprotective agent that mechanistically disrupts the interaction between PSD-95 and neuronal nitric oxide synthase (nNOS) neurotoxic signalling pathways,^{5 6} demonstrated therapeutic efficacy in preclinical studies. Subsequent clinical evaluations, however, yielded heterogeneous outcomes. Notably, nerinetide was associated with improved functional outcome with respect to the subgroup populations and should be confirmed in future trials.^7–10 The γ-aminobutyric acid type A receptors (GABA_AR) signalling which may additional effects provide inhibitory control to counteract hyperexcitability^11–13 that is crucial to the mechanisms of neuronal injury. GABA_ARs also play a crucial role in modulating depression and anxiety.^{14 15} Targeting both pathways simultaneously, as with dual-target agents, represents a promising strategy for developing effective neuroprotective therapies for ischaemic stroke.

Loberamisal is a small molecular inhibitor of the PSD-95–nNOS interaction and selectively potentiates α2-containing GABA_AR.¹⁶ As a dual-target compound, loberamisal showed significant neuroprotection against both acute cerebral ischaemia-reperfusion and permanent ischaemic injury in rodent models.^16–18 In this trial, we aimed to evaluate the efficacy and safety of intravenous loberamisal in patients with acute ischaemic stroke (AIS) within 48 hours of onset.

Methods and design

Overview of the trial

Loberamisal for Acute Ischaemic Stroke (LAIS) is a multicentre, prospective, randomised, double-blind, placebo-controlled phase 3 trial that evaluates the efficacy and safety of loberamisal vs placebo in patients with AIS within 48 hours from symptom onset. A total of 36 centres in China will be recruited in this trial. The trial will be conducted in strict adherence to the ethical principles outlined in the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use–Good Clinical Practice (ICH-GCP) guidelines and the Declaration of Helsinki. The study protocol, informed consent documents and all subsequent amendments were reviewed and approved by the Institutional Review Board (IRB) of Beijing Tiantan Hospital, as well as the IRBs of all participating clinical centres. Prior to initiation, the trial was prospectively registered on ClinicalTrials.gov (identifier: NCT06517173). A detailed assessment flowchart is provided in table 1.

Table 1. Trial assessment flow chart.

	Baseline	Treatment		Follow-up
Visit	Visit 1		Visit 2	Visit 3	Visit 4
Day visit	The onset to the first dose	First dose	Day 10±3	Day 30±7	Day 90±7
Informed consent	X
Demographic data and disease characteristics	X
Medical and medication history	X
Inclusion/exclusion criteria	X
Vital signs	X		X	X	X
Physical examination	X		X	X	X
Haematology	X		X	X	X
Urinalysis	X		X	X	X
Liver and kidney test	X		X	X	X
Myocardial enzyme spectrum	X		X	X	X
Electrolyte	X		X	X	X
Fasting blood glucose	X		X	X	X
Blood lipids	X		X	X	X
Coagulation test	X		X	X	X
Homocysteine	X		X	X	X
ECG	X		X	X	X
Pregnancy test	X				X
Brain CT	X
Brain MRI	X
mRS	X		X	X	X
NIHSS	X		X	X
Barthel Index					X
HAMA					X
MADRS					X
SSS-TOAST	X
Randomisation	X
Administration		X
Concomitant medications		X
Adverse events		X

HAMA, Hamilton Anxiety Scale; MADRS, Montgomery-Asberg Depression Rating Scale; mRS, modified Rankin Scale; NIHSS, National Institutes of Health Stroke Scale; SSS-TOAST, Stop Stroke Study-Trial of Org 10172 in Acute Stroke Treatment.

Participants

Participants will be eligible if they are ≥18 years and <81 years, present with AIS within 48 hours of symptoms onset, and have a score on baseline National Institutes of Health Stroke Scale (NIHSS) between 7 and 20 (inclusive) and a prestroke modified Rankin Scale (mRS) of ≤1, as judged by the investigator. Patients will be excluded if they are with haemorrhage and severe disturbance of consciousness, or diagnosed with transient ischaemic attack (TIA) etc. Also, patients with a previous diagnosis of severe mental disorder, severe dementia, depression or anxiety, and those receiving antidepressant or anxiolytic treatment will be excluded from the trial. The detailed inclusion and exclusion criteria are systematically presented in boxes 1 and 2, respectively. Written informed consent will be obtained from all participants or their legally authorised representatives before enrolment in the study.

Box 1. Inclusion criteria.

Inclusion criteria

1. Age ≥18 years and <81 years, regardless of sex.

2. After the onset of this disease, the National Institutes of Health Stroke Scale (NIHSS) score is between 7 and 20 (inclusive), and the sum of the scores for item 5 (upper extremity) and item 6 (lower extremity) is ≥2 points.

3. Symptom onset time ≤48 hours (including 48 hours).

4. Diagnosed with ischaemic stroke according to the ‘Diagnostic Criteria for Various Types of Cerebrovascular Diseases in China 2019,’ with first-time onset or good recovery after the last episode (modified Rankin Scale (mRS) score ≤1 before this onset).

5. Written informed consent obtained from the participant or their legal representative, approved by the ethics committee.

Box 2. Exclusion criteria.

Exclusion criteria

1. Presence of intracranial haemorrhagic disease on head imaging, including haemorrhagic stroke, epidural haematoma, intracerebral haematoma, intraventricular haemorrhage or subarachnoid haemorrhage. Participants with only minimal bleeding may be considered for enrolment at the investigator’s discretion.

2. Severe consciousness disorder: the item score of National Institutes of Health Stroke Scale’s (NIHSS) 1a consciousness level is greater than 1 point.

3. Diagnosis of transient ischaemic attack (TIA).

4. Blood pressure remains ≥220 mm Hg systolic or ≥120 mm Hg diastolic after control.

5. Previously diagnosed patients with severe mental disorders and severe dementia.

6. Patients previously diagnosed with depression or anxiety disorder.

7. Patients undergoing antidepressant or antianxiety treatment.

8. Diagnosis of severe active liver disease, such as acute hepatitis, chronic active hepatitis, liver cirrhosis, etc; or alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >2.0×Upper Limit of Normal (ULN).

9. Diagnosis of severe active kidney disease or renal insufficiency, or serum creatinine >1.5×ULN.

10. After the onset of the disease, drugs with brain cryoprotection in the instructions have been used, such as edaravone, edaravone-trolox, nimodipine, gangliosides, citicoline, piracetam, oxiracetam, bupirate, urokinase, cinnarizine, nerve growth factor, cerebrolysin (cerebroprotein hydrolysate), deproteinised calf serum injection or deproteinised calf extract injection.

11. After the onset of this disease, thrombectomy or interventional therapy has been applied or planned to be applied.

12. Previously diagnosed with concurrent malignant tumours and undergoing antitumour treatment.

13. Previously diagnosed with severe systemic diseases, with an estimated survival period of <90 days.

14. The patient is in pregnancy, lactation and there is a possibility of pregnancy in the patient/patient partner who plans to conceive during the trial period.

15. Previously known allergies to the study drug or any of its excipients (15-hydroxystearic acid polyethylene glycol ester, propylene glycol, mannitol, potassium dihydrogen phosphate, dipotassium hydrogen phosphate trihydrate).

16. A history of major surgeries within 4 weeks prior to enrolment and assessed by the investigator as affecting neurological function scores or affecting 90-day survival.

17. Participation in another clinical study within 30 days prior to randomisation or ongoing participation in another clinical study.

18. Any other condition deemed by the investigator to preclude participation in this clinical study.

Randomisation and masking

Eligible patients enrolled in the trial will be randomly allocated to treatment group and placebo group in 1:1 ratio based on random number table (generated by Clinflash Interactive Response Technology (Clinflash IRT), V2.8.3). A centralised competitive enrolment randomisation approach is applied. Stratification factors for randomisation include onset to treatment time (≤12 hours vs >12 hours) and study centre. After participants are deemed eligible, the investigator or authorised personnel obtain the randomisation number and corresponding drug code through the randomisation system, and dispense the assigned study medication accordingly. The study employed a double-blind design, in which intravenous loberamisal and placebo were identical in colour and packaging (including batch number and expiration date).

Intervention

The intravenous loberamisal and placebo will be provided by NeuroDawn Pharmaceutical Co., Ltd, Nanjing, China. Patients will be randomised to receive intravenous loberamisal (40 mg/dose) or placebo for 10 consecutive days. The investigational drug is administered via intravenous infusion once daily, with an infusion duration of 60±10 min. If the participant experiences discomfort during the infusion, the investigator may, after evaluation, consider extending the infusion time, temporarily pausing or discontinuing the treatment. In-hospital management for all participants will be performed according to the Chinese Guidelines for Diagnosis and Treatment of AIS 2023.³ In-person clinical follow-up, which was the preferred approach for follow-up, was obtained at 10 days, 30 days and 90 days from randomisation. Where in-person follow-up was not possible, video conferencing or telephone follow-up was obtained.

Outcomes

Efficacy outcomes

The primary outcome is proportion of patients achieving mRS 0–1 at 90 days.

Secondary efficacy outcomes include

1. Proportion of patients with good functional outcome at day 90 post-treatment.

2. mRS shift analysis at 90 days.

3. Proportion of patients achieving ≥4-point reduction in NIHSS score from baseline at day 10 and day 30 post-treatment.

4. Proportion of patients with Barthel Index ≥95 at day 90 post-treatment.

Safety outcomes

1. Adverse events (AEs).

2. Treatment-emergent adverse events (TEAEs).

3. Significant adverse events, defined as any non-serious adverse events that lead to interruption of treatment or permanent discontinuation of the drug.

4. Serious adverse events (SAEs).

5. Suspected unexpected serious adverse reactions (SUSARs).

6. Discontinuation of treatment due to adverse events.

Exploratory outcomes

1. Depressive symptoms within 90 days, defined as a Montgomery-Asberg Depression Rating Scale (MADRS) score ≥12.

2. Anxiety symptoms within 90 days, defined as a Hamilton Anxiety Scale (HAMA) score ≥14.

Concomitant events and handling strategies

In accordance with ICH E9(R1) guidelines, the trial implemented predefined strategies to address concomitant events. A composite strategy was employed for treatment discontinuations due to inefficacy or patient death. For premature terminations resulting from adverse events or other non-efficacy-related reasons, a therapeutic strategy was applied. The prohibited medications remained subject to the composite strategy.

Sample size estimates

The sample size for this study was based on the primary efficacy outcome. Previous clinical trials’ results indicated an expected response rate of 71.5% for the loberamisal group and 60.7% for the placebo group. Assuming a significance level of α=0.05 (two-sided), power of 1 − β=90% and a 1:1 ratio, the required sample size for each group is 399 subjects. Considering a dropout rate of up to 20%, the final sample size for each group is approximately 499 subjects, resulting in a total planned sample size of 998 subjects.

Statistical analyses

Efficacy analyses will be performed in the intent-to-treat population (ITT), which includes patients who undergo randomisation and received at least once the study agent. For the primary efficacy outcomes, missing data will be imputed using last observation carried forward (LOCF) and will be set as greater than 1 if no post-treatment mRS scores recorded. The analysis will be based on complete case data. The proportions of patients achieving an mRS score of 0–1 at 90 days will be summarised for each group, and the relative risk (RR) with 95% CI of loberamisal compared with placebo will be calculated using Mantel-Haenszel method, with stratification factor (onset to treatment time: <12 hours, ≥12 hours) considered. Sensitivity analyses were also performed. Besides, the primary efficacy outcome will be analysed in the subgroups: age (<65 years vs ≥65 years), sex (men vs women), time from onset to actual treatment (<12 hours vs ≥12 hours), prestroke mRS score (0 vs 1), pretreatment NIHSS score (<15 vs ≥15), history of stroke (yes vs no) and thrombolysis treatment (yes vs no).

For the binary secondary efficacy outcomes and exploratory outcomes, analyses were performed using similar statistical methods as those applied to the primary outcome. For mRS shift analysis at day 90, ordinal logistic regression will be performed.

Safety analyses will be performed on the safety set, which includes participants who received at least one dose of the drug treatment and underwent subsequent safety evaluation at least once. Similar to the binary efficacy outcome analyses, safety outcomes will be summarised by group, and RR with 95% CI will be calculated.

All data analyses will be conducted using SAS software version 9.4 (Statistical Analysis System, SAS Institute Inc., Cary, NC, USA).

Discussion

The LAIS trial will provide definitive results on the efficacy and safety of intravenous loberamisal for 10 days compared with placebo in the treatment of patients with AIS presenting within 48 hours after symptom onset.

Despite the historical failure of over 1000 neuroprotective agents in stroke clinical translation, the success of edaravone dexborneol, the dual-pathway targeting agent, demonstrated clinically relevant therapeutic efficacy in AIS patients, with consistent treatment effects observed across both intravenous and sublingual administration routes. Nerinetide, a neuroprotective eicosapeptide targeting PSD-95, shows promising clinical benefits in AIS. The Efficacy and Safety of Nerinetide for the Treatment of Acute Ischemic Stroke (ESCAPE-NA1) trial revealed that nerinetide administration within 12 hours of symptom onset exerted cytoprotective effects in AIS patients undergoing endovascular thrombectomy without alteplase co-administration.⁷ Subsequent evaluations in the ESCAPE-NEXT trial (Efficacy and Safety of Nerinetide in Acute Ischaemic Stroke in Patients Undergoing Endovascular Thrombectomy Without Previous Thrombolysis) failed to demonstrate clinical improvement in large-vessel occlusion (LVO) stroke patients receiving thrombectomy alone.⁸ The Field Randomization of Nerinetide (NA-1) Therapy in Early Responders (FRONTIER) trial investigating prehospital nerinetide initiation within 3 hours of symptom onset showed no efficacy but suggested synergistic benefits when combined with reperfusion therapies.⁹ A pooled analysis integrating ESCAPE-NA1, ESCAPE-NEXT and FRONTIER trials identified statistically significant functional outcome improvements in reperfusion-treated patients within a 3-hour therapeutic window.¹⁰ Pharmacodynamic limitations emerged due to nerinetide-plasmin interactions, restricting its use in thrombolysis-treated cohorts.^{7 19} This pharmacokinetic challenge has driven development of next-generation PSD-95 inhibitors, exemplified by NoNO-42—a plasmin-compatible analogue currently under investigation in the ACT-42 trial (NCT06403267, NoNO-42 Trial in Acute Ischemic Stroke Patients Selected for Thrombolysis With or Without Endovascular Thrombectomy) for AIS patients receiving reperfusion therapy within 3 hours of symptom onset. These clinical trials provide preliminary evidence supporting the feasibility of cytoprotective interventions in human stroke, while underscoring the necessity for validation through large-scale, multicentre studies to establish therapeutic reproducibility.

Loberamisal represents a structurally distinct small-molecule inhibitor targeting the PSD-95/nNOS protein-protein interaction, currently advancing through clinical development. Mechanistically differentiated from first-generation agents like nerinetide, loberamisal exhibits resistance to tissue-type plasminogen activator (tPA)-mediated degradation, enabling synergistic application with thrombolytic therapies and broadening its therapeutic applicability.¹⁶ Besides, the selective potentiation of α2-containing GABA_AR enhanced the neuroprotection of loberamisal. Preclinical validation across murine stroke models revealed sustained neuroprotection with loberamisal administration ≤12 hours of symptom onset, demonstrating comparable efficacy in both permanent occlusion and transient ischaemia-reperfusion paradigms.¹⁶ The multicentre phase 2 dose-finding trial (NCT06429384) systematically evaluated three once-daily regimens (20 mg, 40 mg, 60 mg) vs placebo. While all doses exhibited favourable safety profiles, the 40 mg group demonstrated a 16.0% absolute increase in functional independence rates (mRS ≤1). This optimal risk-benefit profile justified selection of the 40 mg dose for phase 3 evaluation.

This study has several limitations. First, the enrollment of Chinese patients only and exclusion of patients eligible for endovascular thrombectomy may restrict the generalisability of the findings. Second, the therapeutic time window for intravenous loberamisal was confined to 48 hours after symptom onset, which is relatively narrow and may not capture delayed treatment effects.

In conclusion, the result of LAIS trial will elucidate the potential therapeutic advantage of intravenous loberamisal and enhance confidence in the clinical application of neuroprotective therapy.

Data availability statement

Data sharing not applicable as no datasets generated and/or analysed for this study.