Efficacy and Safety of Intra-Arterial Albumin as Adjunct to Mechanical Thrombectomy in Acute Ischemic Stroke (AMASS2)

January 16, 2026 updated by: Ming Wei, Tianjin Huanhu Hospital

Efficacy and Safety of Intra-Arterial Albumin as Adjunct to Mechanical Thrombectomy in Acute Ischemic Stroke: A Multicenter, Prospective, Open-Label, Endpoint-Blinded, Randomized Controlled Clinical Trial (AMASS2)

Stroke remains a predominant global public health challenge, ranking as the third leading cause of death and the fourth leading contributor to disability-adjusted life years (DALYs). According to the Global Burden of Disease Study 2021, there are approximately 93.8 million prevalent stroke cases and 11.9 million new cases worldwide. China bears one of the heaviest burdens, with over 2 million new cases annually. Acute ischemic stroke (AIS), caused by acute cerebrovascular occlusion, accounts for 80% of all strokes. Approximately 30% of AIS cases result from large vessel occlusion (LVO), which typically carries a poor prognosis due to the extensive area of infarction . Research indicates that early recanalization significantly improves clinical outcomes. Currently, intravenous thrombolysis (IVT) and mechanical thrombectomy (MT) are the standard treatments for achieving recanalization . For LVO-related AIS, MT has become the preferred clinical approach due to its extended therapeutic window and superior recanalization rates . However, despite successful recanalization in over 70% of patients, nearly 50% fail to achieve functional independence at 90 days, and mortality remains above 15% . Therefore, enhancing long-term functional outcomes in post-MT patients is a critical unmet clinical need. Human albumin is the most abundant protein in plasma. Beyond maintaining colloid osmotic pressure, it also possesses multiple biological effects, including anti-inflammatory, anti-platelet aggregation, antioxidant, and endothelial protective properties. We conducted a Phase I clinical trial (AMASS-1) for patients post-mechanical thrombectomy, administering human albumin via the internal carotid artery. The results showed that intra-arterial infusion of 20% human albumin at a dose of 0.60 g/kg was safe, with no significant differences in serious adverse reactions such as mortality [Albumin group (6.7%) vs Control group (6.7%), P > 0.05] and symptomatic intracranial hemorrhage [Albumin group (6.7%) vs Control group (13.3%), P > 0.05] compared to the control group. In summary, albumin adjunctive therapy demonstrates good safety and potential neuroprotective effects in patients after mechanical thrombectomy. To further systematically evaluate its efficacy and safety, we plan to conduct a Phase II clinical trial of mechanical thrombectomy combined with intra-arterial albumin infusion for acute ischemic stroke. This is a multicenter, prospective, open-label, endpoint-blinded, randomized controlled trial designed to evaluate the efficacy and safety of intra-arterial infusion of 20% human serum albumin combined with mechanical thrombectomy versus mechanical thrombectomy alone in patients with acute ischemic stroke due to anterior circulation large vessel occlusion who have achieved recanalization after mechanical thrombectomy. A total of 306 patients are planned to be enrolled and randomly assigned in a 1:1 ratio using a dynamic minimization method to two groups: the Albumin Group (0.6 g/kg 20% human serum albumin plus Mechanical Thrombectomy) and the Control Group (Mechanical Thrombectomy alone). The primary efficacy objective of this study is to evaluate whether immediate intra-arterial infusion of 20% human albumin (0.6 g/kg) via the internal carotid artery following successful recanalization (eTICI ≥2b) improves clinical outcomes in patients with acute anterior circulation large vessel occlusion stroke, compared with mechanical thrombectomy alone. The study also aims to evaluate the safety and feasibility of immediate intra-arterial infusion of 20% human albumin (0.6 g/kg) via the internal carotid artery in patients with acute anterior circulation large vessel occlusion stroke who have achieved successful recanalization (eTICI ≥2b) following standard mechanical thrombectomy.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
306

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age ≥ 18 years
  • Acute anterior circulation large vessel occlusion (including ICA/MCA-M1 tandem occlusion or isolated MCA-M1 occlusion) confirmed by CTA, MRA, or DSA, with successful recanalization (eTICI score ≥2b) confirmed by the final intraoperative DSA following mechanical thrombectomy
  • Baseline NIHSS scores ≥ 6
  • Non-contrast CT ASPECTS ≥6
  • Time from stroke onset (or last known well) to arterial puncture within 24 hours
  • Pre-stroke functional independence, defined as a modified Rankin Scale (mRS) score <2
  • Written informed consent obtained from the patient or a legally authorized representative

Exclusion Criteria:

  • Intracranial hemorrhage confirmed by cranial CT or MRI
  • Midline shift with significant mass effect on cranial CT or MRI
  • Isolated internal carotid artery (ICA) occlusion
  • History of heart failure or severe cardiovascular disease, including but not limited to pulmonary hypertension or pericardial effusion
  • Hemodynamically unstable arrhythmia (based on patient self-report or detected prior to infusion)
  • Symptoms or electrocardiographic evidence of acute myocardial infarction upon admission
  • Acute or chronic renal failure (serum creatinine >2.0 mg/dL
  • Severe anemia (hematocrit <32%
  • Known hypersensitivity to albumin or blood products
  • Pregnancy
  • Persistent hypertension (blood pressure ≥180/100mmHg) prior to albumin infusion
  • Current participation in other clinical trials
  • Life expectancy of less than 3 months
  • Concomitant severe pulmonary disease, such as chronic obstructive pulmonary disease, pulmonary fibrosis, pleural effusion, or acute respiratory distress syndrome
  • Any other condition that, in the opinion of the investigator, renders the patient unsuitable for participation in the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Albumin Group

Albumin Group Subjects assigned to the albumin treatment group after achieving successful recanalization (eTICI ≥ 2b) confirmed by DSA post-thrombectomy will receive a 20% human albumin solution at a dose of 0.60 g/kg. The solution will be administered as a constant-rate infusion into the proximal internal carotid artery over 20 minutes. Vital signs and potential infusion-related reactions must be closely monitored throughout the procedure.

Mechanical thrombectomy must be performed using clinically approved devices. The specific technical approach is to be determined by the neurointerventional physician based on the patient's individual clinical condition.
Drug: 20% human serum albumin
20% human albumin solution at a dose of 0.60g/kg will be administered as a constant-rate infusion into the proximal internal carotid artery over 20 minutes.
No Intervention: Control Group

Subjects in the control group who have achieved successful recanalization (eTICI ≥ 2b) as confirmed by DSA following mechanical thrombectomy will not receive the investigational infusion and will undergo standard medical management only.

The mechanical thrombectomy procedure must be performed using clinically approved devices. The specific technical approach is to be determined at the discretion of the neurointerventional physician based on the patient's clinical condition.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Distribution of mRS scores at 90 (±14) days post-randomization
Time Frame: at 90 (±14) days post-randomization
Distribution of mRS scores
at 90 (±14) days post-randomization

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Proportion of subjects with a favorable outcome at 90 (±14) days post-randomization (defined as mRS 0-2);
Time Frame: at 90 (±14) days post-randomization
Proportion of subjects with a favorable outcome, defined as mRS 0-2
at 90 (±14) days post-randomization
Proportion of subjects with functional independence at 90 (±14) days post-randomization (defined as mRS 0-1)
Time Frame: at 90 (±14) days post-randomization
Proportion of subjects with functional independence, defined as mRS 0-1
at 90 (±14) days post-randomization
Infarct volume at 24 (±6) hours post-randomization (measured via MRI-DWI)
Time Frame: at 24 (±6) hours post-randomization
Infarct volume, measured via MRI-DWI
at 24 (±6) hours post-randomization
Infarct volume growth from baseline to 24 (±6) hours post-randomization
Time Frame: from baseline to 24 (±6) hours post-randomization
Infarct volume growth
from baseline to 24 (±6) hours post-randomization
Recanalization rate at 24 (±6) hours post-randomization
Time Frame: at 24 (±6) hours post-randomization
Recanalization rate
at 24 (±6) hours post-randomization
NIHSS score at 24 (±6) hours post-randomization
Time Frame: at 24 (±6) hours post-randomization
NIHSS score
at 24 (±6) hours post-randomization
NIHSS score at 7 (±1) days or at discharge, whichever occurs first
Time Frame: at 7 (±1) days or at discharge, whichever occurs first
NIHSS score
at 7 (±1) days or at discharge, whichever occurs first
EQ-5D-5L score at 90 (±14) days post-randomization
Time Frame: at 90 (±14) days post-randomization
EQ-5D-5L score
at 90 (±14) days post-randomization
Proportion of subjects with a Barthel Index (BI) ≥95 at 90 (±14) days post-randomization
Time Frame: at 90 (±14) days post-randomization
Proportion of subjects with a Barthel Index (BI)
at 90 (±14) days post-randomization
Distribution of mRS scores at 180 (±30) days and 1 year (±30 days) post-randomization
Time Frame: at 180 (±30) days and 1 year (±30 days) post-randomization
Distribution of mRS scores
at 180 (±30) days and 1 year (±30 days) post-randomization
Proportion of subjects with a favorable outcome (mRS 0-2) at 180 (±30) days and 1 year (±30 days) post-randomization
Time Frame: at 180 (±30) days and 1 year (±30 days) post-randomization
Proportion of subjects with a favorable outcome (mRS 0-2)
at 180 (±30) days and 1 year (±30 days) post-randomization
EQ-5D-5L score at 180 (±30) days and 1 year (±30 days) post-randomization
Time Frame: at 180 (±30) days and 1 year (±30 days) post-randomization
EQ-5D-5L score
at 180 (±30) days and 1 year (±30 days) post-randomization
Proportion of subjects with a Barthel Index (BI) ≥95 at 180 (±30) days and 1 year (±30 days) post-randomization
Time Frame: at 180 (±30) days and 1 year (±30 days) post-randomization
Proportion of subjects with a Barthel Index (BI) ≥95
at 180 (±30) days and 1 year (±30 days) post-randomization
All-cause mortality within 90 (±14) days post-randomization
Time Frame: within 90 (±14) days post-randomization
All-cause mortality
within 90 (±14) days post-randomization
Symptomatic intracranial hemorrhage (sICH) at 24 (±6) hours post-randomization (according to ECASS III criteria)
Time Frame: at 24 (±6) hours post-randomization
Symptomatic intracranial hemorrhage (sICH) ,according to ECASS III criteria
at 24 (±6) hours post-randomization
Serious adverse events (SAEs) within 90 (±14) days post-randomization
Time Frame: within 90 (±14) days post-randomization
SAEs
within 90 (±14) days post-randomization
Adverse events (AEs) within 90 (±14) days post-randomization
Time Frame: within 90 (±14) days post-randomization
AEs
within 90 (±14) days post-randomization
Early neurological deterioration (END), defined as an increase in NIHSS score of ≥4 points from baseline at 24 hours post-randomization
Time Frame: from baseline at 24 hours post-randomization
END, defined as an increase in NIHSS score of ≥4 points from baseline at 24 hours post-randomization
from baseline at 24 hours post-randomization
Proportion of subjects with severe disability at 90 (±14) days post-randomization (defined as mRS 4-6)
Time Frame: at 90 (±14) days post-randomization
Proportion of subjects with severe disability , defined as mRS 4-6
at 90 (±14) days post-randomization
Albumin-related adverse events within 90 (±14) days post-randomization
Time Frame: within 90 (±14) days post-randomization
Albumin-related adverse events
within 90 (±14) days post-randomization
SAEs and AEs within 180 (±30) days post-randomization
Time Frame: within 180 (±30) days post-randomization
SAEs and AEs
within 180 (±30) days post-randomization
SAEs and AEs within 1 year (±30 days) post-randomization
Time Frame: within 1 year (±30 days) post-randomization
SAEs and AEs
within 1 year (±30 days) post-randomization

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Levels of inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-10) in the blood at 24 (±6) hours post-randomization
Time Frame: at 24 (±6) hours post-randomization
Levels of inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-10) in the blood
at 24 (±6) hours post-randomization
Serum albumin and B-type natriuretic peptide (BNP) levels at 24 (±6) hours post-randomization
Time Frame: at 24 (±6) hours post-randomization
Serum albumin and B-type natriuretic peptide (BNP) levels
at 24 (±6) hours post-randomization
Levels of inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-10) in the blood at 7 (±1) days post-randomization or at discharge (whichever occurs first)
Time Frame: at 7 (±1) days post-randomization or at discharge (whichever occurs first)
Levels of inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-10) in the blood
at 7 (±1) days post-randomization or at discharge (whichever occurs first)
Serum albumin and BNP levels at 7 (±1) days post-randomization or at dis charge (whichever occurs first)
Time Frame: at 7 (±1) days post-randomization or at dis charge (whichever occurs first)
Serum albumin and BNP levels
at 7 (±1) days post-randomization or at dis charge (whichever occurs first)
Net water uptake (NWU) at 24 (±6) hours post-randomization
Time Frame: at 24 (±6) hours post-randomization
Net water uptake (NWU)
at 24 (±6) hours post-randomization
Progression of net water uptake from baseline to 24 (±6) hours post-randomization
Time Frame: from baseline to 24 (±6) hours post-randomization
Progression of net water uptake
from baseline to 24 (±6) hours post-randomization
Cerebrospinal fluid (CSF) volume at 24 (±6) hours post-randomization
Time Frame: at 24 (±6) hours post-randomization
Cerebrospinal fluid (CSF) volume
at 24 (±6) hours post-randomization
Change in cerebrospinal fluid volume from baseline to 24 (±6) hours post-randomization
Time Frame: from baseline to 24 (±6) hours post-randomization
Change in cerebrospinal fluid volume
from baseline to 24 (±6) hours post-randomization
Analysis of the Index for Connectivity via Perivascular Spaces (ALPS index) at 24 (±6) hours post-randomization
Time Frame: at 24 (±6) hours post-randomization
Analysis of the Index for Connectivity via Perivascular Spaces (ALPS index)
at 24 (±6) hours post-randomization

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Tianjin Huanhu Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 30, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 30, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 16, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 16, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 26, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 26, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 16, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • TJHH_WM_20260111

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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