Innovations in Acute Stroke Reperfusion Strategies

Biosimilar Tenecteplase Versus Alteplase in Acute Ischemic Stroke: A Real World Study

Background and Purpose

There is an unmet need for a more effective thrombolytic agent in acute ischemic stroke (AIS) management. Various studies and meta-analysis suggest tenecteplase (TNK) as non-inferior over alteplase (rTPA). The present single-center study compares biosimilar TNK and rTPA in a tertiary care setting.

Methods

Data of patients who presented with AIS and underwent intravenous thrombolysis (IVT) were recruited retrospectively from January 2018 to July 2021. Primary efficacy outcome was a modified Rankin score (mRS) at 90 days dichotomized at < = 2. Qualitative and quantitative variables were assessed using Chi-square test and Student's t-test, respectively.

Results

A total of 160 patients, 103 in the rTPA and 57 in TNK group, were analyzed. The baseline characteristics were well matched apart from hypertension. Large artery atherosclerosis was the most frequent subtype of stroke among the two groups. Good functional outcome was seen in 47.92% of patients TNK and 64.77% of patients in rTPA group (p = 0.069). No difference was seen in the rates of any ICH (p = 0.29) and mortality at 3 months (p = 0.32) among the two groups.

Conclusion

This present study observed no difference in the efficacy and safety between biosimilar TNK and rTPA. Our findings are in concordance with published trials showing equivalence between the two molecules.

Tenecteplase versus alteplase for large vessel occlusion recanalization (T-FLAVOR): Trial protocol

Background

Tenecteplase has higher fibrin specificity with a longer half-life and the potential to achieve higher rates of recanalization than alteplase. A critical limitation of tenecteplase is no commercial use in Japan and no experience with its administration to Japanese patients.

Hypothesis

Tenecteplase is superior to alteplase in achieving recanalization on the initial angiogram when administered ≤4.5-hour of stroke onset in patients planned for mechanical thrombectomy (MT) in Japan where alteplase at the unique dose of 0.6mg/kg is officially used.

Methods

The Tenecteplase versus alteplase For LArge Vessel Occlusion Recanalization (T-FLAVOR) trial is an investigator-initiated, phase II, multicenter, prospective, randomized, open-label, masked-endpoint, superiority study. Eligibility criteria include acute ischemic stroke with pre-stroke modified Rankin Scale score ≤3 and large vessel occlusion (internal carotid artery, middle cerebral artery, or basilar artery) eligible for intravenous thrombolysis ≤4.5-hour and MT ≤6-hour of stroke onset. After completing the safety confirmation phase involving three patients who received non-masked tenecteplase (0.25 mg/kg), 220 patients will be randomized to two groups (1:1), intravenous alteplase (0.6mg/kg, n = 110) or tenecteplase (0.25mg/kg, n = 110), prior to MT.

Outcomes

In the safety confirmation phase, the primary outcome is symptomatic intracranial hemorrhage (sICH) ≤24-36-hour. In the randomized, comparative phase, the primary efficacy outcome is substantial angiographic reperfusion (mTICI grade 2b/2c/3) or absence of retrievable thrombus on the initial angiogram. The primary safety outcome is sICH ≤24-36-hour and 90-day mortality.

Discussion

T-FLAVOR may help determine if tenecteplase should be recommended as a routine clinical strategy before MT for Japanese stroke patients.

Trial registration

jRCTs051210055

Adapting Clinical Practice of Thrombolysis for Acute Ischemic Stroke Beyond 4.5 Hours: A Review of the Literature

Several clinical trials have demonstrated that advanced neuroimaging can select patients for recanalization therapy in an extended time window. The favorable functional outcomes and safety profile of these studies have led to the incorporation of neuroimaging in endovascular treatment guidelines, and most recently, also extended to decision making on thrombolysis. Two randomized clinical trials have demonstrated that patients who are not amenable to endovascular thrombectomy within 4.5 hours from symptoms discovery or beyond 4.5 hours from the last-known-well time may also be safely treated with intravenous thrombolysis and have a clinical benefit above the risk of safety concerns. With the growing aging population, increased stroke incidence in the young, and the impact of evolving medical practice, healthcare and stroke systems of care need to adapt continuously to provide evidence-based care efficiently. Therefore, understanding and incorporating appropriate screening strategies is critical for the prompt recognition of potentially eligible patients for extended-window intravenous thrombolysis. Here we review the clinical trial evidence for thrombolysis for acute ischemic stroke in the extended time window and provide a review of new enrolling clinical trials that include thrombolysis intervention beyond the 4.5 hour window.

Comparison of thrombolytic agents in treatment of patients with acute ischemic stroke; findings from a single centre follow up study in real-life settings

BACKGROUND AND OBJECTIVES

Health outcome data of thrombolysis in patients with acute ischemic stroke in real life-settings in India are scarce. We studied the clinical profile, risk factors and functional outcome of patients with acute ischemic stroke (AIS) who were thrombolysed.

METHODS

In a single centre retrospective study from January 2017 to June 2020, we analysed the data of adult patients with AIS presented within 4.5 h of symptom onset. We included patients if they had NIHSS score ≥4, modified Rankin score of 2 or less before the stroke onset and without evidence of haemorrhage. Modified Rankin score of two or less at the end of three months was defined as the primary efficacy outcome. The development of symptomatic intracerebral haemorrhage was considered as the primary safety outcome. We tried to analyse the primary safety and efficacy outcomes between two thrombolytic agents.

RESULTS

Ninety patients (Tenecteplase = 61; Alteplase, n = 29) underwent stroke thrombolysis during the study period. The mean age was 64.3 years in Tenecteplase group and 63.2 years in Alteplase group. Twenty patients were aged more than 75 years. Hypertension was the most common comorbidity in both the groups (72% and 72.4%). Median mRS score at 3-months was 1 in Tenecteplase group and 0.5 in Alteplase group (p < 0.001), however there was no statistically significant difference between both treatment groups in terms of NIHS score at 24 h (70.4% vs 51.7%, p = 0.08), functional recovery calculated with mRS at 3-month (83.6% vs 79.3%, p = 0.62) or in terms of symptomatic ICH (9.8% and 17.2% p = 0.36).

CONCLUSION

Tenecteplase appears to have similar clinical outcomes as Alteplase for stroke thrombolysis. Given the relatively low-cost and ease of administration, Tenecteplase may be better than Alteplase for management of acute ischemic stroke.

Are there socio-economic inequities in access to reperfusion therapy: The stroke 69 cohort

BACKGROUND AND PURPOSE

Low socio-economic status of individuals has been reported to be associated with a higher incidence of stroke and influence the diagnosis after revascularization. However, whether it is associated with poorer acute stroke management is less clear. To determine whether social deprivation was associated with a poorer access to reperfusion therapy, either intravenous thrombolysis (IVT) and/or endovascular thrombectomy (EVT) in a population-based cohort.

METHODS

Over a 14-month period, all consecutive adult patients admitted to any emergency department or a comprehensive or primary stroke center (CSC/PSC) of the Rhône county with a confirmed ischemic stroke were included. The socioeconomic status of each patient was measured using the European Deprivation Index (EDI). The association between EDI and access to reperfusion therapy was assessed in univariate and multivariate logistic regression analyses.

RESULTS

Among the 1226 consecutive IS patients, 316 (25%) were admitted directly in a PSC or CSC, 241 (19.7%) received a reperfusion therapy; 155 IVT alone, 20 EVT alone, and 66 both therapies. Median age was 79 years, 1030 patients had an EDI level of 1 to 4, and 196 an EDI of 5 (the most deprived group). The most deprived patients (EDI level 5) did not have a poorer access to reperfusion therapy compared to all other patients in univariate (OR 1.22, 95%CI [0.85; 1.77]) nor in multivariate analyses (adjOR 0.97, 95%CI [0.57; 1.66]).

CONCLUSIONS

We did not find any significant association between socioeconomic deprivation and access to reperfusion therapy. This suggests that the implementation of EVT was not associated with increased access inequities.

Neuroprotective effect of magnesium supplementation on cerebral ischemic diseases

Ischemic encephalopathy is associated with a high mortality and rate of disability. The most common type of ischemic encephalopathy, ischemic stroke, is the second leading cause of death in the world. At present, the main treatment for ischemic stroke is to reopen blocked blood vessels. However, despite revascularization, many patients are not able to achieve good functional results. At the same time, the strict time window (<4.5 h) of thrombolytic therapy limits clinical application. Therefore, it is important to explore effective neuroprotective drugs for the treatment of ischemic stroke. Magnesium is a natural calcium antagonist, which exerts neuroprotective effects through various mechanisms. However, while most basic studies have shown that magnesium supplementation can help treat cerebral ischemia, intravenous magnesium supplementation in large clinical trials has failed to improve prognosis of ischemic patients. Therefore, we review the basic and clinical studies of magnesium supplementation for cerebral ischemia. According to the route of administration, treatment can be divided into intraperitoneal magnesium supplementation, intravenous magnesium supplementation, arterial magnesium supplementation and intracranial magnesium supplementation. We also summarized the potential influencing factors of magnesium ion intervention in cerebral ischemia injury. Finally, in combination with influencing factors derived from basic research, this article proposes three future research directions, including magnesium supplementation into the circulatory system combined with magnesium supplementation in the lateral ventricle, magnesium supplementation in the lateral ventricle combined with hypothermia therapy, and lateral ventricle magnesium supplementation combined with intracarotid magnesium supplementation combined with selective hypothermia.

Minocycline exhibits synergism with conditioned medium of bone marrow mesenchymal stem cells against ischemic stroke

Several lines of evidence show that a conditioned medium of bone marrow mesenchymal stem cells (BM-MSCcm) improve functional recovery after ischemic stroke but do not reduce ischemic lesions. It is important to develop a treatment strategy that can exhibit a synergistic effect with BM-MSCcm against ischemic stroke. In this study, the effect of BM-MSCcm and/or minocycline was examined in culture and in a middle cerebral artery occlusion (MCAo) animal model. In neuron-glial cultures, BM-MSCcm and combined treatment, but not minocycline, effectively increased neuronal connection and oligodendroglial survival. In contrast, minocycline and combined treatment, but not BM-MSCcm, reduced toxin-induced free radical production in cultures. Either minocycline or BM-MSCcm, or in combination, conferred protective effects against oxygen glucose deprivation-induced cell damage. In an in vivo study, BM-MSCcm and minocycline were administered to rats 2 h after MCAo. Monotherapy with BM-MSCcm or minocycline after ischemic stroke resulted in 9.4% or 17.5% reduction in infarction volume, respectively, but there was no significant difference. Interestingly, there was a 33.9% significant reduction in infarction volume by combined treatment with BM-MSCcm and minocycline in an in vivo study. The combined therapy also significantly improved grasping power, which was not altered by monotherapy. Furthermore, combined therapy increased the expression of neuronal nuclei in the peri-infarct area and hippocampus, and concurrently decreased the expression of ED1 in rat brain and the peri-infarct zone. Our data suggest that minocycline exhibits a synergistic effect with BM-MSCcm against ischemic stroke not only to improve neurological functional outcome but also to reduce cerebral infarction.

Mechanisms in blood-brain barrier opening and metabolism-challenged cerebrovascular ischemia with emphasis on ischemic stroke

Stroke is the leading cause of disability among adults as well as the 2nd leading cause of death globally. Ischemic stroke accounts for about 85% of strokes, and currently, tissue plasminogen activator (tPA), whose therapeutic window is limited to up to 4.5 h for the appropriate population, is the only FDA approved drug in practice and medicine. After a stroke, a cascade of pathophysiological events results in the opening of the blood-brain barrier (BBB) through which further complications, disabilities, and mortality are likely to threaten the patient's health. Strikingly, tPA administration in eligible patients might cause hemorrhagic transformation and sustained damage to BBB integrity. One must, therefore, delineate upon stroke onset which cellular and molecular factors mediate BBB permeability as well as what key roles BBB rupture plays in the pathophysiology of stroke. In this review article, given our past findings of mechanisms underlying BBB opening in stroke animal models, we elucidate cellular, subcellular, and molecular factors involved in BBB permeability after ischemic stroke. The contribution of each factor to stroke severity and outcome is further discussed. Determinant factors in BBB permeability and stroke include mitochondria, miRNAs, matrix metalloproteinases (MMPs), immune cells, cytokines, chemokines, and adhesion proteins. Once these factors are interrogated and their roles in the pathophysiology of stroke are determined, novel targets for drug discovery and development can be uncovered in addition to novel therapeutic avenues for human stroke management.

Current Drug Treatment of Acute Ischemic Stroke: Challenges and Opportunities

Patient-level health outcomes for acute ischemic stroke have significantly improved in the last decade primarily because of superior overall case management, availability of tailored drug interventions, and advances in endovascular procedures. Nevertheless, disease registries show a "quality gap" across social determinants of health and between in-hospital and community-onset strokes. Several factors, including financing and infrastructure constraints, limited expertise, and clinical uncertainty, still prevent adherence to evidence-based clinical guidelines and optimal care pathways. This paper critically appraises existing evidence on the use of drug therapies in acute ischemic stroke, in an attempt to resolve physician-related subjective barriers for effective acute management of the disease. We conclude that intravenous administration of rt-PA (recombinant tissue-type plasminogen activator, alteplase) is an essential component of acute-phase pharmacologic treatment and a driver for the improvement of overall ischemic stroke health outcomes. The safety profile of alteplase and similar treatments are well within the patient benefit zone of eligible patients when compared to non-treatment alternatives. Monomodal neuroprotective drugs with single or pleiotropic mechanisms of action have failed to support long-term sustainable results. Drugs with complex mechanisms of action that promote neurorecovery, such as cerebrolysin, are valid options for adjunctive treatment of acute ischemic stroke. Recent years have shown clear improvements in the methodology and design of clinical trials, with an increase in overall internal and external validity. A better understanding of study limitations has not hindered, but enhanced their potential to contribute, together with sometimes superior data sources, to health decision making.

ADAMTS13: An Emerging Target in Stroke Therapy

Thrombosis is the predominant underlying mechanism of acute ischemic stroke (AIS). Though thrombolysis with tPA has been proven to be effective in treating AIS within the time window, the majority of AIS patients fail to receive tPA due to various reasons. Current medical therapies for AIS have limited efficacy and pose a risk of intracerebral hemorrhage. ADAMTS13 (a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13) is a metalloprotease that effectively breaks down the von Willebrand Factor (VWF), a key factor in thrombus formation. Previous studies have proven that dysfunction of ADAMTS13 is associated with many diseases. Recently, ADAMTS13 has been reported to be closely related to stroke. In this review, we briefly described the structure of ADAMTS13 and its role in thrombosis, inflammation, as well as angiogenesis. We then focused on the relationship between ADAMTS13 and AIS, ranging from ischemic stroke occurrence, to AIS treatment and prognosis. Based on research findings from in vitro, animal, and clinical studies, we propose that ADAMTS13 is a potential biomarker to guide appropriate treatment for ischemic stroke and a promising therapeutic agent for tPA resistant thrombi.