The efficacy and safety of tenecteplase compared with alteplase in adult patients with acute ischemic stroke: an updated systematic review and meta-analysis of ten randomized controlled trials

Alteplase (tPA) is the only thrombolytic agent approved by the USFDA for acute ischemic stroke (AIS). Various randomized controlled trials (RCTs) have reported that Tenecteplase (TNK) is non-inferior to tPA resulting in its approval in various countries. We compared the efficacy and safety of TNK with tPA in adult patients with AIS by performing an updated systematic review and meta-analysis of recently published RCTs. Thus, PubMed and Cochrane databases were searched for RCTs until April 27, 2023. Data is represented as log-odds ratio (logOR) with 95% confidence interval (CI). The efficacy outcome measures included early neurological improvement (ENI), recanalization, functional outcomes at 90-days (modified Rankin Scale (mRS) 0–1 and 0–2), any intracranial hemorrhage (ICH), symptomatic ICH, and mortality within 90-days. Ten RCTs involving 5105 adult patients with AIS were included. The rates of ENI (logOR: 0.11; 95%CI: − 0.02, 0.23; p-value: 0.09), recanalization (logOR: 0.33; 95%CI: − 0.02, 0.68; p-value: 0.07), mRS 0–1 at 90-days (logOR: 0.09; 95%CI: − 0.02, 0.21; p-value: 0.11), and mRS 0–2 at 90-days (logOR: 0.07; 95%CI: − 0.29, 0.44; p-value: 0.70) were comparable among TNK and tPA. Similarly, TNK and tPA were comparable regarding any ICH (logOR: 0.06; 95%CI: − 0.11, 0.24; p-value: 0.47), symptomatic ICH (logOR: − 0.14; 95%CI: − 0.47, 0.20; p-value: 0.42), and all-cause mortality (logOR: − 0.04; 95%CI: − 0.23, 0.15; p-value: 0.70). Based on the included RCTs, TNK is comparable to tPA regarding efficacy and safety. Thus, TNK can be recommended as an alternative to tPA in adult patients with AIS.


Introduction
With around 6.5 million annual deaths, stroke is the second leading cause of death globally [1].In 2019, acute ischemic stroke (AIS), the most common stroke type, resulted in 3.29 million deaths, and this is projected to rise to 4.90 million by 2030 [2].In patients with AIS, thrombolysis is preferred [3], and Alteplase (tPA) is the drug of choice [4].For more than two decades, tPA remains the only thrombolytic agent approved by the USFDA for AIS.Though tPA produces rapid symptomatic improvement, when administered within the 4.5-h window period, and reduces the disability by 28% at 90-days [5], its utility is limited by the narrow time window, and adverse events (AEs) [6].Alteplase is reported to have limited fibrinolytic activity, as less than 50% patients achieve recanalization [7]; and among these patients, only 50% recanalize within 2-h of tPA use [8].Additionally, tPA is linked to the adverse effects involving the ischemic brain, including cytotoxicity and raised blood brain barrier permeability leading to cerebral edema [9].
Following the completion of ASSENT 2 Trial in 2000, Tenecteplase (TNK), a variant of tPA, was approved by the USFDA for thrombolysis in patients with acute myocardial infarction [10].Tenecteplase was developed to overcome the limitations of tPA, and is associated with various advantages, including economical, longer plasma half-life, high fibrin specificity, improved plasminogen activator inhibitor-1 resistance, and can be administered as a single bolus against the requirement of an infusion pump for the administration of tPA, thereby making it useful in the pre-hospital set-up [11].
Though various randomized controlled trials (RCTs) have reported non-inferiority of TNK against tPA, regarding efficacy and safety, TNK remains to be approved in US for the treatment of AIS, while it is approved in other countries [12].A recent meta-analysis (MA) concluded that TNK has better pharmacokinetic profile, higher rates of recanalization, as well as early neurological improvement (ENI), and thus can be used as an alternative to tPA [13].However, this MA included studies of various design, in addition to RCTs, thus introducing heterogeneity in the findings.While another recent MA demonstrated no significant difference between TNK and tPA, regarding functional outcome at 90-days and safety outcomes, including mortality and symptomatic intracerebral hemorrhage (SICH) [14].Various recently published RCTs with large sample size have reported favorable outcome with TNK relative to tPA [11,[15][16][17][18][19].Thus, in light of recently available evidences, we performed an updated MA with an aim to compare TNK with tPA in adult patients with AIS.

Protocol registration
The present MAs adhere to the 2020 guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) [20].The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO; Registration number: CRD42023437364).

Data sources and search strategy
We performed a literature search in PubMed and Cochrane databases to identify all free full text RCTs evaluating the efficacy and safety of intravenous thrombolysis with TNK and tPA for the treatment of AIS.The search period ranged from database inception to the April 27, 2023, and the literature was limited to English language.The keywords used included: "acute ischemic stroke, " "acute cerebral infarction, " "cerebrovascular accident, " "brain vascular accident, " "tenecteplase, " "recombinant human TNK tissue-type plasminogen activator, " "alteplase, " and "tissue plasminogen activator."

Eligibility criteria
This MA included RCTs fulfilling the following PICO criteria: population (P): adult patients with AIS and undergoing thrombolysis; intervention (I): intravenous TNK irrespective of the dose.Additionally, studies evaluating intraarterial TNK were excluded; control (C): tPA.Studies with no tPA as control group were excluded; outcomes (O): efficacy outcomes included early neurological improvement (ENI) based on ≥ 8 points reduction in the National Institutes of Health Stroke Scale (NIHSS), excellent neurological recovery based on modified Rankin Scale (mRS) 0-1, good neurological recovery based on mRS 0-2, and successful recanalization based on modified treatment in cerebral ischemia classification or Thrombolysis in Cerebral Infarction.Additionally, safety outcomes included any ICH, SICH, and all-cause mortality.
The articles in which patients did not have AIS, did not receive TNK and tPA, duplicate studies including the same patients presented in other included paper, nonrandomized trials, single-arm trials, observational studies, review articles, case reports, case series, letters to editor, conference abstracts, and posters were excluded.This MA included only the free full text RCTs, while paid RCTs and original studies with other study designs were excluded.

Selection process
For data extraction separately, two authors (KC and NS) performed the title and abstract screening against the above-mentioned eligibility criteria.This was followed by a full text screening of any retained studies of the first screening step.In both the stages, any disagreement was resolved by discussion to reach a consensus.The references of previously published meta-analyses, review articles, and original articles were screened manually.Additionally, the manual search involved screening through the references of the included articles to retrieve any missed papers.

Data extraction
Following the study selection, data was extracted, by two authors (KC and NS), with the help of a preformed data extraction excel sheet.The extracted data included study characteristics (first author name, year of publication, country, study design, sample size in each group, intervention dosages, main eligibility criteria, and time window); baseline information (age, sex, number of patients in each group, onset to infusion time, NIHSS score, time from onset to thrombolysis, and relevant stroke risk factors); and efficacy as well as safety outcomes data mentioned above.

Risk of bias
Two authors evaluated all the studies for the risk of bias (ROB) by utilizing the "Cochrane RoB 2: a revised tool for assessing the risk of bias in RCTs" [21].Any discrepancies arising during the entire process were handled through discussion.

Statistical analyses
With the help of STATA 10, a pairwise meta-analysis was performed to compare TNK (any dose) with tPA.From the included studies, dichotomous outcomes were used to generate log odds (logOR) with 95% confidence intervals (CIs).A meta-analysis was performed for each of the outcomes of interest.Heterogeneity was assessed with the I 2 statistic.If the I 2 statistic was > 50%, heterogeneity was considered significant and thus, the random effect model was used.Else, the fixed effect (Mantel-Haenszel) model was used.The pooled logORs were considered heterogenous if I 2 was > 50% and/or p-value < 0.05, based on Q-statistics.The publication bias was evaluated with the funnel plots.Statistical significance was considered at p < 0.05.

Data availability
The data supporting the findings of the present MA are available from the corresponding author on reasonable request.

Publication bias
With the help of funnel plot, we assessed the publication bias.If the funnel plot had symmetric distribution, there was absence of publication bias.While, the presence of asymmetric distribution suggested publication bias.As illustrated in Fig. 5A, B, funnel plots for each outcome measure had standard symmetric distribution, thereby suggesting no publication bias in the included RCTs.

Discussion
The principal findings of the present pair-wise MA suggest that TNK and tPA were comparable regarding efficacy measures, including rates of ENI, recanalization, excellent functional outcome at 90-days, and good functional outcome at 90-days.Moreover, TNK and tPA were comparable regarding safety measures, including rates of any ICH, SICH, and all-cause mortality.Thus, the present MA, involving the data of 5105 adult patients with AIS, demonstrates non-inferiority of TNK over tPA.
The quality of evidence is high, as the included RCTs have a low ROB, the included patients as well as the study outcomes are clinically relevant, and the degree of heterogeneity is not significant (I 2 range: 0-49.02%),except mRS 0-2 (I 2 : 85.08%; p-value: 0.0001).Apart from quality of evidence and comparable outcome measures, TNK is economical and associated with ease of administration      relative to tPA.Based on these merits, it is sufficient to recommend TNK over tPA in adult patients with AIS presenting within 4.5-h of onset.
Comparable efficacy and safety outcome measures among TNK and tPA, observed in the present MA, is consistent with the findings of recently published MA [14,27].Various RCTs have reported similar findings [15,17,18,[23][24][25].Parsons et al. reported that TNK resulted in significantly greater reperfusion and clinical improvement at 24-h relative to tPA.Tenecteplase (0.25 mg/kg) was superior to tPA for all efficacy outcomes, including absence of serious disability at 90-days [22].Campbell et al. observed that TNK (0.25 mg/kg) led to significantly greater reperfusion and functional outcome at 90-days [26].Bivard et al. evaluated the utility of TNK (0.25 mg/ kg) in mobile stroke units and found that patients who received TNK had significantly smaller perfusion lesion volume and greater reduction in NIHSS at hospital arrival [11].However, Kvistad et al. found that TNK led to significantly lower functional outcomes, higher rates of any ICH, and higher 90-days mortality [16].This adverse outcome was ascribed to higher dose of TNK (0.4 mg/ kg).
Better outcomes observed with TNK are attributed to its favorable pharmacokinetic properties, including a long duration of action, greater fibrin specificity, and more potent clot dissolution, resulting in faster vessel recanalization [28].Moreover, the ability to administer TNK as a rapid, single bolus infusion permits give-and-go strategy, thereby reducing the administration time to around a minute.This results in reduced door-in to door-out time.This is of particular importance in remote settings with inadequate resources that lack access to thrombectomy centers, and rely on ambulances for transporting the patients to specialized stroke centers.This is contrary to tPA that requires multiple boluses and around 1-h for infusion [29].
A recently published randomized, controlled, noninferiority trial comparing TNK with tPA in patients with AIS was not included in the present MA, as full-text of the article could not be retrieved.The ongoing phase 2 and 3 clinical trials comparing TNK with tPA in adult patients with AIS are: NCT03854500 (The Norwegian tenecteplase stroke trial 2 (NOR-TEST 2, Phase 3) [30], NCT05281549 (Thrombolysis treated with TNK-tPA in acute ischemic stroke patients (3T Stroke-II, Phase 2)) [31], NCT05745259 (Thrombolysis treated with TNK-tPA in acute ischemic stroke patients (3T Stroke-III, Phase 3)) [32], and NCT05626972 (Tenecteplase compared to alteplase for patients with large vessel occlusion suspicion before thrombectomy, Phase 3) [33].Moreover, another phase 3 clinical trial, NCT04915729, is evaluating TNK and tPA for improvement in recovery of post-stroke physical activity [34].Although the available evidence is sufficient to make a recommendation in favor of TNK relative to tPA in AIS, the results of ongoing studies are likely to add strength to the justification.
With inclusion of recently published RCT [18], the present MA provides the latest evidence for thrombolysis in adult patients with AIS.However, this MA has certain limitations, including: first, all the included RCTs, except one [23], had open-label and blinded outcome design, thereby introducing the performance bias.Second, the included RCTs differed in eligibility criteria, and methodology.Third, full-text of recently published RCT, Ferguson and Yadav [19], could not be retrieved.Forth, we did not compare the effect of various doses of TNK relative to tPA.

Conclusion
In the present MA, involving ten RCTs, we observed that TNK and tPA had comparable efficacy and safety.Based on the ease of administration and favorable pharmacokinetic profile, the present MA supports the use of TNK, as a reasonable alternative to tPA, for the treatment of adult patients with AIS.

Figure 4
Figure 4 illustrates the ROB assessed with the Cochrane ROB 2 tool.Overall, all the included RCTs had a low ROB.Additionally, all the RCTs had low ROB, when assessed with individual domains, including randomization process, deviation from the intended intervention, missing outcome data, measurement of the outcome, and selection of the reported result.

Fig. 3 Fig. 4 Fig. 5 A
Fig. 3 Forest plots of safety outcome measures.A Any ICH; B Symptomatic ICH; C mRS All-cause mortality.TNK Tenecteplase, tPA Alteplase, CI Confidence interval, ICH Intracranial hemorrhage; Statistical significance considered at p < 0.05

Table 1
Summary of the included studies ACA Anterior cerebral artery, BA Basilar artery, CI Confidence interval, CT Computed tomography, eGFR estimated glomerular filtration rate, ICA Internal carotid, MCA Middle cerebral artery, mRS modified Rankin Scale, NIHSS National Institutes of Health Stroke Scale, PCA Posterior cerebral artery, PROBE Prospective randomized open blinded end-point, RCT Randomized controlled trial, TNK Tenecteplase, tPA Alteplase

Table 2
Baseline characteristics of the included studies