Tenecteplase With or Without Mechanical Thrombectomy in Acute Ischemic Stroke at 4.5 to 24 h: An Updated Meta-Analysis of Randomized Controlled Trials

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Various randomized controlled trials (RCTs) have investigated the efficacy of extending the therapeutic window up to 24 hours. This updated meta-analysis aims to synthesize the results of these RCTs comparing TNK to best medical treatment (BMT) with or without endovascular thrombectomy. Authors conducted an updated pooled analysis of previous randomized controlled trials investigating the efficacy and safety of TNK administration within the extended therapeutical window.

The topic is very relevant to the field considering the morbidity and mortality of Acute ischemic stroke and burden on economy. 

It address a specific gap in the field and endorses that TNK use is associated with higher rates of recanalization, reflecting a greater proportion of  saved ischemic penumbra as assessed by perfusion imaging.

 

Methodology: is appropriate. Authors followed PRISMA guidelines, all RCTs comparing TNK  with BMT in adult patients between 4.5 and 24 hours were systematically searched. The primary endpoint was good functional outcome at 90 days (mRS 0-2) which was appropriate.

 

It definitely adds to the current literature on this subject though validates the other published material on similar subject.

In conclusion this meta-analysis demonstrated that TNK used between 4.5h and 24h is associated with improved rates of both good and excellent functional outcomes at 90  days compared with standard of care, with a more pronounced benefit observed in  patients treated with IVT alone, rather than those undergoing EVT plus IVT.

 

The conclusions are consistent with the evidence and arguments presented. The conclusion is supported by sufficient data.

The references are appropriate.

This manuscript is crisp and engage the readers throughout.

Discussion is concise.

Author Response

We sincerely thank the Reviewer for the careful evaluation of our manuscript and for the positive and constructive comments. Please find our point-by-point responses below.

Comment 1

The topic is very relevant to the field considering the morbidity and mortality of acute ischemic stroke and its economic burden. The study addresses a specific gap in the field and endorses that TNK use is associated with higher rates of recanalization, reflecting a greater proportion of saved ischemic penumbra as assessed by perfusion imaging.

Response:
We appreciate the Reviewer’s recognition of the clinical and socioeconomic importance of this topic. Acute ischemic stroke remains a major cause of disability and death worldwide, and identifying effective reperfusion strategies in the extended therapeutic window is of substantial clinical relevance. Our objective was indeed to address the existing evidence gap regarding the efficacy and safety of tenecteplase in the extended time window. We are pleased that the Reviewer recognizes the potential mechanistic relevance of improved recanalization and penumbral salvage associated with TNK treatment.

Comment 2

Methodology is appropriate. Authors followed PRISMA guidelines, all RCTs comparing TNK with BMT in adult patients between 4.5 and 24 hours were systematically searched. The primary endpoint was good functional outcome at 90 days (mRS 0–2), which was appropriate.

Response:
We appreciate the Reviewer’s positive assessment of our methodology. We carefully adhered to PRISMA recommendations to ensure transparency and methodological rigor. The selection of 90-day functional independence (mRS 0–2) as the primary endpoint was based on its widespread acceptance as a clinically meaningful outcome measure in acute stroke trials.

Comment 3

It definitely adds to the current literature on this subject, though it validates other published material on a similar subject.

Response:
We thank the Reviewer for this observation. We agree that our findings are generally consistent with previously published studies. However, we believe that the inclusion of recently completed randomized controlled trials and the updated pooled analysis provide a more comprehensive and robust estimate of the treatment effect, thereby strengthening the existing evidence base.

Comment 4

This meta-analysis demonstrated that TNK used between 4.5 and 24 hours is associated with improved rates of both good and excellent functional outcomes at 90 days compared with standard of care, with a more pronounced benefit observed in patients treated with IVT alone rather than those undergoing EVT plus IVT.

Response:
We appreciate the Reviewer’s accurate summary of our main findings. We agree that the observed differential effect between treatment subgroups is an important finding that may help guide future research and patient selection strategies in the extended therapeutic window.

Comment 5

The conclusions are consistent with the evidence and arguments presented. The conclusion is supported by sufficient data.The references are appropriate.

Response:
We thank the Reviewer for acknowledging the consistency between our conclusions and the evidence presented. We have made every effort to ensure that our interpretations remain balanced and supported by the available data.

Comment 6

This manuscript is crisp and engages the readers throughout. Discussion is concise.

Response:
We are grateful for this encouraging feedback and are pleased that the manuscript was found to be clear, concise, and engaging. We aimed to provide a focused discussion that highlights the clinical implications of our findings while avoiding unnecessary repetition of the results.

Once again, we sincerely thank the Reviewer for the positive evaluation of our work and for the valuable comments.

 

 

 

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

In this article, the authors performed a comprehensive meta-analysis of seven randomized controlled trials (RCTs) evaluating tenecteplase (TNK) administered 4.5–24 hours after acute ischemic stroke and comparing TNK with best medical treatment (BMT) including alteplase with or without mechanical thrombectomy (EVT). The authors found that TNK administration within the extended time window was associated with significantly higher proportion of good and excellent functional outcomes at 90 days and increased reperfusion rate especially in patients treated with IVT alone vs bridging therapy. Mortality was similar between groups while the incidence of symptomatic intracranial hemorrhage (sICH) was higher but not statistically significant.

A recently published meta-analysis reported similar findings (reference 29). However, the current meta-analysis was well conducted and methodologically sound following PRISMA guidelines. The manuscript is well written and clearly structured. The topic is clinically relevant and may be of interest to the readers of Neurology International.

Below are a few comments that could be addressed to improve robust interpretation of findings.

1. Abstract (Results): I suggest providing details regarding the effect of TNK on the reperfusion rate and clarifying that the increase in sICH incidence with TNK was not statistically significant.
2. Clarify the use of OR vs HR throughout the manuscript. In particular, the primary endpoint was measured at fixed time point but it was reported both as HR and OR.
3. Heterogeneity was properly assessed but the sources of heterogeneity and its clinical implication should be further discussed. Were other measures of heterogeneity considered?
4. I suggest expanding discussion on differences in definition and measurement of reperfusion across trials and the limitations in pooling data for this endpoint.

Minor comments:

1. Abbreviations should be defined only when first used and not throughout the manuscript.
2. Consider using consistent terminology for clarity: bridging therapy vs IVT+EVT; BMT vs standard of care.
3. There are minor typographical errors that need to be corrected (e.g., spacing).

Author Response

We sincerely thank the Reviewer for the careful and positive evaluation of our manuscript and for acknowledging the methodological rigor, clarity, and clinical relevance of our work. We are particularly grateful for the recognition that our meta-analysis was conducted in accordance with PRISMA guidelines and is well structured and clearly written. We agree that our findings are generally aligned with the existing literature; however, we believe that the inclusion of newly available randomized controlled trials and the updated pooled quantitative synthesis provide a more comprehensive and contemporary estimate of the efficacy and safety of tenecteplase in the extended therapeutic window. We thank the Reviewer for the constructive comments provided in the following sections, which have helped us further improve the robustness and interpretability of the manuscript. All points have been carefully addressed in the revised version, as detailed in the point-by-point responses below.

 

Comment 1

Abstract (Results): I suggest providing details regarding the effect of TNK on the reperfusion rate and clarifying that the increase in sICH incidence with TNK was not statistically significant.

 

 

Response:  

We thank the Reviewer for this helpful suggestion. In accordance with the comment, we revised the Results section of the Abstract to provide additional information regarding the effect of TNK on reperfusion and to clarify the interpretation of the safety findings (line 20-30). Specifically, we now state that TNK treatment was associated with higher reperfusion rates compared with BMT. Furthermore, we explicitly indicate that although the incidence of symptomatic intracranial hemorrhage (sICH) was numerically higher in the TNK group, the difference did not reach statistical significance. These modifications were made to improve the clarity and accuracy of the presentation of our findings.

 

Comment 2

 

Clarify the use of OR vs HR throughout the manuscript. In particular, the primary endpoint was measured at fixed time point but it was reported both as HR and OR.

 

Response: 

We thank the Reviewer for this important observation. In response to this comment, we revised the manuscript to ensure consistency in the reporting of effect measures throughout the text and figures. Specifically, all pooled analyses are now reported using odds ratios (ORs), including both the manuscript text and forest plots, as the evaluated outcomes were assessed at fixed follow-up time points rather than through time-to-event analyses. We believe this modification improves the methodological consistency and clarity of the presentation of results.

 

Comment 3

 

Heterogeneity was properly assessed but the sources of heterogeneity and its clinical implication should be further discussed. Were other measures of heterogeneity considered?

 

Response: 

We thank the Reviewer for this important comment. In response, we expanded the Discussion section (line 276 -293) to further address potential sources of heterogeneity and their possible clinical implications. In particular, we discussed the heterogeneity related to the use of endovascular thrombectomy (EVT) across studies, as well as differences in imaging selection strategies and diagnostic modalities used to define ischemic core, penumbra, and reperfusion.

Specifically, the included trials employed different imaging techniques (CT perfusion, diffusion-weighted MRI, perfusion–diffusion mismatch imaging) and heterogeneous threshold criteria, including variable cut-off values for ischemic core volume, perfusion lesion size, mismatch ratios, and Tmax delays. These methodological differences may have influenced patient selection, baseline infarct biology, and the estimation of reperfusion outcomes, thereby contributing to between-study heterogeneity.

 

Comment 4

I suggest expanding discussion on differences in definition and measurement of reperfusion across trials and the limitations in pooling data for this endpoint.

 

Response:

We thank the Reviewer for this insightful and important comment. We agree that heterogeneity in the definition and measurement of reperfusion across the included trials represents a relevant methodological issue that may influence the interpretation of pooled estimates. In response, we have expanded the Discussion (line 294-305) to explicitly address these differences. As highlighted by the Reviewer, the included studies employed heterogeneous imaging modalities and criteria to define salvageable tissue and reperfusion. Specifically, eligibility and perfusion assessment were based on different combinations of CT perfusion (CTP), diffusion-weighted imaging (DWI), and perfusion–diffusion MRI, using various automated post-processing software platforms (including RAPID, 3D-Slicer, CTPdoc, and AutoMIStar). Moreover, thresholds for defining ischemic core and penumbra varied across trials, including differences in relative cerebral blood flow cut-offs (<30%), time-to-maximum (Tmax >6 seconds), core volume limits (ranging from <50 mL to <70 mL), and mismatch ratios (ranging from >1.2 to >1.8). We have now emphasized that these methodological inconsistencies may have introduced variability in the assessment of reperfusion and penumbral salvage, potentially affecting between-study comparability and limiting the precision of pooled estimates for this endpoint. We further acknowledge that differences in imaging timing, software algorithms, and operational definitions of reperfusion across studies may have contributed to residual heterogeneity that cannot be fully accounted for in the meta-analysis. Finally, we have clarified in the revised Discussion that, while pooling these data provides an overall estimate of treatment effect, the observed variability across trials should be considered when interpreting the results, particularly for imaging-derived secondary endpoints such as reperfusion.

 

Minor comments:

1. Abbreviations should be defined only when first used and not throughout the manuscript.
2. Consider using consistent terminology for clarity: bridging therapy vs IVT+EVT; BMT vs standard of care.
3. There are minor typographical errors that need to be corrected (e.g., spacing).

 

Response to minor comments:

We really thank the Reviewer for these helpful comments. Here the responses:

1. Abbreviations have now been revised throughout the manuscript and are defined only at their first appearance, in accordance with journal style recommendations.
2. We agree regarding the importance of consistent terminology. Accordingly, we have standardized the terminology throughout the manuscript, consistently using “bridging therapy” instead of alternating with “IVT+EVT”, and “best medical treatment (BMT)” in place of varying expressions such as “standard of care”.
3. Minor typographical and formatting errors, including spacing inconsistencies, have been reviewed and corrected throughout the manuscript.

 

Reviewer 3 Report

Comments and Suggestions for Authors

This is an interesting meta-analysis of randomized, controlled trials addressing the issue of the benefit of Tenecteplase as a fibrinolytic treatment applied in patients with stroke out of the initial short-time window. The subject is handled adequately, statistical analysis is planned and used properly, literature survey is correct and conclusions drawn are justified. The paper could clearly profit from a few additional comments on a couple of issues for better understanding of the beneficial effects.

• Authors should comment in the introduction on the longer elimination half-life and higher fibrin specificity of tenecteplase as an advantage of the pharmacokinetic and pharmacodynamic profile. The latter though could prove to be deleterious, since tenecteplase bound on non-fixed D-Dimer structures could circulate longer and potentially cause distant bleeding events out of the targeted fibrin covered lesion of the to-be-treated cerebral infarction. Studies though did not show increased bleeding complications compared to alteplase. Authors could add this information in the introduction (e.g. lines 50-57) for better understanding of the benefits.
• Authors could try to explain why two of the studies (TRACE-III and OPTION) were considerably better than the others in terms of the outcomes (s. Fig. 1 and Fig. 2), what was the reason (lower initial lesion volume? Hidden limitation?).

Author Response

We sincerely thank the Reviewer for the positive and thoughtful evaluation of our manuscript. We are very grateful for the recognition of the adequacy of the study design, the appropriateness of the statistical analysis, the completeness of the literature search, and the validity of the conclusions drawn. We also appreciate the Reviewer’s constructive suggestion that the manuscript could benefit from additional discussion to further clarify and contextualize the observed beneficial effects of tenecteplase. In response, we have carefully expanded the Discussion section to address the requested points, including a more detailed interpretation of between-trial differences, imaging selection criteria, treatment timing, and potential biological mechanisms underlying the observed treatment effects.We believe that these additions have strengthened the manuscript and improved the clarity and depth of interpretation of the findings.

 

Comment 1:

Authors should comment in the introduction on the longer elimination half-life and higher fibrin specificity of tenecteplase as an advantage of the pharmacokinetic and pharmacodynamic profile. The latter though could prove to be deleterious, since tenecteplase bound on non-fixed D-Dimer structures could circulate longer and potentially cause distant bleeding events out of the targeted fibrin covered lesion of the to-be-treated cerebral infarction. Studies though did not show increased bleeding complications compared to alteplase. Authors could add this information in the introduction (e.g. lines 50-57) for better understanding of the benefits.

 

Response:

We thank the Reviewer for this insightful comment. We agree that additional clarification of the pharmacokinetic and pharmacodynamic properties of TNK would improve the reader’s understanding of its clinical profile. In accordance with the suggestion, we have expanded the Introduction to include a discussion of TNK’s longer elimination half-life and higher fibrin specificity compared with alteplase. We also acknowledge the theoretical concern that increased fibrin specificity and prolonged circulation of TNK could, in principle, raise the risk of off-target thrombolytic activity (e.g., interaction with circulating fibrin degradation products such as D-dimers), potentially leading to distant bleeding events. However, we have clarified that available clinical evidence has not demonstrated a significatly higher increased risk of symptomatic or systemic hemorrhagic complications compared with alteplase, supporting its overall safety profile (line 60-67).

 

Comment 2:

Authors could try to explain why two of the studies (TRACE-III and OPTION) were considerably better than the others in terms of the outcomes (s. Fig. 1 and Fig. 2), what was the reason (lower initial lesion volume? Hidden limitation?).

 

Response:

We thank the Reviewer for this important observation. We have now tried to clarify this aspect in the revised Discussion (line 220-264).

The more favourable outcomes observed in TRACE-III and OPTION are likely explained by distinct but complementary selection mechanisms rather than a uniform treatment effect across trials. OPTION enrolled a highly selected population with minimal baseline ischemic injury and exclusion of large vessel occlusion, resulting in near-zero ischemic core volumes and an intrinsically high probability of good functional outcomes, potentially leading to a ceiling effect.In contrast, TRACE-III included patients with intermediate infarct core volumes but very large perfusion lesion volumes, indicating a substantial ischemic penumbra. This imaging profile suggests the presence of viable but hypoperfused tissue and preserved collateral circulation, identifying patients with a high potential for tissue salvage despite delayed presentation. Taken together, these differences suggest that OPTION reflects a “low baseline injury” population with inherently favourable prognosis, whereas TRACE-III represents a “high salvage potential” population characterized by a large mismatch profile. These complementary mechanisms likely contributed to the more pronounced treatment effects observed in these two trials compared with the remaining studies, which enrolled more heterogeneous populations with varying infarct burden, occlusion patterns, and imaging selection criteria. The time-to-randomization may be another determinant of thrombolysis efficacy in acute ischemic stroke, as longer delays are associated with progressive infarct growth, reduction of salvageable penumbra, and a higher likelihood of futile reperfusion. So we evaluated whether time-to-randomization may have influenced the more favourable outcomes observed in these two studies. However, in OPTION, although the median onset-to-randomization time was approximately 12.4 hours, the observed outcomes were likely driven primarily by highly restrictive imaging selection, resulting in minimal baseline ischemic injury (near-zero core volumes). This suggests that the treatment effect was largely influenced by patient selection rather than timing alone. Similarly, in TRACE-III, while a substantial proportion of patients were treated within 9 hours (~33.9%), the study population was characterized by a pronounced perfusion–core mismatch, with relatively small infarct cores and very large perfusion lesions. This indicates substantial salvageable tissue and preserved collateral circulation, which are strong predictors of response to reperfusion therapies, even beyond the influence of time alone. In contrast, other included trials exhibited greater heterogeneity in baseline imaging profiles, vascular occlusion patterns, and eligibility criteria, which may have diluted the observable treatment effect.

 

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

All comments have been addressed. The manuscript is definitely improved. I have no further comments.