Soluble Immune Checkpoint Molecules as Predictors of Efficacy in Immuno-Oncology Combination Therapy in Advanced Renal Cell Carcinoma

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

As combination strategies consisting immune-modulating drugs and chemotherapy (immune-oncology) are quickly becoming the standard-of-care, as in Japan, it is useful to predict which patients will actually benefit from these treatments.

The authors of this paper present a solid study that looks into the relation between soluble immune checkpoint molecules sPD-1, sPD-L2, and sLAG-3, and patient survival. The results are concisely presented, and discussed in the context of relevant literature. Overall, the authors show that sPD-L2 and sLAG-3 are predictive for treatment outcome of immune-oncology therapy. While the manuscript is already of good quality I have the following suggestions.

1. Table 1 provides a clear overview of patient characteristics, but as a reader I would prefer to see it structured in a heatmap, so that the reader can be informed on a patient-by-patient basis instead of a bulk overview.

2. Personally I would be interested to see if sPD-L2 and sLAG-3 are predictive when the patient group is stratified by treatment combination, rather than analyzed in bulk (treatment vs no treatment). Did the authors consider this, or was this technically not possible? It can be worthwhile to at least mention it in the text.

3. The ultimate experiment to perform would be to try and classify the same patients as used in the study, based on the expression of sPD-L2 and sLAG-3, and see if it can indeed be used to select patients for immuno-oncology therapy. What would be the success rate? I think the outcome would either (i) support the claims of the study, if the result is positive, and/or (ii) underscore the need for extra investigations, in case more markers are need to improve the predictability of treatment outcome, which are both useful pieces of information.

Comments on the Quality of English Language

The quality of English needs little to no improvement as the readability is good.

Author Response

Response to Reviewer #1

Comments 1: Table 1 provides a clear overview of patient characteristics, but as a reader I would prefer to see it structured in a heatmap, so that the reader can be informed on a patient-by-patient basis instead of a bulk overview. 

Response:

Thank you for your valuable suggestion. As the reviewer pointed out, I have attempted to create a heatmap for visual clarity for the reader. However, I have not been able to create a clear heatmap. This is due to the fact that it contains several different factors and that the units and numerical digits are different even for soluble immune checkpoint molecules. I consider the description of heatmap inappropriate and have left the patient background as Table 1.

Comments 2: Personally I would be interested to see if sPD-L2 and sLAG-3 are predictive when the patient group is stratified by treatment combination, rather than analyzed in bulk (treatment vs no treatment). Did the authors consider this, or was this technically not possible? It can be worthwhile to at least mention it in the text.

Response:

Thank you for your valuable comment. As suggested by the reviewer, we also think that stratified analysis by treatment (IO + IO vs IO + TKI) would be important. However, as indicated in the limitation in the Discussion, the sample size in this study is very small and we find it difficult to analyze by stratified treatment. We have added the following statement in the Discussion.

line 249-252; Discussion:

IO combination therapy (IO + IO and IO + TKI) are combined with different types of agents with different mechanisms of action, and it is debatable whether it is correct to compare these regimens in parallel.

Comments 3: The ultimate experiment to perform would be to try and classify the same patients as used in the study, based on the expression of sPD-L2 and sLAG-3, and see if it can indeed be used to select patients for immuno-oncology therapy. What would be the success rate? I think the outcome would either (i) support the claims of the study, if the result is positive, and/or (ii) underscore the need for extra investigations, in case more markers are need to improve the predictability of treatment outcome, which are both useful pieces of information.

Response:

Thanks for your helpful comments. This study only analyzes data from our institution and does not analyze data from another cohort. Therefore, we have not been able to verify what the success rate is and whether it is consistent with other cohorts. Therefore, we have added the following statement in the Discussion.

line 246-247; Discussion:

Our study had several limitations, including its single institute retrospective design and small sample size.

line 263-264; Conclusion:

Therefore, additional studies focusing on improving patient survival and the efficacy of IO combination therapy are required in order to validate our findings.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript presents a significant investigation concerning biomarkers poised to forecast the efficacy of combination immunooncological therapy in advanced kidney cancer—a crucial endeavor considering the dearth of biomarkers within this domain. The authors have identified soluble molecules governing the immune system, notably sPD-L2 and sLAG-3, as potential prognostic indicators for the effectiveness of IO therapy. Nonetheless, the manuscript is subject to certain limitations. Primarily, the study encompasses a limited cohort of patients, thereby potentially constraining the extrapolation of findings. Furthermore, the retrospective nature of the project renders the results vulnerable to errors associated with data analysis. Despite the scrutiny applied to sPD-L1, the study fails to corroborate its role as a prognostic biomarker for IO therapy efficacy, meriting further deliberation. Moreover, the absence of representative images depicting IHC staining of PD-L2 and LAG-3 is notable.

Author Response

Response to Reviewer #2

Comments:

The manuscript presents a significant investigation concerning biomarkers poised to forecast the efficacy of combination immunooncological therapy in advanced kidney cancer—a crucial endeavor considering the dearth of biomarkers within this domain. The authors have identified soluble molecules governing the immune system, notably sPD-L2 and sLAG-3, as potential prognostic indicators for the effectiveness of IO therapy. Nonetheless, the manuscript is subject to certain limitations. Primarily, the study encompasses a limited cohort of patients, thereby potentially constraining the extrapolation of findings. Furthermore, the retrospective nature of the project renders the results vulnerable to errors associated with data analysis. Despite the scrutiny applied to sPD-L1, the study fails to corroborate its role as a prognostic biomarker for IO therapy efficacy, meriting further deliberation. Moreover, the absence of representative images depicting IHC staining of PD-L2 and LAG-3 is notable.

Response:

Thank you for your helpful comments. This study has several limitations, and further study is needed to validate our findings. Therefore, we have revised the limitation in the Discussion and Conclusion as shown in red color. Additionally, as suggested by the reviewer, we have attached a representative image of PD-L2 and LAG-3 in immunohistochemistry in Figure 3.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have sufficiently implemented comments provided in the first review round. I believe that the scope of the manuscript fits well with the audience and the impact factor of the journal. As the manuscript was already good enough for publication by minor revisions, I now recommend that this manuscript is published in Current Oncology. 

Reviewer 2 Report

Comments and Suggestions for Authors

Based on their responses and the quality of their work, I recommend proceeding with the publication of their work.