PONE-D-23-41958Comparison of semaglutide in combined with empagliflozin versus semaglutide and empagliflozin monotherapy in non-alcoholic fatty liver disease with type 2 diabetes: study protocol for a randomised controlled clinical trialPLOS ONE

Dear Dr. Tian,

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Please, address all issues raised by all reviewers before sumit a revised version of your manuscript.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

The research question outlined is expected to address a valid academic problem or topic and contribute to the base of knowledge in the field.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

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2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses?

The manuscript should describe the methods in sufficient detail to prevent undisclosed flexibility in the experimental procedure or analysis pipeline, including sufficient outcome-neutral conditions (e.g. necessary controls, absence of floor or ceiling effects) to test the proposed hypotheses and a statistical power analysis where applicable. As there may be aspects of the methodology and analysis which can only be refined once the work is undertaken, authors should outline potential assumptions and explicitly describe what aspects of the proposed analyses, if any, are exploratory.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

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3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable?

Descriptions of methods and materials in the protocol should be reported in sufficient detail for another researcher to reproduce all experiments and analyses. The protocol should describe the appropriate controls, sample size calculations, and replication needed to ensure that the data are robust and reproducible.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: No

Reviewer #4: Yes

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4. Have the authors described where all data underlying the findings will be made available when the study is complete?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception, at the time of publication. The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: No

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

(Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Dear Editor, I’ve read with interest the draft called “Comparison of semaglutide in combined with empagliflozin versus semaglutide and empagliflozin monotherapy in non-alcoholic fatty liver disease with type 2 diabetes: study protocol for a randomised controlled clinical trial” by Yu-Hao Lin et al. However, some issues need to be raised.

- Acronyms need corresponding full word when compare firstly. Please, check throughout the entire manuscript.

- Abstract: The sentence “As the glucose-lowering agents…with NAFLD and T2DM” is not completely clear. I would suggest revising this period.

- Introduction: “Increased adiposity and insulin resistance contribute… of free fatty acids”. This period lacks reference. I would suggest seeing this recent review (Non-alcoholic Fatty Liver Disease (NAFLD), Type 2 Diabetes, and Non-viral Hepatocarcinoma: Pathophysiological Mechanisms and New Therapeutic Strategies. Biomedicines. 2023 Feb 6;11(2):468. doi: 10.3390/biomedicines11020468.).

- Methods: “trail”, please correct the typing error and revise throughout all the manuscript.

- Methods: I would suggest adding “Insulin treatment” among Exclusion Criteria.

- An English language revision is required.

Reviewer #2: The manuscript “Semaglutide Combined with Empagliflozin vs. Monotherapy for Non-Alcoholic Fatty Liver Disease in Type 2 Diabetes: A Randomized Clinical Trial” by Lin et al.

Overall, the use of English in the provided text is clear and formal, though a revision is necessary. The content is presented in a logical manner. The abstract provides a concise summary of the study's objectives, methods, key findings, and conclusions.

Here are some suggestions for improvement:

1. Title: I would change it as follows: “Semaglutide Combined with Empagliflozin vs. Monotherapy for Non-Alcoholic Fatty Liver Disease in Type 2 Diabetes: A Randomized Clinical Trial”

2. Abstract: revise English to streamline the language for improved readability while maintaining the essential information.

3. Introduction: please discuss this article as well doi: 10.3390/biomedicines11020322

4. Offer a brief context or explanation about FibroScan

5. Statistical analysis: Specify the variables that will be used in the ANCOVA model, particularly the covariates. For example, mention whether baseline values will be included as covariates.

6. Modified Intention-to-Treat Principle: Clarify the specific criteria for the modified intention-to-treat analysis, especially any rules for handling missing data or participants who deviate from the protocol.

7. Modified Intention-to-Treat Principle: Clarify the specific criteria for the modified intention-to-treat analysis, especially any rules for handling missing data or participants who deviate from the protocol.

8. Discussion: modify concurrent with coexistence

9. In the second paragraph, explain briefly why ultrasound is chosen to observe changes in CAP and LSM. Mention its advantages over liver biopsy in the context of the study: "Given the limitations of repeated liver biopsy, we have opted for ultrasound to observe changes in CAP and LSM among patients with T2DM and NAFLD in our study. Ultrasound is a noninvasive alternative that mitigates the invasive nature of sampling, addresses patient reluctance, and reduces postoperative risks, especially when repeated sampling is required."

10. Methods: correct trail with trial.

11. Exclusion criteria: the role of insulin and of other medications for type 2 diabetes, as well as dietary and physical activity intervention should be taken into account.

Reviewer #3: This is a protocol paper of a study comparing the efficacy of a GLP1 receptor agonist and a SGLT2 inhibitor in combination with each other and with a single agent in the treatment of NAFLD with type 2 diabetes.

The impact of the combination of the two drugs on the treatment of NAFLD is very interesting.

Major points

1. In the context of the study, it is understandable that CAP was selected as the primary outcome. However, the rationale for FFA and glucagon is not clear, and it should be clearly stated in the paper why they were selected as primary outcomes rather than secondary outcomes.

2. There is no mention of diet and exercise, and if these differ between groups, it may affect the results.

3. In the "interventions" paragraph, it is stated that patients who cannot sustain semaglutide 0.5 mg are excluded from the study. Considering that this is a double-blind study, shouldn't patients who cannot sustain treatment in all groups during the semaglutide 0.5 mg dosing period be excluded? Also, it is unclear how to handle cases in which doses other than semaglutide 0.5 mg cannot be sustained (i.e., 0.25 mg and 1 mg). What are the cases in which the dose cannot be tolerated?

Minor points

1. Inclusion criteria should specify the diagnostic basis for NAFLD and type 2 diabetes mellitus.

2. It should also be stated whether there are no restrictions on the lower and upper limits of HbA1c as well as liver enzymes. If there are no restrictions, can we say that a patient has type 2 diabetes with the same NAFLD whether the HbA1c is 5% or 12%?

Reviewer #4: Authors plan to conduct a 52-week double-blinded, randomized controlled trial to evaluate the efficacy and safety of semaglutide plus empagliflozin with each treatment alone in patients with NAFLD and T2DM. They will recruit 105 overweight/obese subjects with NAFLD and T2DM. They will evaluate the change from baseline to week 52 in primary outcome as well as several secondary endpoints.

1. Why only overweight/obese subjects?

2. Is there any safety concern to use semaglutide and empagliflozin at the same time?

3. Patients who cannot tolerate 0.5mg semaglutide will be excluded. What proportion of sample is expected to be dropped due to this? How will this affect the power?

4. Since the dosage of semaglutide is potentially different, will this affect the evaluation?

5. How to deal with adverse events during the trial? Will this affect the evaluation results?

6. Recruitment started in April 14, 2024. In other words, it has started! So how will the review affect the earlier recruitment?

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

Reviewer #4: No

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Semaglutide Combined with Empagliflozin vs. Monotherapy for Non-Alcoholic Fatty Liver Disease in Type 2 Diabetes: Study Protocol for A Randomized Clinical Trial

PONE-D-23-41958R1

Dear Dr. Tian,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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Kind regards,

Ferdinando Carlo Sasso, PhD, MD

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

No further comments

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Does the manuscript provide a valid rationale for the proposed study, with clearly identified and justified research questions?

The research question outlined is expected to address a valid academic problem or topic and contribute to the base of knowledge in the field.

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

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2. Is the protocol technically sound and planned in a manner that will lead to a meaningful outcome and allow testing the stated hypotheses?

The manuscript should describe the methods in sufficient detail to prevent undisclosed flexibility in the experimental procedure or analysis pipeline, including sufficient outcome-neutral conditions (e.g. necessary controls, absence of floor or ceiling effects) to test the proposed hypotheses and a statistical power analysis where applicable. As there may be aspects of the methodology and analysis which can only be refined once the work is undertaken, authors should outline potential assumptions and explicitly describe what aspects of the proposed analyses, if any, are exploratory.

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

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3. Is the methodology feasible and described in sufficient detail to allow the work to be replicable?

Descriptions of methods and materials in the protocol should be reported in sufficient detail for another researcher to reproduce all experiments and analyses. The protocol should describe the appropriate controls, sample size calculations, and replication needed to ensure that the data are robust and reproducible.

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

4. Have the authors described where all data underlying the findings will be made available when the study is complete?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception, at the time of publication. The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #2: Yes

Reviewer #3: Yes

Reviewer #4: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above and, if applicable, provide comments about issues authors must address before this protocol can be accepted for publication. You may also include additional comments for the author, including concerns about research or publication ethics.

You may also provide optional suggestions and comments to authors that they might find helpful in planning their study.

(Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #2: I have no further comments. In my opinion the paper can be further processed for publication. English has improved.

Reviewer #3: The authors have been courteous in revising the manuscript. I am satisfied that my questions have been replied appropriately.

Reviewer #4: Thanks for the response. All the raised comments have been successfully addressed. I have no further comments

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #2: No

Reviewer #3: No

Reviewer #4: No

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