Remdesivir-bisPropionate, a better derivative of remdesivir against SARS-CoV-2: Comparison of in vitro and in vivo PK/PD Study as well as its therapeutic potential

Ashok Chakraborty; Anil Diwan; Vijetha Chiniga; Vinod Arora; Yogesh Thakur; Jayant Tatake; Rajesh Pandey; Preetam Holkar; Neelam Holkar

doi:10.1371/journal.pone.0324811

Peer Review History

Original SubmissionDecember 10, 2024
2 Mar 2025 Decision Letter - Tamer M. Ibrahim, Editor PONE-D-24-39848Remdesivir-bisPropionate, a better Derivative of Remdesivir against SARS-CoV-2: Comparison of in vitro and in vivo PK/PD Study as well as its Therapeutic PotentialPLOS ONE Dear Dr. Chakraborty, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Apr 16 2025 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols . We look forward to receiving your revised manuscript. Kind regards, Tamer M. Ibrahim Academic Editor PLOS ONE Journal Requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. PLOS requires an ORCID iD for the corresponding author in Editorial Manager on papers submitted after December 6th, 2016. Please ensure that you have an ORCID iD and that it is validated in Editorial Manager. To do this, go to ‘Update my Information’ (in the upper left-hand corner of the main menu), and click on the Fetch/Validate link next to the ORCID field. This will take you to the ORCID site and allow you to create a new iD or authenticate a pre-existing iD in Editorial Manager. 3. To comply with PLOS ONE submissions requirements, in your Methods section, please provide additional information regarding the experiments involving animals and ensure you have included details on (1) methods of sacrifice, (2) methods of anesthesia and/or analgesia, and (3) efforts to alleviate suffering. 4. Please include captions for your Supporting Information files at the end of your manuscript, and update any in-text citations to match accordingly. Please see our Supporting Information guidelines for more information: http://journals.plos.org/plosone/s/supporting-information [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #2: No Reviewer #3: Partly ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: No Reviewer #2: N/A Reviewer #3: No ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). 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 ****** 4. 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: No Reviewer #3: No ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The manuscript entitled “Remdesivir-bisPropionate, a better Derivative of Remdesivir against SARS-CoV-2:Comparison of in vitro and in vivo PK/PD Study as well as its Therapeutic Potential” has many mistakes, authors need to rectify many portions. o The introduction transitions abruptly between SARS-CoV-2 mechanisms, RDV pharmacology, and experimental approaches. Use connecting sentences or introductory phrases to guide the reader through the topics. Simplify or briefly summarize chemical details in the introduction, focusing on their relevance to the study. o What specific data or references support the claim about RDV’s low efficacy in humans? o Revise to: "FDA approved remdesivir, which was initially found effective against SARS-CoV in cell culture systems but showed less than 10% efficacy in humans, as reported." o Variations in terminology, such as "RDV" vs. "Remdesivir," and inconsistent naming of derivatives like "Remdesivir-bP." o Summarize ethical compliance in one concise paragraph. o Add quantitative comparisons (e.g., half-life, stability metrics) alongside qualitative findings. o Table-1 and Figure references are not accompanied by sufficient explanation in the text. o The author required to update recent references can be seen PMID: 35014595, 36936534, 35401674, 33618621, 35265451 o Provide a short explanation of why NV387 was chosen and its anticipated benefits. o Why does the introduction lack a proper background explaining why h-CoV-NL63 was chosen over SARS-CoV-2 itself as the model? Present statistical significance (p-values, confidence intervals) for the stability grading claims. o Specify which formulation components caused this side effect and how it could be mitigated. Good Luck! Reviewer #2: Review Report: 1. The abstract should be in a single paragraph with continuous form without breaking the sentences. Need to change the format. 2. The introduction part is not according to the journal style. So many sub headings in without objectives of the research work. 3. The materials and methods section, the authors just cut and paste of the student’s thesis, without following the PLOS ONE authors guideline. 4. The results and discussion part needs to rewritten. 5. Tables and figures are necessary. But the tables format needs to be changed as well as the clarity of the figures need to be improved. Reviewer #3: Dear Author, Thank you for submitting your abstract. Your study presents a promising approach to enhancing the stability and antiviral efficacy of remdesivir through the development of a bis-propionate derivative and the application of a protective biopolymer. Below are my comments and recommendations to improve clarity, scientific rigor, and adherence to journal requirements: 1. Title: The title effectively captures the focus of the study; however, refinement is needed to enhance clarity, conciseness, and scientific precision. Consider rewording to ensure it accurately reflects the study's scope and findings while maintaining readability. 2. Abstract: While the abstract presents the key aspects of the study, it does not fully align with the journal’s formatting and structural requirements. Ensure that it adheres to the prescribed format, including clear background, objective, methods, results, and conclusion sections, if required. 3. Introduction, Methods, Results, and Discussion: These sections require substantial revision to align with journal guidelines. The introduction should clearly define the research gap and rationale, the methods should provide sufficient experimental details for reproducibility, and the results and discussion should be presented in a logical and well-structured manner. Strengthening data interpretation and contextualizing findings within the existing literature will improve scientific rigor. 4. Overall Manuscript Quality: A more refined and structured revision is necessary to enhance readability, coherence, and alignment with journal standards. Consider revising the manuscript to improve clarity, logical flow, and adherence to scientific writing conventions. I strongly recommend revising the manuscript in accordance with the journal’s formatting and content guidelines to improve its suitability for publication ****** 6. 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 #1: Yes: Shahzaib Ahamad Reviewer #2: Yes: Sitesh Chandra Bachar Reviewer #3: No ******** [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org . Please note that Supporting Information files do not need this step. Attachments Attachment Submitted filename: Review Report PONE-D-24-39848.doc https://doi.org/10.1371/journal.pone.0324811.r001
Revision 1
14 Apr 2025 Author Response PONE-D-24-39848 [03/28/2025] Remdesivir-bisPropionate, a better Derivative of Remdesivir against SARS-CoV-2: Comparison of in vitro and in vivo PK/PD Study as well as its Therapeutic Potential PLOS ONE Reviewer #1: The manuscript entitled “Remdesivir-bisPropionate, a better Derivative of Remdesivir against SARS-CoV-2: Comparison of in vitro and in vivo PK/PD Study as well as its Therapeutic Potential” has many mistakes, authors need to rectify many portions. o The introduction transitions abruptly between SARS-CoV-2 mechanisms, RDV pharmacology, and experimental approaches. Use connecting sentences or introductory phrases to guide the reader through the topics. Simplify or briefly summarize chemical details in the introduction, focusing on their relevance to the study. AC: Revised accordingly as shown below: Introduction COVID-19, a communicable pandemic respiratory infectious disease, is caused by a single-stranded RNA virus (SARS-CoV-2), which is similar to SARS-CoV-1. However, SARS-CoV-2 is more virulent than SARS-CoV-1, as the former causes cytokine release, septic shock, and blood clot formation that ultimately becomes cause fatal death in some individuals [1, 2]. As a mechanism of action the virus uses five different proteins, one is the spike protein “S”, which helps the virus to bind with the host cell receptor, and the others are “M” membrane protein, “E” envelope protein, “N” nucleocapsid protein, and certain other accessory proteins [3]. The M protein maintains the viral integrity [4], while the E protein plays a vital role in assembling the corona virus. The “N” protein maintains the nucleocapsid structure into a helical assembly. The accessory proteins are responsible for viral-host interactions and also for replication of virus [5, 6]. The viral replication involves an RNA-dependent RNA polymerase (RdRp), helicase, exonuclease N and some accessory proteins [5-8]. Fig.1 represents the schematic structure of SARS coronavirus. o What specific data or references support the claim about RDV’s low efficacy in humans? AC: The low EC50 values from in vitro studies did not reflect the drug’s clinical results, which was less than 10% efficacy in humans, as reported [33]. Further, the non-uniform distribution of remdesivir raises causes unwanted drug accumulation, potential toxicity, and the development of drug resistance discourage its use in human (Wang Z, Yang L, Song X-Q. Oral GS-441524 derivatives: next-generation inhibitors of SARS‐CoV‐2 RNA‐dependent RNA polymerase. Front Immunol. 2022;13:1015355. doi:10.3389/fimmu.2022.1015355). o Variations in terminology, such as "RDV" vs. "Remdesivir," and inconsistent naming of derivatives like "Remdesivir-bP." AC: Corrected o Summarize ethical compliance in one concise paragraph. AC: Done accordingly o Add quantitative comparisons (e.g., half-life, stability metrics) alongside qualitative findings. AC: Done accordingly o Table-1 and Figure references are not accompanied by sufficient explanation in the text. AC: Table-1 is mentioned in “Experimental procedure” section. o The author required to update recent references can be seen PMID: 35014595, 35401674, 33618621, 35265451 AC: Now, Included in the discussion section with 3 new Refs. o Provide a short explanation of why NV387 was chosen and its anticipated benefits. AC: HCoV-NL63 was reported in 1981 and 1988 that the virus has been circulating and causing disease in the human population for a long time. This virus causes LRTIs and URTIs in 1.0–9.3% of children, the elderly and the immune-compromised, with symptoms ranging from mild to severe. Current data clearly show that HCoV-NL63, which is BSL-2 compatible, share the same cellular receptor, ACE-2, similar to the most pathogenic BSL-2-incompatible SARS virus. Some similarities along with some dissimilarities of NL-63 and SARS-CoV in host cell entry mechanism and pathogenicity may open up a new strategy to find a proper therapeutics for the most virulent SARS virus. o Why does the introduction lack a proper background explaining why h-CoV-NL63 was chosen over SARS-CoV-2 itself as the model? AC: Now included in more appropriate position in the Materials and Method section where the infection methodologies were written. o Present statistical significance (p-values, confidence intervals) for the stability grading claims. AC: Done accordingly o Specify which formulation components caused this side effect and how it could be mitigated. AC: We didn’t notice and therefore didn’t mention any such side-effects. Reviewer #2: Review Report: 1. The abstract should be in a single paragraph with continuous form without breaking the sentences. Need to change the format. AC: Rewritten accordingly 2. The introduction part is not according to the journal style. So many sub headings in without objectives of the research work. AC: Rearranged and rephrased. 3. The materials and methods section, the authors just cut and paste of the student’s thesis, without following the PLOS ONE authors guideline. AC: Changed per advice of the reviewer. 4. The results and discussion part needs to rewritten. AC: Changed per advice of the reviewer. 5. Tables and figures are necessary. But the tables format needs to be changed as well as the clarity of the figures need to be improved. AC: Changed per advice of the reviewer. Reviewer #3: Dear Author, Thank you for submitting your abstract. Your study presents a promising approach to enhancing the stability and antiviral efficacy of remdesivir through the development of a bis-propionate derivative and the application of a protective biopolymer. Below are my comments and recommendations to improve clarity, scientific rigor, and adherence to journal requirements: 1. Title: The title effectively captures the focus of the study; however, refinement is needed to enhance clarity, conciseness, and scientific precision. Consider rewording to ensure it accurately reflects the study's scope and findings while maintaining readability. AC: Title changes as: Remdesivir-bisPropionate, a better Derivative of Remdesivir to target SARS-CoV-2 2. Abstract: While the abstract presents the key aspects of the study, it does not fully align with the journal’s formatting and structural requirements. Ensure that it adheres to the prescribed format, including clear background, objective, methods, results, and conclusion sections, if required. AC: Now it is rearranged as: Abstract FDA approved remdesivir, which was though very effective against SARS-corona virus in cell culture system but in human its efficacy was below 10%, as reported. The main reasons are due to the poor stability of remdesivir in presence plasma. In order to increase the protective strength of remdesivir we took couple of approaches, one, to make an alternative but better derivative of remdesivir as remdesivir bis-propionate, and the other is to use our platform- designed biopolymer (NV387) to protect remdesivir compound from degradation in presence of plasma. Here we present our results as: (1) Remdesivir-bP is much more stable in vivo compared to remdesivir alone. (2) Remdesivir-bP when encapsulated within biopolymer, NV387, its stability is further enhanced. (3) The antiviral activity is also increased against NL-63 infection to rat model, compared to naked and/or encapsulated remdesivir. (4) The antiviral efficacy of the remdesivir pro-drug, therefore, can be mathematically drawn as follows: remdesivir-bP-encapsulated > remdesivir-encapsulated > remdesivir-bP > remdesivir. 3. Introduction, Methods, Results, and Discussion: These sections require substantial revision to align with journal guidelines. The introduction should clearly define the research gap and rationale, the methods should provide sufficient experimental details for reproducibility, and the results and discussion should be presented in a logical and well-structured manner. Strengthening data interpretation and contextualizing findings within the existing literature will improve scientific rigor. AC: Rearranged and rephrased. 4. Overall Manuscript Quality: A more refined and structured revision is necessary to enhance readability, coherence, and alignment with journal standards. Consider revising the manuscript to improve clarity, logical flow, and adherence to scientific writing conventions. AC: Rearranged and rephrased. I strongly recommend revising the manuscript in accordance with the journal’s formatting and content guidelines to improve its suitability for publication. AC: Rearranged and rephrased. Attachments Attachment Submitted filename: 3-PONE-Rebuttal-032825.pdf https://doi.org/10.1371/journal.pone.0324811.r002
2 May 2025 Decision Letter - Tamer M. Ibrahim, Editor Remdesivir-bisPropionate, a better Derivative of Remdesivir against SARS-CoV-2: Comparison of in vitro and in vivo PK/PD Study as well as its Therapeutic Potential PONE-D-24-39848R1 Dear Dr. Chakraborty, 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. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice will be generated when your article is formally accepted. Please note, if your institution has a publishing partnership with PLOS and your article meets the relevant criteria, all or part of your publication costs will be covered. Please make sure your user information is up-to-date by logging into Editorial Manager at Editorial Manager® and clicking the ‘Update My Information' link at the top of the page. If you have any questions relating to publication charges, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Tamer M. Ibrahim Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: https://doi.org/10.1371/journal.pone.0324811.r003
Formally Accepted
Acceptance Letter - Tamer M. Ibrahim, Editor PONE-D-24-39848R1 PLOS ONE Dear Dr. Chakraborty, I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now being handed over to our production team. At this stage, our production department will prepare your paper for publication. This includes ensuring the following: * All references, tables, and figures are properly cited * All relevant supporting information is included in the manuscript submission, * There are no issues that prevent the paper from being properly typeset You will receive further instructions from the production team, including instructions on how to review your proof when it is ready. Please keep in mind that we are working through a large volume of accepted articles, so please give us a few days to review your paper and let you know the next and final steps. Lastly, if your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. If we can help with anything else, please email us at customercare@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Associate Professor Tamer M. Ibrahim Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0324811.r004

Open letter on the publication of peer review reports

PLOS recognizes the benefits of transparency in the peer review process. Therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. Reviewers remain anonymous, unless they choose to reveal their names.

We encourage other journals to join us in this initiative. We hope that our action inspires the community, including researchers, research funders, and research institutions, to recognize the benefits of published peer review reports for all parts of the research system.

Learn more at ASAPbio .