Targeted Therapy with Sirolimus and Nivolumab in a Child with Refractory Multifocal Anaplastic Ependymoma

Round 1

Reviewer 1 Report

Manuscript:

Targeted therapy with sirolimus and nivolumab in a child with refractory multifocal anaplastic ependymoma

Journal: Cancers

This manuscript is well aligned with Cancers.

I am confident to review this paper as I have worked in the field of paediatic brain cancer since 2004. I have a good understanding of the underlying genetic mechanisms of these diseases, especially ependymoma, as well as their clinical treatments and late effects. My own research focuses on novel therapeutics and I have strong knowledge of the PI3K pathway.

The entire paper contains some grammatical/language errors. I recommend the journal employ a copy editor to correct these errors to improve the quality of the readers’ experience.

Specific comments:

Abstract

• Rephrase “badly poor.”
• Correct “immune histochemistry”
• It is inappropriate to suggest that any aberration detected in a tumour should be targeted with an experimental drug. The following statement needs to be toned down “This experimental therapy was targeted on immune histochemistry analyses of the patient last relapse tumor sample, and this procedure should be routinely done to find new therapeutical approaches in recurrent solid tumors.”

Introduction

The introduction provides a good overview of ependymoma, and provides context for the manuscript.

Results

• The case report description should be broken down into multiple paragraphs
• The authors should clarify which of the following were detected using IHC and which were determined using molecular biology: p65+, LICAM+, OLIG2-, p53+, GFAP+, EMA+, Synaptophysine+, ATRX+, m-TOR+, PD-L1+ (20%), PD-1-.
• correct spelling “Synaptophysine”
• The simple presence of mTOR doesn’t indicate the pathway is activated. Additional details of the tests performed are required. IHC of the last resection and the primary disease should be included to demonstrate the extent of mTOR activation using multiple markers (eg. phospho-S6), for this case and on other ependymomas for comparison
• Similarly PD-L1 IHC data in a figure would be informative for other pathologists to compare.
• Information on the dosing regimen for nivolumab (and how this was integrated with sirolimus dosing) should be added.
• Figure 1 needs more labelling – the time points are not legible. Different MR sequences are shown – these should be defined/described
• In order to conclude the patient experienced stable disease due to the therapy MR images (with time points described) prior to the start of treatment are required.

Discussion/Conclusions

• This statement needs a citation “Unfortunately, the majority of these studies report disappointing outcomes, despite preclinical data suggested better results.”

• Correct the following “in this entity treatment”
• Rephrase “the association therapy”
• The authors state the patient experienced stable disease in most parts, but then “transient partial response” in the conclusion. Evidence of partial response was not provided.

• The final paragraph appears truncated:
  “In conclusions, nivolumab plus sirolimus was well tolerated in our patient with recurrent/refractory EPN, and obtained transient partial response. ICPI therapy should be limited to those with elevated PD-L1 expression upon these findings. On these findings,
  Authorship: KP had the idea”
• The authors state “ICPI therapy should be limited to those with elevated PD-L1 expression upon these findings” but provide no evidence of correlation between the lack of PD-L1 expression and failure to respond. In many other examples, there are patients who respond to ICPI without thei tumours exhibiting marked PD-L1 expression.

Methods

Major issues:

• There is no methodology described – I suggest at the minimum including information on the methods of detection of p65+, LICAM+, OLIG2-, p53+, GFAP+, EMA+, Synaptophysin+, ATRX+, m-TOR+, PD-L1+ (20%), PD-1-.
• Additional details of the treatment protocol should be included – a schematic diagram in a figure would be valuable.

Author Response

Abstract

The sentences were modified.

Methods

Now it is specified that analyses in tumor samples was an immune phenotype and not molecular.

For drug schedules: sirolimus was given every day at 2 mg/Kg/day and nivolumab 3 mg/Kg every 2 weeks, it is well explained in the paper.

Citation was added.

Figure was labelled.

In the discussion, the final sentence was modified.

Reviewer 2 Report

We've read with great interest the paper "Targeted therapy with sirolimus and nivolumab in a child with  refractory multifocal anaplastic ependymoma" by  Perruccio et al. The case report is well written and highly significant as it documents the efficiency of a novel targeted therapy in a child with EPN. Below you may find my comments:

1. Including a timeline in the report with all the interventions given to the patient over the 4 years would be a helpful guide
2. The authors referred to other studies/reports showing the efficiency of ICPI in adult cancers (line 41-45) without elaborating much. Brief explanation of the referenced published data regarding the disease severity, outcomes, and long-term effects is highly important in proving the efficacy and safety of the adopted treatment 
3. When the patient was referred to the author's center, they decided to treat her with oral etoposide and dexamethasone (which was stopped later due to VZV infection) without supporting their decision with the reasonable grounds
4. Lines 65 and 85: The treatment given resulted in good clinical conditions without effecting the disease progression which raises questions regarding the underlying mechanism of the intervention and its long-term effects (considering the disease will keep progressing)
5. Targeted therapy with sirolimus and nivolumab every 2 weeks started in February 2020 and in this period of time the patient was already being treated etoposide and dexamethasone. Is it possible that such treatment enhanced the outcomes of the targeted therapy?
6. It was mentioned that molecular assessment of tumor samples showed a good expression of PD-L1 and m-TOR without supporting the data with images 
7. Figure 1, the MRI shows substantial stability in the disease in brain and spinal cord but the time window is relatively short (between April and August 2020). Considering that the follow up remained for one year (line 85), a better representation would be showing an MRI within time window of one year
8.  The authors in the discussion section mentioned that the patient had no toxicity and very good quality of life (line 131 and 132) without any supporting evidence in the report. It is not clear the basis of the life quality assessment

Author Response

1. Patient treatment over years is well explained in details.
2. I specified in the paper the good results in adult cancer treatment
3. Oral etopoide is indicated in AIEOP EPN treatment guidelines. Dexamethasone was done as anti-edema treatment when patient developed worse clinical conditions and was stopped when VZV infection occurred in July 2019.
4. Actually the patient is in progression but no neurological symptoms occurred yet.
5. It is a possibility, but we rely on the targeted therapy.
6. I don't have images available because it is a immune phenotype analyses done in another Center.
7. Figure was edited.
8. Good QOL means a completely normal life for a 7-year old girl, without any restrictions and without hospitalization.

Round 2

Reviewer 1 Report

The authors have not used track changes in their revised manuscript.

It is not my role to carefully compare both versions to determine if they have sufficiently addressed my comments.

Numerous grammatical and spelling errors remain.

The figure legend is still insufficient.

For radiotherapy: 35 fractions of 4 Gy, does not equal a total of 59.4 Gy.

Author Response

I'm sorry the new version was not track changed, now it is but I modified only a paragraph (it is in green) because the other observation were general and I answered without changing the manuscript.

Moreover, I'd like to underlie that the paper was revised by a mother language person.

Figure legend was modified.