Draft monograph: PT-141 (bremelanotide) — submissions
The 17 submissions received, published in full with declared interests and secretariat responses.
§2Submissions and responses
17 submissions were received. Each is published in full below with its declared interest, the secretariat response and the disposition. The Institute publishes submissions it did not accept in the same form as those it did.
The interaction section lists mechanisms rather than interactions
Having read the draft under consultation, which concerns PT-141 (bremelanotide), the respondent submits as follows.
The section describes pathways by which an interaction could occur. It does not say which interactions have been observed, in what setting, or with what consequence. A reader dispensing alongside other therapy cannot act on a mechanism.
The respondent proposes that observed interactions be separated from theoretical ones, and that the theoretical ones be labelled as such.
The secretariat accepts the separation and declines to expand the section beyond the evidence.
The interaction section is now divided into interactions reported in clinical use and interactions predicted from mechanism, with the second labelled as prediction. Where neither exists the section says so in one line rather than being padded.
Effect estimates are given without naming the comparator
The respondent submits on PT-141 (bremelanotide). The point would apply equally to any document in the series.
Several estimates in the draft state an effect without stating what it was measured against. An estimate against placebo and an estimate against an active comparator are not the same quantity and the draft presents them in one column.
The respondent proposes that the comparator be part of every outcome row rather than a footnote, and that estimates against different comparators never share a column.
The secretariat accepts this submission. A footnoted comparator is a comparator a reader will not carry into the next row.
The comparator is now stated in every outcome row, and estimates against different comparators are reported in separate tables with the comparator named in the table caption.
The absence of a rare harm in the trial set is presented as reassurance
Having read the draft monograph on PT-141 (bremelanotide), the respondent puts one point to the committee.
The draft states that a specific serious event was not observed in the contributing trials. The respondent states that trials of the size conducted here could not have detected an event at the frequency in question, and that reporting the absence without that arithmetic converts an uninformative result into a reassuring one.
The respondent proposes that the detectable frequency be stated wherever the absence of an event is reported.
The respondent supports submission 001 so far as it goes and adds the matter set out here.
The secretariat accepts this submission. The Institute's own framework treats an absent event in an underpowered set as uninformative, and the draft departed from it.
Wherever the monograph reports that an event was not observed, it now states the total exposure and the frequency the contributing trials could have detected, so that the absence is read as the limit of the evidence rather than as a finding.
Open-label extension data are presented alongside randomised data without distinction
The respondent has read the draft covering PT-141 (bremelanotide) and makes one submission.
Long-term figures in the clinical section come from open-label extensions in which every participant received the active compound and those who did not tolerate it had already withdrawn. They are printed in the same table as randomised comparisons and in the same typeface.
The respondent proposes that extension data be presented in a separate table, or at minimum in a separately labelled block, and that the surviving-population problem be stated once where it arises.
The respondent read submission 002 after drafting this one and has not altered it, the two points being distinct.
The secretariat accepts this submission. An extension estimate answers a different question from a randomised one and should not be read as though it answered the same one.
Extension data now appear in a separate table headed as uncontrolled follow-up, with a standing note on differential withdrawal.
Mechanistic claims for a peptide fragment are carried without evidence that the fragment acts as described
The respondent submits on PT-141 (bremelanotide), on a matter that is not specific to this draft but is visible in it.
The respondent states that the draft repeats a mechanistic account originating in supply documentation rather than in the primary literature, and that the account attributes activity to a fragment on the basis of the activity of the parent molecule.
The respondent proposes that any mechanistic claim be traceable to a primary source and removed where it is not.
Submission 001 concerns the same document. The respondent’s point is a different one.
The secretariat accepts this submission. A mechanism repeated from marketing material has no evidential status regardless of how widely it is repeated.
Mechanistic claims not traceable to a primary source are removed, and those retained carry their source and a statement of whether the underlying work was conducted in vitro, in animals or in humans.
Regulatory status is stated without naming the jurisdiction
The respondent notes that PT-141 (bremelanotide) is supplied for indications for which it has never been assessed, and submits in that context.
The draft states that the compound is approved, or not approved, without saying by whom. The respondent, employed by a health-technology assessment body, states that approval status differs between jurisdictions for several compounds in the series and that an unqualified statement will be wrong somewhere.
The respondent proposes that every status statement name the authority and carry the date on which the status was checked.
The secretariat accepts this submission. An unattributed status statement is a claim the Institute cannot support.
Every regulatory status statement now names the authority, states the date on which the status was verified, and is recorded per jurisdiction rather than as a single global assertion.
The population to which the headline estimate applies is not stated with the estimate
The respondent submits on PT-141 (bremelanotide).
The draft carries a headline effect estimate in the abstract without the eligibility criteria of the trials that produced it. The respondent states that the estimate applies to a trial population with specific age, comorbidity and baseline criteria, and that a reader will apply it to whoever is in front of them.
The respondent proposes a one-line population statement adjacent to every headline estimate.
The secretariat accepts this submission. An estimate detached from its population is an estimate of nothing in particular.
Every headline estimate now carries a one-line statement of the population in which it was observed, and the full eligibility criteria are reported in the included-studies table rather than only in the source.
Trials are described as terminated where they completed as planned
This submission concerns PT-141 (bremelanotide) and a convention used across the Institute’s output.
The respondent states that the draft uses the word terminated for trials stopped at pre-specified interim analyses, for trials stopped for futility and for trials closed for commercial reasons, and that these are three different facts.
The respondent proposes that the status vocabulary be fixed and defined in the glossary.
The secretariat accepts this submission in part. The vocabulary is fixed and defined. The proposal to distinguish commercial closure from futility in every case is accepted only where the Institute holds a document stating the reason.
Trial status now uses a fixed vocabulary defined in the glossary, and where the reason for stopping is not evidenced by a document the Institute holds, the status is recorded as stopped with the reason not established rather than assigned.
What happens when the compound is stopped is not addressed
The respondent read the draft on PT-141 (bremelanotide) and has confined this submission to one matter.
The draft assesses the effect of the compound while it is being taken. The respondent, who declares having used a compound in the class under prescription, states that the question a person actually faces is what happens afterwards, and that the monograph is silent on it.
The respondent proposes that the trajectory after discontinuation be an assessed outcome wherever any contributing trial measured it, and a recorded evidence gap wherever none did.
The secretariat accepts this submission. The omission was one of framing rather than of evidence, and the framing followed the trials rather than the decision.
Discontinuation trajectory is now an assessed outcome in every monograph where a contributing trial measured it, and a recorded evidence gap in every monograph where none did, so that its absence is visible rather than silent.
Two factual descriptions of the sponsor's programme are inaccurate
The respondent has read PT-141 (bremelanotide) in draft and makes a single submission.
The submission is made on behalf of the marketing-authorisation holder and is confined to two matters of fact. The draft describes a trial as terminated where the sponsor closed it at a pre-specified interim analysis, and gives a dose in a unit that does not match the approved labelling.
Supporting documentation, comprising the published trial report and the current summary of product characteristics, accompanied the submission. No view is expressed on the certainty ratings, which the sponsor considers a matter for the assessment committee.
This submission is made in the same spirit as submission 006 and on a different aspect of the draft.
The secretariat accepts this submission. Both points are matters of fact, both were checkable against documents the Institute holds, and both were wrong in the draft.
The trial status now reads as completed at a pre-specified interim analysis, with the analysis identified, and the dose is stated in the unit used in the approved labelling. The submission is identified as an industry submission on its face in accordance with the conflicts policy.
Point estimates are given without an interval
The respondent’s comment on the draft for PT-141 (bremelanotide) arises from the regulatory history of the class.
Several estimates in the draft appear as single figures. The respondent states that a point estimate without an interval invites a precision the underlying data do not support, and that the effect is worst where the estimate is drawn from a small contributing set.
The respondent proposes that no point estimate appear anywhere in the document set without its interval, including in summary tables and in the abstract.
The secretariat accepts this submission in part. Intervals are added wherever the source reports one. The proposal is declined for figures the source published without an interval, because the Institute will not compute an interval a source did not report.
Every estimate now carries its interval where the source reported one, and where it did not, the estimate is annotated as reported without an interval rather than left to appear as a precise figure.
The document should not describe uses outside the approved indication
This submission concerns PT-141 (bremelanotide) and makes one point.
The submission is made on behalf of a marketing-authorisation holder. It states that the draft describes uses of the compound that fall outside the approved indication, that such uses are not supported by the sponsor, and that describing them may be read as legitimising them.
The sponsor asks that the sections concerned be removed, or in the alternative that they carry a prominent statement that the sponsor does not support such use.
The secretariat does not accept this submission. The Institute records what is supplied and what is used, because a reader encountering a compound outside a regulated route is the reader most in need of an assessment of the evidence for it.
The sections remain. Every such section already states the regulatory status of the use described and states that the evidence for it is assessed separately from the evidence for the approved indication. The submission is published in full and identified as an industry submission.
Declared interests should appear on the document rather than on a separate page
The respondent has read PT-141 (bremelanotide) and submits on a matter of presentation.
The draft links to a central conflicts register. The respondent argues that a reader assessing whether to rely on a particular document should not have to leave it to find out who assessed it and what they declared.
The respondent proposes that the interests of every named contributor to a document be printed on that document.
The secretariat notes this submission and records that the draft already provides for it, which the respondent could reasonably have missed because the provision sits in an appendix.
Every document carries the declared interests of its named contributors in its front matter, and the central register exists so that a reader can see a person across all documents rather than one at a time. No amendment arises; the provision has been moved from the appendix into the body of the methodology document so that it is findable.
Registered trials that never reported are absent from the monograph
The respondent read PT-141 (bremelanotide) in draft. The point applies to it and to the series generally.
The respondent states that the trial list appears to be drawn from published reports, and that registered trials which completed without a report are therefore invisible. The proportion of a programme that never reported is itself a finding about the evidence base.
The respondent proposes that every registered trial of the compound be listed, with its reporting status, whether or not a report exists.
The respondent has read submission 012 above and makes this submission independently of it.
The secretariat accepts this submission. A trial list built from publications reproduces publication bias in the shape of the document.
The trial list now includes every registered trial the Institute identified, with its reporting status stated, and the monograph reports the proportion of registered trials for which no result has been posted or published.
Storage and reconstitution guidance is given without stating what it rests on
The draft states storage conditions and a period of use after reconstitution. The respondent asks what evidence supports the period, and states that in the absence of a stability study on this presentation the figure is a convention rather than a finding.
The respondent proposes that any in-use period be accompanied by the stability evidence that produced it, or removed.
The secretariat accepts this submission in part. The period is retained where a stability study on a comparable presentation exists and is cited. Where no such study exists the figure is removed rather than annotated, because an annotated figure is still a figure a reader will use.
In-use periods now appear only where supported by a cited stability determination on a stated presentation, and elsewhere the monograph records that no in-use stability evidence was identified for this presentation.
The monograph does not tell a reader that two vials of the same compound may not contain the same thing
This is a submission on PT-141 (bremelanotide).
The analytical section describes what a determination measures and the supply section describes what suppliers document. Neither says that the quantity of peptide in two vials bearing the same label may differ by more than the difference between two doses in the trial schedule.
The respondent proposes an explicit statement, in §8, that a purity figure describes the lot it was measured on and nothing else, and that the practical consequence is that a dose calculated from a label is an estimate.
The respondent notes submission 014 above and does not repeat the ground it covers.
The secretariat accepts this submission. It is the single most consequential thing a reader of this series can be told and it was distributed across three sections rather than stated once.
A standing paragraph now appears at the head of §8 in every monograph, stating that a determination applies to the lot measured and that a label mass is not a determination.
The compound is supplied under names the monograph does not list
The respondent submits on the draft monograph for PT-141 (bremelanotide). This class has a documented adverse-effect profile and a document about it should carry that profile with the prominence the evidence supports.
The respondent states that the compound is supplied under several trade names, research codes and transliterations, and that a reader holding a label bearing one of them will not find the monograph.
A list of names observed in supply, with the source of each observation, accompanied the submission.
This submission is made by a respondent with a different professional interest in the outcome from the one behind submission 008.
The secretariat accepts this submission. A monograph a reader cannot find is not serving the reader.
The synonym list is extended to include every name the Institute can evidence from a document it holds, each recorded with its source. Names asserted without a supporting document are not added, and the distinction is stated at the head of the list.
References cited on this page
References are numbered in order of first citation in this document. Each superscript in the text links to its entry below.
- International Organization for Standardization. ISO/IEC 17025:2017 General Requirements for the Competence of Testing and Calibration Laboratories. ISO/IEC Standard 2017;3rd edition. identifier not held by the Institute
Identifiers are reproduced only where the Institute holds them. Where a digital object identifier or PubMed identifier is not shown, the Institute has recorded the journal and year and has not constructed an identifier.