Draft monograph: retatrutide — submissions
The 14 submissions received, published in full with declared interests and secretariat responses.
§2Submissions and responses
14 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 analytical section assumes a reference standard that is not generally available
This submission addresses the draft monograph on Retatrutide. The respondent went through the document twice, once as a specialist and once as a reader arriving without the background.
The draft describes identity and content determinations that require a reference standard of assigned content. For this compound no such standard is in general circulation, and a laboratory following the section as written cannot perform the determination described.
The respondent, employed by a contract analytical laboratory, proposes that the monograph state explicitly where a reference standard is unavailable and what a determination performed without one can still establish.
The secretariat accepts this submission. The section described an ideal case and did not say so.
The analytical section now states whether a reference standard is in general circulation for this compound and, where it is not, states which determinations remain possible and which become qualitative. A content figure obtained without a reference standard is recorded as an estimate against a stated assumption rather than as a determination.
The interaction section lists mechanisms rather than interactions
The draft on Retatrutide is a substantial document and the respondent has confined this submission to one matter.
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.
The recorded evidence gaps omit outcomes a reader would consider material
The respondent works on cardiometabolic outcomes and read the draft on Retatrutide with that literature in view.
The evidence-gap section records what has not been studied. The respondent, a practising clinician, states that the list is drawn from the outcomes the trials chose to measure and therefore reproduces the sponsor's outcome selection rather than correcting for it.
The respondent proposes that the gap list be constructed from the outcomes a prescribing decision turns on, and that outcomes measured by no trial appear in it as such.
The secretariat accepts this submission in part. The gap list is reconstructed from the decision-relevant outcome set rather than from the measured set. The proposal that every unmeasured outcome be listed is declined, because an unbounded list of things not studied is not a finding.
The evidence-gap section is now derived from the anchor and decision-relevant outcomes for the indication, and any such outcome measured by no contributing trial is recorded as not measured rather than omitted.
The absence of a rare harm in the trial set is presented as reassurance
This is a submission on the draft covering Retatrutide, from a respondent whose work is with the people taking compounds of this class rather than with the trials that produced them.
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 notes that submission 001 has already been made and confines this submission to a matter not covered by it.
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.
What happens when the compound is stopped is not addressed
This submission concerns Retatrutide and a convention used across the Institute’s output.
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.
Nothing is said about impaired renal or hepatic clearance
The respondent submits on Retatrutide. The point would apply equally to any document in the series.
The pharmacokinetic section gives clearance and half-life in healthy volunteers or in the trial population. It does not say whether either has been characterised in impaired renal or hepatic function, which is the question a clinician reaches the section with.
The respondent proposes that the pharmacokinetic section state, for each compound, whether a dedicated study in impaired function exists, and where none does, say so rather than leaving the field out.
The secretariat accepts this submission. A missing row and an absent study look the same on the page and are not the same thing.
The pharmacokinetic table now carries renal and hepatic rows in every monograph, populated with the study where one exists and with an explicit statement of absence where none does.
The pharmacokinetic section does not connect half-life to the dosing schedule
The respondent submits on Retatrutide.
The draft reports a half-life and, separately, a dosing interval. The respondent, a clinical pharmacologist, states that the relationship between the two is what determines accumulation and time to steady state, and that the monograph leaves the reader to derive it.
The respondent proposes that time to steady state be stated explicitly, with the assumption from which it was derived.
The respondent has read submission 003 with interest and adds one observation the secretariat may find useful.
The secretariat accepts this submission. The derivation is short, it is decision-relevant, and leaving it to the reader invites it to be done wrong.
The pharmacokinetic section now states approximate time to steady state alongside the half-life and dosing interval, with the assumption of first-order elimination stated, and records where the assumption is not supported for this compound.
The monograph should reproduce the approved labelling rather than paraphrase it
This submission concerns the draft on Retatrutide. The respondent assesses incretin-class evidence for a national body and comments in a personal capacity.
The submission is made on behalf of the marketing-authorisation holder. It states that the draft paraphrases the approved indication, the posology and the contraindications, and that any paraphrase risks diverging from the authorised text.
The sponsor asks that the authorised wording be reproduced verbatim in each case, and offers the current summary of product characteristics as the source.
The secretariat accepts this submission in part. The authorised indication and the contraindications are reproduced verbatim and attributed. The posology is not, because the monograph reports what the trials administered as well as what the labelling authorises, and the two are frequently different.
The approved indication and contraindications are now reproduced verbatim from the named authorisation with its version and date, and the posology section reports the labelled schedule and the schedules studied side by side, with the source of each stated.
A near-isobaric analogue is not distinguished by the identity determination described
The respondent submits on Retatrutide, on a matter that is not specific to this draft but is visible in it.
The identity determination described in the draft resolves the compound from unrelated substances but would not distinguish it from a closely related analogue whose mass differs by approximately one dalton.
The respondent proposes that the monograph state the resolution required for that discrimination, and state that a nominal-mass instrument reporting an integer mass has not made it.
The secretariat accepts this submission. The point is decisive where one member of a near-isobaric pair is an approved medicine and the other is not.
The analytical section now states the resolving power required to discriminate the pair, names the pair explicitly, and records that an identity claim made below that resolution is not conformant with the identity standard.
The indication table mixes approved indications with uses for which the compound is merely supplied
Having reviewed the draft on Retatrutide, the respondent makes a single submission, on the view that one point put clearly is more use to the secretariat than six put together.
The indication table lists indications in a single sequence. Some are approved by a competent authority, some are the subject of trials that have not reported, and some are uses observed in supply with no trial evidence at all.
The respondent states that the three categories should not share a table without being distinguished in it.
This submission is made by a respondent with a different professional interest in the outcome from the one behind submission 007.
The secretariat accepts this submission. A shared table is an implicit claim of comparable standing.
The indication table now carries a status column with three values, approved, under investigation and supplied without trial evidence, and the value is stated for every row. Rows in the third category also state that no certainty rating is assigned because there is no evidence base to rate.
A sortable table implies a comparison the underlying data do not support
The draft on Retatrutide was read in full. The respondent notes at the outset that this class has an unusually deep randomised evidence base, and that a monograph on it is fairly judged against a higher standard than one on a compound with none.
The draft presents a sortable table whose columns are drawn from sources of differing quality. The respondent states that sorting on such a column produces an ordering that looks like a ranking and is not one.
The respondent proposes that sorting be disabled on any column whose values are not commensurable.
This point is adjacent to the one made in submission 008 and the respondent puts it in a form the secretariat can act on.
The secretariat notes this submission and records that the point is correct in principle.
No amendment arises here because every sortable table in the document set already carries a standing statement above it that the ordering is not a ranking and that the values in each column are commensurable only where the column header says so. The proposal to disable sorting was considered and not adopted, because a reader who cannot sort a table generally sorts it elsewhere and without the statement.
The mechanism section is written with more confidence than the clinical section it precedes
The respondent has read the draft monograph on Retatrutide against a caseload in which incretin analogues are prescribed daily.
The pharmacology section states what the compound does at its receptor in the indicative mood and without hedging. The clinical section then reports that the effect has not been demonstrated in people. A reader who stops after the first section, as many will, takes away a claim the document goes on to withdraw.
The respondent does not propose that the pharmacology be hedged, which would be inaccurate, but that each pharmacology section close with a sentence stating which of the described actions has been shown to produce a clinical effect and which has not.
The secretariat accepts the proposal in part. Receptor pharmacology is often well established and hedging it would misdescribe the literature.
Every pharmacology section now closes with a statement identifying which described actions are supported by clinical evidence assessed in §3 and which are not. The pharmacology itself is stated as the sources state it.
The same concept is given three different names in one document
The respondent read the draft on Retatrutide alongside the approved labelling for the class, and submits on one matter arising.
The draft refers to the same quantity as a response rate, a responder proportion and a categorical outcome in different sections. The respondent, who works in health-technology assessment, states that a reader cannot tell whether the three refer to one thing or to three.
The respondent proposes that the glossary term be used at every occurrence and that the glossary entry be linked at first use in each section rather than only at first use in the document.
The secretariat accepts this submission. The variation was stylistic and its cost to the reader exceeds any benefit.
A single term is now used throughout for each defined concept, and the glossary entry is linked at first use within each section rather than once per document.
Glycaemic trials and weight-management trials are drawn on interchangeably
The respondent submits on the draft monograph for Retatrutide. The observation arises from teaching the material rather than from prescribing it.
The compound has two trial programmes with different populations, different doses and different endpoints. The monograph draws on both without saying which programme a given estimate came from, so a reader takes a weight figure obtained at one dose in one population as though it applied at the other.
The respondent proposes that the programme be named against every effect estimate in the assessed-outcome table.
The secretariat accepts this submission. The two programmes are separable and were not being separated.
Every effect estimate now names its programme, and the assessed-outcome table is split where a compound has more than one.
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.