Draft monograph: Lixisenatide — submissions
The 10 submissions received, published in full with declared interests and secretariat responses.
§2Submissions and responses
10 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 monograph does not tell a reader that two vials of the same compound may not contain the same thing
The respondent has read Lixisenatide and submits on a matter of presentation.
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 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.
Anti-drug antibody data are omitted
This submission addresses the draft monograph on Lixisenatide. The respondent went through the document twice, once as a specialist and once as a reader arriving without the background.
The respondent states that immunogenicity is measured in the development programmes of peptide therapeutics and that the monograph does not report it, leaving a reader unable to judge whether loss of effect over time has an immunological explanation.
The respondent proposes that anti-drug antibody incidence and its relation to effect be reported for every compound in the series.
The secretariat accepts this submission in part. Immunogenicity is reported where a contributing trial reported it. The proposal to report it for every compound is declined because for many compounds in the series no such data exist and a uniformly empty row is not informative.
Anti-drug antibody incidence and any reported association with loss of effect are now reported where measured, and recorded as not measured where the contributing trials did not assess them.
Adverse event frequencies are given without the denominator or the exposure period
Having reviewed the draft on Lixisenatide, 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 draft reports adverse event frequencies as percentages. The respondent states that a percentage without a denominator and without an exposure period cannot be compared with any other figure, including the corresponding figure in the comparator arm.
The respondent proposes that every frequency carry the number of participants and the exposure period over which it was observed.
The respondent supports submission 001 so far as it goes and adds the matter set out here.
The secretariat accepts this submission. A frequency detached from its denominator is a number without a quantity.
Every reported frequency now carries the number of participants, the number of events and the exposure period, and comparator-arm figures are reported alongside rather than in a separate table.
The population to which the headline estimate applies is not stated with the estimate
This submission concerns the draft on Lixisenatide. The respondent assesses incretin-class evidence for a national body and comments in a personal capacity.
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.
A near-isobaric analogue is not distinguished by the identity determination described
This is a submission on Lixisenatide.
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.
Absence of evidence is presented in a form a reader will take as negative evidence
The respondent submits on the draft monograph for Lixisenatide. The observation arises from teaching the material rather than from prescribing it.
Where the Institute has identified no study, the draft states that no evidence was found. In several places that sentence sits immediately after a paragraph describing an adverse outcome, and the juxtaposition invites the reading that the compound was studied and found wanting.
The respondent proposes a standing formulation, used identically wherever the situation arises, distinguishing an outcome that was studied and not demonstrated from an outcome that has not been studied at all.
The secretariat accepts this submission. The two states are different, they support different decisions, and the draft rendered them in language a reader could not reliably separate.
A standing formulation has been adopted and is applied wherever an evidence gap is recorded, distinguishing an outcome assessed and not demonstrated from an outcome not assessed. The formulation is identical at every occurrence so that it can be recognised at a glance.
Point estimates are given without an interval
The draft on Lixisenatide 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.
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 preclinical section is extensive and the clinical section is not
The respondent has read the draft monograph on Lixisenatide against a caseload in which incretin analogues are prescribed daily.
The draft summarises a large animal literature and a small or absent human literature. The respondent states that the resulting document reads as though a great deal is known, when what is known concerns rodents.
The respondent proposes that the preclinical section be reduced to a statement of what has been observed in animals and that the detail be removed entirely.
This point is adjacent to the one made in submission 003 and the respondent puts it in a form the secretariat can act on.
The secretariat accepts this submission in part. The section is shortened and given a standing statement. The proposal to remove the detail is declined, because a reader encountering claims derived from that literature needs to be able to see what it actually contains.
The preclinical section is reduced in length, placed after the clinical assessment rather than before it, and opens with a standing statement that an effect observed in an animal model is not a clinical outcome and does not support a certainty rating.
The monograph should reproduce the approved labelling rather than paraphrase it
The draft on Lixisenatide is a substantial document and the respondent has confined this submission to one matter.
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 respondent’s submission overlaps with submission 001 and was prepared without sight of it.
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.
What happens to weight after the compound is stopped is not in the assessed outcomes
The respondent read the draft on Lixisenatide alongside the approved labelling for the class, and submits on one matter arising.
Several trials in the evidence base ran a withdrawal period and reported what happened. That evidence is the single most useful thing a person considering the compound could be told, and it appears in the monograph only as a sentence in the discussion.
The respondent proposes that post-withdrawal trajectory be an assessed outcome in its own right for every compound where a withdrawal period was studied, with its own certainty rating.
This submission is made in the same spirit as submission 003 and on a different aspect of the draft.
The secretariat accepts this submission. The evidence exists, it is directly relevant, and it was not being assessed.
Post-withdrawal trajectory is now an assessed outcome wherever a withdrawal period was studied, rated on the same scale as the others. Where no withdrawal period was studied the outcome is recorded as not assessed.
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.