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.
Regulatory status is stated without naming the jurisdiction
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.
Effect estimates are given without naming the comparator
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 population to which the headline estimate applies is not stated with the estimate
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.
The recorded evidence gaps omit outcomes a reader would consider material
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 analytical section assumes a reference standard that is not generally available
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.
Absence of evidence is presented in a form a reader will take as negative evidence
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.
The document set should be published in translation
The respondent notes that the assessments concern compounds supplied internationally and that publishing only in English restricts access to the assessment to readers who work in it.
The respondent proposes machine translation of the document set as an interim measure, with human review of the certainty language.
The secretariat does not accept this submission, and records that the underlying point is sound and that the proposed remedy is the difficulty.
A translation whose certainty language has drifted is a different assessment carrying the Institute's name, and the Institute cannot review translations it does not have the capacity to review. The documents remain in English. The submission is published in full because the access problem it identifies is real and unresolved.
Guidance on lyophilised storage is missing
The respondent asks that the monograph state storage conditions for lyophilised material as well as for reconstituted solution, since the two differ and the former governs the longer part of the shelf life.
The respondent states that the omission is the more consequential because lyophilised material is what is generally received.
The secretariat notes this submission. The draft addresses lyophilised storage, in the presentation section rather than in the section on in-use handling, which is where the respondent looked.
No amendment to content arises. The two storage statements have been brought together under a single heading so that a reader looking for either finds both.
A purity figure from a certificate is quoted as though it were a content figure
The draft quotes a purity percentage from supply documentation in a sentence about how much compound a vial contains. Chromatographic purity is a relative area within what was detected; it is not a mass fraction and it does not bound vial content.
The respondent, an analytical chemist, proposes that purity and content never appear in the same sentence without an explicit statement that they answer different questions.
The secretariat accepts this submission. The conflation is the error the Institute most often corrects in supply documentation, and it appeared in an Institute draft.
Purity and content are now reported in separate rows with separate definitions, and the monograph states that a purity figure sets no bound on content and that a content figure requires a determination against a standard of assigned content.
The pharmacokinetic section does not connect half-life to the dosing schedule
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 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.
Quantitative claims are reproduced without the method that produced them
Several figures in the draft are quoted from sources that determined them by different methods. A figure obtained by one determination and a figure obtained by another are not comparable, and the draft places them in the same sentence without distinguishing them.
The respondent, an analytical chemist, proposes that every quantitative claim carry the method that produced it at the point of use rather than in the reference.
The secretariat accepts this submission. Placing two figures side by side is an implicit claim that they are the same kind of quantity, and in the cases identified they were not.
Every quantitative claim now carries the determination that produced it at the point of use, and figures obtained by non-comparable methods are no longer presented in the same row or sentence.
A near-isobaric analogue is not distinguished by the identity determination described
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.
Where the compound is a glucagon-like peptide-1 receptor agonist, the cardiovascular outcome evidence should be an assessed outcome
The respondent states that for compounds in this class the cardiovascular outcome evidence, reported for semaglutide in SELECT in the New England Journal of Medicine in 2023 and for liraglutide in LEADER in the same journal in 2016, is the evidence a prescribing decision most often turns on, and that the draft treats it as background.
The respondent proposes that cardiovascular outcomes be an assessed outcome with its own certainty rating for every compound in the class for which such a trial exists.
The secretariat accepts this submission in part. Cardiovascular outcomes become an assessed outcome where a dedicated outcome trial of the compound exists. The proposal to extend the rating across the class by inference is declined, in line with the treatment of class-level extrapolation elsewhere in the series.
Cardiovascular outcomes are now an assessed outcome with their own certainty rating in every monograph for which a dedicated cardiovascular outcome trial of that compound has reported, and are recorded as not assessed elsewhere.
The analytical section is longer than the clinical assessment it accompanies
The respondent, an academic pharmacologist, states that the analytical section occupies more of the monograph than the assessment of clinical effect, and that the proportions imply the Institute considers the analytical question the more important one.
The respondent proposes that the analytical material be moved to the standards series and referenced rather than reproduced.
The secretariat accepts this submission in part. The general analytical material is moved to the standards series and referenced. The compound-specific material stays, because a reader holding a certificate for this compound needs to know what that certificate does and does not establish for this compound.
The analytical section is reduced to compound-specific content and cross-references the relevant standards for the general procedure, which shortens it substantially without removing what is not available elsewhere.
The compound is supplied under names the monograph does not list
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.
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.
Adverse event frequencies are given without the denominator or the exposure period
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 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 preclinical section is extensive and the clinical section is not
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.
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.
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
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