FDA already required this study: PMR 4730-1 names endocrine-related disorders due to chronic menin inhibition
also called revumenib postmarketing requirement · PMR 4730-1 · FDA endocrine menin requirement
When the FDA approved revumenib it did not just note the raised parathyroid hormone; it legally required the company to run a trial to find out whether long-term menin blockade causes hormone-gland disorders. That trial's final report is due in May 2028.
The same thing, for a scientist
The NDA 218944 approval letter imposes postmarketing requirement 4730-1 under FDCA 505(o)(3), stating that spontaneous adverse-event reporting will not suffice to assess signals of serious risk including **elevated parathyroid hormone**, and requiring a clinical trial to determine whether long-term revumenib use is associated with, among other things, *"serious potential risk of endocrine-related disorders due to chronic menin inhibition"*, with all patients to have at least **3 years of treatment** or to have discontinued earlier; trial completion 12/2027 and final report 05/2028 [E1]. This is decisive for how the graph should frame this beat. The premise that *nobody has looked* is wrong. The regulator looked, reached the same mechanistic conclusion this beat reaches, judged it a serious potential risk, and compelled a study. What is true is that **the answer does not exist yet**, and that no paediatric-specific endocrine endpoint is named in the requirement.
The text of the requirement
From the FDA approval letter for NDA 218944 (REVUFORJ), read directly from the letter PDF 1:
"We have determined that an analysis of spontaneous postmarketing adverse events reported under subsection 505(k)(1) of the FDCA will not be sufficient to assess the known serious risks of sudden death, QTc prolongation, differentiation syndrome, and elevated transaminases; and to assess signals of serious risks of elevated parathyroid hormone, increased drug toxicity in patients with severe hepatic and renal impairment, and increased drug toxicity with use of OATP1B1 inhibitors, MATE1 substrates, and sensitive CYP3A4 substrates with revumenib."
"4730-1 Conduct a clinical trial to assess and further characterize known serious risks related to the use of revumenib of sudden death, QTc prolongation, differentiation syndrome and elevated transaminases, and assess serious potential risks such as elevated parathyroid hormone. The trial will determine whether long-term use of revumenib is associated with increased risk of cardiac deaths, recurrent differentiation syndrome, serious hepatotoxicity, and serious potential risk of endocrine-related disorders due to chronic menin inhibition. All patients should have at least 3 years of treatment or discontinued earlier."
Trial Completion: 12/2027. Final Report Submission: 05/2028.
Note the statutory basis: 505(o)(3), not subpart H. This is a safety requirement, not an accelerated-approval confirmatory trial, and FDA explicitly determined that only a clinical trial - not a nonclinical or observational study - would suffice.
What this changes, and what it does not
Changes. Three claims that have circulated in this project should be retired or narrowed:
- "No endocrine parameter appears in menin-inhibitor development." False. Intact PTH was measured in at least 139 patients and is on the label.
- "Nobody has looked." False as stated. FDA looked, named the mechanism ("chronic menin inhibition"), and compelled a trial.
- "The risk is purely a structural inference." No longer. A regulator with access to the full clinical and nonclinical dossiers independently classified endocrine disorders from chronic menin inhibition as a serious potential risk.
Does not change. The requirement has four gaps that are exactly where this beat's value now lies:
- No named paediatric endpoint. Nothing about growth velocity, bone age, IGF-1 or pubertal staging, despite section 8.4 of the same label separately instructing clinicians to monitor bone growth in children.
- No specified analyte panel. "Endocrine-related disorders" is not operationalised. Calcium, phosphate, vitamin D, prolactin, fasting glucose and gastrin are not named.
- No off-treatment follow-up. The requirement is about patients on treatment for 3 years; reversibility after discontinuation, which is the crux for a cured child, is not addressed.
- It is revumenib-only. There is no equivalent public requirement for ziftomenib or bleximenib, and the ziftomenib label reports no parathyroid data at all.
So the right action for this lab is not to raise an alarm. It is to specify the paediatric endocrine panel and the off-treatment follow-up that PMR 4730-1 leaves out - which is what exp-endocrine-surveillance-panel-menin-treated-children does.
| regulator | US FDA, Center for Drug Evaluation and Research |
|---|---|
| application | NDA 218944 (REVUFORJ, revumenib) |
| requirement ID | 4730-1 |
| statutory basis | FDCA 505(o)(3) |
| treatment duration required | at least 3 years or until discontinuation |
| trial completion | 2027-12 |
| final report | 2028-05 |
| corrects prior graph claim | the claim that nobody has looked at the endocrine risk of menin inhibition is false; the regulator looked and compelled a trial, and the answer is due 2028-05 |
named risks
[ "sudden death", "QTc prolongation", "differentiation syndrome", "elevated transaminases", "elevated parathyroid hormone", "endocrine-related disorders due to chronic menin inhibition" ]
gaps in the requirement
[ "no named paediatric endpoint (growth velocity, bone age, IGF-1, puberty)", "no specified analyte panel", "no off-treatment reversibility follow-up", "revumenib only; no public equivalent for ziftomenib or bleximenib" ]
- This entry is the strongest correction in the beat and it cuts against the beat's own premise: the regulator has already identified and mandated study of exactly this risk, so framing it as an overlooked danger misrepresents the record.
- A postmarketing requirement is evidence that a question is open, not that the answer is bad. FDA simultaneously granted a full approval down to age 1.
- The remaining, defensible gap is narrow and specific: no paediatric growth endpoint, no defined analyte panel, no off-treatment follow-up, and nothing at all for the other two menin inhibitors. That is where a lab can add value without overclaiming.
- Does the PMR 4730-1 trial enrol children, and does it collect any growth or pubertal endpoint? The protocol is not public and a single question to the sponsor or a ClinicalTrials.gov entry would answer it.
- Which analytes constitute 'endocrine-related disorders' in the PMR's operational definition? Without calcium, vitamin D and an off-treatment draw the trial could return a null that means little.
- Is there an equivalent endocrine postmarketing requirement for ziftomenib under its own NDA? If not, the class question will remain unanswerable from regulatory data.
- Will the 2028 report distinguish reversible biochemical drift from structural parathyroid disease? Only paired on- and off-treatment PTH can, and the requirement as written does not compel off-treatment sampling.
- E1established confidence 5 of 5: Multiple independent lines of evidence; treated as settled in the field.database
FDA's NDA 218944 approval letter for REVUFORJ imposes postmarketing requirement 4730-1 under FDCA 505(o)(3), requiring a clinical trial to assess serious potential risks including elevated parathyroid hormone and to determine whether long-term revumenib use is associated with serious potential risk of endocrine-related disorders due to chronic menin inhibition, with all patients to have at least 3 years of treatment or to have discontinued earlier; trial completion 12/2027 and final report submission 05/2028.
NDA 218944 approval letter for REVUFORJ (revumenib), including postmarketing requirements 4730-1 to 4730-6 · US Food and Drug Administration, Center for Drug Evaluation and Research · Drugs@FDA, NDA 218944 approval letter 2024What this evidence cannot show
Text extracted directly from the approval-letter PDF and read verbatim on 2026-09-18; the quoted passages are from pages 2-3 of the letter. A postmarketing requirement is a regulatory judgement of a potential risk, not a demonstration of harm - FDA imposes PMRs precisely because the question is open. The requirement's design is not public, so it is not known whether children are included, what analytes are collected, or whether off-treatment follow-up is planned.
Evidence that argues against this (1)
- The same regulatory action licensed the drug for children aged 1 year and older on a full, non-accelerated approval. FDA judged the benefit-risk favourable in infants while considering the endocrine question open. A PMR is the mechanism regulators use for questions they consider worth answering but not disqualifying, and reading it as vindication of a safety concern overstates it. Syndax Pharmaceuticals / US FDA 2025
- E2established confidence 5 of 5: Multiple independent lines of evidence; treated as settled in the field.database
The REVUFORJ label separately instructs clinicians to monitor bone growth and development in paediatric patients on the basis of irreversible femoral growth-plate closure in juvenile rats, and reports a paediatric safety population of 25 infants under 2 years, 78 children aged 2 to under 12 and 29 adolescents.
REVUFORJ (revumenib) tablets, for oral use - US full prescribing information (NDA 218944) · Syndax Pharmaceuticals / US FDA · DailyMed / Drugs@FDA (NDA 218944) 2025What this evidence cannot show
Read verbatim from DailyMed sections 8.4 and 6.1 on 2026-09-18. The label gives the instruction but no measurement schedule, no target parameter and no threshold for action, which is the operational gap this beat can fill.
Evidence that argues against this (1)
- The bone-growth monitoring instruction is the most concrete paediatric endocrine statement in the label and it is a PRECAUTION rather than an observed finding - monitoring is instructed, an effect is not reported. It also arrives without an incidence, a duration threshold or a specified test, which is what an investigator-initiated surveillance protocol would have to supply. FDA Drugs@FDA 2024
- refutes →The same pocket suppresses JUND: menin inhibition's unmeasured endocrine liability in infants
corrects the premise that nobody has looked: FDA named chronic menin inhibition as the mechanism and compelled a trial reporting 2028-05
the regulator classified elevated parathyroid hormone as a signal of serious risk requiring a clinical trial
PMR 4730-1 under FDCA 505(o)(3), at least 3 years of treatment per patient, final report 2028-05
the same approval letter whose postmarketing requirements are imposed under 505(o)(3) rather than subpart H
- ← related toA documented absence: not one endocrine outcome measure across the three lead menin-inhibitor trials
the endpoint gap in the trials is what the postmarketing requirement is meant to close, minus its own paediatric and off-treatment gaps
- ← related toThe reversibility question: months of partial occupancy against a syndrome built from decades of loss
the regulator's own requirement specifies at least 3 years of treatment, which is the exposure the risk argument must be made against
independently reproduces the empirical basis for FDA's determination that spontaneous reporting would not suffice
- ← related toWhat the labels measure in a treated child: bone growth, in one sentence, and nothing else endocrine
The PMR compels a chronic-exposure endocrine trial but names no paediatric endpoint, so the population with the most to lose generates the least data
- ← supportsNobody needs to enrol anyone: the PTH question is a regression on data that already exists
These three models belong in the analysis plan of PMR 4730-1, which FDA required for exactly this question