On September 9, 2026, at ESPE 2026 (European Society for Paediatric Endocrinology), Geneviève Baujat, M.D., of Necker-Enfants Malades Hospital in Paris presented Week 52 data from the open-label sentinel cohort of Ascendis Pharma's reACHin trial of once-weekly TransCon CNP (navepegritide) in infants with achondroplasia. The same-day Form 6-K and the GlobeNewswire wire, fetched here from the BioSpace mirror, are the company primaries. GlobeNewswire itself timed out from this environment.
The sentinel cohort is seven infants (mean age 11.7 months) treated at 100 μg/kg/week. At Week 52, Achondroplasia Foramen Magnum Score (AFMS) was stable or improved in all children, mean sagittal foramen magnum diameter rose 3.15 mm, and no child had decompression surgery. Mean ACH-specific supine length Z-score change was +0.42. Mean annualized growth velocity (AGV) was 9.9 cm/year.
That is a small open-label safety and pharmacokinetics cohort that preceded the blinded period. It is not the randomized efficacy readout. It is not an FDA infant indication. YUVIWEL (navepegritide) is already approved under accelerated approval for pediatric patients 2 years and older with achondroplasia and open epiphyses. Use under 2 years is not on the current U.S. label.
This is the 8:07 Industry News for 14 September 2026. The same-day Pep19 Research Roundup stays as written. This is not vosoritide / Voxzogo CANOPY-HCH-3. reACHin is achondroplasia, ages 0 to <2. CANOPY-HCH-3 is hypochondroplasia. ApproaCH (ages 2 to 11) is a different trial and is not this readout.
What happened
Ascendis said Week 52 sentinel data showed stabilization or improvement in foramen magnum stenosis (skull-base narrowing that can compress the brainstem and spinal cord) plus linear-growth movement in infants aged 0 to <2 years. Baujat presented at ESPE 2026.
The company and 6-K define reACHin as a pivotal Phase 2, randomized, placebo-controlled trial of once-weekly TransCon CNP at 100 μg/kg/week in at least 66 treatment-naïve infants with genetically confirmed achondroplasia, followed by a 52-week open-label extension. Before the double-blind period, seven infants entered an open-label sentinel cohort for safety and pharmacokinetics. Additional Week 52 measures named in the 6-K: AFMS (an MRI-based grade of foramen magnum stenosis), ACH-specific supine length Z-score change, and AGV.
The double-blind portion is now fully enrolled, per the September 9 package. That sentence is an enrollment status. It is not a blinded efficacy table.
| Sentinel fact | Company / 6-K figure |
|---|---|
| Design | Open-label sentinel cohort that preceded the double-blind period |
| N | 7 infants with achondroplasia |
| Mean age | 11.7 months (ages 0 to <2 years) |
| Dose | Once-weekly subcutaneous TransCon CNP 100 μg/kg/week |
| AFMS | Stable or improved from baseline to Week 52 in all children |
| Foramen magnum sagittal diameter | Mean change +3.15 mm |
| Decompression surgery | None during the 52-week period |
| ACH-specific supine length Z-score | Mean change +0.42 |
| AGV | Mean 9.9 cm/year |
| PK | Comparable to older children (company: supports the 100 μg/kg/week dose) |
Baujat's quoted line in the wire is that early weekly TransCon CNP "could help address medical complications and growth limitations." That is a presenter comment on an n=7 open-label cohort. It is not a placebo-controlled infant efficacy claim.
No peer-reviewed journal citation for this sentinel cohort was found in the sources used here. ESPE 2026 is a meeting presentation plus a company 6-K.
What reACHin is (and what the registry still says)
ClinicalTrials.gov NCT06079398, queried 14 September 2026, is the matching English registry record. Protocol ID ASND0030. Sponsor: Ascendis Pharma A/S. Phase 2, multicenter, double-blind, randomized, placebo-controlled trial of once-weekly subcutaneous TransCon CNP for 52 weeks, then an open-label extension, in infants 0 to <2 years with achondroplasia.
The registry brief says the randomized ratio is 2:1 TransCon CNP versus placebo, at 100 μg CNP/kg, in infants with genetically verified heterozygous achondroplasia. Masking is quadruple. Estimated enrollment is 72. The company wire's "at least 66 treatment-naïve infants" is the company size for the double-blind portion. This article keeps both. It does not invent a locked randomized N.
Registry dates, as of the 14 September 2026 query: actual start 23 January 2024; primary completion December 2027 (estimated); completion December 2028 (estimated). Status verified April 2026. Last update posted 8 April 2026. Overall status still RECRUITING. hasResults is false. isFdaRegulatedDrug is true.
A company statement that the double-blind portion is fully enrolled can land while ClinicalTrials.gov still shows RECRUITING. Treat that as possible registry lag. This article does not invent a new NCT status.
Registry eligibility requires caregiver consent, heterozygous genetic confirmation of achondroplasia, and weekly subcutaneous trial treatment by a caregiver. Sentinel participants must be younger than 2 at first investigational-product administration. Exclusions include homozygous ACH, specified prematurity rules, anticipated cervicomedullary decompression, other growth disorders, and any prior stature-directed prescription or investigational product, including human growth hormone or vosoritide. Prior vosoritide is an exclusion. reACHin is not a vosoritide trial.
Named primaries on the registry: incidence of treatment-emergent adverse events, and change from baseline to 52 weeks in length/height Z-score. Those are the blinded trial's registered primaries. They are not the sentinel open-label table above.
ISRCTN15169433 is the companion ISRCTN ID. The ISRCTN HTML from this environment required cookies and JavaScript and did not return a usable record. The ID is kept. No ISRCTN numeric cells are used here.
| Item | Company / 6-K (9 Sept 2026) | NCT06079398 (queried 14 Sept 2026) |
|---|---|---|
| IDs | reACHin; TransCon CNP (navepegritide) | NCT06079398 / ASND0030 |
| Phase | Pivotal Phase 2 | PHASE2 |
| Blinded design | Randomized, placebo-controlled; double-blind portion now fully enrolled (company) | Randomized, parallel, quadruple-masked; 2:1 in the brief |
| N | At least 66 treatment-naïve infants for the double-blind portion | Estimated enrollment 72 |
| Age | 0 to <2 years | 0 to 2 years (maximum 2 years) |
| Dose named | 100 μg/kg/week | 100 μg/kg once weekly, both arms (active or matching placebo) |
| This week's data | Open-label sentinel n=7, Week 52 | Sentinel mentioned in eligibility; no results module |
| Status | Double-blind portion fully enrolled (company) | RECRUITING. Last update 8 April 2026. No results posted. |
YUVIWEL is approved for ages 2+, not for infants
The FDA accelerated-approval letter for NDA 219164 carries Hylton V. Joffe's electronic signature dated 27 February 2026. Yuviwel (navepegritide) injection is approved under accelerated approval (FDCA 506(c) and 21 CFR 314.510) to increase linear growth in pediatric patients 2 years of age and older with achondroplasia with open epiphyses.
The Prescribing Information (revised February 2026) repeats that indication and states it is approved under accelerated approval based on an improvement in annualized growth velocity. Continued approval may be contingent on confirmatory trial(s). Pediatric Use: "The safety and effectiveness of YUVIWEL in pediatric patients less than 2 years of age have not been established."
Accelerated approval is not traditional approval. The letter requires PMR 4969-1: an open-label, external-controlled trial in subjects 2 years and older with open epiphyses to measure final adult height, plus a disproportionality secondary and long-term safety endpoints (examples named: neurological complications, bone deformities, bone age, sleep apnea). Timetable: trial completion September 2034; final report June 2035. If confirmatory work fails to verify benefit or is not pursued with due diligence, FDA may withdraw the approval.
The labeled product is a once-weekly subcutaneous CNP analog, dosed by body weight, and is stopped when epiphyses close. This article does not reprint the weight-band milligram table. That labeled schedule is not an approved infant dose. A research-catalog "CNP" or "navepegritide" vial is not YUVIWEL. A COA check can test whether a certificate names a real lab. It cannot turn a listing into the FDA product.
The company wire says Ascendis's Marketing Authorisation Application for YUVIWEL is under review at the European Medicines Agency, with a regulatory decision anticipated in the fourth quarter of 2026. That is a company timeline. It is not an EMA approval.
The company's "About" block calls TransCon CNP a once-weekly CNP prodrug designed for continuous exposure against overactive FGFR3 signaling. That is company mechanism language, not new infant receptor data from ESPE.
Sentinel Week 52: cranio-cervical junction, growth, safety
The 6-K and the GlobeNewswire/BioSpace wire use the same highlight list. There is no placebo arm in this cohort. There is no published confidence interval, responder definition for "improved" AFMS, or child-level table in the sources fetched here.
Cranio-cervical junction. AFMS stable or improved in all seven children. Mean sagittal foramen magnum diameter +3.15 mm. No decompression surgeries in 52 weeks. Foramen magnum stenosis is a real infant-achondroplasia concern. An open-label n=7 MRI signal is still an open-label n=7 MRI signal. Children already anticipated to need decompression were excluded on the registry.
Linear growth. Mean ACH-specific supine length Z-score +0.42. Mean AGV 9.9 cm/year. ACH-specific Z-score is not a CDC general-population length Z-score. AGV 9.9 cm/year without a concurrent placebo comparator in this cohort is descriptive. It is not a treatment-minus-placebo AGV. Do not file it next to CANOPY-HCH-3's placebo-adjusted AGV.
Pharmacokinetics. The company says PK was comparable to older children and that this supports 100 μg/kg/week. No Cmax, AUC, or half-life table is in the September 9 package.
Safety, as the company reported it. Generally well tolerated; safety data "consistent with those previously reported in other trials." No injection-site reactions over 52 weeks. No deaths, fractures, bone-related safety events, or symptomatic hypotension. No adverse events assessed by investigators as related to treatment, and none that led to treatment disruption, discontinuation, or trial withdrawal.
That last sentence is investigator-assessed relatedness in an unblinded cohort of seven. The labeled product's common adverse reactions (≥5%) include vomiting, injection-site reaction, pain in extremity, and nausea. The label also warns that transient blood-pressure decreases have been reported with a once-daily CNP analog. Sentinel safety lines are this cohort's company report. They are not a rewrite of the ages-2+ label.
What this does not mean
- It is not the blinded reACHin efficacy readout. n=7 open-label sentinel data preceded the randomized period. The pivotal comparison is TransCon CNP versus placebo in at least 66 treatment-naïve infants.
- It is not FDA approval for infants younger than 2 years. The U.S. indication remains ages 2+ with open epiphyses. The label states safety and effectiveness under 2 have not been established.
- It is not a traditional (full) FDA approval even for ages 2+. February 27, 2026 is accelerated approval. Confirmatory final adult height remains outstanding (PMR 4969-1).
- It is not an EMA approval. The MAA is under review. Fourth-quarter 2026 is a company-anticipated decision window.
- It is not hypochondroplasia, and it is not vosoritide. CANOPY-HCH-3 stays as written. Prior vosoritide is an exclusion on NCT06079398.
- It is not ApproaCH. ApproaCH is a different TransCon CNP program in older children. This article does not import ApproaCH numbers.
- AFMS stable or improved in all seven is not a proven surgical-sparing claim. There was no decompression in 52 weeks in a cohort that excluded children already at high surgical risk.
- Mean AGV 9.9 cm/year is not a placebo-adjusted growth primary. There is no sentinel placebo arm in the company table.
- +3.15 mm mean sagittal diameter is not a published distribution. No range, SD, or child-level MRI table is in the wire or 6-K.
- PK "comparable to older children" is a company summary, not a public PK table.
- This is not medical advice, and it is not a consumer dosing protocol. 100 μg/kg/week is the trial and company dose named for this infant cohort. It is not an approved infant dose.
Infant investigational status did not change on 14 September 2026. No PeptidePrices research page for navepegritide was created. NCT06079398 did not gain a posted results module in the query used here.
What to watch
- The randomized reACHin readout. Safety (TEAEs) and 52-week length/height Z-score are the registered primaries. Until that table exists, do not treat sentinel AFMS or AGV as the trial result.
- A ClinicalTrials.gov status refresh. Watch whether RECRUITING becomes active or completed, and whether estimated enrollment 72 is replaced by an actual N.
- A posted results module or a peer-reviewed sentinel paper. ESPE plus a 6-K is not a journal methods paper.
- Whether FDA is asked to expand the YUVIWEL age range. That would be a later supplement. This Week 52 sentinel package is not that filing.
- The EMA clock. Company language is a Q4 2026 decision. That can slip.
- Confirmatory adult-height work for the ages-2+ accelerated approval. PMR 4969-1 completion is listed as September 2034.
FAQs
Did ESPE 2026 prove that navepegritide prevents foramen magnum surgery in infants?
No. In an open-label sentinel cohort of seven infants, AFMS was stable or improved in all children, mean sagittal diameter rose 3.15 mm, and no decompression occurred over 52 weeks. That is not a blinded surgical-prevention trial.
Is YUVIWEL approved for infants younger than 2 years?
No. FDA accelerated approval on 27 February 2026 (NDA 219164) is for pediatric patients 2 years and older with achondroplasia and open epiphyses. The label says safety and effectiveness under 2 have not been established.
Is this the reACHin Phase 2 efficacy result?
No. reACHin's double-blind portion is a placebo-controlled trial of at least 66 treatment-naïve infants (registry estimate 72). The ESPE 2026 numbers are the preceding open-label sentinel cohort.
Is this vosoritide or hypochondroplasia?
No. Navepegritide (TransCon CNP, YUVIWEL) is a once-weekly CNP prodrug. Vosoritide (Voxzogo) is a different daily CNP analog. CANOPY-HCH-3 is hypochondroplasia. reACHin is achondroplasia, ages 0 to <2.
What dose was used?
The sentinel cohort and the company description of reACHin use once-weekly subcutaneous TransCon CNP 100 μg/kg/week. YUVIWEL's labeled dose for ages 2+ is weight-banded and once weekly. Navepegritide is not approved for infants. That does not make 100 μg/kg/week an approved infant dose.
This article is for general informational purposes only and is not medical advice. Talk to a licensed clinician about personal medical decisions. Navepegritide remains investigational in infants younger than 2 years. YUVIWEL's U.S. indication is the labeled age group, under accelerated approval pending confirmatory adult-height data. Nothing here is a dosing protocol or a recommendation to obtain an unapproved product.
Continue your research
- Pep19 oral peptide iScience RCT (same-day Research Roundup)
- Vosoritide CANOPY-HCH-3 hypochondroplasia
- GZC8072 oral weekly peptide GLP-1 first dose
- How to verify a peptide COA
- COA Authenticity Checker
Sources
- Ascendis Pharma. First infant data from trial of once-weekly TransCon CNP (navepegritide) presented at ESPE 2026. GlobeNewswire. 9 September 2026
- Same release, BioSpace mirror (fetched copy of the GlobeNewswire wire). 9 September 2026
- Ascendis Pharma A/S. Form 6-K. Filed 9 September 2026
- ClinicalTrials.gov NCT06079398. reACHin: TransCon CNP versus placebo in infants 0 to <2 years with achondroplasia
- FDA. NDA 219164 accelerated approval letter for Yuviwel (navepegritide). Electronic signature 27 February 2026
- FDA. Yuviwel (navepegritide) Prescribing Information. Revised February 2026