COPENHAGEN, Denmark — Ascendis Pharma A/S (Nasdaq: ASND) today announced new data demonstrating TransCon hGH accelerated TransCon CNP’s benefits beyond linear growth with substantial improvements in arm span, spinal canal dimensions, and lower limb alignment. The new data are from Week 52 of the ongoing Phase 2 COACH Trial of combination therapy with once-weekly TransCon CNP and once-weekly TransCon hGH in children with achondroplasia. Ascendis previously reported Week 52 COACH results that demonstrated mean annualized growth velocity exceeding the 97th-percentile of average stature children, without compromising safety or tolerability and with no acceleration of bone age.
“It is encouraging to see data emerging beyond linear growth, including reported improvements in arm span, spinal dimensions, and leg alignment, which may help broaden how outcomes are understood,” said Michael Hughes, Chair of the Biotech Committee at the Little People of America. “Findings from the COACH Trial contribute to this expanding view and can be meaningful to consider as part of a more comprehensive understanding of treatment effects, alongside continued efforts to engage with the achondroplasia community. As research progresses, longer-term data will be important to understand how these outcomes may translate over time, including areas such as skeletal health, spinal complications, and the need for interventions.”
New Data from Week 52 of the COACH Trial
- Unprecedented improvements in arm span observed at Week 52 with TransCon CNP and TransCon hGH combination therapy, a measure highly meaningful to the achondroplasia community, with the mean change from baseline in achondroplasia (ACH)-specific arm span Z-scores at Week 52 for TransCon CNP treatment-naïve and TransCon CNP-treated children in COACH were +1.02 and +0.66, respectively. The TransCon CNP treatment-naïve cohort improved +9.4 cm and the TransCon CNP-treated cohort improved +7.9 cm. By comparison, humeral gain by limb lengthening surgery is approximately 8 cm per arm and carries a high complication risk.1
- Mean of L1-L5 average changes in interpedicular distance (IPD) for TransCon CNP treatment-naïve and TransCon CNP-treated children on combination therapy in COACH were +1.7 mm and +1.1 mm, respectively, compared to +0.6 mm for children on TransCon CNP monotherapy in ApproaCH. Improvements in IPD offer the potential to reduce nerve compression and pain that can result from a narrowed spinal column.
- For the TransCon CNP treatment-naïve cohort, the mean change in tibial femoral angle (TFA) Z-score was -0.86 with combination therapy at Week 52 in COACH and was -0.47 for TransCon CNP monotherapy at Week 52 in ApproaCH, indicating enhanced straightening of the legs. Children previously treated with long-term TransCon CNP monotherapy for an average of 2.56 years maintained in normal range for TFA Z-score.
- For the TransCon CNP treatment-naïve cohort, the mean change in TFA was -3.0 degrees with combination therapy in COACH and was -1.3 degrees for children on TransCon CNP monotherapy at Week 52 in ApproaCH. Children previously treated with long-term TransCon CNP monotherapy for an average of 2.56 years maintained TFA treatment benefit in the setting of accelerated growth.
- All children completed 52 weeks of treatment and remain on therapy in COACH as of today.
TransCon CNP (navepegritide) is a prodrug of C-type natriuretic peptide (CNP) administered once weekly, providing continuous exposure of active CNP to receptors on tissues throughout the body, including growth plates and skeletal muscle. TransCon hGH (lonapegsomatropin) is a prodrug of somatropin administered once weekly, providing sustained release of active, unmodified somatropin. TransCon CNP was approved under the trade name YUVIWEL® by the U.S. Food & Drug Administration (FDA) in February 2026 and is under review by the European Medicines Agency as a monotherapy for children with achondroplasia. TransCon hGH is approved by the FDA, European Commission, and other regulatory agencies and marketed as SKYTROFA® for the treatment of pediatric and adult growth hormone deficiency; it is investigational in achondroplasia and other indications.
COACH Trial Design
COACH is an ongoing prospective Phase 2 open-label trial to investigate the efficacy, safety, and tolerability of combined treatment with once-weekly TransCon CNP at 100 µg/kg/week and once-weekly TransCon hGH at a starting dose of 0.30 mg/kg/week in children with achondroplasia aged 2 to 11 years. The trial included a cohort of TransCon CNP treatment-naïve children (N=12, mean age 4.67 years) and a cohort of previously TransCon CNP-treated children (N=9, mean age 7.89 years), who had received TransCon CNP (100 µg/kg/week) for a mean of 2.56 years in clinical trials. The trial population is representative of children with achondroplasia and the prior treatment benefits of TransCon CNP monotherapy.
“These unprecedented COACH Trial results demonstrate benefits beyond linear growth, reflecting meaningful clinical improvements identified by the achondroplasia community,” said Aimee D. Shu, M.D., Executive Vice President of Endocrine & Rare Disease Medical Science and Chief Medical Officer at Ascendis Pharma. “Across clinical trials, TransCon CNP has demonstrated unique benefits as monotherapy and now we see potential in combination with TransCon hGH to enhance these transformative changes for individuals with achondroplasia.”
A slide presentation with these new COACH Trial Week 52 data can be found on the Investors & News section of the Ascendis Pharma website: https://investors.ascendispharma.com.
About Achondroplasia
Achondroplasia is a rare genetic condition arising from a systemic fibroblast growth factor receptor 3 (FGFR3) variant that leads to an imbalance in the effects of the FGFR3 and CNP signaling pathways, estimated to affect more than 250,000 people worldwide. While historically considered a bone growth disorder, the FGFR3 variant seen in achondroplasia is expressed in tissues throughout the body, and is associated with an increased risk of muscular, neurological, and cardiorespiratory complications in addition to skeletal dysplasia. Medical complications of achondroplasia can vary from individual to individual and across different stages of life. Throughout infancy and childhood, observed complications include spinal abnormalities, enlarged brain ventricles, impaired muscle strength and reduced stamina, hearing deficits and chronic ear infections, upper airway obstructions, sleep-disordered breathing, hip problems, leg bowing, and chronic pain; some of which persist or worsen in adulthood. These medical complications can affect physical well-being and quality of life, and may be impacted by a range of individual, clinical, and social factors. Some individuals with achondroplasia require multiple procedures and surgeries to address specific functional or anatomical concerns.
About Ascendis Pharma A/S
Ascendis Pharma is a global biopharmaceutical company focused on applying our innovative TransCon technology platform to make a meaningful difference for patients. Guided by our core values of Patients, Science, and Passion, and following our algorithm for product innovation, we apply TransCon to develop new therapies that demonstrate best-in-class potential to address unmet medical needs. Ascendis is headquartered in Copenhagen, Denmark, and has additional facilities in Europe and the United States. Please visit ascendispharma.com to learn more or follow the company on X.
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