A 21-child Phase 2 trial paired Ascendis Pharma's navepegritide, a C-type natriuretic peptide prodrug, with lonapegsomatropin, a growth-hormone prodrug, in achondroplasia. Treatment-naive kids grew 8.69 cm per year versus 5.95 on matched monotherapy, a 2.74 cm per year gain (p less than 0.0001). Nine children already on navepegritide for a year added another 3.28 cm per year. Arm span gained 9.4 cm in the treatment-naive arm, lifting the body-proportionality endpoint that has defined this field.