Growth hormone deficiency has meant daily injections for children, a burden that erodes adherence over years of treatment. Skytrofa (lonapegsomatropin) was among the first long-acting alternatives approved in the U.S.
It is a prodrug in which somatropin is bound to a carrier and released gradually through a cleavable linker, producing sustained exposure from a single weekly dose. The injection is approved for children 1 year and older with growth hormone deficiency who weigh at least 11.5 kg.
Skytrofa faces no biosimilar competition but competes directly with other weekly growth hormones approved around the same period. Conversion from daily somatropin and long-term growth outcome data are the decisive factors for uptake in a market with entrenched incumbents.