```html
The study is important because experience with pegvaliase during pregnancy remains limited, even as more adults using newer PKU therapies consider pregnancy and parenthood.
Why Pregnancy Research Matters in PKU
Maintaining safe blood phenylalanine levels during pregnancy is critically important for people with PKU. High maternal phenylalanine can affect fetal development, which is why pregnancy has traditionally required careful metabolic monitoring and treatment planning.
As treatment options for adults with PKU expand, researchers also need better information about how newer therapies may affect pregnancy, breastfeeding and infant outcomes.
Pegvaliase provides an alternate pathway for breaking down phenylalanine rather than relying on the PAH enzyme that is deficient in PKU.
While pegvaliase is an established treatment for eligible adults with PKU, much less information has historically been available about its use during pregnancy and breastfeeding.
Rather than assigning participants to a treatment, the study collects information from pregnancies in which exposure to pegvaliase has already occurred. Researchers are evaluating maternal health, pregnancy outcomes, fetal outcomes, infant health and breastfeeding-related information.
As of September 2026, BioMarin continues to list PALomino as recruiting.
What Did We Know Before PALomino?
Pregnant participants were generally excluded from the original pegvaliase clinical trials, so early information came largely from individual case reports and real-world clinical experience.
A published case report described a person with PKU who chose to continue pegvaliase during pregnancy, helping begin the conversation about how the therapy might be managed in this setting.
Another report examined restarting pegvaliase during breastfeeding and found no detectable pegvaliase activity in the breast milk samples studied. However, individual cases cannot establish safety for a larger population.
The infants were born without congenital anomalies and had normal reported growth parameters. Researchers did note a higher-than-expected rate of preterm birth in the small group studied.
These findings were encouraging, but the authors emphasized the limitations of the small retrospective dataset. Larger, systematically collected information remains necessary.
Why PALomino Still Matters
Case reports and small retrospective studies can provide valuable early signals, but they cannot answer every question about medication use during pregnancy.
PALomino is designed to collect pregnancy and infant information more systematically across multiple centres. Over time, studies like this may help clinicians and families make better-informed decisions about balancing maternal metabolic control with potential treatment risks.
Research such as PALomino is helping build the evidence needed to support future conversations between patients, metabolic teams and maternal-fetal medicine specialists.
Decisions about starting, continuing, stopping or restarting pegvaliase during pregnancy or breastfeeding should always be individualized with the appropriate health-care team.
Recruitment status, participating countries, eligibility and study contacts can change. CanPKU+ therefore recommends checking the official study and sponsor pages below for current information.
Learn More
Explore the current PALomino study information and related published research.
PALomino on ClinicalTrials.gov Current study status, eligibility and locations BioMarin Clinical Trials Sponsor-maintained information about current PKU research Read the 2024 Pregnancy Outcomes Publication Outcomes from 14 live births following pegvaliase-treated pregnancies Read the Pegvaliase and Breastfeeding Case ReportAbout this article: CanPKU+ provides plain-language research information to help our community understand emerging evidence relevant to PKU.
