FDA announced Thursday it has approved cerliponase alfa (Brineura—BioMarin Pharmaceutical) as a treatment for a particular form of Batten disease. This is the first FDA-approved treatment to slow loss of walking ability in symptomatic pediatric patients aged 3 years and older with late infantile neuronal ceroid lipofuscinosis type 2 (CLN2), also known as tripeptidyl peptidase-1 deficiency. CLN2 disease is one of a group of disorders known as neuronal ceroid lipofuscinoses (NCLs), collectively referred to as Batten disease. CLN2 disease is a rare inherited disorder that primarily affects the nervous system. The late infantile form of the disease—for which signs and symptoms generally begin between aged 2 years and 4 years—features initial symptoms including language delay, recurrent seizures, and ataxia. A single-arm dose escalation clinical study involving 22 symptomatic pediatric patients with CLN2 disease and 42 untreated patients with CLN2 disease from a natural history cohort who were at least 3 years old and had motor or language symptoms found that patients who received cerliponase alfa had fewer declines in walking ability compared with the untreated patients. The drug's safety was evaluated in 24 patients with CLN2 disease aged 3–8 years who received at least one dose of cerliponase alfa in clinical studies. The most frequently reported adverse events in patients treated with cerliponase alfa include fever, ECG abnormalities, hypersensitivity, decrease or increase in CSF protein, vomiting, seizures, hematoma, headache, irritability, increased CSF white blood cell count, device-related infection, feeling jittery, and low blood pressure. BioMarin will have to further evaluate the study of cerliponase alfa in CLN2 patients younger than aged 2 years, including device-related adverse events and complications with routine use. A long-term safety study will also assess cerliponase alfa-treated CLN2 patients for at least 10 years.