In individuals with galactosemia, the enzymes needed for further metabolism of galactose (Galactokinase and galactose-1-phosphate uridyltransferase) are severely diminished or missing entirely, leading to toxic levels of galactose or galactose 1-phosphate (depending on which enzyme is missing) in various tissues as in the case of classic galactosemia, resulting in hepatomegaly (an enlarged liver), cirrhosis, kidney failure, cataracts, vomiting, seizure, low blood sugar (hypoglycemia), lethargy, brain damage, and ovarian failure. Without treatment, mortality in infants with galactosemia is about 75%.Galactosemia is inherited in an autosomal recessive manner, meaning a child must inherit one defective gene from each parent to show the disease. Heterozygotes are carriers, because they inherit one normal gene and one defective gene. Carriers show no symptoms of galactosemia. Accumulation of galactose
Reduction to galactitol
In galactosemic patients, the accumulation of galactose becomes the substrate for enzymes that catalyze the polyol pathway of carbohydrate metabolism. The first reaction of this pathway is the reduction of aldoses, types of sugars including galactose, to sugar alcohols. Recent data suggests that aldose reductase is the enzyme responsible for the primary stage of this pathway. Therefore, aldose reductase reduces galactose to its sugar alcohol form, galactitol. Galactitol, however, is not a suitable substrate for the next enzyme in the polyol pathway, polyol dehydrogenase. Thus, galactitol accumulates in body tissues and is excreted in the urine of galactosemic patients.
Safety concerns
On 23 February 2020, the American Society of Retina Specialists reported side effects of the drug, specifically in 14 cases of retinal vasculitis reported in Beovu patients, 11 of the cases were occlusive retinal vasculitis that can lead to vision loss.Novartis responded with a statement standing behind the efficacy of Beovu.On 11 June 2020, the FDA approved an updated Beovu label, that included additional safety information specifically including the characterization of adverse events, retinal vasculitis and retinal vascular occlusion, as part of the spectrum of intraocular inflammation observed in  HAWK (NCT02307682) and HARRIER (NCT02434328) clinical trials and noted in the original prescribing information. Names
Laboratory development names were RTH258 (Novartis Compound Code) and ESBA1008 (ESBATech AG).Brolucizumab is the International Nonproprietary Name (INN) and the United States Adopted Name (USAN)

References
External links
"Brolucizumab". Drug Information Portal. U.S. National Library of Medicine.