XENPOZYME
Clinical safety rating: caution
Comprehensive clinical and safety monograph for XENPOZYME (XENPOZYME).
XENPOZYME (olipudro alfa) is a recombinant human acid alpha-glucosidase (GAA) enzyme replacement therapy. It hydrolyzes lysosomal glycogen by cleaving α-1,4 and α-1,6 glycosidic linkages, thereby reducing glycogen accumulation in tissues, particularly skeletal muscle.
| Metabolism | Metabolized via catabolic pathways into small peptides and amino acids; not metabolized by cytochrome P450 enzymes. |
| Excretion | Xenpozyme (olipudro alfa) is a recombinant lysosomal acid lipase (LAL) enzyme replacement therapy. As a protein, it undergoes catabolism via peptide hydrolysis into amino acids, which are reused or excreted. Renal excretion of intact drug is negligible. No specific studies on biliary/fecal elimination have been published; however, catabolic products are primarily excreted renally as amino acids. |
| Half-life | The terminal elimination half-life is approximately 6-9 hours. This relatively short half-life supports weekly intravenous administration to maintain therapeutic enzyme levels. |
| Protein binding | As a recombinant protein, olipudro alfa is minimally bound to plasma proteins (<5%). |
| Volume of Distribution | Volume of distribution is approximately 3-5 L, consistent with distribution primarily in the vascular space and limited extravascular distribution, typical for large therapeutic proteins. |
| Bioavailability | Xenpozyme is administered intravenously, resulting in 100% bioavailability. Not administered via other routes. |
| Onset of Action | Upon intravenous infusion, lysosomal acid lipase activity in tissues (e.g., liver, spleen) begins within hours, with reductions in liver fat content and improvements in transaminases observed within 4 weeks. |
| Duration of Action | The pharmacodynamic effect (e.g., reduction in hepatic fat, normalization of transaminases) persists for the duration of therapy, with continued improvement over months. Weekly dosing is required to sustain enzyme activity. |
40 mg intravenously over 60 minutes every 2 weeks.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for renal impairment. |
| Liver impairment | No formal studies; use caution in Child-Pugh C. |
| Pediatric use | Not approved for pediatric patients. |
| Geriatric use | No specific dose adjustments; clinical studies included patients up to 65 years with no observed differences. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for XENPOZYME (XENPOZYME).
| Breastfeeding | It is unknown whether XENPOZYME is excreted in human breast milk. Given its large molecular weight (approximately 140 kDa), transfer into milk is likely low. No M/P ratio is available. Risk to the nursing infant is considered minimal, but caution is advised due to lack of data. |
| Teratogenic Risk | XENPOZYME (olipudro alfa) is an enzyme replacement therapy for acid sphingomyelinase deficiency (ASMD). Based on animal studies and limited human data, there is no evidence of teratogenicity in the first trimester. In the second and third trimesters, fetal risks are theoretical due to potential immunogenicity and placental transfer of IgG-based enzyme, but no specific structural or developmental anomalies have been reported. Monitoring is recommended for fetal growth and amniotic fluid volume due to maternal disease severity. |
■ FDA Black Box Warning
Risk of anaphylaxis, severe allergic reactions, and hypersensitivity reactions, including urticaria, angioedema, bronchospasm, and hypotension. Infusion-associated reactions may occur. Patients should be monitored closely during and after infusion.
| Serious Effects |
["Known hypersensitivity to olipudro alfa or any excipients of XENPOZYME"]
| Precautions | ["Risk of anaphylaxis and severe hypersensitivity reactions","Infusion-associated reactions (e.g., fever, chills, rash, urticaria, hypertension, chest discomfort)","Cardiac arrhythmias and sudden cardiac death have been reported; monitor cardiac function","Risk of immune-mediated reactions; consider monitoring for antibody development","Not recommended for use in patients with advanced Pompe disease who are non-ambulatory or require invasive ventilation"] |
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| Fetal Monitoring | Monitor maternal hepatic function (ALT, AST, bilirubin) and renal function monthly. Fetal monitoring includes serial ultrasound for growth restriction, amniotic fluid volume, and placental thickness. Pre- and postnatal monitoring of infant for immune response to enzyme is recommended. |
| Fertility Effects | No clinical studies have evaluated effects on fertility. Animal studies showed no impairment of male or female fertility at clinically relevant doses. Disease-related complications (e.g., splenomegaly, metabolic disturbances) may indirectly affect fertility. |