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Adverse event reporting can be found at the bottom of the page.


This is intended for HCPs practising in Great Britain (England, Scotland and Wales) only.


The safety of Nexviadyme® has been studied in patients older than 6 months of age acrosss both LOPD and IOPD1

Summary of safety information

Please refer to the Summary of Product Characteristics before prescribing.

Dosage and Administration

Nexviadyme® treatment should be supervised by a physician experienced in the management of patients with Pompe disease or other inherited metabolic or neuromuscular diseases. Patients may be pretreated with antihistamines, antipyretics and/or corticosteroids to prevent or reduce allergic reactions.

The recommended dose of avalglucosidase alfa is 20 mg/kg of body weight administered once every 2 weeks. Nexviadyme vials are for single use only and the medicinal product should be administered as an intravenous infusion. The infusion should be administered incrementally as determined by patient response and comfort; refer to the SmPC for the infusion rate schedule.

Dose modification for IOPD patients

For IOPD patients who experience lack of improvement or insufficient response in cardiac, respiratory, and/or motor function while receiving 20 mg/kg, a dose increase to 40 mg/kg every other week should be considered in the absence of safety concerns (e.g., severe hypersensitivity, anaphylactic reactions, or risk of fluid overload). In patients who do not tolerate avalglucosidase alfa at 40 mg/kg every other week (e.g., severe hypersensitivity, anaphylactic reactions, or risk of fluid overload), consider decreasing the dose to 20 mg/kg every other week.

Special Populations

Click below to learn more about Nexviadyme® safety for special populations.


Life-threatening hypersensitivity to the active substance or to any of the excipients listed in the SmPC.

Precautions and Warnings

Hypersensitivity reactions (including anaphylaxis)

Hypersensitivity reactions, including anaphylaxis, have been reported in Nexviadyme-treated patients. Appropriate medical support measures, including cardiopulmonary resuscitation equipment especially for patients with cardiac hypertrophy and patients with significantly compromised respiratory function, should be readily available when Nexviadyme is administered. If severe hypersensitivity or anaphylaxis occur, Nexviadyme should be discontinued immediately, and appropriate medical treatment should be initiated. The risks and benefits of re-administering Nexviadyme following anaphylaxis or severe hypersensitivity reaction should be considered.


In clinical studies, IARs were reported to occur at any time during and/or within a few hours after the infusion of Nexviadyme and were more likely with higher infusion rates. Patients with an acute underlying illness at the time of Nexviadyme infusion appear to be at greater risk for IARs. Patients with advanced Pompe disease may have compromised cardiac and respiratory function, which may predispose them to a higher risk of severe complications from IARs. If severe IARs occur, immediate discontinuation of the administration of Nexviadyme should be considered and appropriate medical treatment should be initiated. The benefits and risks of readministering Nexviadyme following severe IARs should be considered.


Treatment emergent ADA were reported in both treatment naïve and treatment experienced patients. Adverse-event-driven immunologic testing, including IgG and IgE ADA, may be considered for patients who have risk for allergic reaction or previous anaphylactic reaction to alglucosidase alfa.

Risk of acute cardiorespiratory failure

Caution should be exercised when administering Nexviadyme to patients susceptible to fluid volume overload or patients with acute underlying respiratory illness or compromised cardiac and/or respiratory function for whom fluid restriction is indicated. These patients may be at risk of serious exacerbation of their cardiac or respiratory status during infusion. Appropriate medical support and monitoring measures should be readily available during Nexviadyme infusion.

Cardiac arrhythmia and sudden death during general anaesthesia for central venous catheter placement

Cardiac arrhythmia, including ventricular fibrillation, ventricular tachycardia, and bradycardia, resulting in cardiac arrest or death, or requiring cardiac resuscitation or defibrillation, have been associated with the use of general anaesthesia in IOPD patients with cardiac hypertrophy.


No interaction studies have been performed. Because it is a recombinant human protein, avalglucosidase alfa is an unlikely candidate for cytochrome P450 mediated drug-drug interactions.

Fertility and Lactation

There are no available data on the use of Nexviadyme in pregnant women. The potential risk for humans is unknown. Nexviadyme should be used during pregnancy only if the potential benefits to the mother outweigh the potential risks, including those to the foetus. 


There are no available data on the presence of Nexviadyme in human milk or the effects of Nexviadyme on milk production or the breastfed infant.

Adverse reactions

Very common (≥1/10)

Hypersensitivity, headache, nausea, pruritus and rash.

Common (≥1/100 to <1/10)

Anaphylaxis,  dizziness, tremor, somnolence, burning sensation, ocular hyperaemia, conjunctival hyperaemia, eye pruritus, eyelid oedema, tachycardia, flushing, hypertension, hypotension, cyanosis, hot flush, pallor, cough, dyspnoea, respiratory distress, throat irritation, oropharyngeal pain, diarrhoea, vomiting, lip swelling, swollen tongue, abdominal pain, abdominal pain upper, dyspepsia,  urticaria, erythema, palmer erythema, hyperhidrosis, rash erythematous, rash pruritic, skin plaque, muscle spasms, myalgia, pain in extremity, flank pain, fatigue, chills, chest discomfort, pain, influenza like illness, infusion site pain, pyrexia, asthenia, face oedema, feeling cold, feeling hot, sluggishness, blood pressure increased, oxygen saturation decreased and body temperature increase. 

Prescribers should consult the SmPC in relation to other adverse reactions.

Learn more about Nexviadyme®

Nexviadyme® evidence

Explore the results and evidence supporting Nexviadyme® and how it was studied through several clinical trials.

Treatment with Nexviadyme®

Read more about treatment with Nexviadyme® (avalglucosidase alfa) for patients living with Pompe disease.


Nexviadyme® evidence

Explore the results and evidence supporting Nexviadyme® and how it was studied through several clinical trials.

Treatment with Nexviadyme®

Read more about treatment with Nexviadyme® (avalglucosidase alfa) for patients living with Pompe disease.


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  1. Sanofi. Nexviadyme (avalglucosidase alfa). Summary of Product Characteristics. 2024. Available at:

MAT-XU-2400522 (v1.0) Date of preparation: March 2024