Sanofi Reports Intermittent Nexviazyme Supply Disruptions Affecting Pompe Disease Patients
- The Rare360 Editorial Team
- 4 hours ago
- 10 min read
The Pompe disease community is urged to stay in close contact with healthcare teams as Sanofi reports infusion delays and potential further supply interruptions.
August 15, 2026 - People living with Pompe disease and their families are facing growing uncertainty over access to enzyme replacement therapy (ERT), as Sanofi confirms supply constraints affecting Nexviazyme and Myozyme, two therapies used to treat Pompe disease.
The issue has emerged in the United States and Europe and follows regulatory action involving Sanofi's manufacturing facility in Waterford, Ireland. Recent reporting indicates that the supply constraints are associated with a bottleneck in the final manufacturing and batch-release process at the facility, while Sanofi has warned that it could take months for production and inventories to fully stabilize.
For people with Pompe disease, the situation is particularly concerning because ERT is administered on a recurring schedule and is an important component of disease management. A delayed infusion is therefore more than a routine medication shortage; it can affect treatment schedules, caregivers, travel, work, school and, for some patients, concerns about maintaining respiratory and motor function.
What is happening in the United States?
In a communication sent to members of the U.S. Pompe community, Sanofi said that intermittent release interruptions have affected the availability of Nexviazyme (avalglucosidase alfa-ngpt) in the United States.
Sanofi identified patients with infusions scheduled between August 10 and August 18, 2026 as potentially affected and said that some infusions would need to be rescheduled after August 18. The company said its Patient Support Services (PSS) team is contacting consented patients and caregivers affected by the disruption.
However, Sanofi also cautioned that intermittent release interruptions may continue for the next several months. The company has said that it is working with patients, prescribers and infusion sites on an individual basis and is working with regulatory authorities to minimize the impact on patients and support continuity of care.
Sanofi also stated that every batch released from its Waterford facility continues to meet established requirements for safety, strength and purity.
The supply problem may involve more than Nexviazyme
Recent reporting by Medical Daily and STAT indicates that Sanofi is experiencing supply constraints involving two Pompe therapies: Nexviazyme and Myozyme. The reports describe a bottleneck in the final manufacturing phase, including the batch-release process at the Waterford facility.
Batch release is a critical final stage of pharmaceutical manufacturing. After a medicine is produced, the batch must undergo quality-assurance and regulatory checks before it can be formally released for distribution.
According to reporting cited by Medical Daily, the impact varies by country and product, depending on factors such as available inventory, local demand and the timing of shipments. Some markets may therefore experience limited delays while others face more significant supply constraints. Sanofi has indicated that production may take months to stabilize and that rebuilding normal inventory levels could take longer.
This means that the experience of one patient or country should not automatically be assumed to represent the situation everywhere.
What did the FDA find at the Waterford facility?
On June 22, 2026, the U.S. Food and Drug Administration (FDA) issued a Warning Letter to Genzyme Ireland Limited, a Sanofi company operating the Waterford facility.
The FDA had inspected the facility between January 12 and January 20, 2026, and documented what it described as significant violations of current good manufacturing practice (CGMP) requirements. The Warning Letter identified concerns involving manufacturing and quality systems, laboratory controls, investigations, documentation and data integrity, and manufacturing oversight.
The FDA Warning Letter does not say that Nexviazyme is unsafe.
The FDA letter discusses manufacturing concerns involving products including Thymoglobulin and Altuviiio. It does not state that Nexviazyme was found to be defective, contaminated or unsafe, nor does the letter itself establish that the FDA warning caused the current Pompe therapy shortages.
What is known is that:
The Waterford facility underwent an FDA inspection in January 2026.
The FDA issued its Warning Letter in June 2026.
Sanofi subsequently reported intermittent Nexviazyme release interruptions in the United States.
Recent reporting describes a final manufacturing/batch-release bottleneck affecting Pompe therapies.
Supply constraints involving Nexviazyme and Myozyme have been reported in the U.S. and Europe.
The causal relationship between the FDA Warning Letter and the shortages has not been established by the FDA. Medical Daily specifically emphasizes that the timing and location are documented, but causation should not be assumed.
Europe is also experiencing supply disruptions
The situation is not limited to the United States. In Europe, avalglucosidase alfa is marketed as Nexviadyme. The European Medicines Agency (EMA) lists Nexviadyme as a long-term enzyme replacement therapy for patients with Pompe disease.
National medicine-supply records indicate that several European countries have reported availability problems.
France
France has reported a hospital-level shortage of Nexviadyme 100 mg. According to information reported from France's medicines regulator (ANSM), units of Nexviazyme originally intended for the Australian market were made temporarily available in France beginning July 9, 2026, to help address the shortage.
The imported product is manufactured at the same production site and was described as equivalent to the French product, apart from packaging, labeling and the patient information materials being in English. The expected date for restoration of normal availability was reported as undetermined.
Italy
Italy's medicines agency, AIFA, reported that Nexviadyme 100 mg was not available nationally and authorized importation from abroad at the company's request. AIFA published notices regarding the shortage on July 7 and again on July 17, 2026.
This demonstrates that the response to shortages may differ between countries, with some health systems using emergency or exceptional imports to maintain patient access.
Germany
Germany's official medicine-shortage database has also listed both Nexviadyme and Myozyme as affected by production-related supply problems. A July 28 update listed Nexviadyme with a production problem and a reported shortage period extending through August 13. The same database also recorded a production-related shortage notification for Myozyme, with the reported period extending through August 10.
These national reports demonstrate that supply problems are affecting more than one European market.
However, the severity, duration and patient-level impact are not necessarily identical across countries.
Why does this matter to people living with Pompe?
Pompe disease is a rare inherited metabolic disorder caused by deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). Without sufficient GAA activity, glycogen accumulates inside cells, particularly affecting skeletal and respiratory muscles and, in infantile-onset disease, the heart. ERT provides a laboratory-produced version of the missing enzyme through intravenous infusion.
Nexviadyme is authorized in Europe for long-term ERT for people with Pompe disease, while Nexviazyme is approved in the United States for patients aged one year and older with late-onset Pompe disease.
Treatment is generally administered on a recurring schedule, meaning that supply interruptions can have consequences beyond simply missing an appointment.
For patients and caregivers, a delayed infusion may mean:
cancelled or rescheduled infusion-center appointments;
additional travel and transportation;
missed work or school;
additional caregiver responsibilities;
uncertainty about when the next treatment will occur;
anxiety about disease progression; and
concerns about maintaining respiratory and motor function.
For some patients with more advanced disease, particularly those with significant respiratory impairment, maintaining treatment continuity may be especially important.
Why an interrupted infusion is different from a missed pill?
Pompe disease is a progressive condition in which glycogen continues to accumulate when the underlying enzyme deficiency is not adequately addressed. ERT does not cure Pompe disease, but it provides the enzyme needed to help break down accumulated glycogen.
That makes treatment continuity particularly important for patients who have established disease and depend on regular infusions. At the same time, the clinical consequences of a delay are not identical for every patient.
Disease subtype, age, disease severity, respiratory status, mobility, previous treatment history and the duration of the interruption can all influence the potential impact.
Infants and young children with infantile-onset Pompe disease may have a particularly narrow clinical window because the disease can progress rapidly. Adults with advanced late-onset disease and significant respiratory or mobility impairment may also have less reserve if treatment is interrupted.
This does not mean that every delayed infusion will result in clinical deterioration. Patients should discuss the significance of any delay with their own Pompe specialist.
What Sanofi says patients should expect?
Sanofi has stated that intermittent release interruptions may continue for the next several months as the company works to address the situation.
According to Sanofi:
Patients with affected upcoming infusions should expect their healthcare team and/or Sanofi Patient Support Services to contact them.
Infusions affected by the current disruption may need to be rescheduled. Timing will vary based on country and product.
Sanofi says it is working individually with affected patients, prescribers, and sites of care.
The company says it is working with regulatory authorities to minimize the impact on patients and support continuity of care where possible.
Sanofi states that every batch released from the Waterford facility continues to meet established requirements for safety, strength, and purity.
Sanofi also says its Rare Diseases Medical Affairs team is proactively contacting healthcare professionals who prescribe its Pompe therapies.
Patients and caregivers who have not completed a Sanofi Patient Support Services consent form should contact Sanofi to determine whether completing the form would allow a Case Manager or Patient Education Liaison to communicate directly with them.
What patients and caregivers can do now?
Patients should not independently stop, postpone, double or change their treatment schedule because of the shortage. Instead, patients and caregivers should:
Contact their infusion center or Pompe specialist and confirm whether their upcoming treatment is affected.
Ask when the next infusion is expected to occur.
Confirm whether the medication shipment has been released and when it is expected to arrive.
Ask what symptoms or changes in function should prompt an earlier medical assessment.
Keep their treating team informed about any changes in breathing, mobility, muscle strength, swallowing or other concerning symptoms.
Discuss potential alternatives with their Pompe specialist if the treatment interruption is expected to be prolonged.
Keep records of cancelled or delayed infusions and revised treatment dates.
Follow official updates from Sanofi, national medicines regulators and their healthcare providers.
The burden extends beyond the medicine itself
The current shortage also highlights a frequently overlooked aspect of rare disease treatment: the infrastructure surrounding therapy.
A Pompe infusion often requires coordination between the manufacturer, specialty pharmacy, hospital or infusion center, nursing staff, physicians, caregivers and the patient.
When a shipment is delayed, the disruption can ripple through this entire system.
For families who travel long distances to receive treatment, a last-minute cancellation may mean lost transportation costs and another day away from work or school.
For caregivers, rescheduling may require arranging additional leave, childcare or transportation.
For infusion centers, uncertainty around product availability can complicate staffing and appointment scheduling.
For patients, the psychological burden can be equally significant.
After years of living with a rare and progressive disease, uncertainty about access to a treatment that has become part of a routine can be deeply distressing.
What the Pompe community needs from manufacturers and regulators
The current situation underscores the importance of transparent, timely and patient-centered communication.
Patients and healthcare professionals need clear information about:
which products and markets are affected;
the expected duration of supply constraints;
how available inventory is being allocated;
whether emergency or alternative-country imports are being arranged;
when additional product is expected to be released;
whether production capacity has been restored;
when normal inventory levels are expected to return; and
what support is available to patients whose treatments are delayed.
The experience in France and Italy demonstrates that regulatory authorities can use different mechanisms—including exceptional importation—to address shortages. (VIDAL)
For the global Pompe community, sharing timely information between countries may also help patients, clinicians and advocacy organizations understand where supply pressures are emerging.
Questions patients can ask their healthcare team
For patients who have been notified of a delayed or potentially affected infusion, the following questions may help guide the conversation:
Is my upcoming Nexviazyme infusion affected?
How long is the anticipated delay?
When is my next confirmed infusion date?
What should I monitor while waiting for my infusion?
Are there symptoms that should prompt me to contact my care team immediately?
Does my individual disease history or current clinical status change how we should manage the delay?
Are there alternative treatment options that are appropriate for my specific Pompe diagnosis and circumstances, and what would be involved in considering them?
Will additional monitoring be needed if my infusion is delayed?
A situation that deserves continued transparency
For the Pompe community, the immediate concern is not simply whether a shipment is delayed. Regular access to therapy can be closely connected to patients' sense of stability and confidence in their treatment plans.
Sanofi has acknowledged that the current situation may extend beyond this immediate disruption and has committed to providing additional communication as the situation develops. Continued, timely communication will be particularly important for patients, caregivers, infusion centers, and Pompe specialists as they plan upcoming treatment.
The Pompe community will need continued updates regarding the duration and scope of the supply disruption, the availability of future ERT releases, and any additional actions being taken to protect continuity of treatment.
Contact information provided by Sanofi
· U.S. patients and caregivers:Contact your designated Sanofi Patient Education Liaison/Case Manager or call 1-800-745-4447, option 3.
· U.S. healthcare professionals:Contact Sanofi Medical Information at 1-800-745-4447, option 2, or contact your Rare Diseases field medical liaison.
Sanofi has also directed patients to Care Connect PSS for Patient Support Services consent and assistance.
Sources
U.S. Food and Drug Administration (FDA). Genzyme Ireland Limited — Warning Letter, June 22, 2026. The FDA's official letter documents the inspection findings, CGMP concerns, corrective-action expectations, and regulatory response requirements.
U.S. Food and Drug Administration (FDA). Nexviazyme (avalglucosidase alfa-ngpt) — Orphan Drug Designations and Approvals. Confirms FDA approval of Nexviazyme in August 2021 for patients 1 year and older with late-onset Pompe disease.
U.S. Food and Drug Administration (FDA). Nexviazyme regulatory review. Provides background on Pompe disease, enzyme replacement therapy and Nexviazyme's dosing and treatment context.
U.S. Food and Drug Administration (FDA). Lumizyme (alglucosidase alfa) Prescribing Information. Provides the FDA-approved indication and important safety information for Lumizyme.
U.S. Food and Drug Administration (FDA). Pombiliti Drug Trials Snapshot. Provides information on the FDA-approved use of Pombiliti in combination with Opfolda for certain adults with late-onset Pompe disease.
Medical Daily.Two Pompe Disease Treatments Are in Short Supply Weeks After Regulators Cited the Plant That Releases Them. Published August 11, 2026. The report provides additional information on shortages affecting Nexviazyme and Myozyme, the reported batch-release bottleneck, geographic variation in supply impact, and the distinction between the FDA regulatory action and the cause of the shortage.
European Medicines Agency (EMA).Nexviadyme (avalglucosidase alfa). Provides the European regulatory information and therapeutic indication for Nexviadyme as long-term enzyme replacement therapy for Pompe disease. (European Medicines Agency (EMA))
French medicines availability information / ANSM reporting.France reported a hospital-level Nexviadyme shortage and temporary availability of Nexviazyme units originally intended for the Australian market beginning July 9, 2026. (VIDAL)
Italian Medicines Agency (AIFA).AIFA reported that Nexviadyme was not available nationally and authorized importation from abroad in July 2026. (AIFA)
10. German official medicine-shortage database.Germany's official shortage database reported production-related availability problems for Nexviadyme and Myozyme in July 2026.
11. Sanofi.Communication to the U.S. Pompe community regarding intermittent Nexviazyme release interruptions, affected August 2026 infusion dates, potential continuation of interruptions, and patient-support resources.
Editorial note
This article is intended for Pompe disease community awareness and education and is based on manufacturer communications, regulatory information and recent reporting. It does not replace individualized medical advice.
Patients experiencing a delayed or cancelled infusion should contact their treating healthcare professional or Pompe specialist for guidance specific to their disease, treatment history and clinical circumstances.
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