BioMarin Announces Five-Year Phase 3 Data for POMBILITI® (cipaglucosidase alfa-atga) + OPFOLDA® (miglustat) at World Muscle Society Annual Congress

Long-term data reinforce durable efficacy and safety of POMBILITI + OPFOLDA in late-onset Pompe disease

SAN RAFAEL, Calif., Oct. 2, 2026 /PRNewswire/ -- BioMarin Pharmaceutical Inc. (Nasdaq: BMRN) today announced new data evaluating the efficacy and safety of POMBILITI^® (cipaglucosidase alfa-atga) + OPFOLDA^® (miglustat) in late-onset Pompe disease (LOPD) were presented at the 31st Annual Congress of the World Muscle Society (WMS), in Hiroshima, Japan.

These results from the PROPEL open-label extension (OLE) study of POMBILITI + OPFOLDA, which were shared in a late-breaking presentation, demonstrated durable motor function outcomes and relative stabilization of pulmonary function over long-term follow-up. The analysis included data from 82 individuals who received POMBILITI + OPFOLDA continuously from baseline observed in the initial PROPEL study (PROPEL baseline) to year five. For the enzyme replacement therapy (ERT)-experienced cohort, the mean duration of prior ERT at baseline was 7.6 years. These data represent long-term benefits for people with LOPD followed in the study, including both ERT-experienced and ERT-naïve cohorts. 

"These five-year results demonstrate that POMBILITI and OPFOLDA can provide durable, long-term benefits for people living with late-onset Pompe disease, including those who had been on enzyme replacement therapy for years before enrolling in the study," said Greg Friberg, M.D., Executive Vice President and Chief Research & Development Officer at BioMarin. "Sustaining motor function and limiting pulmonary decline for up to five years in a progressive disease like LOPD is clinically meaningful, and we remain committed to continuing to share long-term evidence to inform the care of people with this rare genetic condition."

Table 1. Efficacy Measures With POMBILITI + OPFOLDA From PROPEL Baseline (BL) for up to Five Years

No new safety signals were identified. 51.2% of participants (n=42) experienced treatment-related adverse events, the majority of which were manageable. Five individuals discontinued treatment for safety reasons, including two due to serious treatment-related adverse events (chills and hypoxia [n=1], anaphylactoid reaction [n=1]).

Phase 1/2 Data Show Positive Dystrophin Expression and Favorable Tolerability With Nivudirsen (BMN 351)

Additional presentations at WMS included data evaluating nivudirsen (BMN 351), an investigational antisense oligonucleotide for ambulatory boys ages 4 to 10 with Duchenne muscular dystrophy (DMD) amenable to exon 51 skipping. Included in these presentations was an update from the ongoing Phase 1/2 351-201 study, which was previously shared at the 19th International Congress on Neuromuscular Diseases in July. Results from 351-201 showed treatment with nivudirsen was generally well tolerated and led to consistently positive outcomes across multiple measures of therapeutic benefit, including expression of near full-length dystrophin.

Below are key presentations at WMS, with all times listed in Japan Standard Time:

Phase 1/2 Results of BMN 351, an Antisense Oligonucleotide for Exon 51 Skip-Amenable Duchenne Muscular Dystrophy
Poster Presentation #2.66P
Wednesday, Sept. 30, 5:15 – 6:15 p.m.

Comprehensive Panel of Pharmacokinetic, Pharmacodynamic and Biomarker Measures Drives Clinical Development of BMN 351 for Duchenne Muscular Dystrophy
E-Poster Presentation #2.43eP
Wednesday, Sept. 30, 5:15 – 6:15 p.m.

Muscle Composition and Muscle Injury Biomarkers Improve With BMN 351 Treatment
E-Poster Presentation #2.59eP
Wednesday, Sept. 30, 5:15 – 6:15 p.m.

Long-Term (Five-Year) Efficacy and Safety of Cipaglucosidase Alfa Plus Miglustat in Adults With Late-Onset Pompe Disease Treated From PROPEL Baseline
E-Poster Presentation #3.081LBeP
Friday, Oct. 2, 2:15 – 3:15 p.m. 

Long-Term (Four-Year) Efficacy and Safety of Cipaglucosidase Alfa Plus Miglustat in Adults With Late-Onset Pompe Disease Treated From PROPEL Baseline
Poster Presentation #3.56P
Friday, Oct. 2, 2:15 – 3:15 p.m.

Baseline Disease Burden and Real-World Monitoring Practices: Global Insights From the followME Pompe Journey Registry
Poster Presentation #3.57P
Friday, Oct. 2, 2:15 – 3:15 p.m.

ATB200-03/07 Danish Subpopulation: Four-Year Efficacy and Safety of Cipaglucosidase Alfa Plus Miglustat in Adults With Late-Onset Pompe Disease
E-Poster Presentation #3.35eP
Friday, Oct. 2, 2:15 – 3:15 p.m.

About the PROPEL Open-Label Extension Study

The Phase 3 open-label extension (OLE) study (ATB200-07; NCT04138277) is a multicenter, international study designed to evaluate the long-term safety and efficacy of POMBILITI + OPFOLDA in adults with late-onset Pompe disease (LOPD) who completed the Phase 3 PROPEL study (ATB200-03; NCT03729362). Of the 118 people treated in the OLE, 82 continued POMBILITI + OPFOLDA treatment from PROPEL (62 ERT-experienced prior to PROPEL; 20 ERT-naïve) and 37 switched from the comparator arm to POMBILITI + OPFOLDA (29 ERT-experienced; eight ERT-naïve).

The study evaluates long-term changes from PROPEL baseline in six-minute walk distance (6MWD, the primary endpoint in PROPEL), forced vital capacity (FVC), creatine kinase (CK) and hexose tetrasaccharide (Hex4) levels, and patient-reported outcomes, as well as long-term safety.

About Study 351-201

The 351-201 trial (NCT06280209) is a Phase 1/2 multicenter open-label dose-escalation study evaluating BMN 351 for the treatment of boys aged 4 to 10 with Duchenne muscular dystrophy with a specific genetic change amenable to exon 51 skipping. The primary endpoints examine the safety and tolerability of BMN 351, the secondary endpoints assess plasma, urine and muscle pharmacokinetics, and key exploratory endpoints include exon-skipping efficiency, dystrophin expression, immunogenicity and functional assessments. 

The study is being conducted in three cohorts, with Cohort 1 being divided into Cohort 1A and Cohort 1B. In Cohort 1A, three boys received increasing doses once every two weeks with a visit to assess safety measures collected the week after dosing prior to escalating doses of BMN 351. In part two, the participants in Cohort 1A transitioned to once-weekly dosing. The participants in Cohort 1B, 2 and 3 will receive low (6 mg/kg), medium (9 mg/kg) and high (12 mg/kg) doses of BMN 351 and continue once-weekly dosing at that same dose.

For more information, please visit clinicaltrials.biomarin.com.

About Late-Onset Pompe Disease

Late-onset Pompe disease (LOPD) is an inherited lysosomal disorder caused by deficiency of the enzyme acid alpha-glucosidase (GAA). Reduced or absent levels of GAA lead to accumulation of glycogen in cells, which is believed to result in the clinical manifestations of Pompe disease. LOPD can be severe and debilitating with progressive muscle weakness throughout the body that worsens over time, particularly in skeletal muscles and muscles that control breathing.

About Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a severe neuromuscular condition that leads to progressive muscle weakness and premature mortality. DMD is caused by genetic changes that result in the absence or dysfunction of dystrophin, an essential protein that is necessary for preserving muscle function.

As an X-linked disorder, DMD primarily affects young boys, with onset of symptoms occurring around 2 to 3 years of age. The incidence of DMD is up to 1 in 3,600 to 6,000 live male births.

Individuals with DMD experience serious functional impairments, including loss of limb strength and ambulation, and respiratory and cardiovascular impacts that require lifelong care.

About POMBILITI + OPFOLDA

POMBILITI + OPFOLDA is a two-component therapy that consists of cipaglucosidase alfa-atga, a bis-M6P-enriched rhGAA that facilitates high-affinity uptake through the M6P receptor while retaining its capacity for processing into the most active form of the enzyme, and the oral enzyme stabilizer, miglustat, that is designed to reduce loss of enzyme activity in the blood.

Patient Support Accessing POMBILITI + OPFOLDA

To reach a BioMarin RareConnections^® Case Manager, please call, toll-free, 1-866-906-6100 or email [email protected]. For more information about POMBILITI + OPFOLDA, please visit www.pombilitiopfolda.com. For additional information regarding these products, please contact BioMarin Medical Information at [email protected].

POMBILITI + OPFOLDA U.S. Indication and Important Safety Information

POMBILITI in combination with OPFOLDA is indicated for the treatment of adult patients with late-onset Pompe disease (lysosomal acid alpha-glucosidase [GAA] deficiency) weighing ≥40 kg and who are not improving on their current enzyme replacement therapy (ERT).

SAFETY INFORMATION

HYPERSENSITIVITY REACTIONS INCLUDING ANAPHYLAXIS: Appropriate medical support measures, including cardiopulmonary resuscitation equipment, should be readily available. If a severe hypersensitivity reaction occurs, POMBILITI should be discontinued immediately and appropriate medical treatment should be initiated. INFUSION-ASSOCIATED REACTIONS (IARs): If severe IARs occur, immediately discontinue POMBILITI and initiate appropriate medical treatment. RISK OF ACUTE CARDIORESPIRATORY FAILURE IN SUSCEPTIBLE PATIENTS: Patients susceptible to fluid volume overload, or those with acute underlying respiratory illness or compromised cardiac or respiratory function, may be at risk of serious exacerbation of their cardiac or respiratory status during POMBILITI infusion. See the full U.S. Prescribing Information for complete Boxed Warning. CONTRAINDICATION: POMBILITI in combination with OPFOLDA is contraindicated in pregnancy. EMBRYO-FETAL TOXICITY: May cause embryo-fetal harm. Advise females of reproductive potential of the potential risk to a fetus and to use effective contraception during treatment and for at least 60 days after the last dose. Adverse Reactions: Most common adverse reactions ≥ 5% are headache, diarrhea, fatigue, nausea, abdominal pain, and pyrexia. Please see U.S. full PRESCRIBING INFORMATION, including BOXED WARNING, for POMBILITI (cipaglucosidase alfa-atga) and full PRESCRIBING INFORMATION for OPFOLDA (miglustat).

About BioMarin

BioMarin is a leading, global rare disease biotechnology company focused on delivering medicines for people living with genetically defined conditions. Founded in 1997, the San Rafael, California-based company has a proven track record of innovation, with nine commercial therapies and a strong clinical and preclinical pipeline. Using a distinctive approach to drug discovery and development, BioMarin seeks to unleash the full potential of genetic science by pursuing category-defining medicines that have a profound impact on patients. To learn more, please visit www.biomarin.com.

Forward-Looking Statements

This press release contains forward-looking statements about the business prospects of BioMarin Pharmaceutical Inc. (BioMarin), including without limitation, statements about: the data to be presented at the 31st Annual Congress of the World Muscle Society (WMS), including the potential benefits and safety of POMBILITI + OPFOLDA in late-onset Pompe disease as well as of nivudirsen (BMN 351) for ambulatory boys ages 4 to 10 with Duchenne muscular dystrophy (DMD) amenable to exon 51 skipping; BioMarin's plans and expectations for the development of POMBILITI + OPFOLDA and nivudirsen; and BioMarin's estimate regarding the incidence of DMD. These forward-looking statements are predictions and involve risks and uncertainties such that actual results may differ materially from these statements. These risks and uncertainties include, among others, results and timing of current and planned preclinical studies and clinical trials and the release of data from those trials; any potential adverse events observed in the continuing monitoring of the patients in the clinical trials; the content and timing of decisions by the U.S. Food and Drug Administration, the European Medicines Agency, the European Commission and other regulatory authorities; and those factors detailed in BioMarin's filings with the Securities and Exchange Commission, including, without limitation, the factors contained under the caption "Risk Factors" in BioMarin's Quarterly Report on Form 10-Q for the quarter ended June 30, 2026, as such factors may be updated by any subsequent reports. Investors are urged not to place undue reliance on forward-looking statements, which speak only as of the date hereof. BioMarin is under no obligation, and expressly disclaims any obligation to update or alter any forward-looking statement, whether as a result of new information, future events or otherwise.

BioMarin^®, BioMarin RareConnections^®, POMBILITI^® and OPFOLDA^® are registered trademarks of BioMarin Pharmaceutical Inc. or its affiliates.

SOURCE BioMarin Pharmaceutical Inc.