Cipaglucosidase Alfa, Miglustat Under Review for Pompe Disease

The Food and Drug Administration has accepted for review the Biologics License Application for cipaglucosidase alfa and the New Drug Application for miglustat for AT-GAA, an investigational 2-component therapy, for the treatment of Pompe disease.

Pompe disease is a rare, degenerative muscle disorder caused by mutations in the acid alpha-glucosidase gene, which leads to the abnormal buildup of glycogen in tissues and subsequent organ impairment.

AT-GAA consists of cipaglucosidase alfa administered in conjunction with miglustat. Cipaglucosidase alfa is a recombinant human acid alpha-glucosidase enzyme with optimized carbohydrate structures to enhance uptake into cells. Miglustat is a stabilizer of cipaglucosidase alfa.

The applications are supported by data from the phase 3 PROPEL trial (ClinicalTrials.gov Identifier: NCT03729362), a phase 1/2 study (ClinicalTrials.gov Identifier: NCT02675465), and an open-label extension phase 3 study (ClinicalTrials.gov Identifier: NCT04138277).

The PROPEL study included 123 adults with late onset Pompe disease who still had the ability to walk and to breathe without mechanical ventilation. Patients were randomly assigned 2:1 to receive either AT-GAA or alglucosidase alfa, an enzyme replacement therapy. The primary endpoint was the mean change in 6 Minute Walk Test (6MWT) distance at 52 weeks from baseline.

Results from PROPEL showed that patients treated with AT-GAA (n=85) walked on average 21 meters farther at week 52 compared with 7 meters for those treated with alglucosidase alfa (n=37). While the AT-GAA arm was reported to be numerically greater for the primary endpoint, it did not achieve statistical significance for superiority compared with the alglucosidase alfa arm (P =.072). The AT-GAA group demonstrated a 0.9% absolute decline in percent-predicted forced vital capacity (FVC) vs a 4.0% absolute decline in the alglucosidase alfa group (P =.023).

In the phase 1/2 study, 20 adults with late onset Pompe disease were treated with AT-GAA for 24 months. Results showed that patients achieved persistent and durable effects on 6MWT distance and other measures of motor function and muscle strength, stability or increases in FVC, and reductions in biomarkers of muscle damage and disease substrate. 

A Prescription Drug User Fee Act target date of July 29, 2022 has been set for the Biologics License Application for cipaglucosidase alfa and May 29, 2022 for the New Drug Application for miglustat.

References

1. U.S. FDA accepts filings for Amicus’ AT-GAA for the treatment of Pompe disease. News release. Amicus Therapeutics. Accessed September 29, 2021. https://www.globenewswire.com/news-release/2021/09/29/2305171/15991/en/U-S-FDA-Accepts-Filings-for-Amicus-AT-GAA-for-the-Treatment-of-Pompe-Disease.html. 
2. Amicus’ AT-GAA shows clinically meaningful & significant improvements in both musculoskeletal and respiratory measures in late-onset Pompe disease compared to standard of care in pivotal phase 3 PROPEL study. News release. Amicus Therapeutics. February 11, 2021. Accessed September 29, 2021. https://ir.amicusrx.com/news-releases/news-release-details/amicus-gaa-shows-clinically-meaningful-significant-improvements.
3. Amicus Therapeutics announces additional positive data in Pompe disease phase 1/2 study of AT-GAA at the 24th International Annual Congress of the World Muscle Society. News release. Amicus Therapeutics. October 2, 2019. Accessed September 29, 2021. https://ir.amicusrx.com/news-releases/news-release-details/amicus-therapeutics-announces-additional-positive-data-pompe-1.