Amicus announces positive results from Phase II Pompe disease study
5 days 1 hours 54 minutes ago - Datamonitor via Comtex
Amicus Therapeutics, Inc., a biopharmaceutical company, has announced positive preliminary results from all four dose cohorts in a Phase II study to evaluate the safety and pharmacokinetic effects of the pharmacological chaperone AT2220 co-administered with enzyme replacement therapy, or ERT, for Pompe disease.
Myozyme and Lumizyme (alglucosidase alfa, or recombinant human GAA enzyme, rhGAA) are the first and only approved treatments for Pompe disease. Based on the Study 010 results, Amicus expects to initiate a repeat-dose clinical study in the third quarter of 2013.
For people with Pompe disease, deficient GAA enzyme leads to the accumulation of glycogen in tissues affected by disease (primarily muscle). Preclinical data1 demonstrated that AT2220 in combination with ERT enhances rhGAA enzyme activity, reduces glycogen accumulation, and potentially mitigates ERT-related immunogenicity in a mouse model of Pompe disease. In Study 010, co-administration of AT2220 to Pompe patients increased rhGAA enzyme activity and enhanced rhGAA enzyme uptake into muscle tissue compared to ERT alone.
John Crowley, chairman and CEO stated, "Study 010 has established human proof-of-concept that AT2220-ERT co-administration increases GAA enzyme activity in muscle. We look forward to initiating our repeat-dose clinical study to investigate the effect of AT2220-ERT co-administration on ERT stability and activity, ERT-related immunogenicity, and other clinical measures. We believe that co-administration may deliver significant benefits compared to ERT alone and become an important therapy for people with Pompe disease."
Study 010 investigated single ascending oral doses of AT2220 co-administered with Myozyme or Lumizyme in patients with Pompe disease. The doses of AT2220 were 50 mg (Cohort 1), 100 mg (Cohort 2), 250 mg (Cohort 3), and 600 mg (Cohort 4). Each patient received one infusion of ERT alone, and then a single oral dose of AT2220 one hour before the next ERT infusion. Single doses of AT2220 co-administered with ERT were well-tolerated, with no drug-related adverse events reported. In addition, AT2220 was cleared from muscle to near-undetectable levels by Day 7 in all four cohorts.
24-hour plasma PK was measured during and after each infusion. Plasma rhGAA activity increased in 23 out of 23 patients (100%) following co-administration and the increases were dose-related. These data suggest that co-administration increases the amount of stabilized, properly folded, and active rhGAA enzyme available for uptake into tissue.
Muscle biopsies were taken to measure GAA enzyme uptake into muscle tissue, with and without AT2220. In Cohort 1, all 4 patients had muscle biopsies on Day 7. In Cohorts 2-4, muscle biopsies were taken on Day 3 for half the patients, and on Day 7 for the other half of patients.
In Cohort 1, no consistent change in GAA enzyme activity was observed at day 7. In Cohorts 2, 3, and 4 the results show that more enzyme is taken up into muscle tissue following AT2220 co-administration compared to ERT alone. The effect was most pronounced at the highest (600 mg) dose of AT2220.
At Day 3 the GAA enzyme activity in muscle following co-administration compared to ERT alone in patients with evaluable biopsies increased by the following; 25% in Cohort 2 (n=3), 7% in Cohort 3 (n=3), and 133% in Cohort 4 (n=2). At Day 7 the GAA enzyme activity in muscle was lower relative to Day 3, as expected based on the cellular half-life of the enzyme. However, following co-administration compared to ERT alone in patients with evaluable biopsies the following increases were sustained: 20% in Cohort 2 (n=3), 40% in Cohort 3 (n=2), and 20% in Cohort 4 (n=3).