Myozyme, said to be the next big thing from Genzyme Corp., remains right on track.
The enzyme-replacement therapy generated positive interim data in its pivotal Pompe disease trial, and the company is sticking to filing plans for mid-2005 after concluding that the study would "very likely meet its primary endpoint."
Findings from the planned preliminary analysis showed that Myozyme (alglucosidase alfa) already met one of its key secondary efficacy endpoints.
The trial's protocol included the interim analysis to allow for the possibility of an expedited submission of a biologics license application.
"There's an urgency to bring a treatment to patients with Pompe disease," Bo Piela, spokesman for Genzyme, told BioWorld Today. "Throughout the development of Myozyme, we've worked as quickly as possible to bring this product forward."
Myozyme has received orphan drug and fast-track status from the FDA, which signed off on the study that generated the following promising data: By 12 months of age, 16 of the 18 patients treated with Myozyme in the study, or 89 percent, were alive and free of invasive ventilator support, compared to 17 percent in a historical cohort used in place of a placebo group given the disease's rapidly progressive and fatal nature.
That measure led the Cambridge, Mass.-based company to believe the study will meet its primary endpoint, the proportion of Myozyme patients who are alive and free of invasive ventilator support at 18 months of age compared with the 2 percent who were alive at that age in the historical cohort. The trial includes 18 patients with infantile-onset Pompe disease who began receiving Myozyme by 6 months of age.
Piela said that Genzyme's plan to set up Myozyme's pivotal testing in infants "gave us the quickest possibility to demonstrate efficacy."
Results for the primary endpoint will be known this summer, when patients will have completed a year of treatment, and also will be included in Genzyme's FDA submission. All results, interim and final, are expected to supplement the company's previously filed European marketing application. It was submitted at the end of last year, and a regulatory ruling is expected by the end of this year.
Other data uncovered in the interim analysis of the study, referred to as AGLU01602, showed that all Myozyme patients had a reversal in cardiomyopathy, a condition in which the heart muscle becomes enlarged and heart function is impaired. Also, 72 percent of Myozyme patients demonstrated gains in motor development and all had gains in cognitive, language and personal/social skills.
Lastly, 83 percent of patients developed antibodies to Myozyme, which Piela called consistent with other enzyme-replacement therapies, and 44 percent experienced infusion-associated reactions.
Pompe disease is an inherited, progressive muscle disease caused by a deficiency of the acid alpha-glucosidase enzyme. A lysosomal storage disorder, it affects fewer than 10,000 people worldwide.
Genzyme, which owns all rights to Myozyme, is pursuing its approval for use as a long-term therapy for all patients with a confirmed diagnosis of the disease. No treatments are approved for it, though more than 100 patients already are receiving Myozyme in studies, through Genzyme's expanded access program or pre-approval mechanisms in several European countries.
"A little later this year, we will be initiating a treatment study in [late onset] adult patients," Piela said, adding that the trial would be designed to provide additional data on Myozyme's use in adults, and would include the largest number of adult patients to date. "Right now, we are conducting an observational study that is enrolling adult patients and is designed to help us to define the appropriate endpoint for the treatment study."
On Tuesday, the company's shares (NASDAQ:GENZ) gained 15 cents to close at $59.50.