MDA RESEARCH YIELDS PROMISING DRUG FOR FATAL INFANT DISEASE

TUCSON, Ariz., Oct. 5, 2000 -- Tests of an enzyme replacement therapy for Pompe's disease, a fatal disease of infants, show the experimental replacement enzyme improved function and increased expected survival time, the Muscular Dystrophy Association (MDA) announced today.

The results were announced at the 50th annual meeting of the American Society of Human Genetics this week in Philadelphia.

MDA has offered to work with the biotechnology company Genzyme of Cambridge, Mass., which holds commercial rights to the enzyme, to expand clinical trials through the Association's network of 230 clinics which treat over 40 neuromuscular disorders.

"MDA's research priority is the support of projects directed at treating neuromuscular disorders. This recent development in Pompe's disease (also known as acid maltase deficiency) is very encouraging, and the Association is enthusiastic about supporting the next phase of research designed to treat the disorder," said Robert Ross, MDA's senior vice president and executive director.

Yuan-Tsong Chen, professor of pediatrics and genetics at Duke University Medical Center in Durham, N.C., developed a modified form of the acid maltase enzyme with MDA support in the late 1990s. Prior to that time, some 20 years of attempts to deliver the missing enzyme to tissues that needed it were unsuccessful, because the unmodified enzyme couldn't enter cells from the bloodstream.

Earlier this year, Genzyme obtained rights to develop and market the modified acid maltase enzyme originally developed by Chen at Duke. This modified enzyme can enter muscle cells through the bloodstream. It's manufactured in the lab in cells called CHO cells.

Acid maltase deficiency is a genetic disorder that affects not only infants but people of all ages. An estimated 5,000 to 10,000 people are affected in the developed world.

In the most severe form of Pompe's disease, in which little or no functioning acid maltase is produced, infants are affected and usually don't live more than a year. Without acid maltase, glycogen, a starchy material, builds up in muscles, including the heart and critical respiratory muscles. This buildup interferes with muscle function and leads to severe weakness, along with cardiac and respiratory failure.

Three infants were treated at Duke and received the enzyme by intravenous infusion for over a year.

Preliminary results indicate that the enzyme can improve cardiac and skeletal muscle function. All three infants have passed what's considered the critical age of 1 year and are currently 15, 17 and 20 months old. They continue to show improved cardiac function, thus avoiding the usual progressive cardiac muscle deterioration resulting in heart failure and death.

Improvements of skeletal muscle function have also been noted, although the significance and extent have been more variable than results seen in the heart. Muscle biopsies have confirmed that significant reductions in toxic glycogen accumulation occurred in at least one patient after the enzyme replacement therapy. The therapy has been well tolerated.

MDA is a voluntary health agency working to defeat neuromuscular disease through programs of worldwide research, comprehensive services, and far-reaching professional and public health education. The Association's programs are funded almost entirely by individual, private contributors. For more information, call (800) 572-1717 or visit www.mda.org.