BOSTON (The Boston Globe) - Genzyme Corp. and Diacrin Inc. say a preliminary analysis of results from a study of their surgical treatment for Parkinson's disease found it didn't necessarily work better than a placebo, or dummy, treatment.

The study was designed to measure the safety and benefits of surgically transplanting neural cells from a fetal pig into the brain to replace cells lost to the disease.

Ten Parkinson's patients were given the treatment, called NeuroCell-PD, while eight underwent placebo surgery. Eighteen months later, the patients in both groups showed similar amounts of improvement, the companies said.

Parkinson's is a disease of the central nervous system characterized by tremors, slowness of movement, and stiffening of the muscles. More than 1 million Americans suffer from the disease, according to the Parkinson's Disease Foundation.

"We were disappointed but not discouraged," said Genzyme spokesman Bo Piela Friday. "The study has made a tremendous contribution to advancing the understanding of how this disease may be treated."

The companies had hoped to begin a final phase of testing for the treatment by June 30. But they said that plans to continue developing the drug have been put on hold until they complete a more rigorous analysis of the results of the study.

"We're rolling up our sleeves now to figure out what the data is really telling us," said Thomas H. Fraser, Diacrin's president and chief executive.

Although there was no statistically significant difference between the two groups, Fraser said, some patients treated with NeuroCell-PD did show marked improvement over the placebo group.

A closer look at the results could show that the treatment works in a specific subset of patients, he said. It may also yield clues as to whether changing the amount of transplanted cells or the location of the transplant could lead to a more successful therapy.

If so, he said, the companies could decide to continue developing the treatment. If a closer examination of the data doesn't reveal a solution, however, the companies may have little choice but to abandon NeuroCell-PD.

"The development of highly innovative therapies is never a straight line," Fraser said. "And these cellular therapies are really on the cutting edge."

William Tanner, an analyst at S.G. Cowen Securities in Boston, said the setback is far more problematic for Diacrin than for Genzyme.

Tanner said investors are focused on Genzyme's products that are on or near the market and are unlikely to have high expectations for its earlier-stage products, such as NeuroCell-PD. A company like Diacrin, however, that doesn't have products on the market is likely to be judged harshly on bad news about early-stage products.

Copyright 2001 The Associated Press. All rights reserved.