Actelion Ltd and Celltech Group plc announced that the companies have modified their existing license agreement covering Zavesca (miglustat), an orally active therapeutic medicine approved for type 1 Gaucher disease in the European Union, the United States, Canada and Israel.

Under the terms of the agreement Actelion remains the license holder for Zavesca worldwide, with the exception of Israel where the drug is also approved. Actelion will be responsible for all clinical, regulatory and marketing activities and will book all sales of Zavesca. Celltech is responsible for manufacturing and receives undisclosed royalties on sales. Actelion originally in-licensed Zavesca from Oxford GlycoSciences, now part of Celltech Group plc.

Actelion will take full responsibility for the management of ongoing or planned clinical trials in the approved indication as well as those exploring the use of Zavesca in other glycolipid storage disorders. In return, Celltech Group plc has agreed to grant Actelion unrestricted license rights for the use of miglustat in the field of glycolipid storage disorders. Previously, Celltech had retained rights to reacquire Zavesca rights after five years of market availability.

Jean-Paul Clozel, MD and CEO of Actelion, said, "Actelion is reinforcing its commitment to further explore the potential of Zavesca in rare metabolic diseases with high unmet medical needs and to improve patient care with new therapeutic options. By reorganizing clinical trial activities, Actelion will be able to optimize its relationships with both regulatory authorities and clinicians."

There is strong preclinical evidence to support the use of Zavesca in other related lipid storage diseases for which currently no therapy exists. Consequently, phase III trials in other lipid storage disorders, such as Late Onset Tay-Sachs, Type 3 Gaucher disease and Niemann-Pick Type C disease, are being conducted.

First results of a 1-year, 30-patient, open-label, controlled study in Late Onset Tay-Sachs disease should be available by the end of 2004. Tay-Sachs disease is a rare autosomal recessive genetic disorder causing a deficiency in ß-hexosaminidase, the enzyme responsible for the breakdown of the lipid GM2. This leads to extensive and toxic accumulation of GM2 and related glycosphingolipids in the lysosomes of neuronal cells, resulting in a neurodegenerative disease including muscle weakness and cramps, tremors, unsteady gait, psychoses and depression. There is currently no drug therapy available to treat patients with Tay-Sachs disease.