Athlone based pharmaceutical company Elan will stop testing the highest dose of its Alzheimer's drug bapineuzumab in final-stage Phase III studies.
In a statement released today with its partner Wyeth, the companies said the decision was made following a review of cases of vasogenic edema, or fluid build-up in the brain, with the 2.0mg/kg dose.
Elan President Carlos Paya said: 'Our review of the safety data and the feedback from the Safety Monitoring Committee made it clear that continued development of the highest dose was not advisable.'
Testing of the 0.5 mg/kg and 1.0 mg/kg doses in two Phase III trials will continue as planned.
The move follows a difficult history for bapineuzumab, which is seen as a risky but potentially lucrative product that could generate billions of dollars in sales, if it works.
Industry analysts said the issues raised by the dosing change might lead to delays.
Researchers said last summer that a Phase II trial of the medicine showed it helped some patients with a certain genetic profile, but raised the risk of potentially serious side effects in the brain.
In spite of those mixed results, Elan and Wyeth - now in the process of being acquired by Pfizer - vowed to pursue larger and more costly Phase III trials in the hope bapineuzumab would become the first drug proven to treat the underlying cause of Alzheimer's disease.
Pfizer has said it sees Alzheimer's as an important area of research.
Elan shares fell 24 cent to finish at €4.80 in Dublin this evening.
