Amgen and Novartis have stopped pivotal tests of CNP520 in Alzheimer’s disease after an interim review found patients on the BACE inhibitor worsened on some measures of cognitive function. The failure is a blow to the hypothesis that anti-amyloid drugs delay or prevent the onset of Alzheimer’s when given before patients develop symptoms.
While the failure of BACE inhibitors at companies including Eli Lilly and Merck severely dented hopes for the class, there remained hope that these were good drugs given to patients whose disease was too advanced to treat. That thinking led Amgen and Novartis to team up in 2015 to develop the latter’s BACE inhibitor, CNP520, in people at high risk of developing Alzheimer’s based on their age and genetic status. The partners planned to enroll about 3,300 people and track them for years.
Now, Amgen and Novartis have brought testing of CNP520 to a premature end. An interim review of unblinded data revealed “worsening in some measures of cognitive function” across two phase 2/3 placebo-controlled trials. Faced with the data, the sponsors concluded the potential benefits for participants no longer outweigh the risks.
Amgen and Novartis are advising participants in the studies to stop taking CNP520 and are working with investigators to wind up the assessment of the drug. That leaves Biogen and Eisai’s elenbecestat as the last major BACE inhibitor in development, but Amgen retains faith in the concept that attracted it to the class.
"We still believe amyloid plays an important but complex role in Alzheimer's disease,” David Reese, executive vice president of R&D at Amgen, said in a statement.
The statements published by Amgen and Novartis make no mention of CAD106, an amyloid-beta immunotherapy that is being tested in one of the two phase 2/3 trials. Novartis clarified the situation in a statement to FierceBiotech.
"The assessment of CAD106 is unrelated to the discontinuation of the CNP520 clinical program and continues," a spokesperson for Novartis said.