What the halted phase III γ-secretase inhibitor trial may (or may not) be telling us
1Department of Pediatrics, University of Rochester Medical Center, Golisano Children's Hospital, NY, USA.
Annals of Neurology
|March 10, 2011
Abstract:
The aborted trial of semagacestat has led some to invoke unanticipated effects of γ-secretase inhibition on formation of amyloid β. However, the many substrates for γ-secretases and the varied biological effects of each of the resultant cleavage products make ascribing causality much more complex than that.
Insights
The semagacestat trial
Area of Science:
- Neuroscience
- Biochemistry
- Pharmacology
Background:
- The drug semagacestat targets gamma-secretase, an enzyme involved in processing amyloid precursor protein.
- Inhibition of gamma-secretase is a strategy explored for Alzheimer's disease treatment.
- The clinical trial of semagacestat was discontinued due to safety concerns.
Purpose of the Study:
- To analyze the complex biological consequences of gamma-secretase inhibition.
- To investigate the challenges in attributing specific effects to gamma-secretase inhibition in clinical trials.
- To explore the role of various gamma-secretase substrates in the drug's effects.
Main Methods:
- Review of existing literature on gamma-secretase function and semagacestat.
- Analysis of preclinical and clinical data related to semagacestat.
- Examination of the known substrates of gamma-secretase and their biological roles.
Main Results:
- Gamma-secretase cleaves multiple substrates beyond amyloid precursor protein.
- The biological impact of inhibiting gamma-secretase is multifaceted due to these substrates.
- Unanticipated effects observed in the semagacestat trial may stem from complex substrate interactions.
Conclusions:
- Attributing causality for observed effects in semagacestat trials is complex.
- The broad substrate specificity of gamma-secretase complicates therapeutic targeting.
- Further research is needed to understand the full biological impact of gamma-secretase inhibition.
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