On 2014 May 19, David Keller commented:

Was this "Lessebo" effect durable for one year after the end of a clinical trial?

A recent clinical trial demonstrated possible beneficial effects of exenatide on slowing the progression of Parkinson disease (1); however, this study was hampered by lack of a double-blinded placebo control arm. Instead, a usual-treatment group was followed passively over time to serve as a comparator. Clearly, some of the benefits seen in the patients who self-injected with exenatide daily could have been due to the "Lessebo" effect during that study, or shortly afterward. But durable benefits were measured in the exenatide intervention group a full year after their last self-injection. How durable is the "Lessebo" effect? Could it account for some or all of the benefit seen with exenatide a full year after the end of that study?

Reference

1: Aviles-Olmos I, Dickson J, Kefalopoulou Z, Djamshidian A, Kahan J, Fmedsci PE, Whitton P, Wyse R, Isaacs T, Lees A, Limousin P, Foltynie T. Motor and Cognitive Advantages Persist 12 Months After Exenatide Exposure in Parkinson's Disease. J Parkinsons Dis. 2014 Mar 24. [Epub ahead of print] PubMed PMID: 24662192.

On 2014 May 19, David Keller commented:

Was this "Lessebo" effect durable for one year after the end of a clinical trial?

A recent clinical trial demonstrated possible beneficial effects of exenatide on slowing the progression of Parkinson disease (1); however, this study was hampered by lack of a double-blinded placebo control arm. Instead, a usual-treatment group was followed passively over time to serve as a comparator. Clearly, some of the benefits seen in the patients who self-injected with exenatide daily could have been due to the "Lessebo" effect during that study, or shortly afterward. But durable benefits were measured in the exenatide intervention group a full year after their last self-injection. How durable is the "Lessebo" effect? Could it account for some or all of the benefit seen with exenatide a full year after the end of that study?

Reference

1: Aviles-Olmos I, Dickson J, Kefalopoulou Z, Djamshidian A, Kahan J, Fmedsci PE, Whitton P, Wyse R, Isaacs T, Lees A, Limousin P, Foltynie T. Motor and Cognitive Advantages Persist 12 Months After Exenatide Exposure in Parkinson's Disease. J Parkinsons Dis. 2014 Mar 24. [Epub ahead of print] PubMed PMID: 24662192.