Controlling Placebo Response in Drug Development: Lessons Learned from Psychopharmacology

Randomised controlled trial of interventions for bothersome tinnitus: DesyncraTM versus cognitive behavioural therapy

OBJECTIVE

Compare the relative efficacy of Desyncra^TM and Cognitive Behavioural Therapy (CBT).

DESIGN AND STUDY SAMPLE

Sixty-one participants were randomly assigned to receive either Desyncra^TM (n = 29) or CBT (n = 32). Randomisation included stratification regarding current hearing aid (HA) use. Depending on group assignment, participants attended approximately 7-12 visits. Tinnitus distress was measured using the Tinnitus Questionnaire (TQ).

RESULTS

Mean TQ scores decreased post-baseline from 5-15 points across treatment arms and strata. Model-based findings for the no-HA stratum showed a difference of -2.0 TQ points favouring Desyncra at 24-weeks, with a 90% posterior interval varying from -5.4 points favouring Desyncra to 0.8 TQ points favouring CBT. For the HA stratum, results show a difference of -1.0 TQ points favouring Desyncra, with a 90% posterior interval ranging from -4.7 points favouring Desyncra to 2.9 points favouring CBT.

CONCLUSIONS

The difference between Desyncra and CBT on average showed greater improvement with Desyncra in the no-HA stratum by about 2 TQ points. To the extent that the study sample represents a clinical population and recognising the assumptions in the design and analysis, these results suggest Desyncra is just as effective or more so than CBT in reducing tinnitus distress.

Randomized Controlled Trial of a Novel Device for Tinnitus Sound Therapy During Sleep

PURPOSE

The aim of this study was to determine if a customized stimulus from the Otoharmonics Levo System reduces tinnitus perceptions and reactions for people with bothersome tinnitus.

METHOD

Sixty participants were randomized to 1 of 3 groups that used sound therapy devices during sleep that differed in their acoustic stimulus: (a) tinnitus-matched (TM), (b) noise stimulus (NS), and (c) bedside sound generator (BSG). Outcome measures were the Tinnitus Functional Index (TFI), numeric rating scale of tinnitus loudness, and tinnitus loudness match. A Bayesian hierarchical model was fit to estimate the differences in treatment efficacy among groups.

RESULTS

Average tinnitus reactions and perceptions improved across treatment groups. We are at least 87% certain that treatment with TM or NS reduces mean TFI compared to treatment with BSG, with an estimated relative efficacy of 4.5-5 points greater reduction. We are at least 95% certain that treatment with TM results in greater reduction in mean numeric rating scale (NRS) of tinnitus loudness compared to the other groups, with an estimated relative efficacy of about 0.75 points greater reduction.

CONCLUSIONS

This study offers some support for greater average improvement in reactions to tinnitus with TM or NS devices compared to the BSG device. The TM group, compared to the BSG and NS groups, showed a greater reduction in ratings of tinnitus loudness on the NRS on average.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.5545759.

The plan of enrichment designs for dealing with high placebo response

To deal with high placebo response in clinical trials for psychiatric and other diseases, different enrichment designs, such as the sequential parallel design, two-way enriched design, and sequential enriched design, have been proposed and implemented recently. Depending on the historical trial information and the trial sponsors' resources, detailed design elements are needed for determining which design to adopt. To assist in making more suitable decisions, we perform evaluations for selecting required design elements in terms of power optimization and sample size planning. We also discuss the implementation of the interim analysis related to its applicability.

What can triumphs and tribulations from drug research in Alzheimer's disease tell us about the development of psychotropic drugs in general?

Drug development for psychiatric disorders has almost ground to a halt. Some newer drugs are better tolerated or safer than older ones, but none is more effective. Years of failure in preventing or delaying the onset of illness, ameliorating symptoms, lowering suicide rates, or improving quality of life has put the commercial investments that had previously funded drug development at risk. To promote the development of psychiatric drugs with greater efficacy, we need to improve the way we bring potentially beneficial drugs to market. We need to acknowledge, as has been done in other specialties, that people differ in their response to drugs. Psychiatric drug research needs to be grounded in a better understanding of molecular brain mechanisms, neural circuits, and their relations to clinical disease. With this understanding, drugs need to be more precisely directed at specific brain targets. In psychiatric drug development, government, industry, regulatory bodies, and academia should realign to ensure medical science is used in the best interests of patients.