Lack of standardisation in investigator ratings and the placebo effect are the major contributory factors to the high failure levels experienced in central nervous system (CNS) clinical trials
In a recent opinion poll conducted by ClinPhone, participants indicated that lack of standardisation in investigator ratings and the placebo effect are the major contributory factors to the high failure levels experienced in central nervous system (CNS) clinical trials.
The opinion poll was conducted as part of ClinPhone's recent webinar series, Study Design Enhancements Using IVR Clinical Assessments: A Focus on CNS Trials.
The series cited several key case studies to show how these challenges have been overcome using computerised clinical assessments, including those delivered by interactive voice response (IVR) systems.
The opinion poll revealed that half of the respondents working in clinical operations in the pharmaceutical industry felt that the consistency of investigator ratings (25%) and large placebo response (25%) were the biggest issues concerning failure of CNS clinical trials.
A further 21% of the respondents reported patient retention as a major factor in study failure.
John Greist, who presented the web sessions, explained the inevitable difference between interviewers - thereby reducing the ability of a study to show treatment effects.
He also used case studies to demonstrate that clinician baseline score inflation has been observed consistently in studies requiring a minimum score for patient enrollment.
Such score inflation leads to artificial improvement of study subjects and exaggerates the placebo effect.
The webinar also addressed how the computerised delivery of IVR-based clinical assessments can be used to both eliminate the issue of inter-rater variability and overcome issues of baseline score inflation by clinicians.
By employing IVR self-report instruments, it is possible to obtain standardised assessments from respondents, thus removing variability in clinician-delivered assessments.
In addition, IVR clinical instruments using Healthcare Technology System's (HTS) Hamilton depression rating scale (Ham-D) and Hamilton anxiety rating scale (Ham-A), among many such validated assessments, can be used to ensure patients meet study inclusion severity criteria and to eliminate score inflation by clinicians.
Further, the IVR Ham-D is among several self-report instruments that US Food and Drug Administration (FDA) recently indicated were acceptable as primary endpoint data in pivotal outpatient depression trials.
HTS assessments for all pharmaceutical sponsored phase I-IV trials are now delivered solely by ClinPhone.
The HTS IVR clinical assessments are offered exclusively by ClinPhone as part of its Patient Direct electronic patient reported outcomes (ePRO) service.
These instruments include Ham-D, Ham-A, Montgomery-Asberg depression rating scale (Madrs), Liebowitz social anxiety scale (LSAS), Short-form McGill pain inventory (SF-MPI), sleep measures employed in Sepracor's approval of ezopiclone, and many more.
Patient Direct offers a simple and intuitive alternative to traditional data recording methods for a wide range of applications from questionnaires to quality of life scoring and medical and psychiatric rating interviews, says Clinphone.
The service has been used in over 70 clinical trials supported by ClinPhone for more than 37,000 patients and has already featured in a wide range of successful new drug applications, it says.
