Scarce quality assurance documentation in major clinical trial registries for approved medicines used in post-marketing clinical trials.

Background: This research reviewed major Clinical Trial Registries (CTRs) and assessed the availability of fields on quality assurance for approved medicines used as Investigational Medicinal Products (IMPs) in phase IV clinical trials.

Methods: Two reviewers independently assessed CTRs of the International Committee of Medical Journal Editors (ICJME) and of World Health Organization (WHO) platforms. Each CTR was checked by two reviewers on availability of fields on brand name, manufacturer's name, approval status, approving authority, compliance with Good Manufacturing Practices, and quality testing. In case of discrepancy, consensus was sought between the two reviewers.

Results: Of 19 identified CTRs, 8 and 6 belonged to WHO and ICMJE, respectively, while 5 were equally part of both platforms. All CTRs had an 'intervention' field where data on IMPs and IMP comparators are captured. The Canadian CTR used 'drug name' rather than 'intervention'. The EU, Peruvian, and UK CTRs had fields for 'brand name'. However, only the EU CTR had fields for 'manufacturer's name', 'approval status', and 'approving authority'. None of the CTRs had fields on 'compliance with Good Manufacturing Practices' or 'quality testing'.

Conclusion: This study demonstrates that none of the CTRs of ICMJE and WHO platforms has adequate fields to establish that the source of post-marketing IMPs is of assured quality. This is astonishing given the lengthy requirements in WHO and ICMJE guidelines. Considering the relation between IMP quality and safety of clinical trial participants, the gap of quality assurance fields should be bridged at CTRs concurrently to adjustments of WHO and ICMJE guidelines on CTRs. Specifically, IMP quality testing addressing issues on IMP appearance, impurities, microbial contamination, and dosing should be conducted and reported before, during, and after clinical trial conduct. Until adoption of these measures, the EU CTR should be preferred for registration of phase IV clinical trials conducted in countries lacking stringent regulatory capacities.