In April 2024 CMA requested that the link to the Oxford Centre for Evidence-Based Medicine (OCEBM) Levels of Evidence in the AUST L(A) guidance be updated to the 2011 version. Version 1.2 of the AUST L(A) guidance published April 2024 reflected the 2009 OCEBM Levels of Evidence, which could have potentially been confusing for applicants.

In response to CMA's identification of this issue, the TGA has published an update to the Assessed listed medicines evidence guidelines – version 1.3, June 2024, with a correction to the link to the 2011 OCEBM Levels of Evidence (page 28). There is no other change to the guidelines.

The 2011 OCEBM Guidelines includes N-of-1 studies as level 1 evidence of treatment benefit. This study method is becoming more widespread and has been used to explore the effect of complementary medicines, as well as prescription medicines. This does not necessarily mean that the TGA will accept N-of-1 evidence for the AUST L(A) pathway however, the Complementary Medicine Evaluation Section has noted that the TGA guidance on RWE (real world evidence) applies to premarket evaluations of medicines including non-prescription medicines. Page 28 of the Assessed listed medicine evidence guidelines directly specifies that ‘the TGA allows other study type and a range of other sources of evidence to be submitted as potential support for the claimed efficacy of a product.’

The TGA have provided that as such, while the AUST L(A) guidelines may not necessarily list all the evidence sources, they are not aware of anything that would restrict a submission being supported with real world evidence/data - noting that, with all evidence, results need to be reliable and robust, and any limitations/deviations need to be addressed. Generalisability of results is an example of a potential limitation to be addressed.