How predictive are photosensitive epilepsy models as proof of principle trials for epilepsy?

• The ability of photosensitive models to predict antiepileptic efficacy is analysed.
• Articles describing photosensitive models in literature were evaluated.
• Efficacious antiepileptic doses were compared to photosensitive efficacious doses.
• There was no difference in antiepileptic and photosensitive efficacious doses.
• Photosensitive models are useful in anti-epileptic drug discovery and development.

PurposeHuman photosensitive epilepsy models have been used as proof of principle (POP) trials for epilepsy. Photosensitive patients are exposed to intermittent photic stimulation and the reduction in sensitivity to the number of standard visual stimulation frequencies is used as an endpoint. The aim of this research was to quantify the predictive capabilities of photosensitive POP trials, through a survey of current literature.MethodsA literature search was undertaken to identify articles describing photosensitive POP trials. Minimally efficacious doses (MEDs) in epilepsy were compared to doses in the POP trials that produced 50–100% response (ED50–100). Ratios of these doses were calculated and summarised statistically.ResultsThe search identified ten articles describing a total of 17 anti-epileptic drugs. Of these, data for both MED and ED50–100 were available for 13 anti-epileptic drugs. The average ratio of MED to ED50–100 was 0.95 (95% CI 0.60–1.30). The difference in MED to ED50–100 ratios between partial epilepsy (0.82) was not significantly different from that of generalised epilepsy (1.08) (p = 0.51).ConclusionPhotosensitive POP trials are a useful tool to quantitatively predict efficacy in epilepsy, and can be useful as early and informative indicators in anti-epileptic drug discovery and development.