A phase 2, open-label, multi-center study to evaluate the efficacy and safety of 99mTc-TRODAT-1 SPECT to detect Parkinson’s disease

To assess the efficacy and safety of ^99mTc-TRODAT-1 SPECT in diagnosing Parkinson’s disease (PD).

^99mTc-TRODAT-1 SPECT imaging was performed in 34 healthy controls and 96 PD patients 2.5 h later after injection. The striatal image was evaluated visually and semi-quantitively. Sensitivity and specificity of ^99mTc-TRODAT-1 SPECT were analyzed according to Hoehn and Yahr scale (HYS). Based on HYS, the PD patients were divided into mild (HYS 1–2) and moderate (HYS 3–5) groups. The uptake ratios of striatum (ST) and cerebellum (CB) in contralateral, ipsilateral and bilateral striatum in different groups were calculated and analyzed. The safety was assessed.

The sensitivity and specificity of ^99mTc-TRODAT-1 SPECT to discriminate PD patients from healthy subjects were 98.96% and 94.12% and it has perfect agreement with HYS (κ = 0.94, p < 0.001). The sensitivity to diagnose mild and moderate PD was 43.42% and 95% separately. The uptake ratio in PD patients was significantly lower than that in healthy controls (1.37 ± 0.13 vs 1.68 ± 0.18, p < 0.001). And the uptake ratio in contralateral side was markedly reduced in unilateral PD patients as compared with the ipsilateral side (1.50 ± 0.20 vs 1.46 ± 0.21, p < 0.001). The striatal uptakes in affected striatum and bilateral striatum were reduced with increasing disease severity between healthy control versus mild stage versus moderate stage in the affected striatum and bilateral striatum in PD patients. No serious adverse events or death was observed after injecting ^99mTc-TRODAT-1.

We demonstrated that ^99mTc-TRODAT-1 was a safety radiotracer which can be used in clinic to diagnose PD using SPECT.