Gold nanocrystals may be effective as adjunctive MS therapy

The results of the VISIONARY-MS study suggest that an oral suspension of catalytically-active gold nanocrystals (CNM-Au8) given in addition to disease-modifying drugs (DMTs) is effective in patients with stable relapsing multiple sclerosis (RMS). There were not only improvements in vision but also in global neurological function.

The first author and presenter of the study Prof. Michael Barnett (University of Sydney, Australia) started by recognising an unmet need in MS care, despite the availability of a large number of highly effective disease-modifying drugs. “However, we still do not have a therapy that promotes remyelination, and we certainly do not have a proven neuroprotective therapy for MS.”

CNM-Au8 is hypothesised to restore neuronal health and function by supporting brain energy metabolism. In preclinical models, this resulted in neuroprotection and remyelination [1].

The current phase 2/3 trial VISIONARY-MS (NCT04626921) was designed as a multicentre, randomised, double-blind study evaluating CNM-Au8 versus placebo over 48 weeks in participants with stable RMS [2]. Patients were randomised 1:1:1 to CNM-Au8 15 mg/day, 30mg/day, or placebo. Prof. Barnett said the study was terminated prematurely because it proved to be too challenging to recruit patients during the COVID-19 pandemic. Of the 150 planned participants, 73 were randomised. Participants were between 18 and 55 years of age, had RMS since <15 years, were clinically stable over the prior 6 months, and had chronic optic neuropathy, with a best corrected-low contrast letter acuity (BC-LCLA) using 2.5% low-contrast Sloan letter chart of 20/40 or worse in the affected eye. The primary endpoint was a change in BC-LCLA score in the most affected eye to week 48. The secondary endpoint was a global neurological improvement, measured by the change in the modified MS Functional Composite (mMSFC) to week 48.

Both the primary and secondary clinical endpoints significantly improved. The BC-LCLA change in the affected eye was significantly different as early as week 24. At week 48, the LS-mean difference was 3.13 (95% CI -0.08–6.33; P=0.056). In the CNM-Au8 group, global neurological improvement at week 48 was also more favourable than in the control group, with an LS-mean difference of 0.28 (0.05–0.51; P=0.0197). The positive result of the latter endpoint was mainly driven by changes in LCLA in both eyes, in the Symbol Digit Modalities Test, and the 9-Hole Peg test of the dominant hand. Prof. Barnett added that CNM-Au8 also improved independent quantitative biomarkers of enhanced axonal integrity, namely multifocal visual evoked potential amplitude, and fractional anisotropy. CNM-Au8 was safe and well-tolerated; treatment-emergent adverse events were mild-to-moderate and transient.

1. 1. Robinson AP, et al. Sci Rep 2020;10(1):1936.
   2. Barnett M. VISIONARY-MS top-line results: A Phase 2, randomized, double-blind, parallel group, placebo-controlled study to assess the safety and efficacy of CNM-Au8, a catalytically active gold nanocrystal suspension in relapsing multiple sclerosis. Session PL5.005, AAN 2023 Annual Meeting, 22–27 April, Boston, USA.

 

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Posted on 1 May, 2023