BackgroundIncreasing evidence indicates a metabolic etiology for migraines, with ketosis potentially rectifying metabolic and clinical features. We conducted a pilot study to evaluate CER-0001, a ketogenic agent, for migraine prevention without dietary changes. MethodsThis was a 2-part, double-blind, randomised, placebo-controlled study conducted in Australia. Adults with at least a 1-year history of migraine and ≥ 1 prior preventive treatment failure were randomised to either oral CER-0001 (up to 30 g twice a day) or placebo for 12 weeks. The primary endpoint was Month 3 change in Migraine Headache Days from baseline. ResultsPart 1 results are presented. 81 participants were randomised and dosed (n = 40 CER-0001, n = 41 placebo), and 61 participants had evaluable efficacy data. No statistically significant difference was observed in the primary endpoint (LSMean difference 0.92 days; p = 0.586). During Month 2, a mean improvement of −2.8 days was observed for CER-0001 (p = 0.056). Withdrawal rates were 45.0% and 53.7% (CER-0001; placebo). The proportion of participants reporting at least one treatment-emergent adverse event was similar between arms (90.0% CER-0001, 82.9% placebo), mostly gastrointestinal (85.0% CER-0001, 70.7% placebo). ConclusionResults suggest positive directional promise over 2–3 months for CER-0001. A new formulation will be used for larger, fully powered phase 2/3 studies. Trial registrationThis study is registered at ClinicalTrials.gov (NCT04437199).