Xanamem shows pro‐cognitive activity with clinically meaningful effect sizes across 3 independent, placebo‐controlled clinical trials

Abstract

AbstractBackgroundXanamem® is a brain‐penetrant inhibitor of 11‐beta hydroxysteroid dehydrogenase type 1, which converts intracellular cortisone to cortisol and is highly expressed in brain regions such as the hippocampus. Elevated plasma and CSF cortisol is strongly associated with cognitive decline.MethodEffects of Xanamem on cognition were assessed in 3 independent, placebo‐controlled, double‐blind trials. The XanaHES (n = 42, 20 mg) and XanaMIA (n = 105, 5 & 10 mg) Phase 1b trials used the computerised Cogstate system to assess cognition in normal, older volunteers. The XanADu‐X biomarker extension study (n = 72, 10 mg) explored clinical and cognitive outcomes in subgroups (n = 34 each) of the XanADu Phase 2a AD trial with higher (H) or lower (L) plasma p‐Tau181 in a new prospective analysis. To compare the results across trials, we focus on the cognitive effect sizes measured by the Cohen’s statistic (treatment effect vs. placebo / pooled baseline standard deviation).ResultXanamem was safe and well‐tolerated with no treatment‐related SAEs and the predominantly mild AEs were generally equally distributed between Xanamem and placebo. In XanaHES and XanaMIA, a pattern of clinically significant improvements was observed in attention and working memory compared to placebo in the Xanamem groups, with Cohen’s d ranging up to 1.27. Improvements from baseline were observed in both Xanamem and placebo in domains of episodic memory and executive function without a treatment difference. In XanADu, Xanamem demonstrated clinically significant benefit with a Cohen’s d of 0.41 on the CDR‐SB compared to placebo in the H group but not in the L group. In both L and H groups improvements in executive function were seen favouring Xanamem (Cohen’s d = 0.34 and 0.26, respectively) and the MMSE (Cohen’s d = 0.32 and 0.16, respectively). There were no improvements observed on original XanADu primary outcome measures of ADAS‐Cog14 and ADCOMs.ConclusionXanamem displays activity in multiple domains of cognition including attention, working memory, and executive function with clinically meaningful effects in normal subjects and in patients with p‐Tau‐elevated mild AD. These data suggest Xanamem may be both a pro‐cognitive drug and disease‐modifying agent and guide design of future trials.