Eleusis SPAC
Practical Limitations of Oral Psilocybin
Plasma psilocin concentration (µg/L)
20
18-
16-
14-
12-
10-
A
Single and Escalating Dose PK¹
Absorption rates varied between 40% to 70% in these academic studies
Subject 1 (3 mg)
Subject 2 (6 mg)
Encapsulating psilocybin is only "half-way" to developing a useful drug therapy
60 120 180 240 300 360 420 480
Time (min)
Single dose Cmax for Subject 3 (12 mg) higher
than Cmax values for Subjects 4, 5, and 6
(15, 18, and 24 mg)
eleusis
Subject 3 (12 mg)
Subject 4 (15 mg)
Subject 5 (18 mg)
Subject 6 (24 mg)
Subject 7 (24 mg)
Subject 8 (30 mg)
Dose-Normalized Psilocin Cmax
(ng/mL)/(mg/kg)
125
100-
75
50
25
0
0.30
Subject
0.60
0.45
Psilocybin Dose (mg/kg)
123456789111
012
10
Study of escalating oral psilocybin doses revealed
considerable inter and intra-individual variability
Oral Psilocybin Limitations
Variability
Considerable variations in absorption and
metabolism necessitated high doses and
gave rise to unpredictable PK/PD¹
■
■
■
Prolonged Administration and Observation
6-hour sessions used for administration and
observation in these studies, and required
monitoring by multiple clinicians²
Difficult to Optimize or Halt
Oral dosing is not amenable to
personalization or rapid termination²
Source: 1) Madsen, M. K. et al. (2019). Psychedelic effects of psilocybin correlate with serotonin 2A receptor occupancy and plasma psilocin levels. Neuropsychopharmacology, 44(7), 1328-1334; Brown, R. T. et al.
(2017). Pharmacokinetics of Escalating Doses of Oral Psilocybin in Healthy Adults. Clinical Pharmacokinetics, 56(12), 1543-1554. 2) Johnson M.. et al. (2008); Human hallucinogen research: guidelines for safety. Journal 12
of Psychopharmacology (Oxford, England), 22(6), 603-620; Rucker, J. et. al (2019) Psilocybin administration to healthy participants: safety and feasibility in a placebo-controlled study. Poster presented at the 58th
Annual Meeting of The American College of Neuropsychopharmacology, Orlando, FL, USA, 8-11 December 2019. Passie, T. (2002). The pharmacology of psilocybin. Addiction Biology, 7(4), 357-364., 2)View entire presentation