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A single‐center, open‐label positron emission tomography study to evaluate brivaracetam and levetiracetam synaptic vesicle glycoprotein 2A binding in healthy volunteers
Author(s) -
Finnema Sjoerd J.,
Rossano Samantha,
Naganawa Mika,
Henry Shannan,
Gao Hong,
Pracitto Richard,
Maguire Ralph P.,
Mercier Joël,
Kervyn Sophie,
Nicolas JeanMarie,
Klitgaard Henrik,
DeBruyn Steven,
Otoul Christian,
Martin Paul,
Muglia Pierandrea,
Matuskey David,
Nabulsi Nabeel B.,
Huang Yiyun,
Kaminski Rafal M.,
Hannestad Jonas,
Stockis Armel,
Carson Richard E.
Publication year - 2019
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/epi.14701
Subject(s) - levetiracetam , medicine , positron emission tomography , anesthesia , pharmacokinetics , dosing , pharmacology , cohort , nuclear medicine , in vivo , epilepsy , microbiology and biotechnology , psychiatry , biology
Summary Objective Brivaracetam (BRV) and levetiracetam (LEV) are antiepileptic drugs that bind synaptic vesicle glycoprotein 2A (SV2A). In vitro and in vivo animal studies suggest faster brain penetration and SV2A occupancy (SO) after dosing with BRV than LEV. We evaluated human brain penetration and SO time course of BRV and LEV at therapeutically relevant doses using the SV2A positron emission tomography (PET) tracer 11 C‐UCB‐J ( EP0074 ; NCT02602860 ). Methods Healthy volunteers were recruited into three cohorts. Cohort 1 (n = 4) was examined with PET at baseline and during displacement after intravenous BRV (100 mg) or LEV (1500 mg). Cohort 2 (n = 5) was studied during displacement and 4 hours postdose (BRV 50‐200 mg or LEV 1500 mg). Cohort 3 (n = 4) was examined at baseline and steady state after 4 days of twice‐daily oral dosing of BRV (50‐100 mg) and 4 hours postdose of LEV (250‐600 mg). Half‐time of 11 C‐UCB‐J signal change was computed from displacement measurements. Half‐saturation concentrations ( IC 50 ) were determined from calculated SO. Results Observed tracer displacement half‐times were 18 ± 6 minutes for BRV (100 mg, n = 4), 9.7 and 10.1 minutes for BRV (200 mg, n = 2), and 28 ± 6 minutes for LEV (1500 mg, n = 6). Estimated corrected half‐times were 8 minutes shorter. The SO was 66%‐70% for 100 mg intravenous BRV, 84%‐85% for 200 mg intravenous BRV, and 78%‐84% for intravenous 1500 mg LEV. The IC 50 of BRV (0.46 μg/mL) was 8.7‐fold lower than of LEV (4.02 μg/mL). BRV data fitted a single SO versus plasma concentration relationship. Steady state SO for 100 mg BRV was 86%‐87% (peak) and 76%‐82% (trough). Significance BRV achieves high SO more rapidly than LEV when intravenously administered at therapeutic doses. Thus, BRV may have utility in treating acute seizures; further clinical studies are needed for confirmation.