Table 2.
Summary of cabotegravir and rilpivirine concentrations in plasma and CSF 1 week (7 ± 3 days) after injection
| Pharmacokinetic parametera | Cabotegravir (μg/mL) |
Rilpivirine (ng/mL) |
||
|---|---|---|---|---|
| Q8W (n = 15) | Q4W (n = 3) | Q8W (n = 15) | Q4W (n = 3) | |
| Total plasma drug | 3.92 (1.30–6.41) | 3.02 (2.37–5.10) | 192 (91.7–378) | 134 (83.0–187) |
| Unbound plasma drug | 0.0047 (0.0007–0.0220) | 0.0019 (0.0014–0.0698) | NP | NP |
| Unbound fraction (%) at Cmax in plasmab | 0.103 (0.056–0.912) | 0.075 (0.062–1.45) | NP | NP |
| Total CSF drug | 0.0106 (0.0053–0.0245)c | 0.0127 (0.0082–0.0159) | 1.84 (NQ to 2.90)c, d | 1.67 (1.40–2.47) |
| Total CSF/total plasma (%) | 0.304 (0.218–0.449)c | 0.344 (0.312–0.421) | 1.07 (NQ to 1.52)c, d | 1.32 (1.25–1.69) |
All values shown are median (minimum–maximum). NP, not performed; NQ, not quantifiable; Q4W, cabotegravir LA 400 mg + rilpivirine LA 600 mg IM every 4 weeks; Q8W, cabotegravir LA 600 mg + rilpivirine LA 900 mg IM every 8 weeks.
All plasma samples and CSF samples were collected between 5 and 9 days after dosing and were within the protocol’s specification of 7 (±3) days after injection.
Cabotegravir and rilpivirine concentrations in plasma that were collected 7 (±3) days post-injection were considered Cmax values.
n = 13; failed to collect CSF for two participants.
One participant had rilpivirine CSF total as NQ (<1 ng/mL) and was imputed with a value of 0.