uca is bioequivalent to a dolutegravir 50 mg tablet and a rilpivirine 25 mg tablet administered together with a meal.
Dolutegravir pharmacokinetics are similar between healthy and HIV-infected subjects. The PK variability of dolutegravir is low to moderate. In Phase I studies in healthy subjects, between-subject CVb% for AUC and Cmax ranged from ~20 to 40% and Cfrom 30 to 65% across studies. The between-subject PK variability of dolutegravir was higher in HIV-infected subjects than healthy subjects. Within-subject variability (CVw%) is lower than between-subject variability.
The pharmacokinetic properties of rilpivirine have been eva luated in adult healthy subjects and in adult antiretroviral treatment-naïve HIV-1 infected patients. Systemic exposure to rilpivirine was generally lower in HIV-1 infected patients than in healthy subjects.
Absorption
Dolutegravir is rapidly absorbed following oral administration, with median Tmax at 2 to 3 hours post dose for tablet formulation. After oral administration, the maximum plasma concentration of rilpivirine is generally achieved within 4-5 hours.
Juluca must be taken with a meal to obtain optimal absorption of rilpivirine (see section 4.2). When Juluca was taken with a meal, the absorption of both dolutegravir and rilpivirine was increased. Moderate and high fat meals increased the dolutegravir AUC(0-∞) by approximately 87% and Cmax by approximately 75%. Rilpivirine AUC(0-∞) was increased by 57% and 72% and Cmax by 89% and 117%, with moderate and high fat meals respectively, compared to fasted conditions. Taking Juluca in fasted condition or with only a protein-rich nutritional drink may result in decreased plasma concentrations of rilpivirine, which could potentially reduce the therapeutic effect of Juluca.
The absolute bioavailability of dolutegravir or rilpivirine has not been established.
Distribution
Dolutegravir is highly bound (>99%) to human plasma proteins based on in vitro data. The apparent volume of distribution is 17 L to 20 L in HIV-infected patients, based on a population pharmacokinetic analysis. Binding of dolutegravir to plasma proteins is independent of dolutegravir concentration. Total blood and plasma drug-related radioactivity concentration ratios averaged between 0.441 to 0.535, indicating minimal association of radioactivity with blood cellular components. The unbound fraction of dolutegravir in plasma is increased at low levels of serum albumin (<35 g/L) as seen in subjects with moderate hepatic impairment.
Dolutegravir is present in cerebrospinal fluid (CSF). In 13 treatment-naïve subjects on a stable dolutegravir plus abacavir/lamivudine regimen, dolutegravir concentration in CSF averaged 18 ng/mL (comparable to unbound plasma concentration, and above the IC50).
Dolutegravir is present in the female and male genital tract. AUC in cervicovaginal fluid, cervical tissue and vaginal tissue were 6-10% of those in corresponding plasma at steady state. AUC in semen was 7% and 17% in rectal tissue of those in corresponding plasma at steady state.
Rilpivirine is approximately 99.7% bound to plasma proteins in vitro, primarily to albumin. The distribution of rilpivirine into compartments other than plasma (e.g., cerebrospinal fluid, genital tract secretions) has not been eva luated in humans.
Biotransformation
Dolutegravir is primarily metabolized through glucuronidation via UGT1A1 with a minor CYP3A component. Dolute |
