Dolutegravir 50 mg, Emtricitabine 200 mg, Tenofovir Alafenamide 25 mg Tablets

DESCOVY is a fixed dose combination of antiretroviral drugs emtricitabine (FTC) and tenofovir alafenamide (TAF) [see Microbiology (12.4)].

Absorption, Distribution, Metabolism, and Excretion — The pharmacokinetic (PK) properties of the components of DESCOVY are provided in Table 7. The multiple dose PK parameters of FTC and TAF and its metabolite tenofovir are provided in Table 8. HIV status has no effect on the pharmacokinetics of FTC and TAF in adults.

Drug Interaction Studies — The effects of coadministered drugs on the exposure of TAF are shown in Table 15 and the effects of DESCOVY or its components on the exposure of coadministered drugs are shown in Table 16 [these studies were conducted with DESCOVY or the components of DESCOVY (FTC or TAF) administered alone]. For information regarding clinical recommendations, see Drug Interactions (7) .

Dolutegravir is an HIV-1 antiretroviral agent [see Microbiology ( 12.4)].

The pharmacokinetic properties of dolutegravir have been evaluated in healthy adult subjects and HIV‑1–infected adult subjects. Exposure to dolutegravir was generally similar between healthy subjects and HIV‑1–infected subjects. The non-linear exposure of dolutegravir following 50 mg twice daily compared with 50 mg once daily in HIV‑1–infected subjects ( Table 9) was attributed to the use of metabolic inducers in the background antiretroviral regimens of subjects receiving dolutegravir 50 mg twice daily in clinical trials.

TIVICAY tablets and TIVICAY PD tablets for oral suspension are not bioequivalent. The relative bioavailability of TIVICAY PD is approximately 1.6-fold higher than TIVICAY; therefore, the 2 dosage forms are not substitutable on a milligram-per-milligram basis [see Dosage and Administration ( 2.3)].

Absorption — Following oral administration of dolutegravir, peak plasma concentrations were observed 1 to 3 hours postdose. With once-daily dosing, pharmacokinetic steady state is achieved within approximately 5 days with average accumulation ratios for AUC, C max, and C 24 hranging from 1.2 to 1.5.

Dolutegravir plasma concentrations increased in a less than dose-proportional manner above 50 mg. Dolutegravir is a P‑gp substrate in vitro. The absolute bioavailability of dolutegravir has not been established.

Effect of Food:TIVICAY or TIVICAY PD may be taken with or without food. Food increased the extent of absorption and slowed the rate of absorption of dolutegravir following a 50-mg dose of TIVICAY. Low-, moderate-, and high-fat meals increased dolutegravir AUC (0-∞)by 33%, 41%, and 66%; increased C maxby 46%, 52%, and 67%; and prolonged T maxto 3, 4, and 5 hours from 2 hours under fasted conditions, respectively.

Distribution — Dolutegravir is highly bound (greater than or equal to 98.9%) to human plasma proteins based on in vivo data and binding is independent of plasma concentration of dolutegravir. The apparent volume of distribution (Vd/F) following 50-mg once-daily administration is estimated at 17.4 L based on a population pharmacokinetic analysis.

Cerebrospinal Fluid (CSF):In 12 treatment-naïve subjects on dolutegravir 50 mg daily plus abacavir/lamivudine, the median dolutegravir concentration in CSF was 13.2 ng/mL (range: 3.74 ng/mL to 18.3 ng/mL) 2 to 6 hours postdose after 16 weeks of treatment. The clinical relevance of this finding has not been established.

Elimination — Dolutegravir has a terminal half-life of approximately 14 hours and an apparent clearance (CL/F) of 1.0 L/h based on population pharmacokinetic analyses.

Metabolism:Dolutegravir is primarily metabolized via UGT1A1 with some contribution from CYP3A.

Polymorphisms in Drug‑ Metabolizing Enzymes:In a meta-analysis of healthy subject trials, subjects with UGT1A1 (n = 7) genotypes conferring poor dolutegravir metabolism had a 32% lower clearance of dolutegravir and 46% higher AUC compared with subjects with genotypes associated with normal metabolism via UGT1A1 (n = 41).

Excretion:After a single oral dose of [ 14C] dolutegravir, 53% of the total oral dose was excreted unchanged in feces. Thirty-one percent of the total oral dose was excreted in urine, represented by an ether glucuronide of dolutegravir (18.9% of total dose), a metabolite formed by oxidation at the benzylic carbon (3.0% of total dose), and its hydrolytic N-dealkylation product (3.6% of total dose). Renal elimination of unchanged drug was low (less than 1% of the dose).

Specific Populations — Pediatric Patients:The pharmacokinetics of dolutegravir were evaluated in the IMPAACT P1093 trial and in 2 weight-band-based pharmacokinetic substudies from the ODYSSEY trial. Steady-state plasma exposure at doses by weight band are summarized in Table 10 [see Clinical Studies ( 14.3)] .

Mean dolutegravir AUC 0-24hand C 24hin HIV-1–infected pediatric subjects were comparable to those in adults after 50 mg once daily or 50 mg twice daily. Mean C maxis higher in pediatrics, but the increase is not considered clinically significant as the safety profiles were similar in pediatric and adult subjects [see Use in Specific Populations ( 8.4)] .

Geriatric Patients:Population pharmacokinetic analysis indicated age had no clinically relevant effect on the pharmacokinetics of dolutegravir.