Phase 3 Trials of Tapinarof Cream for Plaque Psoriasis.

BACKGROUND: Tapinarof cream is a topical aryl hydrocarbon receptor-modulating agent under investigation for the treatment of psoriasis. Tapinarof modulates the expression of interleukin-17 and the skin-barrier proteins filaggrin and loricrin. METHODS: We conducted two identical phase 3 randomized trials of tapinarof in patients with mild-to-severe plaque psoriasis. Adults with a baseline Physician's Global Assessment (PGA) score of 2 (mild) to 4 (severe) (on a scale from 0 to 4, with higher scores indicating more severe psoriasis) and a percent of total body-surface area affected of 3 to 20% were randomly assigned in a 2:1 ratio to use tapinarof 1% cream or vehicle cream once daily for 12 weeks. The primary end point, PGA response, was a PGA score of 0 (clear) or 1 (almost clear) and a decrease from baseline of at least 2 points at week 12. Secondary efficacy end points at week 12 were a reduction of at least 75% in the Psoriasis Area and Severity Index (PASI) score, a PGA score of 0 or 1, the mean change from baseline in the percent of body-surface area affected, and a reduction of at least 90% in the PASI score. Patient-reported outcomes were the mean changes from baseline to week 12 in the proportion of patients who had a decrease of at least 4 points in the Peak Pruritus Numeric Rating Scale (PP-NRS) score (range, 0 [no itch] to 10 [worst imaginable itch]), the PP-NRS total score, the Dermatology Life Quality Index total score, and the Psoriasis Symptom Diary score. RESULTS: In trials 1 and 2, a total of 692 and 674 patients, respectively, were screened, with 510 and 515 patients being enrolled. A PGA response occurred in 35.4% of the patients in the tapinarof group and in 6.0% of those in the vehicle group in trial 1 and in 40.2% and 6.3%, respectively, in trial 2 (P<0.001 for both comparisons). Results for secondary end points and patient-reported outcomes were generally in the same direction as those for the primary end point. Adverse events with tapinarof cream included folliculitis, nasopharyngitis, contact dermatitis, headache, upper respiratory tract infection, and pruritus. CONCLUSIONS: Tapinarof 1% cream once daily was superior to vehicle control in reducing the severity of plaque psoriasis over a period of 12 weeks but was associated with local adverse events and headache. Larger and longer trials are needed to evaluate the efficacy and safety of tapinarof cream as compared with existing treatments for psoriasis. (Funded by Dermavant Sciences; PSOARING 1 and 2 ClinicalTrials.gov numbers, NCT03956355 and NCT03983980, respectively.).

Tapinarof cream 1% once daily: Significant efficacy in the treatment of moderate to severe atopic dermatitis in adults and children down to 2 years of age in the pivotal phase 3 ADORING trials.

BACKGROUND: Tapinarof cream 1% once daily (QD), a topical aryl hydrocarbon receptor agonist, downregulates pro-inflammatory Th2 cytokines, upregulates skin-barrier components, and reduces oxidative stress. OBJECTIVE: To assess tapinarof efficacy and safety in adults and children down to 2 years of age with atopic dermatitis (AD). METHODS: Eight hundred and thirteen patients were randomized to tapinarof or vehicle QD in two 8-week phase 3 trials. RESULTS: The primary efficacy endpoint, Validated Investigator Global Assessment for Atopic Dermatitis score of 0 or 1 and ≥2-grade improvement from baseline at Week 8, was met with statistical significance in both trials: 45.4% versus 13.9% and 46.4% versus 18.0% (tapinarof vs vehicle; both P < .0001). Significantly superior Eczema Area and Severity Index 75 (EASI75) responses were also observed with tapinarof versus vehicle at Week 8: 55.8% versus 22.9% and 59.1% versus 21.2% (both P < .0001). Rapid improvements in patient-reported pruritus were also significant with tapinarof versus vehicle. Common adverse events (≥5%) of folliculitis, headache, and nasopharyngitis were mostly mild or moderate, with lower discontinuations due to adverse events in the tapinarof groups than with vehicle. LIMITATIONS: Long-term efficacy was not assessed. CONCLUSION: Tapinarof demonstrated highly significant efficacy and favorable safety and tolerability in a diverse population of patients with AD down to 2 years of age.

One-year safety and efficacy of tapinarof cream for the treatment of plaque psoriasis: Results from the PSOARING 3 trial.

BACKGROUND: Tapinarof cream 1% once daily, an aryl hydrocarbon receptor-modulating agent, was significantly more efficacious than vehicle and well tolerated in two 12-week phase 3 trials in adults with mild to severe plaque psoriasis. OBJECTIVE: To assess long-term safety, efficacy, remittive effect, durability of response, and tolerability of tapinarof. METHODS: Patients completing the 12-week trials were eligible for 40-weeks' open-label treatment and 4-weeks' follow-up. Treatment was based on the Physician Global Assessment (PGA) score. Patients entering with PGA≥1 received tapinarof until PGA = 0. Patients with PGA = 0 discontinued tapinarof and were monitored for remittive effect. Patients with PGA≥2 were re-treated until PGA = 0. RESULTS: Overall, 91.6% (n = 763) of eligible patients enrolled; 40.9% of patients achieved complete disease clearance (PGA = 0), and 58.2% entering with PGA≥2 achieved PGA = 0 or 1. Mean duration of off therapy remittive effect for patients achieving PGA = 0 was 130.1 days. No new safety signals were observed. Most frequent adverse events were folliculitis (22.7%), contact dermatitis (5.5%), and upper respiratory tract infection (4.7%). LIMITATIONS: Open-label; no control; may not be generalizable to all forms of psoriasis; remittive effect/response rate potentially underestimated. CONCLUSIONS: Efficacy improved beyond the 12-week trials, with a 40.9% complete disease clearance rate, ∼4-month off therapy remittive effect, durability on therapy, and consistent safety.

Dermal Safety of Tapinarof Cream 1%: Results From 4 Phase 1 Trials.

BACKGROUND: Tapinarof (VTAMA®; Dermavant Sciences, Inc.) is a novel, non-steroidal, topical, aryl hydrocarbon receptor agonist, FDA approved for psoriasis treatment and under investigation for atopic dermatitis treatment as a 1% cream formulation for once-daily (QD) application. OBJECTIVE: Evaluate cumulative skin irritation, sensitization, and photoallergic and phototoxic potential of tapinarof cream 1% across a range of dosing frequencies and conditions. METHODS: We conducted 4 randomized, controlled, phase 1 trials of topical tapinarof cream 1% vs vehicle or other appropriate controls in healthy adults. Cumulative skin irritation was assessed following QD application for 21 days under fully occlusive patch conditions. Contact sensitization, photoallergenicity, and phototoxicity were assessed under semi-occlusive patch conditions. The contact sensitization and photoallergenicity trials used an induction phase of repeated applications followed by a 2-week rest period and a 1-time challenge, with rechallenge if responses indicated sensitization/photosensitization; the phototoxicity trial comprised a single application. Ultraviolet A and B irradiation was used to assess photoallergenicity/toxicity. RESULTS: 376 participants were randomized across the 4 trials. In the cumulative irritation trial, tapinarof cream 1% QD was classified as having a slight potential for very mild cumulative irritation under the exaggerated test conditions of repeated dosing for 21 days. There was no evidence of sensitization, photosensitization, or phototoxicity. Tapinarof was well tolerated and there was a low discontinuation rate across all trials. CONCLUSIONS: Tapinarof cream 1% was well tolerated, non-sensitizing, non-phototoxic, and non-photoallergic, with no evidence of clinically meaningful cumulative skin irritation in 4 dermal safety trials in healthy adults. TRIAL REGISTRATION: IND 104601 J Drugs Dermatol. 2022;21(10):1084-1090. doi:10.36849/JDD.6627R1.

Effect of carbamazepine on dolutegravir pharmacokinetics and dosing recommendation.

PURPOSE: Dolutegravir (DTG) is primarily metabolized by UGT1A1 with CYP3A as a minor route. Carbamazepine (CBZ) is a potent inducer of these enzymes; thus, the effect of oral extended-release CBZ on DTG pharmacokinetics (PK) was evaluated to provide dose recommendation when co-administered. METHODS: This was a single-center, open-label, fixed-sequence, crossover study in healthy adults. Subjects received three treatments: DTG 50 mg every 24 h (q24h) × 5 days in period 1, followed by CBZ 100 mg every 12 h (q12h) × 3 days, then 200 mg q12h × 3 days, then 300 mg q12h × 10 days in period 2, and DTG 50 mg q24h + CBZ 300 mg q12h × 5 days in period 3. No washout intervals occurred. Each dose was administered with a moderate-fat meal. Serial PK samples for DTG were collected on day 5 of periods 1 and 3. Plasma DTG PK parameters were determined with non-compartmental analysis. Geometric least-squares mean ratios (GMRs) and 90 % confidence intervals (CIs) were generated by the mixed-effect model for within-subject treatment comparisons. Safety assessments were performed throughout the study. RESULTS: Sixteen subjects enrolled; 14 completed the study. CBZ significantly reduced DTG exposure: GMRs (90 % CI) for DTG + CBZ versus DTG alone were 0.51 (0.48-0.549), 0.67 (0.61-0.73), and 0.27 (0.24-0.31) for area under the curve from time zero to the end of the dosing interval (AUC(0-τ)), maximum observed plasma concentration (Cmax), and plasma concentration at the end of the dosing interval (Cτ), respectively. DTG alone and co-administered with CBZ was well tolerated. CONCLUSION: Integrase strand transfer inhibitor-naive subjects taking CBZ should receive DTG 50 mg twice daily versus once daily, as is recommended with other potent UGT1A/CYP3A inducers. ClinicalTrials.gov: NCT01967771.

Disposition and metabolism of cabotegravir: a comparison of biotransformation and excretion between different species and routes of administration in humans.

1. Cabotegravir [(3S,11aR)-N-[(2,4-difluorophenyl)methyl]-6-hydroxy-3-methyl-5,7-dioxo-2,3,5,7,11,11a-hexahydro[1,3]oxazolo[3,2-a]pyrido[1,2-d]pyrazine-8-carboxamide] is an HIV-1 integrase inhibitor under development as a tablet for both oral lead-in therapy and long-acting (LA) injectable for intramuscular dosing. 2. Metabolism, pharmacokinetics and excretion were investigated in healthy human subjects who received either a single oral dose (28.2 mg) of [(14)C]cabotegravir in a mass balance study, or LA formulations of unlabeled cabotegravir (200-800 mg), intramuscularly or subcutaneously, in a separate study. Metabolism, distribution and excretion of [(14)C]cabotegravir were also investigated in mice, rats and monkeys. 3. Recovery of radioactivity in humans represented a mean total of 85.3% of the dose, including 26.8% in the urine. The mean apparent terminal phase half-life was similar for both cabotegravir and radioactivity, 39 h compared to 41 h. 4. Following oral, intramuscular and subcutaneous administration, cabotegravir was the major component in plasma and the glucuronic acid conjugate (M1) represented the predominant component in urine. Cabotegravir was present in bile along with its major metabolite (M1). 5. The primary metabolite of [(14)C]cabotegravir in mouse, rat and monkey was the same as that in human. In vitro phenotyping experiments demonstrated that cabotegravir was metabolized by UDP-glucuronosyltransferase (UGT) 1A1 and UGT1A9.

Dolutegravir Has No Effect on the Pharmacokinetics of Oral Contraceptives With Norgestimate and Ethinyl Estradiol.

BACKGROUND: Dolutegravir (DTG; Tivicay; ViiV Healthcare, Research Triangle Park, NC) is an HIV-1-unboosted integrase inhibitor with no cytochrome P450 or uridine 5'diphosphate-glucuronosyltransferase inhibition or induction. As DTG is administered to HIV-1-infected women receiving oral contraceptives, assessing the potential for drug interactions was warranted. OBJECTIVE: To determine the impact of DTG on the pharmacokinetics (PK) and pharmacodynamics (PD) of a common oral contraceptive, norgestimate/ethinyl estradiol (NGM/EE; Ortho-Cyclen; Ortho-McNeil-Janssen Pharmaceuticals, Inc, Raritan, NJ). METHODS: This randomized, 2-period, double-blind, placebo-controlled study was conducted within 1 menstrual cycle at 1 clinical center in the United States; 16 women were enrolled. Participants received NGM 0.25 mg/EE 0.035 mg throughout the study. During days 1 to 10, they were randomized to receive twice-daily DTG 50 mg or matching placebo with food and switched to the other treatment during days 12 to 21. RESULTS: Ratios of area under the concentration-time curve from time 0 until end of the dosage interval (AUC0-τ), maximum plasma concentration, and concentration at the end of the dosage interval of norelgestromin with DTG treatment to the same PK parameters with placebo treatment were 0.975, 0.890, and 0.932, respectively; for EE, ratios were 1.03, 0.99, and 1.02, respectively. No significant differences in luteinizing hormone, follicle-stimulating hormone, and progesterone were detected on days 1, 10, 11, 21, and 22. DTG steady-state AUC0-τ was similar to historical data. No severe or grade 3/4 adverse events occurred. CONCLUSIONS: DTG had no effect on NGM/EE PK or PD. NGM/EE can be administered with DTG without dose adjustment.

ING116070: a study of the pharmacokinetics and antiviral activity of dolutegravir in cerebrospinal fluid in HIV-1-infected, antiretroviral therapy-naive subjects.

BACKGROUND: Dolutegravir (DTG), a once-daily, human immunodeficiency virus type 1 (HIV-1) integrase inhibitor, was evaluated for distribution and antiviral activity in cerebrospinal fluid (CSF). METHODS: ING116070 is an ongoing, single-arm, open-label, multicenter study in antiretroviral therapy-naive, HIV-1-infected adults. Subjects received DTG (50 mg) plus abacavir/lamivudine (600/300 mg) once daily. The CSF and plasma (total and unbound) DTG concentrations were measured at weeks 2 and 16. The HIV-1 RNA levels were measured in CSF at baseline and weeks 2 and 16 and in plasma at baseline and weeks 2, 4, 8, 12, and 16. RESULTS: Thirteen white men enrolled in the study; 2 withdrew prematurely, 1 because of a non-drug-related serious adverse event (pharyngitis) and 1 because of lack of treatment efficacy. The median DTG concentrations in CSF were 18 ng/mL (range, 4-23 ng/mL) at week 2 and 13 ng/mL (4-18 ng/mL) at week 16. Ratios of DTG CSF to total plasma concentration were similar to the unbound fraction of DTG in plasma. Median changes from baseline in CSF (n = 11) and plasma (n = 12) HIV-1 RNA were -3.42 and -3.04 log10 copies/mL, respectively. Nine of 11 subjects (82%) had plasma and CSF HIV-1 RNA levels <50 copies/mL and 10 of 11 (91%) had CSF HIV-1 RNA levels <2 copies/mL at week 16. CONCLUSIONS: The DTG concentrations in CSF were similar to unbound plasma concentrations and exceeded the in vitro 50% inhibitory concentration for wild-type HIV (0.2 ng/mL), suggesting that DTG achieves therapeutic concentrations in the central nervous system. The HIV-1 RNA reductions were similar in CSF and plasma. Clinical Trials Registration. NCT01499199.

Effect of fosamprenavir-ritonavir on the pharmacokinetics of dolutegravir in healthy subjects.

Dolutegravir (DTG) is an HIV integrase inhibitor (INI) with demonstrated activity in INI-naive and INI-resistant patients. The objective of this open-label, 2-period, single-sequence study was to evaluate the effect of fosamprenavir-ritonavir (FPV-RTV) on the steady-state plasma pharmacokinetics of DTG. Twelve healthy subjects received 50 mg DTG once daily for 5 days (period 1), followed by 10 days of 50 mg DTG once daily in combination with 700/100 mg FPV-RTV every 12 h (period 2). All doses were administered in the fasting state. Serial pharmacokinetic samples for DTG and amprenavir and safety assessments were obtained throughout the study. Noncompartmental pharmacokinetic analysis was performed, and geometric least-squares mean ratios and 90% confidence intervals were generated for within-subject treatment comparison. Fosamprenavir-ritonavir decreased the DTG area under the concentration-time curve, maximum concentration in plasma, and concentration in plasma at the end of the dosing interval by 35%, 24%, and 49%, respectively. Both DTG and DTG with FPV-RTV were well tolerated; no subject withdrew because of adverse events. The most frequently reported drug-related adverse events were rash, abnormal dreams, and nasopharyngitis. The modest decrease in DTG exposure when it was coadministered with FPV-RTV is not considered clinically significant, and DTG dose adjustment is not required with coadministration of FPV-RTV in INI-naive patient populations on the basis of established "no-effect" boundaries of DTG. In the INI-resistant population, as a cautionary measure, alternative combinations that do not include FPV-RTV should be considered. (This study has been registered at ClinicalTrials.gov under identifier NCT01209065.).

Effects of boceprevir and telaprevir on the pharmacokinetics of dolutegravir.

AIMS: The aim was to evaluate the effect of boceprevir and telaprevir on dolutegravir pharmacokinetics (PK); the effect of dolutegravir on boceprevir and telaprevir PK was assessed through comparison with historical data for each hepatitis C virus (HCV) drug's prescribing information alone. METHODS: This was a single-centre, randomized, open-label, two-cohort, two-period, one-way study in healthy adult subjects. Dolutegravir 50 mg once daily was administered for 5 days in Period 1, and dolutegravir 50 mg once daily was coadministered with either boceprevir 800 mg every 8 h (Cohort 1) or telaprevir 750 mg every 8 h (Cohort 2) for 10 days in Period 2. RESULTS: No deaths or serious adverse events were reported during the study. Four subjects were withdrawn from the study because of adverse events (elevated alanine aminotransferase, cellulitis, increased serum creatinine and dizziness). One subject became pregnant during the study. Coadministration of dolutegravir with boceprevir had no effect on dolutegravir area under the plasma concentration-time curve (AUC) and maximal plasma concentration (Cmax ) and caused a small increase in concentration at the end of the dosing interval (Cτ ; 8%). Coadministration of dolutegravir with telaprevir resulted in increased dolutegravir plasma exposures compared with those after administration of dolutegravir alone; AUC0- τ , Cmax and Cτ increased by 25, 19 and 37%, respectively. Coadministration of boceprevir or telaprevir with dolutegravir had no clinically significant effect on dolutegravir PK. Plasma boceprevir and telaprevir PK data for either combined treatment were similar to historical data, indicating no effect of dolutegravir on boceprevir or telaprevir exposure. CONCLUSIONS: Dolutegravir can be coadministered with boceprevir or telaprevir in patients coinfected with HIV and HCV with no dose adjustment.

Pharmacokinetics of dolutegravir in HIV-seronegative subjects with severe renal impairment.

PURPOSE: Dolutegravir (DTG), an unboosted HIV integrase inhibitor (INI), is metabolized by UGT1A1 and to a minor extent by CYP3A. Renal elimination of unchanged DTG is very low (< 1 %). As renal impairment may affect pharmacokinetics (PK), even for drugs primarily metabolized or secreted in bile, this study investigated the effect of renal impairment on the PK of DTG. METHODS: This was an open-label, single-dose study of oral DTG 50 mg administered to subjects with severe renal impairment (creatinine clearance [CLcr] <30 mL/min; not on dialysis) and to healthy controls (CLcr >90 mL/min) matched for gender, age and body mass index (8 subjects per group). Serial PK samples were collected up to 72 h post-dose for determination of DTG and DTG-glucuronide (DTG-Gluc) concentrations in plasma. DTG unbound fraction in plasma was determined at 3 and 24 h. PK parameters were determined by non-compartmental methods and compared between groups by analysis of covariance. RESULTS: DTG was well tolerated with a low incidence of Grade 1 adverse events. DTG PK parameters showed significant overlap between groups. DTG mean exposure was lower in subjects with severe renal impairment compared to healthy, matched subjects: AUC(0-∞) and Cmax were 40 % and 23 % lower, while mean DTG-Gluc was increased. Renal impairment did not affect DTG fraction unbound in plasma. CONCLUSIONS: The modest reductions in mean PK exposures for DTG and increases for DTG-Gluc in the severe renal impairment group are not considered clinically significant. DTG does not require dose adjustment in patients with renal impairment.

Effects of enzyme inducers efavirenz and tipranavir/ritonavir on the pharmacokinetics of the HIV integrase inhibitor dolutegravir.

PURPOSE: Dolutegravir (DTG) is an unboosted, integrase inhibitor for the treatment of HIV infection. Two studies evaluated the effects of efavirenz (EFV) and tipranavir/ritonavir (TPV/r) on DTG pharmacokinetics (PK) in healthy subjects. METHODS: The first study was an open-label crossover where 12 subjects received DTG 50 mg every 24 hours (q24h) for 5 days, followed by DTG 50 mg and EFV 600 mg q24h for 14 days. The second study was an open-label crossover where 18 subjects received DTG 50 mg q24h for 5 days followed by TPV/r 500/200 mg every 12 hours (q12h) for 7 days and then DTG 50 mg q24h and TPV/r 500/200 mg q12h for a further 5 days. Safety assessments and serial PK samples were collected. Non-compartmental PK analysis and geometric mean ratios and 90% confidence intervals were generated. RESULTS: The combination of DTG with EFV or TPV/r was generally well tolerated. Four subjects discontinued the TPV/r study due to increases in alanine aminotransferase that were considered related to TPV/r. Co-administration with EFV resulted in decreases of 57, 39 and 75% in DTG AUC(0-τ), Cmax and Cτ, respectively. Co-administration with TPV/r resulted in decreases of 59, 46 and 76% in DTG AUC(0-τ), Cmax and Cτ, respectively. CONCLUSIONS: Given the reductions in exposure and PK/pharmacodynamic relationships in phase II/III trials, DTG should be given at an increased dose of 50 mg twice daily when co-administered with EFV or TPV/r, and alternative regimens without inducers should be considered in integrase inhibitor-resistant patients.

Lack of pharmacokinetic interaction between rilpivirine and integrase inhibitors dolutegravir and GSK1265744.

Dolutegravir (DTG) and GSK1265744 are HIV integrase inhibitors (INIs) in clinical development. The oral formulation of rilpivirine (RPV), a nonnucleoside reverse transcriptase inhibitor (NNRTI), has been approved for treatment-naive HIV infection. Long-acting depot injections of GSK1265744 and RPV are also being developed. This study evaluated the potential for drug interactions between RPV and these INIs. This phase 1, open-label, two-cohort, three-period, single-sequence crossover study evaluated oral coadministration of RPV with DTG or GSK1265744. Healthy subjects received DTG (50 mg every 24 h for 5 days) or GSK1265744 (30 mg every 24 h for 12 days) in period 1 followed by a washout, RPV (25 mg every 24 h for 11 or 12 days) in period 2, immediately followed by RPV (25 mg every 24 h) plus DTG (50 mg every 24 h) for 5 days or GSK1265744 (30 mg every 24 h) for 12 days in period 3. Steady-state pharmacokinetic (PK) parameters were estimated using noncompartmental analysis of data collected on the last day of each period. The combinations of RPV and DTG (n = 16) and of RPV and GSK1265744 (n = 11) were well tolerated; no grade 3 or 4 adverse events (AEs) or AE-related discontinuations were observed. The 90% confidence intervals for the area under the curve from time zero until the end of the dosage interval [AUC0-τ] and maximum concentration of drug in serum (Cmax) geometric mean ratios were within 0.8 to 1.25. Following administration of DTG + RPV, DTG and RPV Cτ increased by 22% and 21%, respectively. Following administration of GSK1265744 + RPV, RPV Cτ decreased 8%. DTG and GSK1265744 can be administered with RPV without dosage adjustment for either agent. These results support coadministration of RPV with DTG or GSK1265744 as either oral or long-acting depot injection regimens. (This study has been registered at ClinicalTrials.gov under registration no. NCT01467531.).

Effect of prednisone on the pharmacokinetics of the integrase inhibitor dolutegravir.

Prednisone, a corticosteroid frequently used to treat common AIDS-related illnesses and comorbidities, has been shown to induce drug metabolism. This study was performed to determine whether prednisone coadministration affected the pharmacokinetics of dolutegravir (DTG). In this open-label, repeat-dose study, 12 healthy subjects were administered DTG at 50 mg daily alone for 5 days and then with concomitant prednisone for 10 days (prednisone at 60 mg daily for 5 days, followed by a 5-day taper). Serial blood sampling and safety assessments were performed during the trial. Pharmacokinetic parameters were determined using noncompartmental methods and geometric least-square mean ratios, and 90% confidence intervals were generated. Coadministration of DTG and 5-day high-dose prednisone with a 5-day taper had a modest effect on DTG exposure. The area under the DTG plasma concentration-time curve, maximum observed DTG concentration, and 24-hour postdose DTG concentration were increased by 11%, 6%, and 17%, respectively, on day 10 of the combination. Similar results were observed after 5 days of DTG and prednisone. Dolutegravir and prednisone coadministration was well tolerated. The changes in plasma exposures of DTG in healthy individuals as a result of prednisone dosing were not clinically significant. No dose adjustment is required for DTG coadministered with prednisone. (This study has been registered at ClinicalTrials.gov under registration no. NCT01425099.).

Effects of etravirine on the pharmacokinetics of the integrase inhibitor S/GSK1265744.

HIV integrase inhibitors such as raltegravir and elvitegravir halt HIV progression, but treatment-emergent resistance and cross-resistance have been observed. The nonnucleoside reverse transcriptase inhibitor etravirine (ETR) may be used in combination with integrase inhibitors in patients with drug resistance. This single-center, open-label, two-period, single-sequence crossover study evaluated the effects of ETR coadministration on the pharmacokinetic profile of S/GSK1265744, an investigational integrase inhibitor in phase 2 studies. Healthy subjects received 30 mg of S/GSK1265744 alone once daily for 10 days (period 1) and in combination with 200 mg of ETR twice daily for 14 days (period 2). Serial plasma samples for pharmacokinetic analyses were collected on day 10 during period 1 and on day 14 during period 2. All treatments were well tolerated. Etravirine had no effects on S/GSK1265744 geometric mean ratios of the area under the curve from time zero until the end of the dosing interval (1.01; 90% confidence interval [CI], 0.956 to 1.06), of the maximum observed plasma concentration (1.04; 90% CI, 0.987 to 1.09), or of the plasma concentration at the end of the dosing interval (0.999; 90% CI, 0.942 to 1.06). Etravirine pharmacokinetics (PK) parameters observed following coadministration with S/GSK1265744 were in the range of historical values reported for ETR alone in healthy subjects. These results indicate that 30 mg of S/GSK1265744 for 10 days as monotherapy followed by an additional 14 days in combination with ETR was well tolerated in healthy subjects and that no dose adjustment of S/GSK1265744 is required when it is coadministered with ETR.

Metabolism, excretion, and mass balance of the HIV-1 integrase inhibitor dolutegravir in humans.

The pharmacokinetics, metabolism, and excretion of dolutegravir, an unboosted, once-daily human immunodeficiency virus type 1 integrase inhibitor, were studied in healthy male subjects following single oral administration of [(14)C]dolutegravir at a dose of 20 mg (80 µCi). Dolutegravir was well tolerated, and absorption of dolutegravir from the suspension formulation was rapid (median time to peak concentration, 0.5 h), declining in a biphasic fashion. Dolutegravir and the radioactivity had similar terminal plasma half-lives (t1/2) (15.6 versus 15.7 h), indicating metabolism was formation rate limited with no long-lived metabolites. Only minimal association with blood cellular components was noted with systemic radioactivity. Recovery was essentially complete (mean, 95.6%), with 64.0% and 31.6% of the dose recovered in feces and urine, respectively. Unchanged dolutegravir was the predominant circulating radioactive component in plasma and was consistent with minimal presystemic clearance. Dolutegravir was extensively metabolized. An inactive ether glucuronide, formed primarily via UGT1A1, was the principal biotransformation product at 18.9% of the dose excreted in urine and the principal metabolite in plasma. Two minor biotransformation pathways were oxidation by CYP3A4 (7.9% of the dose) and an oxidative defluorination and glutathione substitution (1.8% of the dose). No disproportionate human metabolites were observed.

A phase 1 study to evaluate the effect of dolutegravir on renal function via measurement of iohexol and para-aminohippurate clearance in healthy subjects.

AIM: Dolutegravir (DTG; S/GSK1349572) is under clinical development as a once daily, unboosted integrase inhibitor for the treatment of HIV infection. The effect of DTG on glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and creatinine clearance (CLcr ) was evaluated in 34 healthy volunteers. METHODS: Subjects received DTG 50 mg (once daily or twice daily) or placebo for 14 days. GFR was measured by iohexol plasma clearance, ERPF was assessed by para-aminohippurate plasma clearance and CLcr was measured by 24 h urine collection. RESULTS: All treatments were generally well tolerated. A modest decrease (10-14%) in CLcr was observed, consistent with clinical study observations. DTG 50 mg once daily and twice daily had no significant effect on GFR or ERPF compared with placebo over 14 days in healthy subjects. CONCLUSIONS: These findings support in vitro data that DTG increases serum creatinine by the benign inhibition of the organic cation transporter 2, which is responsible for tubular secretion of creatinine.

Effect of food on the pharmacokinetics of the integrase inhibitor dolutegravir.

Healthy subjects received dolutegravir at 50 mg in a single-dose crossover study while they were in the fasted state or with low-, moderate-, or high-fat meals. Food increased dolutegravir exposure and reduced the rate of absorption. The area under the concentration-time curve from 0 h to infinity (AUC(0-∞)) increased by 33%, 41%, and 66% when administered with low-, moderate-, or high-fat meals, respectively, compared with fasting. This increase in dolutegravir exposure is not anticipated to impact clinical safety, and therefore dolutegravir can be taken with or without food and without regard to fat content.

Tapinarof Cream 1% for Extensive Plaque Psoriasis: A Maximal Use Trial on Safety, Tolerability, and Pharmacokinetics.

BACKGROUND: Tapinarof is a novel topical therapeutic aryl hydrocarbon receptor modulating agent in development for the treatment of psoriasis and atopic dermatitis. OBJECTIVE: This multicenter, open-label trial assessed the safety, tolerability, pharmacokinetics (PK), and efficacy of tapinarof cream 1% once daily (QD) under maximal use conditions in extensive plaque psoriasis. METHODS: Adults with a baseline Physician Global Assessment (PGA) score of ≥ 3 and body surface area (BSA) involvement ≥ 20% received tapinarof cream 1% QD for 29 days. Safety and tolerability assessments included adverse events (AEs) and local tolerability scales. PK parameters were calculated using non-compartmental analysis. Efficacy assessments included change in PGA, Psoriasis Area and Severity Index score, and %BSA affected. RESULTS: Twenty-one patients were enrolled. Common AEs were folliculitis, headache, back pain, and pruritus (none led to discontinuation). Tapinarof plasma exposure was low, with the majority of concentrations being below detectable limits. At day 29, 14 patients (73.7%) had a ≥ 1-grade improvement in PGA score and six patients (31.6%) had a ≥ 2-grade improvement; four patients (21.1%) achieved treatment success (PGA 0 or 1 and ≥ 2-grade improvement). CONCLUSION: Tapinarof cream 1% QD was well tolerated, with limited systemic exposure and significant efficacy at 4 weeks in patients with extensive plaque psoriasis. ClinicalTrials.gov Identifier NCT04042103.

Effects of etravirine alone and with ritonavir-boosted protease inhibitors on the pharmacokinetics of dolutegravir.

Dolutegravir (DTG) is an unboosted, once-daily integrase inhibitor currently in phase 3 trials. Two studies evaluated the effects of etravirine (ETR) alone and in combination with ritonavir (RTV)-boosted protease inhibitors (PIs) on DTG pharmacokinetics (PK) in healthy subjects. DTG 50 mg every 24 h (q24h) was administered alone for 5 days in period 1, followed by combination with ETR at 200 mg q12h for 14 days in period 2 (study 1) or with ETR/lopinavir (LPV)/RTV at 200/400/100 mg q12h or ETR/darunavir (DRV)/RTV at 200/600/100 mg q12h for 14 days in period 2 (study 2). PK samples were collected on day 5 in period 1 and day 14 in period 2. All of the treatments were well tolerated. ETR significantly decreased exposures of DTG, with geometric mean ratios of 0.294 (90% confidence intervals, 0.257 to 0.337) for the area under the curve from time zero until the end of the dosage interval (AUC(0-τ)), 0.484 (0.433 to 0.542) for the observed maximum plasma concentration (C(max)), and 0.121 (0.093 to 0.157) for the plasma concentration at the end of the dosage interval (C(τ)). ETR combined with an RTV-boosted PI affected the exposure of DTG to a lesser degree: ETR/LPV/RTV treatment had no effect on the DTG plasma AUC(0-τ) and C(max), whereas the C(τ) increased by 28%. ETR/DRV/RTV modestly decreased the plasma DTG AUC(0-τ), C(max), and C(τ) by 25, 12, and 37%, respectively. Such effects of ETR/LPV/RTV and ETR/DRV/RTV are not considered clinically relevant. The combination of DTG and ETR alone should be avoided; however, DTG may be coadministered with ETR without a dosage adjustment if LPV/RTV or DRV/RTV is concurrently administered.