Lack of pharmacokinetic interaction between the HIV-1 maturation inhibitor GSK3640254 and combination oral contraceptives in healthy women

Drug-drug interactions between antiretrovirals and hormonal contraception: An updated systematic review

OBJECTIVE

To summarize and update information regarding drug-drug interactions (DDIs) between antiretrovirals (ARVs) and hormonal contraceptives (HCs).

STUDY DESIGN

Systematic review.

RESULTS

We included 49 articles, with clinical, ARV, or HC PK outcomes reported by 39, 25, and 30 articles, respectively, with some articles reporting outcomes in two or more categories. Fifteen of 18 articles assessing DDIs between efavirenz and progestin implants, emergency contraception, or combined hormonal intravaginal rings found higher pregnancy rates, luteal progesterone levels suggesting ovulation, or reduced progestin PK values. Five studies documented that CYP2B6 single nucleotide polymorphisms exacerbated this DDI. One cohort detected doubled bone density loss with concomitant depot medroxyprogesterone acetate (DMPA) and tenofovir disoproxil fumarate (TDF)-containing ART use versus TDF alone. No other studies described DDIs impacting clinical outcomes. Few adverse events were attributed to ARV-HC use with none exceeding Grade 2. Evidence quality was generally moderate, with dis-similar treatment and control groups, identifying and controlling for confounding, and minimizing attrition bias in the study design being the most frequent limitations.

CONCLUSION

TDF-DMPA DDIs warrant longer-term study on bone health and consideration of alternate combinations. For efavirenz-based ART, client counseling on relative risks, including both potential increase in pregnancy rate with concomitant efavirenz and implant use and lower pregnancy rates compared to other HCs even with concomitant efavirenz use, should continue to allow users comprehensive method choice.

IMPLICATIONS

Most ARVs and HCs may be used safely and effectively together. Efavirenz-based ART requires careful counseling and data for possible interactions between HCs and new ARV classes are anticipated.

Pharmacokinetics and tolerability of the maturation inhibitor GSK3640254 coadministered with darunavir/ritonavir and/or etravirine in healthy adults

AIMS

This phase I study investigated potential drug-drug interactions of the maturation inhibitor GSK3640254 (GSK'254) with darunavir/ritonavir (DRV/RTV) and/or etravirine (ETR).

METHODS

In this randomized, open-label, single-sequence, multiple-dose study, healthy participants received GSK'254 200 mg once daily alone or coadministered with DRV/RTV 600/100 mg twice daily (BID; n = 19), ETR 200 mg BID (n = 19) or DRV/RTV 600/100 mg + ETR 200 mg BID (n = 16) under fed conditions. Primary endpoints were steady-state area under the plasma concentration-time curve from time 0 to the end of the dosing interval (AUC0-τ ) and maximum observed concentration (Cmax ). Secondary endpoints included trough concentration (Cτ ), safety and tolerability. Pharmacokinetic parameters were calculated using standard noncompartmental analysis, and geometric least-squares mean ratios were derived from linear mixed-effects models.

RESULTS

GSK'254 AUC0-τ (geometric least-squares mean ratio [90% confidence interval], 1.14 [1.00-1.29]), Cmax (1.07 [0.92-1.24]) and Cτ (1.17 [1.01-1.35]) were similar when administered alone and with DRV/RTV. Etravirine coadministration decreased GSK'254 AUC0-τ (0.53 [0.48-0.59]), Cmax (0.60 [0.53-0.68]) and Cτ (0.51 [0.39-0.66]). Similar reductions were not observed with GSK'254 + DRV/RTV + ETR (AUC0-τ , 0.94 [0.82-1.09]; Cmax , 0.89 [0.75-1.07]; Cτ , 1.02 [0.89-1.18]). GSK'254 had no meaningful effect on DRV/RTV or ETR concentrations. All reported adverse events (AEs) were grade 1; 3 led to withdrawal and resolved (rash, asymptomatic electrocardiogram T-wave inversion, periorbital oedema). Most common AEs were diarrhoea (n = 9) and headache (n = 7). No deaths or serious AEs occurred.

CONCLUSION

GSK'254 pharmacokinetics was not meaningfully affected by DRV/RTV or DRV/RTV + ETR, but were reduced with only ETR; no new tolerability concerns were observed.

Effects of the HIV-1 maturation inhibitor GSK3640254 on QT interval in healthy participants

GSK3640254 (GSK'254) is a novel HIV-1 maturation inhibitor with pharmacokinetics supporting once-daily (QD) therapy for HIV-1 treatment. This thorough QT/corrected QT (QTc) study evaluated the effect of GSK'254 on cardiac repolarization. In this two-part, randomized study, healthy participants received GSK'254 or placebo QD for 7 days (part 1) to determine safety and pharmacokinetics of a 500-mg supratherapeutic dose. Four sequential treatment periods composed the main QTc study (part 2): GSK'254 100 mg, GSK'254 500 mg, placebo QD for 7 days, or placebo QD for 6 days with a 400-mg moxifloxacin dose on Day 7 (all with a moderate-fat meal). Concentration-QTc analyses modeled the relationship between GSK'254 plasma concentrations and placebo-adjusted change from baseline in QT interval corrected with Fridericia's formula (ΔΔQTcF). Of 50 participants enrolled, 48 completed the study (part 1, 8/8; part 2, 40/42). Least-squares (LS) mean change from baseline in QTcF for GSK'254 100 mg followed the placebo pattern across time points (maximum LS mean ΔΔQTcF, 1.7 ms); the upper bound of the 90% CI remained <10 ms. Maximum LS mean ΔΔQTcF for GSK'254 500 mg exceeded the 10-ms threshold: 10.6 ms (90% CI 7.75-13.38). Neither GSK'254 dose had clinically relevant effects on heart rate or cardiac conduction. By concentration-QTc analysis, no effect on ΔΔQTcF >10 ms is expected up to GSK'254 concentrations of ~3070 ng mL-1 . No clinically relevant effects on cardiac parameters were seen in healthy participants with GSK'254 at the 100-mg dose.

Open-label, drug-drug interaction study between the HIV-1 maturation inhibitor GSK3640254 and a metabolic probe cocktail in healthy participants

AIMS

GSK3640254 (GSK'254) is an HIV-1 maturation inhibitor with pharmacokinetics (PK) supporting once-daily dosing. GSK'254 will be co-administered with cytochrome P450 enzyme substrates and drug transporters, including other antiretrovirals, in people living with HIV-1 (PLWH).

METHODS

In this open-label study, healthy participants received a single dose of a cocktail of eight cytochrome P450 and transporter probe substrates on Day 1, followed by a 10-day washout before receiving GSK'254 200 mg once daily from Days 11 to 20 and a single dose of cocktail + GSK'254 200 mg on Day 21. Geometric least-squares mean ratios and 90% confidence intervals were obtained using linear mixed-effects models. Adverse events (AEs) were monitored.

RESULTS

Of 20 participants enrolled, 19 completed the study. Plasma concentrations of all cocktail substrates were generally similar with or without GSK'254 co-administration. All 90% confidence intervals around geometric least-squares mean ratios for cocktail substrate PK parameters indicated no to weak interactions. Steady-state plasma GSK'254 concentrations were achieved by Day 17 and maintained through Day 21. Nine participants (45%) reported 17 AEs; most (88%) were grade 1. Two grade 2 treatment-related AEs (maculopapular rash [leading to withdrawal] and papular rash) were reported during GSK'254 administration alone.

CONCLUSIONS

Co-administration of GSK'254 with a metabolic probe cocktail in healthy participants indicated very low risk of clinically relevant effect on PK of any substrates or associated metabolites. No new safety/tolerability concerns were identified. These results support ongoing phase IIb and planned phase III studies of GSK'254 in people living with HIV-1.

Relative Bioavailability and Food Effect of GSK3640254 Tablet and Capsule Formulations in Healthy Participants

GSK3640254 is a next‐generation maturation inhibitor with demonstrated potency across HIV‐1 subtypes and a high barrier to emergent resistance. This phase I, 2‐part, randomized, open‐label study (ClinicalTrials.gov identifier, NCT04263142) in healthy participants assessed the relative bioavailability of a single dose of GSK3640254 200 mg in tablet and capsule formulations (part 1) and the effect of food on the pharmacokinetic profile of the tablet formulation (part 2). Overall, 39 participants were randomized to treatment (part 1, n = 18; part 2, n = 21). All participants in part 1 completed the study; 2 participants in part 2 withdrew before study completion (adverse event, n = 1; physician decision, n = 1). In part 1, plasma exposures of the GSK3640254 tablet formulation were not meaningfully different from those of the capsule formulation when administered in the presence of a moderate‐fat meal. In part 2, GSK3640254 plasma exposures increased by ≈3‐ to 4‐fold under high‐ and moderate‐fat conditions, respectively, compared with fasted conditions. No major safety or tolerability findings were observed. The highest incidence of adverse events (24%) was reported under high‐fat conditions. Taken together, these data support the use of the tablet formulation coadministered with food in the clinical development of GSK3640254 for treatment of HIV‐1.