Development and validation of equilibrium dialysis UHPLC-MS/MS measurement procedures for total and unbound concentrations of bictegravir, dolutegravir, darunavir and doravirine in human plasma. Application to patients with HIV

BACKGROUND

Fixed-dose combinations of antiretroviral drugs are commonly used to treat HIV infection and therapeutic monitoring is not part of routine clinical practice. However, drug concentrations monitoring might have role in different clinical scenarios as well as for research purposes. This study aimed to develop and validate UHPLC-MS/MS procedures for measuring total and unbound concentrations of bictegravir, dolutegravir, darunavir and doravirine in human plasma.

MATERIAL AND METHODS

Equilibrium dialysis preceded sample preparation (based on protein precipitation) for measuring unbound antiretroviral concentrations. Chromatographic separations were achieved on an Acquity®-UPLC® HSS™-T3 column (50 mm × 2.1 mm; 1.8 µm) using a non-linear water/acetonitrile gradient containing 0.1 % formic acid at a 0.5 mL/min flow rate. Antiretrovirals were detected by tandem mass spectrometry in positive electrospray ionisation and multiple reaction monitoring modes.

RESULTS

No significant interferences or carry-over were observed. Imprecisions, absolute relative biases, normalised matrix effects and recoveries were ≤15.0 %, ≤11.1 %, (94.7-104.1)% and (96.7-105.5)%, respectively. Non-linear measuring intervals were observed between (25-10,000) µg/L for total/plasma dialysate concentrations and linearity schemes (1.00-100) µg/L for buffer dialysate concentrations.

CONCLUSIONS

The UHPLC-MS/MS procedures developed could be used for research purposes and therapeutic drug monitoring of antiretrovirals in routine clinical practice.

Decay of HIV RNA in Seminal Plasma and Rectal Fluid in Treatment-Naive Adults Starting Antiretroviral Therapy With Dolutegravir Plus Lamivudine or Bictegravir/Emtricitabine/Tenofovir Alafenamide

BACKGROUND

Decay of HIV in seminal plasma (SP) and rectal fluid (RF) has not yet been described for the antiretroviral combination of dolutegravir (DTG) + lamivudine (3TC).

METHODS

In this randomized multicenter pilot trial, males who were antiretroviral naive were randomized (2:1) to DTG + 3TC or bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). HIV-1 RNA was measured in blood plasma (BP), SP, and RF at baseline; days 3, 7, 14, and 28; and weeks 12 and 24.

RESULTS

Of 25 individuals enrolled, 24 completed the study (DTG + 3TC, n = 16; BIC/FTC/TAF, n = 8). No significant differences were observed between groups for median decline in HIV-1 RNA from baseline at each time point or median time to achieve HIV-1 RNA <20 copies/mL in BP and SP and <20 copies/swab in RF. HIV-1 RNA decay patterns were compared in individuals receiving DTG + 3TC. Despite significantly higher percentages for changes from baseline in BP, median (IQR) times to HIV-1 RNA suppression were shorter in SP (7 days; 0-8.75) and RF (10.5 days; 3-17.5) than in BP (28 days; 14-84; P < .001).

CONCLUSIONS

Comparable HIV-1 RNA decay in BP, SP, and RF was observed between DTG + 3TC and BIC/FTC/TAF. As shown with triple-drug integrase inhibitor-based regimens, rapid HIV-1 RNA suppression in SP and RF is achieved with DTG + 3TC, despite decay patterns differing from those of BP.

CLINICAL TRIALS REGISTRATION

EudraCT 2019-004109-28.

Doravirine Concentrations and Human Immunodeficiency Virus Type 1 RNA in the Genital Fluids of Virologically Suppressed Adults Switching to Doravirine Plus Emtricitabine/Tenofovir Alafenamide

Doravirine (DOR) concentrations and HIV-1 RNA were evaluated in genital fluids from adults with HIV on stable therapy who switched to DOR + FTC/TAF. High protein-unbound DOR concentrations were observed in both seminal plasma and cervicovaginal fluid. DOR + FTC/TAF maintained viral suppression in genital fluids in all but 1 participant.

Nothing is perfect: the safety issues of integrase inhibitor regimens

INTRODUCTION

Since the administration of the first integrase strand transfer inhibitor (INSTI) in 2007, most international treatment guidelines consider INSTI-based regimens to be the preferred antiretroviral combinations for HIV-1-infected patients as a result of their safety and efficacy profile. INSTIs are generally well tolerated, and reported rates of discontinuation due to drug-related adverse events (AEs) have been very low to date. However, recent reports indicate that physicians should be aware of potential INSTI-related AEs to ensure good clinical practice.

AREAS COVERED

The authors performed a critical review of the safety issues affecting INSTIs based on published evidence from original studies and new data from researchers.

EXPERT OPINION

Almost all antiretroviral drugs, including INSTIs, are associated with undesirable AEs. Dolutegravir in particular has been associated with more frequent AEs such as neuropsychiatric disorders, neural tube defect in newborns, and weight gain. Data with bictegravir in routine practice are still scarce. While this association and its clinical relevance are not clear, physicians should be alert to the appearance of the aforementioned AEs and others in the future. In the meantime, INSTIs continue to be the preferred option in guidelines on antiretroviral therapy.

Measurement of total and unbound bictegravir concentrations in plasma and cerebrospinal fluid by UHPLC-MS/MS

Bictegravir is a novel integrase strand transfer inhibitor, administrated in co-formulation with tenofovir alafenamide and emtricitabine (Biktarvy®), indicated in the management of HIV-1 infection in patients not previously treated with antiretroviral therapy. Bictegravir is highly bound to plasma proteins, and this significantly determines its clearance, solubility, and activity. These characteristics are crucial determinants of bictegravir penetration into human body compartments, as the central nervous system. We developed and validated UHPLC-MS/MS procedures to measure total and unbound bictegravir concentrations in plasma and cerebrospinal fluid. Simple protein precipitation with acetonitrile was implemented to prepare plasma and cerebrospinal fluid samples. Sample preparation was preceded by ultrafiltration for measuring unbound bictegravir concentrations. Chromatographic separations were achieved on an Acquity® UHPLC® BEH^TM (2.1 × 100 mm id, 1.7 μm) reverse-phase C₁₈ column using an isocratic mobile phase 20:80 (v/v) water/acetonitrile with 0.1% formic. Bictegravir and its internal standard (bictegravir-¹⁵N d₂) were detected by electrospray ionization mass spectrometry in positive and multiple reaction monitoring modes, using transitions of 450.2→289.2/145.4 and 453.2→289.2, respectively. Ultrafiltration procedures presented non-specific bindings of (8.6 ± 1.2) % for bictegravir in plasma and (26.6 ± 3.1) % for bictegravir in cerebrospinal fluid. Linearity was observed between (10.70-8560) μg/L, (1.07-856.0) μg/L for total and unbound bictegravir in plasma, and 0.107-26.75 μg/L for total and unbound bictegravir in cerebrospinal fluid. Imprecisions, absolute relative biases, normalized-matrix factors, and normalized-recoveries were ≤14.4%, ≤13.8%, (97.4-102.5) %, and (99.8-105.1) %, respectively. No significant interferences and carry-over were observed. The validated UHPLC-MS/MS procedures could be useful for pharmacokinetic and pharmacodynamic studies.