Clinical Pharmacokinetics of the Novel HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitor Doravirine: An Assessment of the Effect of Patient Characteristics and Drug-Drug Interactions

In Silico Pharmacokinetics Evaluation of Forgiveness for Doravirine and Rilpivirine

BACKGROUND

This study aimed to evaluate the concentrations of rilpivirine (RLP) and doravirine (DOR) after 3 days-off using simulations from population pharmacokinetics models.

METHODS

The authors conducted a series of 500 sets of 10,000 Monte Carlo simulations to examine the steady-state conditions for 2 common dosage levels: 25 mg/d for RLP and 100 mg/d for DOR. These simulations were conducted under 2 scenarios: 1 without drug cessation and another after a 3-day break. The validity of the implementation was established through a comparison of median trough concentrations (C24h) with previously reported data. Subsequently, the proportion of simulated patients with C24h and C72h after 3 days-off (C72h/3do) that exceeded the inhibitory concentration 50 (IC50), 5.2 mcg/L for DOR and 20.5 mcg/L for RLP respectively, was calculated. The inhibitory quotient (IQ) was also computed, which was 6 times IC50 for DOR and 4.5 times IC50 for RLP. Finally, nomograms were constructed to estimate the probability of having C72h/3do > IC50 or > IQ for different ranges of C24h.

RESULTS

Simulated C24h median ± SD for RLP were 61.8 ± 0.4 mcg/L and for DOR 397 ± 0 mcg/L. For RLP, 99.3 ± 0.1% exceeded IC50 at C24h, 16.4 ± 0.4% at C72h/3do, and none surpassed the IQ threshold. In contrast, DOR had 100% ± 0% above IC50 at C24h, 93.6 ± 0.2% at C72h/3do, and 58.6 ± 0.5% exceeded the IQ.

CONCLUSIONS

These findings suggest that treatment with DOR may offer a more forgiving therapeutic profile than RLP, given the larger proportion of patients achieving effective drug exposure with DOR. However, it is important to acknowledge a significant limitation of this study, namely, the assumption that drug concentration is a perfect surrogate for drug effectiveness.

Switch to fixed-dose doravirine (100 mg) with islatravir (0·75 mg) once daily in virologically suppressed adults with HIV-1 on antiretroviral therapy: 48-week results of a phase 3, randomised, open-label, non-inferiority trial

BACKGROUND

Doravirine and islatravir is an investigational, once-daily, single-tablet regimen with high antiviral potency, favourable safety and tolerability, and low propensity for resistance. We report week 48 results from a phase 3 trial evaluating switch from stable, oral antiretroviral therapy (ART) to the fixed combination of doravirine (100 mg) and islatravir (0·75 mg).

METHODS

This phase 3, multicentre, randomised, active-controlled, open-label, non-inferiority trial was conducted at 77 research, community, and hospital-based clinics in 15 countries. Adults aged 18 years or older with fewer than 50 HIV-1 RNA copies per mL on any oral, two-drug or three-drug ART regimen for at least 3 months, and no history of previous virological failure on any past or current regimen were randomly assigned (1:1) by a computer-generated randomisation schedule to switch to doravirine (100 mg) and islatravir (0·75 mg) or to continue their baseline ART regimen. Block randomisation was based on a block size of four, and randomisation was stratified by baseline regimen (ie, protease inhibitor, integrase inhibitor, or other). Participants in the doravirine and islatravir group were instructed to take one tablet at approximately the same time each day, and participants in the baseline ART group continued to take the medication according to the locally approved label. HIV-1 RNA and safety evaluations were done at baseline and weeks 4, 12, 24, 36, and 48. CD4 cell counts were measured at baseline, week 24, and week 48. The primary endpoint was proportion of participants with greater than or equal to 50 HIV-1 RNA copies per mL at week 48 in the full analysis set (ie, all participants who received at least one dose of study drug) using the US Food and Drug Administration snapshot approach and prespecified non-inferiority margin of 4%. This study is registered with ClinicalTrials.gov (NCT04223778) and is completed.

FINDINGS

Between Feb 18 and Oct 2, 2020, 740 individuals were screened for eligibility, of whom 672 (90·8%) participants (249 [37·1%] women and 423 [62·9%] men; median CD4 count of 678 cells per μL [IQR 496-868]) were randomly assigned to doravirine (100 mg) and islatravir (0·75 mg; n=336) or to continue baseline ART (n=336). The last follow-up visit occurred on Sept 8, 2021. At week 48, zero of 336 participants in the doravirine and islatravir group versus five (1·5%) of 336 participants in the baseline ART group had greater than or equal to 50 HIV-1 RNA copies per mL (difference -1·5, 95% CI -3·4 to -0·3). The per-protocol analysis showed consistent results. Headache was the most common adverse event in both groups (35 [10·4%] of 336 participants in the doravirine and islatravir group, 16 [4·8%] of 336 in the baseline ART group), infection rates were similar (113 [33·6%] in both groups), and discontinuations due to adverse events were low (seven [2·1%] vs one [0·3%]). 66 (19·6%) of 336 participants had treatment-related adverse events in the doravirine and islatravir group compared with 30 (8·9%) of 336 in the baseline ART group. In the islatravir and doravirine group, CD4 cell counts (mean change -30·3 cells per μL) and total lymphocyte counts (mean change -0·26 × 109/L) were decreased at 48 weeks.

INTERPRETATION

Switching to single-tablet doravirine (100 mg) and islatravir (0·75 mg) maintained viral suppression up to week 48 and was non-inferior to antiretroviral combinations used in clinical practice for adults with HIV-1; however, decreases in CD4 cell and total lymphocyte counts do not support further development of once-daily doravirine (100 mg) and islatravir (0·75 mg).

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co.

Efficacy, Safety, and Tolerability of Doravirine/Lamivudine/Tenofovir Disoproxil Fumarate Fixed-Dose Combination Tablets in Adolescents Living With HIV: Results Through Week 96 from IMPAACT 2014

BACKGROUND

IMPAACT 2014 study is a phase I/II, multicenter, open-label, nonrandomized study of doravirine (DOR) co-formulated with lamivudine (3TC) and tenofovir disoproxil fumarate (TDF) as fixed-dose combination (DOR FDC) in adolescents with HIV-1. We report the efficacy, safety, and tolerability of DOR FDC through 96 weeks.

METHODS

Participants were adolescents aged 12 to <18 years who weighed at least 45 kg and who were either antiretroviral (ARV)-naïve or virologically suppressed without documented resistance mutations to DOR/3TC/TDF. The efficacy endpoint was the proportion of participants with HIV-1 RNA <40 copies/mL assessed at weeks 48 and 96 using the observed failure approach. Safety and tolerability outcomes were incidence of adverse events (AEs) and treatment discontinuations.

RESULTS

A total of 45 adolescents, median age 15 (range, 12-17) years, 58% females, were enrolled and 2 (4.4%) participants were ARV naïve. Of the 45 participants, 42 (93.3%) completed the study and 41 (91.1%) completed the study treatment. At week 48, 41/42 (97.6%; 95% confidence interval [CI], 87.4-99.9) and week 96, 37/40 (92.5%; 95% CI, 79.6-98.4) participants had achieved or maintained HIV-1 RNA <40 copies/mL. There were no treatment-related discontinuations due to AEs and no drug-related AEs ≥grade 3 or deaths.

CONCLUSIONS

We found once-daily dosing of DOR FDC to be safe and well tolerated for maintaining viral suppression through 96 weeks in adolescents living with HIV-1.

Microphysiological model reveals the promise of memory-like natural killer cell immunotherapy for HIV± cancer

Numerous studies are exploring the use of cell adoptive therapies to treat hematological malignancies as well as solid tumors. However, there are numerous factors that dampen the immune response, including viruses like human immunodeficiency virus. In this study, we leverage human-derived microphysiological models to reverse-engineer the HIV-immune system interaction and evaluate the potential of memory-like natural killer cells for HIV+ head and neck cancer, one of the most common tumors in patients living with human immunodeficiency virus. Here, we evaluate multiple aspects of the memory-like natural killer cell response in human-derived bioengineered environments, including immune cell extravasation, tumor penetration, tumor killing, T cell dependence, virus suppression, and compatibility with retroviral medication. Overall, these results suggest that memory-like natural killer cells are capable of operating without T cell assistance and could simultaneously destroy head and neck cancer cells as well as reduce viral latency.

Clinical Relevance of Drug Interactions in People Living with Human Immunodeficiency Virus on Antiretroviral Therapy-Update 2022: Systematic Review

BACKGROUND

The clinical outcomes of antiretroviral drugs may be modified through drug interactions; thus, it is important to update the drug interactions in people living with HIV (PLHIV).

AIM

To update clinically relevant drug interactions in PLHIV on antiretroviral therapy with novel drug interactions published from 2017 to 2022.

METHODS

A systematic review in Medline/PubMed database from July 2017 to December 2022 using the Mesh terms antiretroviral agents and drug interactions or herb-drug interactions or food-drug interactions. Publications with drug interactions in humans, in English or Spanish, and with full-text access were retrieved. The clinical relevance of drug interactions was grouped into five levels according to the gravity and probability of occurrence.

RESULTS

A total of 366 articles were identified, with 219 (including 87 citation lists) were included, which allowed for the identification of 471 drug interaction pairs; among them, 291 were systematically reported for the first time. In total 42 (14.4%) and 137 (47.1%) were level one and two, respectively, and 233 (80.1%) pairs were explained with the pharmacokinetic mechanism. Among these 291 pairs, protease inhibitors (PIs) and ritonavir/cobicistat-boosted PIs, as well as integrase strand transfer inhibitors (InSTIs), with 70 (24.1%) and 65 (22.3%) drug interaction pairs of levels one and two, respectively, were more frequent.

CONCLUSIONS

In PLHIV on antiretroviral therapy, we identify 291 drug interaction pairs systematically reported for the first time, with 179 (61.5%) being assessed as clinically relevant (levels one and two). The pharmacokinetic mechanism was the most frequently identified. PIs, ritonavir/cobicistat-boosted PIs, and InSTIs were the antiretroviral groups with the highest number of clinically relevant drug interaction pairs (levels one and two).

Synthesis and Biological Evaluation of Benzothiazolyl-pyridine Hybrids as New Antiviral Agents against H5N1 Bird Flu and SARS-COV-2 Viruses

A novel series of benzothiazolyl-pyridine hybrids 8a-h and 14a-e were produced from the reaction of enamine derivative 4 with each of the arylcyanoacetamides 5a-h and cyanoacetohydrazides 9a-e. The new products were characterized by spectral techniques (IR, 1H NMR, 13C NMR, and MS). Biological evaluation of 8a-h and 14a-e in vitro against H5N1 and SARS-COV-2 viruses showed that several compounds had significant activity. Compounds 8f-h, which contain fluorine atoms, have better activity against H5N1 and anti-SARS-CoV-2 viruses than the other compounds included in this study. Compound 8h has a trifluoromethyl group at position-3 of the phenyl ring and exhibits a high activity against H5N1 virus with 93 and 60% inhibition at concentrations of 0.5 and 0.25 μmol/μL, respectively, among the tested compounds, and it also showed anti-SARS-CoV-2 virus with a half-maximum inhibition rate of 3.669 μM, among the remaining compounds. The mechanism of action of 8f-h, which is expected to be repurposed against COVID-19, was investigated. The results showed that the compounds have virucidal effects at different stages of the three mechanisms of action. Furthermore, compounds 8f-h were found to possess CoV-3CL protease inhibitory activities with IC50 values of 544.6, 868.2, and 240.6 μg/mL, respectively, compared to IC50 = 129.8 μg/mL of the standard drug lopinavir. Interestingly, compounds 8f-h also showed high inhibitory activity against the H5N1 virus as well as the SARS-CoV-2 virus. Moreover, compounds 8f-h fit admirably into the active site of the SARS-CoV-2 main protease (PDB ID: 6LU7) using the molecular docking Moe software 2015.10.

Diffuse Large B-Cell Lymphoma in the HIV Setting

Despite the widespread use of combined antiretroviral therapy (cART) and the subsequent decrease in AIDS-defining cancers, HIV-related lymphomas remain a leading cause of morbidity and mortality in people with HIV (PWH). Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL) subtype in PWH. This lymphoma is a heterogeneous disease including morphological variants and molecular subtypes according to the cell of origin or the mutation profile. In the pre-cART era, treatment with standard-dose chemotherapy induced high rates of toxicity and outcomes were very poor. The introduction of cART and the incorporation of infection prophylaxis allowed the use of conventional intensive chemotherapy regimens used in the general population, such as R-CHOP or R-EPOCH. The use of cART during chemotherapy treatment was initially controversial due to the potential risk of adverse drug-drug interactions. However, the availability of current cART regimens with less potential to cause drug interactions and evidence that cART improves survival rates in NHL strongly support the use of cART in PWH with DLBCL. Consequently, interdisciplinary collaboration between HIV specialists and hemato-oncologists for the management of potential interactions and overlapping toxicities between antiretroviral and antineoplastic drugs is crucial for the optimal treatment of PWH with NHL.

Pharmacokinetics, Tolerability, and Safety of Doravirine and Doravirine/Lamivudine/Tenofovir Disoproxil Fumarate Fixed-Dose Combination Tablets in Adolescents Living With HIV: Week 24 Results From IMPAACT 2014

BACKGROUND

We studied the pharmacokinetics (PK) and safety of 100-mg doravirine and doravirine/lamivudine/tenofovir disoproxil fumarate fixed-dose combination (100/300/300 mg DOR FDC) treatment in adolescents with HIV-1.

METHODS

Adolescents ages 12 to younger than 18 years were enrolled in 2 sequential cohorts. Cohort 1 evaluated intensive PK and short-term safety of 100-mg single-dose doravirine in adolescents ≥35 kg. Cohort 2 participants either initiated treatment with DOR FDC (antiretroviral (ARV)-naïve) or switched to DOR FDC from a previous ARV regimen (virologically suppressed). The first 10 Cohort 2 participants had intensive PK evaluations, and safety, sparse PK, and HIV RNA were assessed through week 24.

RESULTS

Fifty-five adolescents, median age 15.0 years and baseline weight 51.5 kg, were enrolled. Nine participants completed Cohort 1 PK assessments (8 of the 9 participants weighed ≥45 kg) and 45 initiated study drug in Cohort 2. The doravirine geometric mean (GM) AUC 0-∞ was 34.8 μM∙hour, and the GM C 24 was 514 nM after a single dose, with a predicted steady-state GM C 24,ss,pred of 690 nM. Cohort 2 enrolled adolescents weighing ≥45 kg. Plasma concentrations of doravirine, tenofovir, and lamivudine achieved by Cohort 2 participants were similar to those reported in adults. No drug-related serious or grade 3 or 4 adverse events occurred. Forty-two of 45 participants (93.3%; 95% CI: [81.7, 98.6]) achieved or maintained HIV-1 RNA <40 copies/mL.

CONCLUSIONS

Doravirine and DOR FDC achieved target PK in adolescents with HIV-1. DOR FDC was well-tolerated and maintained excellent virologic efficacy through 24 weeks, offering a favorable option for adolescents.

Evaluation of drug-drug interaction between rilpivirine and rifapentine using PBPK modelling

Tuberculosis remains the leading cause of death among people living with HIV. Rifapentine is increasingly used to treat active disease or prevent reactivation, in both cases given either as weekly or daily therapy. However, rifapentine is an inducer of CYP3A4, potentially interacting with antiretrovirals like rilpivirine. This in silico study investigates the drug-drug interaction (DDI) magnitude between daily oral rilpivirine 25 mg with either daily 600 mg or weekly 900 mg rifapentine. A physiologically based pharmacokinetic (PBPK) model was built in Simbiology (Matlab R2018a) to simulate the drug-drug interaction. The simulated PK parameters from the PBPK model were verified against reported clinical data for rilpivirine and rifapentine separately, daily rifapentine with midazolam, and weekly rifapentine with doravirine. The simulations of concomitant administration of rifapentine with rilpivirine at steady-state lead to a maximum decrease on AUC_0-24 and C_trough by 83% and 92% on day 5 for the daily rifapentine regimen and 68% and 92% for the weekly regimen on day 3. In the weekly regimen, prior to the following dose, AUC_0-24 and C_trough were still reduced by 47% and 53%. In both simulations, the induction effect ceased 2 weeks after the interruption of rifapentine's treatment. A daily double dose of rilpivirine after initiating rifapentine 900 mg weekly was simulated but failed to compensate the drug-drug interaction. The drug-drug interaction model suggested a significant decrease on rilpivirine exposure which is unlikely to be corrected by dose increment, thus coadministration should be avoided.

Doravirine: its role in HIV treatment

PURPOSE OF REVIEW

We reviewed evidence concerning the novel nonnucleoside reverse transcriptase inhibitor doravirine, aiming to identify situations where it may be selected in preference to integrase inhibitors.

RECENT FINDINGS

Doravirine is licenced for the treatment of HIV-1 in North America and Europe. In two multicentre randomized controlled trials, noninferiority with comparator drugs efavirenz and darunavir/ritonavir was observed at 96 weeks. Doravirine is associated with a lower incidence of neuropsychiatric side effects relative to efavirenz, and favourable lipid changes relative to darunavir over 96 weeks. A lower incidence of weight gain, relative to indirect comparisons with integrase inhibitors, was observed. Doravirine has a high genetic barrier to resistance with retained activity in the presence of single NNRTI mutations K103N, Y181C and G190A. Primary drug resistance is infrequent and may be higher in South Africa relative to European populations. Doravirine may be used in renal or hepatic impairment and has a low potential for drug-drug interactions.

SUMMARY

Doravirine is a well tolerated and effective agent in ART-naive patients. Direct comparison with integrase inhibitors, and evidence on the outcomes of treatment with doravirine in the presence of prior NNRTI experience are required to better elucidate which patients will benefit most from doravirine therapy.

Pharmacokinetic interactions of modern antiretroviral therapy

Drug--drug interactions (DDIs) have been a clinical challenge in HIV medicine for over two decades. The newer antiretroviral drugs (ARTs) have significantly fewer DDIs than protease inhibitors and boosted integrase inhibitors (INSTIs). The lower propensity of such newer antiretrovirals (e.g. unboosted integrase inhibitors; doravirine) to cause DDIs, has been largely offset by the ageing cohort of patients with multiple comorbidities, who are taking multiple chronic medicines. Furthermore, the introduction of newly marketed drugs into clinical practice needs to be closely monitored, as the new drugs may be perpetrators of DDIs, leading to a potential change in the efficacy or toxicity of the coadministered antiretrovirals.

Low prevalence of doravirine-associated resistance mutations among polish human immunodeficiency-1 (HIV-1)–infected patients

Introduction

Doravirine (DOR) is a novel non-nucleoside reverse transcriptase inhibitor (NNRTI) that retains activity against common NNRTI resistance mutations. In this study, we aimed to investigate the prevalence of DOR resistance mutations compared with that of resistance mutations for other NNRTIs among HIV-1-infected treatment‐experienced and -naïve patients from Poland.

Methods

Resistance to DOR and other NNRTIs was assessed in two datasets: 1760 antiretroviral treatment-naïve HIV-1 patients and 200 treatment‐experienced patients. All 1960 sequences were derived from the patients using bulk sequencing. For resistance analyses, Stanford HIV drug resistance database scores were used.

Results

Overall, DOR resistance was present in 32 patients (1.62%), of whom 13 (0.74%) were naïve and 19 (9.50%) were treatment-experienced. The most common DOR resistance mutations observed among the naïve patients were A98G and K101E (0.2% each), and those among cART-experienced patients were L100I (2.0%), K101E, V108I, H221Y, and P225H (1.5% each). Furthermore, among the naïve patients, less common resistance to DOR (0.7%) compared with that to nevirapine (NVP) (2.1%; p = 0.0013) and rilpivirine (5.40%; p < 0.0001) was observed. For sequences obtained from treatment-experienced patients, the frequency of resistance to DOR (9.5%) was lower than that for efavirenz (25.5%; p < 0.0001) and NVP (26.0%; p < 0.0001).

Conclusions

The frequency of transmitted drug resistance to DOR is low, allowing for effective treatment of antiretroviral treatment-naïve patients and rapid treatment initiation. In cART-experienced patients, this agent remains an attractive NNRTI option with a higher genetic barrier to resistance.

Hodgkin Lymphoma in People Living with HIV

Simple Summary

Hodgkin lymphoma (HL) is a non-AIDS defining neoplasm, but people living with HIV (PLWH) have between a 5- and 26-fold higher risk of developing it than the general population. Epstein-Barr virus is present in almost all HIV-related HL cases, and plays an important role in its etiopathogenesis. Despite the aggressive characteristics, the prognosis of HL affecting PLWH is similar to that of the general population if patients are treated following the same recommendations. Administration of cART concomitantly with chemotherapy is highly recommended. However, this combination may be challenging due to drug–drug interactions and overlapping toxicity. Thus, interdisciplinary collaboration between hemato-oncologists and HIV specialists is crucial for the optimal treatment of both lymphoma and HIV infection.

Abstract

Despite widespread use of combined antiretroviral therapy (cART) and increased life expectancy in people living with HIV (PLWH), HIV-related lymphomas (HRL) remain a leading cause of cancer morbidity and mortality for PLWH, even in patients optimally treated with cART. While the incidence of aggressive forms of non-Hodgkin lymphoma decreased after the advent of cART, incidence of Hodgkin lymphoma (HL) has increased among PLWH in recent decades. The coinfection of Epstein–Barr virus plays a crucial role in the pathogenesis of HL in the HIV setting. Currently, PLWH with HRL, including HL, are treated similarly to HIV-negative patients and, importantly, the prognosis of HL in PLWH is approaching that of the general population. In this regard, effective cART during chemotherapy is strongly recommended since it has been shown to improve survival rates in all lymphoma subtypes, including HL. As a consequence, interdisciplinary collaboration between HIV specialists and hemato-oncologists for the management of potential drug–drug interactions and overlapping toxicities between antiretroviral and antineoplastic drugs is crucial for the optimal treatment of PLWH with HL. In this article the authors review and update the epidemiological, clinical and biological aspects of HL presenting in PLWH with special emphasis on advances in prognosis and the factors that have contributed to it.

Placental transfer of doravirine, a recent HIV-1 NNRTI in the ex vivo human cotyledon perfusion model

BACKGROUND

The recent HIV-1 NNRTI doravirine is likely to be used in pregnant women despite the complete lack of data on safety and exposure in the fetus. The objective of this study was to determine its placental transfer.

METHODS

Maternal-to-fetal transfer was investigated using the open-circuit ex vivo dually perfused human cotyledon model. Doravirine was added to a maternal perfusate (theoretical doravirine concentration of 250 ng/mL) containing 2 g/L human albumin and 20 g/L antipyrine, a marker to validate the cotyledon's viability, and cotyledons were dually perfused for up to 90 min.

RESULTS

In five experiments, the median (IQR) doravirine concentrations in the maternal and fetal compartments were, respectively, 303 (178-420) and 40 (30-54) ng/mL, the fetal-to-maternal ratio was 16% (12%-18%) and the clearance index (in comparison with antipyrine transfer) was 48% (35%-64%). The median accumulation index in cotyledon tissue was 39% (range 10%-66%).

CONCLUSIONS

Doravirine both crosses and accumulates in the placenta. This may be useful as pre/post-exposure prophylaxis to reduce the risk of vertical HIV transmission but carries the potential for fetal toxicities. Further investigation is required to determine the safety and efficacy of this new antiretroviral agent in pregnancy.

A Phase 1 Study to Evaluate the Drug Interaction Between Islatravir (MK-8591) and Doravirine in Adults Without HIV

BACKGROUND AND OBJECTIVES

Islatravir (MK-8591) is a novel nucleoside analogue in development for the treatment and prevention of HIV-1 infection. Doravirine is a non-nucleoside reverse transcriptase inhibitor indicated for the treatment of HIV-1 infection. This study evaluated the pharmacokinetics, safety, and tolerability of islatravir and doravirine coadministration in a double-blind, placebo-controlled, randomized, fixed-sequence study.

METHODS

Adult participants without HIV infection were administered oral doravirine 100 mg (n = 10) or placebo (n = 4) once daily (QD) for 5 days, immediately followed by oral islatravir 2.25 mg (n = 10) or placebo QD (n = 4) for 14 days; islatravir 2.25 mg and doravirine 100 mg QD, or placebo QD, were then coadministered for 5 days. Pharmacokinetic and safety data were collected.

RESULTS

Doravirine geometric least-squares mean ratios (90% confidence intervals (CIs)) of (doravirine + islatravir)/doravirine for the area under the plasma drug concentration-time curve over 24 h (AUC0-24h), maximum plasma concentration (Cmax), and plasma concentration at 24 h post-dose (C24h) were not meaningfully impacted. Islatravir geometric least-squares mean ratios (90% CI) of (islatravir + doravirine)/islatravir for AUC0-24h and Cmax were both close to unity, 1.06 (1.01, 1.12) and 1.08 (0.91, 1.27), respectively. All study regimens were generally well tolerated.

CONCLUSION

These results indicate that coadministration of islatravir and doravirine had no clinically meaningful effect on the pharmacokinetics of either drug, and support further clinical investigation of islatravir in combination with doravirine for the treatment of HIV-1 infection.