Molnupiravir: Mechanism of action, clinical, and translational science.

Molnupiravir is an oral prodrug of the broadly active, antiviral ribonucleoside analog N-hydroxycytidine (NHC). The primary circulating metabolite NHC is taken up into cells and phosphorylated to NHC-triphosphate (NHC-TP). NHC-TP serves as a competitive substrate for viral RNA-dependent RNA polymerase (RdRp), which results in an accumulation of errors in the viral genome, rendering virus replication incompetent. Molnupiravir has demonstrated activity against SARS-CoV-2 both clinically and preclinically and has a high barrier to development of viral resistance. Little to no molnupiravir is observed in plasma due to rapid hydrolysis to NHC. Maximum concentrations of NHC are reached at 1.5 h following administration in a fasted state. The effective half-life of NHC is 3.3 h, reflecting minimal accumulation in the plasma following twice-daily (Q12H) dosing. The terminal half-life of NHC is 20.6 h. NHC-TP exhibits a flatter profile with a lower peak-to-trough ratio compared with NHC, which supports Q12H dosing. Renal and hepatic pathways are not major routes of elimination, as NHC is primarily cleared by metabolism to uridine and cytidine, which then mix with the endogenous nucleotide pools. In a phase III study of nonhospitalized patients with COVID-19 (MOVe-OUT), 5 days of treatment with 800 mg molnupiravir Q12H significantly reduced the incidence of hospitalization or death compared with placebo. Patients treated with molnupiravir also had a greater reduction in SARS-CoV-2 viral load and improved clinical outcomes, compared with those receiving placebo. The clinical effectiveness of molnupiravir has been further demonstrated in several real-world evidence studies. Molnupiravir is currently authorized or approved in more than 25 countries.

Safety and efficacy of doravirine as first-line therapy in adults with HIV-1: week 192 results from the open-label extensions of the DRIVE-FORWARD and DRIVE-AHEAD phase 3 trials.

BACKGROUND: In two phase 3 trials for first-line therapy in adults with HIV-1, doravirine showed non-inferior efficacy, a favourable safety profile, and a superior lipid profile to darunavir and efavirenz through to 48 and 96 weeks. Here we report 192-week results from both studies. METHODS: DRIVE-FORWARD and DRIVE-AHEAD are multicentre, double-blind, randomised, active comparator-controlled, phase 3 trials of first-line antiretroviral treatment in adults with HIV-1. Eligible participants (aged ≥18 years) were naive to antiretroviral therapy, had plasma HIV-1 RNA 1000 copies per mL or more at screening, had no known resistance to any of the trial drugs, and had creatinine clearance 50 mL per min or more. DRIVE-FORWARD was conducted at 125 sites in 15 countries and compared doravirine (100 mg) with ritonavir-boosted darunavir (ritonavir [100 mg] and darunavir [800 mg]), each administered orally once daily with two nucleoside or nucleotide reverse transcriptase inhibitors (tenofovir disoproxil fumarate [300 mg] and emtricitabine [200 mg] or abacavir sulfate [600 mg] and lamivudine [300 mg]). DRIVE-AHEAD was conducted at 126 sites in 23 countries and compared doravirine (100 mg), lamivudine (300 mg), and tenofovir disoproxil fumarate (300 mg) with that of efavirenz (600 mg), emtricitabine (200 mg), and tenofovir disoproxil fumarate (300 mg), all administered orally once daily. DRIVE-FORWARD enrolment was between Dec 1, 2014, and June 1, 2020, and DRIVE-AHEAD enrolment was between June 10, 2015, and Aug 10, 2020. After the 96-week double-blind phase, eligible participants could enter an open-label extension and either continue doravirine or switch from comparator to doravirine for an additional 96 weeks. Efficacy (HIV-1 RNA <50 copies per mL) and safety assessments (adverse events and changes in laboratory parameters) were pooled. The DRIVE-FORWARD and DRIVE-AHEAD trials were registered with ClinicalTrials.gov, NCT02275780 and NCT02403674. FINDINGS: Of 1494 participants treated in the double-blind phase (1261 [84%] male and 233 [16%] female), 550 continued doravirine and 502 switched to doravirine in the extension. Using the FDA snapshot approach, HIV-1 RNA less than 50 copies per mL was maintained in 457 (83%) of 550 participants who continued doravirine and 404 (80%) of 502 participants who switched to doravirine. Protocol-defined virological failure and development of resistance were low, occurring mainly before week 96. Two (<1%) of 550 participants who continued doravirine reported serious drug-related adverse events, and three (1%) who continued doravirine and one (<1%) of 502 who switched to doravirine discontinued due to drug-related adverse events. Participants continuing or switching to doravirine showed generally favourable lipid profiles, little weight gain, and small decreases in estimated glomerular filtration rates, with no discontinuations due to increased creatinine or renal adverse events. INTERPRETATION: Favourable efficacy and safety profiles for doravirine at week 96 were maintained through to week 192 in participants who continued or switched to doravirine, supporting use of doravirine for long-term first-line HIV-1 treatment and for virologically suppressed adults switching therapy. FUNDING: Merck Sharp & Dohme, a subsidiary of Merck & Co, Rahway, NJ, USA.

Efficacy, safety and central nervous system effects after switch from efavirenz/tenofovir/emtricitabine to doravirine/tenofovir/lamivudine.

OBJECTIVE: Doravirine is an alternative treatment option for individuals who do not tolerate efavirenz. We assessed efficacy, safety, and CNS effects in adults with HIV-1 and CNS complaints who switched from an efavirenz-based regimen to a doravirine-based regimen. DESIGN: Multicenter, double-blind, randomized trial (NCT02652260). METHODS: Virologically suppressed adults receiving efavirenz/emtricitabine/tenofovir (EFV/FTC/TDF), or its components, with ongoing EFV-associated CNS toxicity grade 2 or higher (DAIDS criteria) were switched to doravirine/lamivudine/tenofovir (DOR/3TC/TDF) on day 1 (Immediate Switch Group [ISG]) or after 12 weeks (Deferred Switch Group [DSG]). CNS toxicity data were collected by self-administered questionnaire. The primary endpoint was the proportion of participants with any grade 2 or higher CNS toxicity at week 12. Secondary endpoints included virologic response and effect on fasting lipids. RESULTS: Eighty-six participants (58% men, 56% black, median age 41 years, median 4 years on prior EFV regimen) were enrolled (43 ISG, 43 DSG) and included in the analyses. At week 12, 42% of ISG and 37% of DSG had at least 1 grade 2 or higher CNS toxicity [difference 4.7%, 95% CI (-16 to 25%); P = 0.33]. At 24 weeks postswitch, HIV-1 RNA less than 50 copies/ml was maintained in 95.3% of participants, and fasting lipids were significantly decreased (LDL-cholesterol -11.0, non-HDL-cholesterol -13.2, HDL-cholesterol -7.7, total cholesterol -20.9, and triglycerides -13.0 mg/dl). CONCLUSION: In participants who had CNS complaints while receiving EFV/FTC/TDF, improvement in CNS toxicities attributable to EFV was not significantly different after switching to DOR/3TC/TDF compared with remaining on EFV/FTC/TDF. Virologic efficacy was maintained and lipid profiles improved after switching to DOR/3TC/TDF.

Doravirine/Lamivudine/Tenofovir Disoproxil Fumarate (TDF) Versus Efavirenz/Emtricitabine/TDF in Treatment-naive Adults With Human Immunodeficiency Virus Type 1 Infection: Week 96 Results of the Randomized, Double-blind, Phase 3 DRIVE-AHEAD Noninferiority Trial.

BACKGROUND: Doravirine (DOR) is a nonnucleoside reverse-transcriptase inhibitor. In the phase 3 DRIVE-AHEAD trial in treatment-naive adults with human immunodeficiency virus type 1 (HIV-1) infection, DOR demonstrated noninferior efficacy compared with efavirenz (EFV) and superior profiles for neuropsychiatric tolerability and lipids at 48 weeks. We present data through week 96. METHODS: DRIVE-AHEAD is a phase 3, multicenter, double-blind, noninferiority trial in antiretroviral treatment-naive adults with HIV-1 RNA ≥1000 copies/mL. Participants were randomized to a daily fixed-dose tablet of DOR (100 mg), lamivudine (3TC; 300 mg) and tenofovir disoproxil fumarate (TDF; 300 mg) (DOR/3TC/TDF) or EFV (600 mg), emtricitabine (FTC; 200 mg) and TDF (300 mg) (EFV/FTC/TDF). The efficacy end point of interest at week 96 was the proportion of participants with HIV-1 RNA levels <50 copies/mL (Food and Drug Administration Snapshot Approach) with a predefined noninferiority margin of 10% to support week 48 results. Safety end points of interest included prespecified neuropsychiatric adverse events and the mean change in fasting lipids at week 96. RESULTS: Of 734 participants randomized, 728 received study drugs and were included in analyses. At week 96, HIV-1 RNA <50 copies/mL was achieved by 77.5% of DOR/3TC/TDF vs 73.6% of EFV/FTC/TDF participants, with a treatment difference of 3.8% (95% confidence interval, -2.4% to 10%). Virologic failure rates were low and similar across treatment arms, with no additional resistance to DOR observed between weeks 48 and 96. Prespecified neuropsychiatric adverse events and rash were less frequent in DOR/3TC/TDF than in EFV/FTC/TDF participants through week 96. At week 96, fasting low-density lipoprotein cholesterol and non-high-density lipoprotein cholesterol (HDL-C) levels increased in the EFV/FTC/TDF group but not in the DOR/3TC/TDF group; the mean changes from baseline in total cholesterol/HDL-C ratio were similar. CLINICAL TRIALS REGISTRATION: NCT02403674.

Review of Doravirine Resistance Patterns Identified in Participants During Clinical Development.

BACKGROUND: Doravirine (DOR) is a novel non-nucleoside reverse transcriptase inhibitor (NNRTI) approved for the treatment of HIV-1 infection in patients with no known DOR resistance-associated mutations. DOR was rationally designed to address limitations associated with other approved NNRTIs, particularly resistance from common NNRTI resistance-associated mutants containing K103N, Y181C, or G190A reverse transcriptase substitutions. SETTING: Data to date from both in vitro studies and clinical trials have been compiled to summarize the resistance profile of DOR. METHODS: We analyzed data from in vitro studies and phase 2 and 3 trials to assess the emergence of resistance-associated mutations and their impact on efficacy among participants treated with DOR. RESULTS: DOR exhibited a distinct resistance profile compared with efavirenz and rilpivirine in vitro and in vivo; mutant viruses that were resistant to DOR showed limited cross-resistance to efavirenz and rilpivirine. In clinical trials, the development of DOR resistance-associated substitutions in reverse transcriptase was uncommon. CONCLUSION: Overall, minimal cross-resistance across NNRTIs was observed for DOR and limited development of DOR-related resistance. These data should assist clinicians in further understanding the resistance profile of DOR, so appropriate treatment decisions can be made for their patients.

Once-daily Doravirine for Initial Treatment of Adults Living With Human Immunodeficiency Virus-1: An Integrated Safety Analysis.

BACKGROUND: A prespecified integrated safety analysis was conducted for 3 doravirine (DOR) double-blind trials (Phase IIb: P007 [NCT01632345]; Phase III: DRIVE-FORWARD [NCT02275780] and DRIVE-AHEAD [NCT02403674]). METHODS: DOR (100 mg) arms from these trials were compared with darunavir plus ritonavir (DRV+r) in DRIVE-FORWARD and efavirenz (EFV) in P007 and DRIVE-AHEAD. Background therapies were emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) in P007; abacavir/lamivudine (ABC/3TC) or FTC/TDF in DRIVE-FORWARD; and 3TC/TDF for DOR and FTC/TDF for EFV in DRIVE-AHEAD. The primary endpoint was the proportion of participants discontinuing due to adverse events (AEs) through Week 48. RESULTS: Discontinuation rates due to AEs were similar for participants on DOR and DRV+r (2.5% vs 3.1%, respectively) and lower for those on DOR than for those on EFV (2.5% vs 6.6%, respectively). Rates of drug-related AEs for DOR, DRV+r, and EFV were 30.9%, 32.1%, and 61.4%, respectively. In an analysis of DOR versus EFV, the treatment difference for discontinuations due to AEs was -3.4%, favoring DOR (95% confidence interval -6.2 to -0.8; P = .012). Fewer participants experienced neuropsychiatric AEs on DOR than on EFV (25.0% vs 55.9%, respectively), and fewer experienced diarrhea on DOR than on DRV+r (12.4% vs 22.5%, respectively). Changes from baseline in most lipid parameters also favored DOR. CONCLUSIONS: At Week 48, DOR at 100 mg had a favorable safety profile compared with EFV or DRV+r and a favorable tolerability profile compared with EFV. CLINICAL TRIALS REGISTRATION: NCT01632345; NCT02275780 and NCT02403674.

Once-daily Doravirine in Human Immunodeficiency Virus Type 1-Infected, Antiretroviral-naive Adults: An Integrated Efficacy Analysis.

BACKGROUND: Doravirine (DOR) demonstrated noninferior efficacy to darunavir plus ritonavir (DRV+r) and efavirenz (EFV) in 2 ongoing phase 3 trials: DRIVE-FORWARD (NCT02275780) and DRIVE-AHEAD (NCT02403674). METHODS: This prespecified analysis pooled efficacy data through the first 48 weeks of DRIVE-FORWARD and DRIVE-AHEAD from the DOR groups (DOR/lamivudine [3TC]/tenofovir disoproxil fumarate [TDF] or DOR [100 mg daily] with emtricitabine [FTC]/TDF or abacavir [ABC]/3TC [n = 747]) compared with DRV+r (800/100 mg daily) with FTC/TDF or ABC/3TC (n = 383) or EFV/FTC/TDF (600/200/300 mg daily; n = 364). Efficacy assessments included the proportion of participants with human immunodeficiency virus type 1 (HIV-1) RNA <50 copies/mL and change in CD4+ T-cell count. RESULTS: At week 48, DOR demonstrated noninferior efficacy to DRV+r and EFV, with 84.1% of DOR-treated participants achieving HIV-1 RNA <50 copies/mL compared with 79.9% of the DRV+r and 80.8% of the EFV groups. Results were similar across demographic/prognostic subpopulations, including baseline plasma HIV-1 RNA, gender, race, and HIV-1 subtype. Mean increases from baseline in CD4+ T-cell count through 48 weeks were 195.5 cells/mm3 for DOR, 185.6 cells/mm3 for DRV+r, and 188.4 cells/mm3 for EFV/FTC/TDF. CONCLUSIONS: DOR, as a single entity (in combination with other antiretroviral agents) and as a fixed-dose combination (DOR/3TC/TDF), demonstrated noninferior efficacy to DRV+r and EFV as assessed by the proportion of HIV-1-infected, treatment-naive adults with HIV-1 RNA <50 copies/mL. CLINICAL TRIALS REGISTRATION: NCT02275780 and NCT02403674.

Doravirine versus ritonavir-boosted darunavir in antiretroviral-naive adults with HIV-1 (DRIVE-FORWARD): 96-week results of a randomised, double-blind, non-inferiority, phase 3 trial.

BACKGROUND: Doravirine is a novel, non-nucleoside reverse transcriptase inhibitor that has shown non-inferior efficacy to ritonavir-boosted darunavir, with a superior lipid profile, in adults with HIV who were treatment naive at week 48 in the phase 3 DRIVE-FORWARD trial. Here we present the 96-week data for the study. METHODS: This randomised, controlled, double-blind, multicentre, non-inferiority, phase 3 study was undertaken at 125 clinical centres in 15 countries. Eligible participants were adults (aged ≥18 years) infected with HIV-1 who were naive to antiretroviral therapy, with a plasma HIV-1 RNA concentration of 1000 copies per mL or higher at screening, and no known resistance to any of the study drugs. Participants were randomly assigned (1:1) using an interactive voice and web response system, stratified by baseline HIV-1 RNA concentration and background nucleoside reverse transcriptase inhibitor therapy, to doravirine (100 mg per day) or ritonavir-boosted darunavir (100 mg ritonavir and 800 mg darunavir per day), both with investigator-selected nucleoside reverse transcriptase inhibitors: emtricitabine and tenofovir disoproxil fumarate or abacavir and lamivudine. Participants and investigators were masked to treatment assignment until week 96. The primary efficacy endpoint was the proportion of participants who had a plasma HIV-1 RNA concentration of less than 50 copies per mL at week 48, which has been reported previously. Here we report the key secondary efficacy endpoint of the proportion of participants who achieved this concentration by week 96, assessed in all participants who received at least one dose of any study drug, regardless of whether it was their randomly assigned treatment. We used a US Food and Drug Administration snapshot approach and a margin of 10 percentage points to define the non-inferiority of doravirine to ritonavir-boosted darunavir at 96 weeks. Key safety endpoints were change in fasting serum lipid concentrations, the incidence of adverse events, and time to discontinuation due to an adverse event, assessed in all participants who received at least one dose of any study medication. This study is registered with ClinicalTrials.gov, NCT02275780, and is closed to accrual. FINDINGS: Between Dec 1, 2014, and Oct 20, 2015, 1027 individuals were screened, of whom 769 participants were randomly assigned to doravirine (n=385) or ritonavir-boosted darunavir (n=384), and 383 in both groups were given at least one dose of their allocated treatment. Most participants were male (645 [84%] of 766) and white (560 [73%]), with a mean age of 35·2 years (SD 10·6). 292 participants in the doravirine group and 273 in the darunavir group completed 96 weeks of treatment. At week 96, a higher proportion of the doravirine group (277 [73%] of 383) achieved an HIV-1 RNA concentration of less than 50 copies per mL than did of the darunavir group (248 [66%] of 383; difference 7·1%, 95% CI 0·5-13·7). Responses were similar regardless of baseline characteristics. Treatment-emergent resistance to any study drug occurred in two (1%) of 383 participants in the doravirine group and one (<1%) of 383 in the ritonavir-boosted darunavir group. Significant differences were seen between treatment groups in mean changes from baseline in LDL cholesterol (-14·6 mg/dL, 95% CI -18·2 to -11·0) and non-HDL cholesterol (-18·4 mg/dL, -22·5 to -14·3). Frequencies of adverse events were similar between groups. No significant treatment difference (log-rank nominal p=0·063) through week 96 was observed in time to discontinuation due to an adverse event. The most common adverse events (week 0-96) were diarrhoea (65 [17%] in the doravirine group vs 91 [24%] in the ritonavir-boosted darunavir group), nausea (45 [12%] vs 52 [14%]), headache (57 [15%] vs 46 [12%]), and upper respiratory tract infection (51 [13%] vs 30 [8%]). Two participants, one in each group, died during treatment; neither death was considered to be related to study medication. INTERPRETATION: These results through 96 weeks support the efficacy and safety results reported previously for doravirine at 48 weeks, supporting the use of doravirine for the long-term treatment of adults with previously untreated HIV-1 infection. FUNDING: Merck.

Doravirine dose selection and 96-week safety and efficacy versus efavirenz in antiretroviral therapy-naive adults with HIV-1 infection in a Phase IIb trial.

BACKGROUND: The safety and efficacy of doravirine were compared with that of efavirenz as initial treatment of adults living with HIV-1 infection (NCT01632345). METHODS: A Phase IIb double-blind trial with participants stratified by screening HIV-1 RNA (≤ or >100,000 copies/ml) and randomized 1:1:1:1:1 to receive once-daily doravirine (25, 50, 100 or 200 mg) or efavirenz 600 mg (Part I) for up to 96 weeks, with open-label tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg (TDF/FTC). After dose selection at week 24, doravirine 100 mg was provided to participants receiving the other doses of doravirine and additional participants were randomized 1:1 to receive once-daily doravirine 100 mg or efavirenz 600 mg for 96 weeks with TDF/FTC (Part II). Primary outcomes were the proportion of participants with HIV-1 RNA <40 copies/ml at week 24, and central nervous system (CNS) adverse events (AEs) by weeks 8 and 24 (Parts I+II combined). RESULTS: 210 and 132 participants were randomized in Parts I and II, respectively, and 216 (108 on doravirine 100 mg, 108 on efavirenz) were evaluable for Parts I+II combined. At week 24, the proportion of participants with HIV-1 RNA <40 copies/ml was 72.9% for doravirine 100 mg and 73.1% for efavirenz (difference -0.5 [95% CI -12.3, 11.2]). In addition, CNS AEs were reported by 26.9% and 47.2% of doravirine and efavirenz recipients, respectively (difference -20.4 [95% CI -32.6, -7.5]; P=0.002). CONCLUSIONS: Doravirine 100 mg with TDF/FTC demonstrated similar antiretroviral activity and superior CNS safety compared with efavirenz 600 mg with TDF/FTC.

Switching to Doravirine/Lamivudine/Tenofovir Disoproxil Fumarate (DOR/3TC/TDF) Maintains HIV-1 Virologic Suppression Through 48 Weeks: Results of the DRIVE-SHIFT Trial.

BACKGROUND: Doravirine is a novel, nonnucleoside reverse transcriptase inhibitor with demonstrated efficacy in treatment-naive adults with HIV-1. METHODS: In this open-label, active-controlled, noninferiority trial, adults with HIV-1 virologically suppressed for ≥6 months on 2 nucleoside reverse transcriptase inhibitors plus a boosted protease inhibitor, boosted elvitegravir, or a non-nucleoside reverse transcriptase inhibitor were randomized (2:1) to switch to once-daily, single-tablet doravirine 100 mg with lamivudine 300 mg and tenofovir disoproxil fumarate 300 mg (DOR/3TC/TDF) or to continue their current therapy (Baseline Regimen) for 24 weeks. The primary endpoint was the proportion of participants with HIV-1 RNA <50 copies/mL (defined by the FDA Snapshot approach), with the primary comparison between DOR/3TC/TDF at week 48 and Baseline Regimen at week 24 and a secondary comparison between the groups at week 24 (noninferiority margin, -8%). RESULTS: Six hundred seventy participants (447 DOR/3TC/TDF, 223 Baseline Regimen) were treated and included in the analyses. At week 24, 93.7% on DOR/3TC/TDF vs 94.6% on Baseline Regimen had HIV-1 RNA <50 copies/mL [difference -0.9 (-4.7 to 3.0)]. At week 48, 90.8% on DOR/3TC/TDF had HIV-1 RNA <50 copies/mL, demonstrating noninferiority vs Baseline Regimen at week 24 [difference -3.8 (-7.9 to 0.3)]. In participants on ritonavir-boosted protease inhibitor at entry, mean reductions in fasting LDL-C and non-HDL-C at week 24 were significantly greater for DOR/3TC/TDF vs Baseline Regimen (P < 0.0001). Adverse events occurred in 68.9% on DOR/3TC/TDF and 52.5% on Baseline Regimen by week 24, leading to treatment discontinuation in 2.5% and 0.4%, respectively. CONCLUSIONS: Switching to once-daily DOR/3TC/TDF is a generally well-tolerated option for maintaining viral suppression in patients considering a change in therapy. REGISTRATION: ClinicalTrials.gov NCT02397096.

Doravirine/Lamivudine/Tenofovir Disoproxil Fumarate is Non-inferior to Efavirenz/Emtricitabine/Tenofovir Disoproxil Fumarate in Treatment-naive Adults With Human Immunodeficiency Virus-1 Infection: Week 48 Results of the DRIVE-AHEAD Trial.

Background: Doravirine (DOR), a novel non-nucleoside reverse-transcriptase inhibitor (NNRTI), is active against wild-type Human Immunodeficiency Virus (HIV)-1 and the most common NNRTI-resistant variants, and has a favorable and unique in vitro resistance profile. Methods: DRIVE-AHEAD is a phase 3, double-blind, non-inferiority trial. Antiretroviral treatment-naive adults with ≥1000 HIV-1 RNA copies/mL were randomized (1:1) to once-daily, fixed-dose DOR at 100 mg, lamivudine at 300 mg, and tenofovir disoproxil fumarate (TDF) at 300 mg (DOR/3TC/TDF) or to efavirenz at 600 mg, emtricitabine at 200 mg, and TDF at 300 mg (EFV/FTC/TDF) for 96 weeks. The primary efficacy endpoint was the proportion of participants with <50 HIV-1 RNA copies/mL at week 48 (Food and Drug Administration snapshot approach; non-inferiority margin 10%). Results: Of the 734 participants randomized, 728 were treated (364 per group) and included in the analyses. At week 48, 84.3% (307/364) of DOR/3TC/TDF recipients and 80.8% (294/364) of EFV/FTC/TDF recipients achieved <50 HIV-1 RNA copies/mL (difference 3.5%, 95% CI, -2.0, 9.0). DOR/3TC/TDF recipients had significantly lower rates of dizziness (8.8% vs 37.1%), sleep disorders/disturbances (12.1% vs 25.2%), and altered sensorium (4.4% vs 8.2%) than EFV/FTC/TDF recipients. Mean changes in fasting low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) were significantly different between DOR/3TC/TDF and EFV/FTC/TDF (-1.6 vs +8.7 mg/dL and -3.8 vs +13.3 mg/dL, respectively). Conclusions: In HIV-1 treatment-naive adults, DOR/3TC/TDF demonstrated non-inferior efficacy to EFV/FTC/TDF at week 48 and was well tolerated, with significantly fewer neuropsychiatric events and minimal changes in LDL-C and non-HDL-C compared with EFV/FTC/TDF. Clinical Trials Registration: NCT02403674.

Doravirine versus ritonavir-boosted darunavir in antiretroviral-naive adults with HIV-1 (DRIVE-FORWARD): 48-week results of a randomised, double-blind, phase 3, non-inferiority trial.

BACKGROUND: Doravirine is a novel non-nucleoside reverse transcriptase inhibitor (NNRTI) with a pharmacokinetic profile supporting once-daily dosing, and potent in-vitro activity against the most common NNRTI-resistant HIV-1 variants. We compared doravirine with ritonavir-boosted darunavir, when both were given with two nucleoside reverse transcriptase inhibitors (NRTIs), in adults with previously untreated HIV-1 infection. METHODS: In this randomised, controlled, double-blind, multicentre, non-inferiority trial, adults with HIV-1 infection were screened and enrolled at 125 clinical centres in 15 countries. Eligible participants (aged ≥18 years) were naive to antiretroviral therapy with plasma HIV-1 RNA of at least 1000 copies per mL at screening. Participants who had previously been treated for a viral infection other than HIV-1, those taking immunosuppressive drugs, and individuals with active acute hepatitis were excluded. Participants were randomly assigned (1:1) via an interactive voice and web response system to receive oral doravirine 100 mg or darunavir 800 mg plus ritonavir 100 mg once daily, with two investigator-selected NRTIs (tenofovir and emtricitabine or abacavir and lamivudine) for up to 96 weeks. Randomisation was stratified by HIV-1 RNA measurements at screening (≤100 000 vs >100 000 copies per mL) and the NRTI pair. Study participants, funding institution staff, investigators, and study site personnel were masked to treatment group assignment. The primary efficacy endpoint was the proportion of participants achieving HIV-1 RNA of less than 50 copies per mL at week 48 defined by the US Food and Drug Administration snapshot algorithm, with non-inferiority established if the lower bound of the two-sided 95% CI for the treatment difference (doravirine minus darunavir) was greater than -10 percentage points. All participants who received at least one dose of study drug were included in the primary efficacy and safety analyses. This trial is active, but not recruiting, and is registered with ClinicalTrials.gov, number NCT02275780. FINDINGS: Between Dec 1, 2014, and Oct 20, 2015, 1027 participants were screened for eligibility, of whom 769 participants were randomly assigned to treatment (385 with doravirine and 384 with ritonavir-boosted darunavir). 56 participants discontinued treatment in the doravirine group compared with 71 in the darunavir group, mostly due to loss to follow-up. 383 participants who received doravirine and 383 who received darunavir were included in the primary efficacy analyses. At week 48, 321 (84%) participants in the doravirine group and 306 (80%) in the darunavir group achieved plasma HIV-1 RNA of less than 50 copies per mL (difference 3·9%, 95% CI -1·6 to 9·4), indicating non-inferiority of the doravirine regimen. The most common study drug-related adverse events were diarrhoea (21 [5%] of 383 participants in the doravirine group and 49 [13%] of 383 participants in the darunavir group), nausea (25 [7%] vs 29 [8%]), and headache (23 [6%] vs ten [3%]). 18 participants (six [2%] of 383 participants in the doravirine group vs 12 [3%] of 383 participants in the darunavir group) discontinued treatment due to adverse events, which were considered drug-related in four (1%) participants in the doravirine group and 8 (2%) participants in the darunavir group. Serious adverse events occurred in 19 (5%) of 383 participants in the doravirine group and 23 (6%) of 383 in the darunavir roup, and were considered study-drug related in one (<1%) participant of each group. INTERPRETATION: In treatment-naive adults with HIV-1 infection, doravirine combined with two NRTIs might offer a valuable treatment option for adults with previously untreated HIV-1 infection. FUNDING: Merck & Co.

Detection of HIV-1 CXCR4 tropism and resistance in treatment experienced subjects receiving CCR5 antagonist-Vicriviroc.

BACKGROUND: Vicriviroc (VCV), a small-molecule antagonist of the C-C chemokine receptor 5 (CCR5), blocks HIV's entry into CD4+ cells. Small studies have suggested that resistance to CCR5 antagonists is slow to develop. OBJECTIVES: To examine resistance to VCV in isolates from treatment experienced patients who experienced virologic failure in two phase 3 trials. STUDY DESIGN: Genotypic and phenotypic susceptibility to VCV, and other antiretroviral drugs were evaluated at baseline and at defined intervals during the study. In a post hoc analysis, viral tropism at baseline was evaluated using the Trofile-ES assay. Only subjects with R5-tropic virus were included in the analysis. Viral envelope sequencing was performed on samples from subjects with emergent VCV resistance defined using a relative MPI cutoff. RESULTS: 71/486 subjects treated with VCV for 48 weeks met the protocol-defined virologic failure criteria. 7/71 (10%) had DM/X4 virus at the time of virologic failure; VCV resistance was identified in 4/486 treated subjects (1%). No control subject had detectable DM/X4 virus or VCV resistance at virologic failure. Clonal analysis of envelope sequences from VCV-resistant virus identified 2-5 amino acid substitutions at or near the crown of the V3 loop; however, no signature V3 mutations were identified. Changes outside the V3 loop were also observed in resistant clones; no consistent variant pattern was observed. CONCLUSIONS: In these trials, use of a sensitive tropism assay and potent antiretroviral drug combinations contributed to the infrequent detection of X4-tropic virus and VCV resistance. Substitutions in the V3 loop were associated with VCV resistance, however, no specific pattern of amino acid changes were sufficient to reliably predict VCV susceptibility.

Effects of a novel estrogen-free, progesterone receptor modulator contraceptive vaginal ring on inhibition of ovulation, bleeding patterns and endometrium in normal women.

BACKGROUND: Progesterone receptor modulators (PRMs) delivered by contraceptive vaginal rings provide an opportunity for development of an estrogen-free contraceptive that does not require daily oral intake of steroids. The objective of this proof-of-concept study was to determine whether continuous delivery of 600-800 mcg of ulipristal acetate (UPA) from a contraceptive vaginal ring could achieve 80% to 90% inhibition of ovulation. STUDY DESIGN: This was a prospective, controlled, open-labeled, multicenter international trial to examine the effectiveness and safety of this prototype vaginal ring. Thirty-nine healthy women, 21-40 years old and not at risk of pregnancy, were enrolled at three clinic sites. Volunteers participated in a control cycle, a 12-week treatment period and a post-treatment cycle. Pharmacodynamic effects on follicular function and inhibition of ovulation, effects on endometrium, bleeding patterns and serum UPA levels were evaluated. RESULTS: Mean UPA levels during treatment were nearly constant, approximately 5.1 ng/mL throughout the study. Ovulation was documented in 32% of 111 "4-week treatment cycles." A correlation was observed between serum UPA and degree of inhibition of ovarian activity. There was no evidence of hyperplasia of endometrium, but PRM-associated endometrial changes were frequently observed (41%). CONCLUSION: In this study, the minimum effective contraceptive dose was not established. Further studies are required testing higher doses of UPA to attain ovulation suppression in a higher percentage of subjects.

An initial pharmacokinetic study with a Metered Dose Transdermal Systemfor delivery of the progestogen Nestorone as a possible future contraceptive.

BACKGROUND: Transdermal delivery of steroids is gaining popularity for contraception and hormone replacement therapy. This study aimed to test metered spray delivery of a precise dosage of Nestorone (NES) progestogen as a possible transdermal progestogen-only contraceptive. STUDY DESIGN: Six healthy postmenopausal volunteers, not recently using any hormonal therapies, comprise the sample for this study. Each subject was studied on two occasions with multiple blood sampling for assay of NES over a 24-h period: on the first occasion, after a single dosage of 3 x 90 microL NES sprays using a specially devised, precisely metered delivery device; on the second occasion, following the fifth in a series of five daily transdermal dosages of 3 x 90 microL of NES spray. Conventional pharmacokinetic parameters were calculated. NES was assayed in serum using a specific radioimmunoassay. RESULTS: Mean serum levels of NES peaked at around 20 h following dosing, and levels plateaued at 285-290 pmol/L after 4-5 days of daily spray application. All subjects achieved satisfactory serum levels, although substantial intersubject variation was noted. The apparent elimination half-life of NES after the last dose on Day 5 was 26.8 h. No unexpected adverse events were encountered. CONCLUSION: This early pharmacokinetic trial of a new transdermal steroid delivery system has demonstrated the feasibility of achieving serum levels of NES sufficient to block ovulation and potentially provide effective contraception.

Pharmacokinetic study to compare the absorption and tolerability of two doses of levonorgestrel following single vaginal administration of levonorgestrel in Carraguard gel: a new formulation for "dual protection" contraception.

OBJECTIVE: The study was conducted to assess levonorgestrel (LNG) serum levels achieved after a single administration of two different doses of Carraguard vaginal gel containing LNG (CARRA/LNG), designed for use as microbicide and contraceptive for potential dual protection. MATERIALS AND METHODS: This was a randomized double-blind pharmacokinetic study conducted in 12 subjects enrolled at two centers. Each subject received a single vaginal administration of CARRA/LNG containing either 0.75 or 1.5 mg LNG per 4 mL of gel on Days 10-12 of the menstrual cycle. LNG serum levels were measured at 0, 1, 2, 4, 8 and 12 h after administration and for the following 7 days. LH and progesterone (for a preliminary evaluation of effect on the ovarian function) as well as SHBG were measured in the daily samples. RESULTS: Serum LNG maximum concentrations (Cmax) were 14.1+/-2.1 and 11.7+/-2.7 nmol/L and Tmax was 12.0 and 6.0 h for the low and high dose, respectively, with large intersubject variability within the first 48 h. Mean levels at 96 h were 10% of Cmax. Differences in AUC between both doses were not statistically significant. SHBG levels decreased approximately 25% by Day 4 after administration. Luteal activity was observed in 3/6 and 5/6 of the subjects in the low- and high-dose group, respectively. CONCLUSION: This study demonstrates that the CARRA/LNG gel can sustain elevated serum levels of the contraceptive steroid for up to 96 h after a single application. The serum levels attained with the 0.75-mg formulation are in the range expected to perturb the ovulatory process as observed in some subjects. The lack of correlation between the administered dose and serum concentrations of the steroid may be related to a rate-limiting absorption of LNG from the vaginal mucosa. The results reported here suggest that the CARRA/LNG formulation has good potential to become a dual-protection method, possibly preventing conception and sexually transmitted infections.

Effects of oral and transvaginal ethinyl estradiol on hemostatic factors and hepatic proteins in a randomized, crossover study.

CONTEXT: The use of combined hormonal contraceptives with ethinyl estradiol (EE) and a progestin results in alterations in potential biomarkers of venous thromboembolism risk. Evaluation of the impact of delivery route on these changes is difficult due to an interaction between EE and the progestin component. OBJECTIVE: The aim of the study was to compare the impact of oral and vaginal administration of EE alone on hemostatic variables and estrogen-sensitive liver proteins. DESIGN: This was a single-center, randomized, crossover study with two treatment cycles separated by a washout cycle. SETTING: The study was conducted in an academic outpatient center. PARTICIPANTS: Fourteen healthy postmenopausal women were enrolled; 13 completed the study and were included in the analyses. INTERVENTION: Participants were randomized to receive EE (15 microg/d) delivered by oral tablet or vaginal ring for 21 d in one of two treatment sequences. MAIN OUTCOME MEASURES: Changes in plasma concentration or activity of 10 hemostatic variables and six estrogen-sensitive liver proteins between baseline and d 21 of treatment were the primary outcomes. RESULTS: Prothrombin fragment 1 + 2 plasma level was unaffected by treatment or delivery route. Angiotensinogen (expressed as plasma level of angiotensin I) increased similarly with oral and vaginal delivery; mean (sd) increases were 2757 (1033) and 2864 (893) ng /ml, respectively (P = 0.0002). Alterations in other study variables, except total cholesterol, were similar with oral and vaginal administration. CONCLUSION: Our results provide evidence that the customary effects of combined hormonal contraceptives on hemostatic variables and estrogen-sensitive liver proteins are largely related to EE and independent of delivery route during short-term treatment.

Progesterone induces calcitonin expression in the baboon endometrium within the window of uterine receptivity.

The mammalian uterus can accept a developing blastocyst for implantation only within a limited period of time, termed the receptive phase. Our previous studies showed that the expression of calcitonin, a peptide hormone that regulates calcium homeostasis, is induced by progesterone immediately preceding implantation, and is required for the generation of a receptive rat uterus. In this study, we investigated the expression and hormonal regulation of calcitonin in the baboon endometrium during the window of implantation. We monitored the spatio-temporal expression of calcitonin at various days of the menstrual cycle. Reverse transcriptase-polymerase chain reaction analysis of the baboon endometrium on Days 9 and 10 postovulation revealed stage-specific expression of calcitonin mRNA, which overlapped with the window of uterine receptivity. Immunocytochemical analysis of baboon endometrium sections localized calcitonin expression in the glandular epithelial and stromal cells. Treatment of animals with the antiprogestin ZK 137.316 dramatically reduced calcitonin expression, indicating that calcitonin expression in the baboon endometrium is under progesterone regulation. Collectively, these findings strongly suggest that the appearance of calcitonin in progesterone-dominated endometrium is conserved among species and may serve as a marker of uterine receptivity for embryo implantation.