Mg Of Ritonavir Research Articles

Oral Nirmatrelvir–Ritonavir as Postexposure Prophylaxis for Covid-19

BackgroundClinical trials of treatments for coronavirus disease 2019 (Covid-19) have not shown a significant benefit of postexposure prophylaxis.MethodsWe conducted a phase 2–3 double-blind trial to assess the efficacy and safety of nirmatrelvir–ritonavir in asymptomatic, rapid antigen test–negative adults who had been exposed to a household contact with Covid-19 within 96 hours before randomization. The participants were randomly assigned in a 1:1:1 ratio to receive nirmatrelvir–ritonavir (300 mg of nirmatrelvir and 100 mg of ritonavir) every 12 hours for 5 days or for 10 days or matching placebo for 5 or 10 days. The primary end point was the development of symptomatic SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection, confirmed on reverse-transcriptase–polymerase-chain-reaction (RT-PCR) or rapid antigen testing, through 14 days in participants who had a negative RT-PCR test at baseline.ResultsA total of 2736 participants were randomly assigned to a trial group — 921 to the 5-day nirmatrelvir–ritonavir group, 917 to the 10-day nirmatrelvir–ritonavir group, and 898 to the placebo group. Symptomatic, confirmed SARS-CoV-2 infection developed by day 14 in 2.6% of the participants in the 5-day nirmatrelvir–ritonavir group, 2.4% of those in the 10-day nirmatrelvir–ritonavir group, and 3.9% of those in the placebo group. In each nirmatrelvir–ritonavir group, the percentage of participants in whom symptomatic, confirmed SARS-CoV-2 infection developed did not differ significantly from that in the placebo group, with risk reductions relative to placebo of 29.8% (95% confidence interval [CI], –16.7 to 57.8; P=0.17) in the 5-day nirmatrelvir–ritonavir group and 35.5% (95% CI, –11.5 to 62.7; P=0.12) in the 10-day nirmatrelvir–ritonavir group. The incidence of adverse events was similar across the trial groups, with dysgeusia being the most frequently reported adverse event (in 5.9% and 6.8% of the participants in the 5-day and 10-day nirmatrelvir–ritonavir groups, respectively, and in 0.7% of those in the placebo group).ConclusionsIn this placebo-controlled trial, postexposure prophylaxis with nirmatrelvir–ritonavir for 5 or 10 days did not significantly reduce the risk of symptomatic SARS-CoV-2 infection. (Funded by Pfizer; ClinicalTrials.gov number, NCT05047601.)

COVID-19 Rebound After VV116 vs Nirmatrelvir-Ritonavir Treatment

With the widespread use of anti-SARS-CoV-2 drugs, accumulating data have revealed potential viral load rebound after treatment. To compare COVID-19 rebound after a standard 5-day course of antiviral treatment with VV116 vs nirmatrelvir-ritonavir. This is a single-center, investigator-blinded, randomized clinical trial conducted in Shanghai, China. Adult patients with mild-to-moderate COVID-19 and within 5 days of SARS-CoV-2 infection were enrolled between December 20, 2022, and January 19, 2023, and randomly allocated to receive either VV116 or nirmatrelvir-ritonavir. Participants in the VV116 treatment group received oral 600-mg VV116 tablets every 12 hours on day 1 and 300 mg every 12 hours on days 2 through 5. Participants in the nirmatrelvir-ritonavir treatment group received oral nirmatrelvir-ritonavir tablets with 300 mg of nirmatrelvir plus 100 mg of ritonavir every 12 hours for 5 days. Participants were followed up every other day until day 28 and every week until day 60. The primary outcome was viral load rebound (VLR), defined as a half-log increase in viral RNA copies per milliliter compared with treatment completion. Secondary outcomes included a reduction in the cycle threshold value of 1.5 or more, time until VLR, and symptom rebound, defined as an increase of more than 2 points in symptom score compared with treatment completion. The primary outcome and secondary outcomes were analyzed using the full analysis set. Sensitivity analyses were conducted using the per protocol set. Adverse events were analyzed using the safety analysis set. The full analysis set included 345 participants (mean [SD] age, 53.2 [16.8] years; 175 [50.7%] were men) who received VV116 (n = 165) or nirmatrelvir-ritonavir (n = 180). Viral load rebound occurred in 33 patients (20.0%) in the VV116 group and 39 patients (21.7%) in the nirmatrelvir-ritonavir group (P = .70). Symptom rebound occurred in 41 of 160 patients (25.6%) in the VV116 group and 40 of 163 patients (24.5%) in the nirmatrelvir-ritonavir group (P = .82). Viral whole-genome sequencing of 24 rebound cases revealed the same lineage at baseline and at viral load rebound in each case. In this randomized clinical trial of patients with mild-to-moderate COVID-19, viral load rebound and symptom rebound were both common after a standard 5-day course of treatment with either VV116 or nirmatrelvir-ritonavir. Prolongation of treatment duration might be investigated to reduce COVID-19 rebound. Chinese Clinical Trial Registry Identifier: ChiCTR2200066811.

Oral Simnotrelvir for Adult Patients with Mild-to-Moderate Covid-19

BackgroundSimnotrelvir is an oral 3-chymotrypsin–like protease inhibitor that has been found to have in vitro activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential efficacy in a phase 1B trial.MethodsIn this phase 2–3, double-blind, randomized, placebo-controlled trial, we assigned patients who had mild-to-moderate coronavirus disease 2019 (Covid-19) and onset of symptoms within the past 3 days in a 1:1 ratio to receive 750 mg of simnotrelvir plus 100 mg of ritonavir or placebo twice daily for 5 days. The primary efficacy end point was the time to sustained resolution of symptoms, defined as the absence of 11 Covid-19–related symptoms for 2 consecutive days. Safety and changes in viral load were also assessed.ResultsA total of 1208 patients were enrolled at 35 sites in China; 603 were assigned to receive simnotrelvir and 605 to receive placebo. Among patients in the modified intention-to-treat population who received the first dose of trial drug or placebo within 72 hours after symptom onset, the time to sustained resolution of Covid-19 symptoms was significantly shorter in the simnotrelvir group than in the placebo group (180.1 hours [95% confidence interval {CI}, 162.1 to 201.6] vs. 216.0 hours [95% CI, 203.4 to 228.1]; median difference, −35.8 hours [95% CI, −60.1 to −12.4]; P=0.006 by Peto–Prentice test). On day 5, the decrease in viral load from baseline was greater in the simnotrelvir group than in the placebo group (mean difference [±SE], −1.51±0.14 log10 copies per milliliter; 95% CI, −1.79 to −1.24). The incidence of adverse events during treatment was higher in the simnotrelvir group than in the placebo group (29.0% vs. 21.6%). Most adverse events were mild or moderate.ConclusionsEarly administration of simnotrelvir plus ritonavir shortened the time to the resolution of symptoms among adult patients with Covid-19, without evident safety concerns. (Funded by Jiangsu Simcere Pharmaceutical; ClinicalTrials.gov number, NCT05506176.)

A Comprehensive Review of the Clinical Pharmacokinetics, Pharmacodynamics, and Drug Interactions of Nirmatrelvir/Ritonavir.

Nirmatrelvir is a potent and selective inhibitor of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease that is used as an oral antiviral coronavirus disease 2019 (COVID-19) treatment. To sustain unbound systemic trough concentrations above the antiviral in vitro 90% effective concentration value (EC90), nirmatrelvir is coadministered with 100 mg of ritonavir, a pharmacokinetic enhancer. Ritonavir inhibits nirmatrelvir's cytochrome P450 (CYP) 3A4-mediated metabolism which results in renal elimination becoming the primary route of nirmatrelvir elimination when dosed concomitantly. Nirmatrelvir exhibits absorption-limited nonlinear pharmacokinetics. When coadministered with ritonavir in patients with mild-to-moderate COVID-19, nirmatrelvir reaches a maximum concentration of 3.43 µg/mL (11.7× EC90) in approximately 3 h on day 5 of dosing, with a geometric mean day 5 trough concentration of 1.57 µg/mL (5.4× EC90). Drug interactions with nirmatrelvir/ritonavir (PAXLOVIDTM) are primarily attributed to ritonavir-mediated CYP3A4 inhibition, and to a lesser extent CYP2D6 and P-glycoprotein inhibition. Population pharmacokinetics and quantitative systems pharmacology modeling support twice daily dosing of 300 mg/100 mg nirmatrelvir/ritonavir for 5 days, with a reduced 150 mg/100 mg dose for patients with moderate renal impairment. Rapid clinical development of nirmatrelvir/ritonavir in response to the emerging COVID-19 pandemic was enabled by innovations in clinical pharmacology research, including an adaptive phase 1 trial design allowing direct to pivotal phase 3 development, fluorine nuclear magnetic resonance spectroscopy to delineate absorption, distribution, metabolism, and excretion profiles, and innovative applications of model-informed drug development to accelerate development.

Efficacy and safety of Huashi Baidu granule plus Nirmatrelvir-Ritonavir combination therapy in patients with high-risk factors infected with Omicron (B.1.1.529): A multi-arm single-center, open-label, randomized controlled trial

BackgroundHuashi Baidu granule (HSBD) and Paxlovid (Nirmatrelvir-Ritonavir) are antiviral Chinese patent medicine and western medicine specially developed for treating coronavirus disease 2019 (COVID-19). Their efficacy and safety in treating COVID-19 are still under investigated. PurposeTo assess and compare the efficacy and safety of HSBD, Paxlovid, and the combination in treating high-risk patients infected with SARS-CoV-2 Omicron. Study designThe study was a prospective single-center, open-label, randomized, controlled clinical trial conducted from April 18 to June 5, 2022. (ClinicalTrial.gov registration number: ChiCTR2200059390) Methods312 severe patients aged 18 years and older infected with SARS-CoV-2 Omicron from Shuguang Hospital in Shanghai were randomly allocated to HSBD monotherapy (orally 137 g twice daily for 7 days, n = 105), Paxlovid monotherapy (orally 300 mg of Nirmatrelvir plus 100 mg of Ritonavir every 12 h for 5 days, n = 103), or combination therapy (n = 104). The primary outcome was SARS-CoV-2 nucleic acid negative conversion within 7-day treatment. The secondary outcome included hospital discharging conditions, severe conversion of symptom, and adverse events. ResultsOf 312 participants, 85 (82%) of 104 in combination therapy, 71 (68%) of 105 in HSBD monotherapy, and 73 (71%) of 103 in Paxlovid monotherapy had a primary outcome event. The hazard ratios of primary outcome were 1.37 (95% CI 1.03 – 1.84, p = 0.012) for combination versus HSBD, 1.28 (0.98–1.69, p = 0.043) for combination versus Paxlovid, and 0.88 (0.66–1.18, p = 0.33) for HSBD versus Paxlovid. There was no statistical difference of efficacy between HSBD and Paxlovid, while combination therapy exhibited more effective than either alone. For secondary outcomes, the hospital discharging rates within 7 days exhibited the significant increase in combination therapy than in HSBD or Paxlovid monotherapy (71% (74/104) vs 55% (58/105) vs 52% (54/103), p < 0.05). The risk of severe conversion of symptom showed no statistical significance among three interventions (1% (1/104) vs 3% (3/105) vs 3% (3/103), p > 0.05). No severe adverse events occurred among combination therapy and monotherapies in the trial. ConclusionFor patients with severe COVID-19, HSBD exhibits similar efficacy to Paxlovid, while combination therapy is more likely to increase the curative efficacy of Omicron variant than monotherapies, with few serious adverse events.

Efficacy and safety of Paxlovid in severe adult patients with SARS-Cov-2 infection: a multicenter randomized controlled study

Nirmatrelvir plus ritonavir (Paxlovid) reduced the risk of hospitalization or death by 89% in high-risk, ambulatory adults with COVID-19. We aimed at studying the efficacy and safety of Paxlovid in hospitalized adult patients with SARS-Cov-2 (Omicron BA.2.2 variant) infection and severe comorbidities. We conducted an open-label, multicenter, randomized controlled trial in which hospitalized adult patients with severe comorbidities were eligible and assigned in a 1:1 ratio to receive either 300mg of nirmatrelvir plus 100mg of ritonavir every 12h for 5 days with standard treatment or only standard treatment. All-cause mortality on day 28, the duration of SARS-CoV-2 RNA clearance, and safety were evaluated. 264 patients (mean age, 70.35 years; 122 [46.21%] female) who met the criteria were enrolled at 5 sites in Shanghai from April 10 to May 19 in 2022. After randomization, a total of 132 patients were assigned to receive Paxlovid treatment plus standard treatment, and 132 patients were assigned to receive only standard treatment. The overall 28-day mortality was 4.92%, 8 patients died in the standard treatment group and 5 died in the Paxlovid plus standard treatment group. There was no significant difference in mortality from any cause at 28 days between the Paxlovid plus standard treatment group and the standard treatment group (absolute risk difference [ARD], 2.27; 95% CI-2.94 to 7.49, P=0.39). There was no significant difference in the duration of SARS-CoV-2 RNA clearance among the two groups (mean days, 10 in Paxlovid plus standard treatment group and 10.50 in the standard treatment group; ARD,-0.62; 95% CI-2.29 to 1.05, P=0.42). The incidence of adverse events that occurred during the treatment period was similar in the two groups (any adverse event, 10.61% with Paxlovid plus standard treatment vs. 7.58% with the standard, P=0.39; serious adverse events, 4.55% vs. 3.788%, P=0.76). Paxlovid showed no significant reduction in the risk of all-cause mortality on day 28 and the duration of SARS-CoV-2 RNA clearance in hospitalized adult COVID-19 patients with severe comorbidities. National Natural Science Foundation of China (grant number: 82172152, 81873944).

Prescribing Nirmatrelvir/Ritonavir for COVID-19 in Advanced CKD.

Prescribing Nirmatrelvir/Ritonavir for COVID-19 in Advanced CKD.

A Mechanistic Absorption and Disposition Model of Ritonavir to Predict Exposure and Drug-Drug Interaction Potential of CYP3A4/5 and CYP2D6 Substrates.

Due to health authority warnings and the recommended limited use of ketoconazole as a model inhibitor of cytochrome P450 (CYP)3A4 in clinical drug-drug interaction (DDI) studies, there is a need to search for alternatives. Ritonavir is a strong inhibitor for CYP3A4/5-mediated DDIs and has been proposed as a suitable alternative to ketoconazole. It can also be used as a weak inhibitor for CYP2D6-mediated DDIs. Most of the currently available physiologically based pharmacokinetic (PBPK) inhibitor models developed for predicting DDIs use first-order absorption models, which do not mechanistically capture the effect of formulations on the systemic exposure of the inhibitor. Thus, the main purpose of the current study was to verify the predictive performance of a mechanistic absorption and disposition model of ritonavir when it was applied to the inhibition of CYP2D6 and CYP3A4/5 by ritonavir. A PBPK model that incorporates formulation characteristics and enzyme kinetic parameters for post-absorptive pharmacokinetic processes of ritonavir was constructed. Key absorption-related parameters in the model were determined using mechanistic modelling of in vitro biopharmaceutics experiments. The model was verified for systemic exposure and DDI risk assessment using clinical observations from 13 and 18 studies, respectively. Maximal inhibition of hepatic (3.53% of the activity remaining) and gut (5.16% of the activity remaining) CYP3A4 activity was observed when ritonavir was orally administered in doses of 100 mg or higher. The PBPK model accurately described the concentrations of ritonavir in the different simulated studies. The prediction accuracy for maximum concentration (Cmax) and area under the plasma concentration versus time curve (AUC) were assessed. The bias (average fold error, AFE) for the prediction of Cmax and AUC was 0.92 and 1.06, respectively, and the precision (absolute average fold error, AAFE) was 1.29 and 1.23, respectively. The PBPK model predictions for all Cmax and AUC ratios when ritonavir was used as an inhibitor of CYP metabolism fell within twofold of the clinical observations. The prediction accuracy for Cmax and AUC ratios had a bias (AFE) of 0.85 and 0.99, respectively, and a precision (AAFE) of 1.21 and 1.33, respectively. The current model, which incorporates formulation characteristics and mechanistic disposition parameters, can be used to assess the DDI potential of CYP3A4/5 and CYP2D6 substrates administered with a twice-daily dose of 100mg of ritonavir for 14 days.

Efficacy and safety of dolutegravir or darunavir in combination with lamivudine plus either zidovudine or tenofovir for second-line treatment of HIV infection (NADIA): week 96 results from a prospective, multicentre, open-label, factorial, randomised, non-inferiority trial

WHO guidelines recommend dolutegravir plus two nucleoside reverse transcriptase inhibitors (NRTIs) for second-line HIV therapy, with NRTI switching from first-line tenofovir to zidovudine. We aimed to examine whether dolutegravir is non-inferior to darunavir, the best-in-class protease inhibitor drug, and whether maintaining tenofovir in second-line therapy is non-inferior to switching to zidovudine. In this prospective, multicentre, open-label, factorial, randomised, non-inferiority trial (NADIA), participants with confirmed HIV first-line treatment failure (HIV-1 RNA ≥1000 copies per mL) were recruited at seven clinical sites in Kenya, Uganda, and Zimbabwe. Following a 2 × 2 factorial design and stratified by site and screening HIV-1 RNA concentration, participants were randomly assigned (1:1:1:1) to receive a 96-week regimen containing either dolutegravir (50 mg once daily) or ritonavir-boosted darunavir (800 mg of darunavir plus 100 mg of ritonavir once daily) in combination with either tenofovir (300 mg once daily) plus lamivudine (300 mg once daily) or zidovudine (300 mg twice daily) plus lamivudine (150 mg twice daily). The NRTI drugs allocated by randomisation were administered orally in fixed-dose combination pills; other drugs were administered orally as separate pills. The previously reported primary outcome was the proportion of participants with a plasma HIV-1 RNA concentration of less than 400 copies per mL at 48 weeks. Here, we report the main secondary outcome: the proportion of participants with a plasma HIV-1 RNA concentration of less than 400 copies per mL at 96 weeks (non-inferiority margin 12%). We analysed this outcome and safety outcomes in the intention-to-treat population, which excluded only those who were randomly assigned in error and withdrawn before receiving trial drugs. This study was registered at ClinicalTrials.gov, NCT03988452, and is complete. Between July 30 and Dec 18, 2019, we screened 783 patients and enrolled 465. One participant was randomly assigned in error and immediately withdrawn. The remaining 464 participants were randomly assigned to receive either dolutegravir (n=235) or ritonavir-boosted darunavir (n=229) and to receive lamivudine plus either tenofovir (n=233) or zidovudine (n=231). At week 96, 211 (90%) of 235 participants in the dolutegravir group and 199 (87%) of 229 participants in the darunavir group had HIV-1 RNA less than 400 copies per mL (percentage point difference 2·9, 95% CI -3·0 to 8·7), indicating non-inferiority. Nine (4%) participants (all in the dolutegravir group) developed dolutegravir resistance; no participants developed darunavir resistance (p=0·0023). In the other randomised comparison, 214 (92%) of 233 patients in the tenofovir group and 196 (85%) of 231 patients in the zidovudine group had HIV-1 RNA less than 400 copies per mL (percentage point difference 7·0, 95% CI 1·2 to 12·8), showing non-inferiority and indicating the superiority of tenofovir (p=0·019). The proportions of participants with any grade 3-4 adverse event were similar between the dolutegravir (26 [11%]) and darunavir (28 [12%]) groups and between the tenofovir (22 [9%]) and zidovudine (32 [14%]) groups. There were no deaths related to study medication. Dolutegravir-based and darunavir-based regimens maintain good viral suppression during 96 weeks; dolutegravir is non-inferior to darunavir but is at greater risk of resistance in second-line therapy. Tenofovir should be continued in second-line therapy, rather than being switched to zidovudine. Janssen.

Oral Nirmatrelvir for High-Risk, Nonhospitalized Adults with Covid-19

BackgroundNirmatrelvir is an orally administered severe acute respiratory syndrome coronavirus 2 main protease (Mpro) inhibitor with potent pan–human-coronavirus activity in vitro.MethodsWe conducted a phase 2–3 double-blind, randomized, controlled trial in which symptomatic, unvaccinated, nonhospitalized adults at high risk for progression to severe coronavirus disease 2019 (Covid-19) were assigned in a 1:1 ratio to receive either 300 mg of nirmatrelvir plus 100 mg of ritonavir (a pharmacokinetic enhancer) or placebo every 12 hours for 5 days. Covid-19–related hospitalization or death from any cause through day 28, viral load, and safety were evaluated.ResultsA total of 2246 patients underwent randomization; 1120 patients received nirmatrelvir plus ritonavir (nirmatrelvir group) and 1126 received placebo (placebo group). In the planned interim analysis of patients treated within 3 days after symptom onset (modified intention-to treat population, comprising 774 of the 1361 patients in the full analysis population), the incidence of Covid-19–related hospitalization or death by day 28 was lower in the nirmatrelvir group than in the placebo group by 6.32 percentage points (95% confidence interval [CI], −9.04 to −3.59; P<0.001; relative risk reduction, 89.1%); the incidence was 0.77% (3 of 389 patients) in the nirmatrelvir group, with 0 deaths, as compared with 7.01% (27 of 385 patients) in the placebo group, with 7 deaths. Efficacy was maintained in the final analysis involving the 1379 patients in the modified intention-to-treat population, with a difference of −5.81 percentage points (95% CI, −7.78 to −3.84; P<0.001; relative risk reduction, 88.9%). All 13 deaths occurred in the placebo group. The viral load was lower with nirmatrelvir plus ritonavir than with placebo at day 5 of treatment, with an adjusted mean difference of −0.868 log10 copies per milliliter when treatment was initiated within 3 days after the onset of symptoms. The incidence of adverse events that emerged during the treatment period was similar in the two groups (any adverse event, 22.6% with nirmatrelvir plus ritonavir vs. 23.9% with placebo; serious adverse events, 1.6% vs. 6.6%; and adverse events leading to discontinuation of the drugs or placebo, 2.1% vs. 4.2%). Dysgeusia (5.6% vs. 0.3%) and diarrhea (3.1% vs. 1.6%) occurred more frequently with nirmatrelvir plus ritonavir than with placebo.ConclusionsTreatment of symptomatic Covid-19 with nirmatrelvir plus ritonavir resulted in a risk of progression to severe Covid-19 that was 89% lower than the risk with placebo, without evident safety concerns. (Supported by Pfizer; ClinicalTrials.gov number, NCT04960202.)

Changes in lipidomic profile by anti-retroviral treatment regimen: An ACTG 5257 ancillary study.

High cardiovascular disease risk in people living with HIV is partly attributed to antiretroviral therapy (ART). Lipid response to ART has been extensively studied, yet, little is known how small molecule lipids respond to Integrase inhibitor-based (INSTI-based) compared to Protease inhibitor-based (PI-based) ART regimens.Ancillary study to a phase 3, randomized, open-label trial [AIDS Clinical Trial Group A5257 Study] in treatment-naive HIV-infected patients randomized in a 1:1:1 ratio to receive ritonavir-boosted atazanavir (ATV/r), ritonavir-boosted darunavir (DRV/r) (both PI-based), or raltegravir with Tenofovir Disoproxil Fumarate-TDF plus emtricitabine (RAL, INSTI-based).We examined small molecule lipid response in a subcohort of 75 participants. Lipidomic assays of plasma samples collected pre- and post-ART treatment (48 weeks) were conducted using ultra-performance liquid chromatography coupled to time-of-flight mass spectrometry. The effect of ART regimens was regressed on lipid species response adjusting for the baseline covariates (lipids, age, sex, race, CD4 level, BMI, and smoking). Results were validated in the Centers for AIDS Research Network of Integrated Clinical Systems study (N = 16).Out of 417 annotated lipids, glycerophospholipids (P = .007) and sphingolipids (P = .028) had a higher response to ATV/r and DRV/r compared to RAL. The lysophosphatidylcholine (LPCs(16:1),(17:1),(20:3)) and phosphophatidylcholine species (PCs(40:7),(38:4)) had an opposite response to RAL versus ATV/r in the discovery and validation cohort. The INSTI-based regimen had an opposite response of ceramide species ((d38:1), (d42:2)), PCs((35:2), (38:4)), phosphatidylethanolamines (PEs(38:4), (38:6)), and sphingomyelin(SMd38:1) species compared with the PI-based regimens. There were no differences observed between 2 PI-based regimens.We observed differences in response of small molecule lipid species by ART regimens in treatment-naive people living with HIV.

Efficacy and Safety of Switching to Dolutegravir With Boosted Darunavir in Virologically Suppressed Adults With HIV-1: A Randomized, Open-Label, Multicenter, Phase 3, Noninferiority Trial: The DUALIS Study

BackgroundDolutegravir (DTG) and boosted darunavir (bDRV) are potent antiretrovirals with a high resistance barrier and might be valuable switch options for people with HIV (PWH).MethodsDUALIS, a randomized, open-label, phase 3b, noninferiority clinical trial, compared the switch to DTG + bDRV (2DR) with continuation of 2 nucleoside reverse transcriptase inhibitors (2NRTI) + bDRV (3DR). PWH with HIV RNA <50 copies/mL taking 2NRTI + bDRV (3DR) for ≥24 weeks (1 accepted blip <200 copies/mL) were randomized to either switch to DTG 50 mg + DRV 800 mg (boosted with 100 mg of ritonavir) or continue taking 3DR. The primary end point (PE) was the proportion of HIV RNA <50 copies/mL at week (W) 48. Change in NRTI backbone was not classified as failure. The estimated sample size for PE analysis was 292; the noninferiority margin was ≤–10.0%.ResultsIn total, 263 subjects were randomized and treated (2DR n = 131, 3DR n = 132; 90.1% male; 89.7% Caucasian; median age [interquartile range], 48 [39–54] years). At W48, 86.3% (n = 113/131) of the 2DR subject and 87.9% (n = 116/132) of the 3DR subjects had HIV RNA <50 copies/mL; the difference between arms was –1.6% (95.48% CI, based on the adjusted alpha level accounting for the interim analysis at W24, –9.9% to +6.7%; discontinuations due to adverse events: 2DR, 4.6% [n = 6]; 3DR, 0.8% [n = 1]). Kaplan-Meier estimates of confirmed HIV RNA ≥50 copies/mL at W48 were 1.6% (n = 2) in the 2DR and 3.1% (n = 4) in the 3DR group. Development of treatment-emergent resistance was not observed.ConclusionsSwitching to DTG + bDRV was noninferior to continuing 3DR in subjects already treated with bDRV.

PIN37 - Economic Evaluation Of Cobicistat-Boosted Darunavir In Hiv-Infected Patients In Mexico

Cobicistat (cobi) is a new booster alternative whose physicochemical properties allow the co-formulation with darunavir to obtain the fixed dose combination of darunavir/cobicistat 800/150 mg (DRV/cobi) in a single tablet per day. This analysis aims to present the economic evaluation of darunavir in a daily dose of 800 mg boosted with 150 mg of cobi or with 100 mg of ritonavir (rtv) in the Mexican context. A complete economic evaluation was carried out through a cost minimization analysis since DRV/cobi and darunavir boosted with rtv (DRV+rtv) have shown bioequivalence in published studies. The efficacy of DRV/cobi is directed only by darunavir as it is the component with antiviral activity; cobi works as an enhancer to achieve optimal concentrations of darunavir in blood. Therefore, the efficiency shown by DRV+rtv is extrapolated to DRV/cobi. The costs of the drugs to calculate the annual cost of treatment were obtained from published sources (1USD = $ 19MXN). A deterministic sensitivity analysis was performed to test the robustness of the model. DRV/cobi showed annual savings per patient of 9.5%. This savings are equivalent to the annual cost of treatment with ritonavir. The annual cost of treatment with DRV/cobi is $2,096 versus the annual cost of DRV+ rtv which is $2,316. The robustness of the analysis was confirmed by a sensitivity analysis on the DRV/cobi acquisition price. The fixed dose combination in one tablet per day of DRV/cobi is a cost-saving and convenient alternative in terms of supply and storage for the institutions in the public health sector in Mexico that use DRV+rtv. Additionally, DRV/cobi favors adherence in patients and decreases the probability of virological failure.

399P - A phase I dose-escalation trial of bi-daily (BID) weekly oral docetaxel as ModraDoc006 in combination with ritonavir

The development of an oral formulation of the anti-cancer drug docetaxel is hampered by its poor bio-availability. In (pre-)clinical studies, absorption from the gastro-intestinal tract could significantly be improved by the use of a solid dispersion formulation and the co-administration of ritonavir, an inhibitor of CYP3A4 and P-glycoprotein. The primary aim of this trial was to assess the feasibility, determine the maximum tolerated dose (MTD) and the recommended phase two dose (RP2D) of the co-administration of the novel oral docetaxel formulation ModraDoc006 (10 mg tablet) with 100 mg of ritonavir (/r) in a BID weekly schedule. Patients with metastatic solid tumors, ≥18 years old, and a WHO performance status ≤2 were included. ModraDoc006/r was administered BID weekly with a 7-12 hour interval. Dose-escalation was performed using a classical 3 + 3 design. Pharmacokinetic sampling was performed during the first two weeks of treatment up to 48 hours after study drug administration. Safety was evaluated using CTCAE v3.0. The dose-limiting toxicity (DLT) period was defined as the first four weeks of treatment. Anti-tumor activity was assessed every 6-8 weeks with a CT or MRI scan. ModraDoc006/r was administered to 26 patients at three dose-levels. Seven DLTs were observed in three patients. Observed DLTs were grade 3 nausea (2x), mucositis (2x), dehydration (1x), neutropenic fever (1x) and inability to restart treatment within 3 weeks due to treatment related toxicity (1x). The most common adverse events observed were nausea, vomiting, diarrhea and fatigue, most often grade 1-2. No hypersensitivity reactions, peripheral polyneuropathy or grade 4 neutropenia were observed. The MTD and RP2D were determined as 30/20 mg ModraDoc006/r (morning/afternoon dose) per week. The area under the plasma concentration time curve (AUC) of docetaxel at this dose was 1250 ±443 ng*h/ml. Three partial responses and six stable diseases were reported as best response to treatment. Oral administration of BID weekly ModraDoc006/r is feasible. The MTD and RP2D of ModraDoc006/r are 30/20 mg per week. Anti-tumor activity is promising.

Metabolism and Disposition of the Hepatitis C Protease Inhibitor Paritaprevir in Humans.

Paritaprevir (also known as ABT-450), a potent NS3-4A serine protease inhibitor [identified by AbbVie (North Chicago, IL) and Enanta Pharmaceuticals (Watertown, MA)] of the hepatitis C virus (HCV), has been developed in combination with ombitasvir and dasabuvir in a three-direct-acting antiviral agent (DAA) oral regimen for the treatment of patients infected with HCV genotype 1. This article describes the mass balance, metabolism, and disposition of paritaprevir in humans. After the administration of a single 200-mg oral dose of [(14)C]paritaprevir coadministered with 100 mg of ritonavir to four male healthy volunteers, the mean total percentage of the administered radioactive dose recovered was 96.5%, with recovery in individual subjects ranging from 96.0% to 96.9%. Radioactivity derived from [(14)C]paritaprevir was primarily eliminated in feces (87.8% of the dose). Radioactivity recovered in urine accounted for 8.8% of the dose. The biotransformation of paritaprevir in humans involves: 1) P450-mediated oxidation on the olefinic linker, the phenanthridine group, the methylpyrazinyl group, or combinations thereof; and 2) amide hydrolysis at the acyl cyclopropane-sulfonamide moiety and the pyrazine-2-carboxamide moiety. Paritaprevir was the major component in plasma [90.1% of total radioactivity in plasma, AUC from time 0 to 12 hours (AUC0-12hours) pool]. Five minor metabolites were identified in plasma, including the metabolites M2, M29, M3, M13, and M6; none of the metabolites accounted for greater than 10% of the total radioactivity. Paritaprevir was primarily eliminated through the biliary-fecal route followed by microflora-mediated sulfonamide hydrolysis to M29 as a major component in feces (approximately 60% of dose). In summary, the biotransformation and clearance pathways of paritaprevir were characterized, and the structures of metabolites in circulation and excreta were elucidated.

Safety and efficacy of the HIV-1 attachment inhibitor prodrug BMS-663068 in treatment-experienced individuals: 24 week results of AI438011, a phase 2b, randomised controlled trial

BMS-663068 is an oral prodrug of BMS-626529, an attachment inhibitor that binds to HIV-1 gp120, blocking viral attachment to host CD4 cells. AI438011 is an ongoing trial investigating the efficacy, safety, and dose-response of BMS-663068 in treatment-experienced, HIV-1-infected patients. Herein we present the results of the primary analysis. AI438011 is a phase 2b, randomised, active-controlled trial, at 53 hospitals and outpatient clinics across ten countries in North and South America, Europe, and Africa. Individuals with an HIV-1 RNA viral load of at least 1000 copies per mL and a BMS-626529 half-maximum inhibitory concentration lower than 100 nmol/L were randomly assigned (1:1:1:1:1) to receive either BMS-663068 at 400 mg twice daily, 800 mg twice daily, 600 mg once daily, or 1200 mg once daily or ritonavir-boosted atazanavir (300 mg of atazanavir and 100 mg of ritonavir once daily), each with 400 mg of raltegravir twice daily and 300 mg of tenofovir disoproxil fumarate once daily as a backbone. The sponsor, participants, and investigators were masked for BMS-663068 dose but not for allocation. Primary endpoints were the proportion of patients with an HIV-1 RNA viral load less than 50 copies per mL (response rate) at week 24 and the frequency of serious adverse events and adverse events leading to discontinuation, up to the week 24 analysis. The primary analyses included all patients who received at least one dose of study drug (modified intention-to-treat population). This study is registered at ClinicalTrials.gov, NCT01384734. Between July 26, 2011, and July 16, 2012, 581 participants were assessed for eligibility. Of these, 254 patients were randomly assigned to receive either BMS-663068 (n=52 for the 400 mg twice daily group, n=50 for the 800 mg twice daily group, n=51 for the 600 mg once daily group, and n=50 for the 1200 mg once daily group) or ritonavir-boosted atazanavir (n=51). 200 patients received at least one dose of BMS-663068, and 51 patients received at least one dose of ritonavir-boosted atazanavir. At week 24, 40 (80%) of 50 patients in the BMS-663068 400 mg twice daily group, 34 (69%) of 49 patients in the 800 mg twice daily group, 39 (76%) of 51 patients in the 600 mg once daily group, and 36 (72%) of 50 patients in the 1200 mg once daily group had an HIV-1 RNA viral load less than 50 copies per mL, compared with 38 (75%) of 51 patients in the ritonavir-boosted atazanavir group. Serious adverse events were noted in 13 (7%) of 200 patients in the BMS-663068 groups and five (10%) of the 51 patients in the ritonavir-boosted atazanavir group. Four (2%) of the 200 patients in the BMS-663068 groups and two (4%) of the 51 patients in the ritonavir-boosted atazanavir group discontinued because of adverse events. No serious adverse events or adverse events leading to discontinuation were BMS-663068-related. Grade 2-4 adverse events related to study drug(s) occurred in 17 (9%) of 200 patients across the BMS-663068 groups and 14 (27%) of 51 patients in the ritonavir-boosted atazanavir group. For the BMS-663068 groups these events were mostly single instances with no dose relation and for the ritonavir-boosted atazanavir group these were mostly gastrointestinal or hepatobiliary disorders associated with hyperbilirubinaemia. In a comparison with ritonavir-boosted atazanavir, efficacy and safety of BMS-663068 up to the week 24 analysis support continued development of BMS-663068, which is being assessed in a phase 3 trial in heavily treatment-experienced individuals. Bristol-Myers Squibb.

An Interferon-free Antiviral Regimen for HCV after Liver Transplantation

BackgroundHepatitis C virus (HCV) infection is the leading indication for liver transplantation worldwide, and interferon-containing regimens are associated with low response rates owing to treatment-limiting toxic effects in immunosuppressed liver-transplant recipients. We evaluated the interferon-free regimen of the NS5A inhibitor ombitasvir coformulated with the ritonavir-boosted protease inhibitor ABT-450 (ABT-450/r), the nonnucleoside NS5B polymerase inhibitor dasabuvir, and ribavirin in liver-transplant recipients with recurrent HCV genotype 1 infection.MethodsWe enrolled 34 liver-transplant recipients with no fibrosis or mild fibrosis, who received ombitasvir–ABT-450/r (at a once-daily dose of 25 mg of ombitasvir, 150 mg of ABT-450, and 100 mg of ritonavir), dasabuvir (250 mg twice daily), and ribavirin for 24 weeks. Selection of the initial ribavirin dose and subsequent dose modifications for anemia were at the investigator's discretion. The primary efficacy end point was a sustained virologic response 12 weeks after the end of treatment.ResultsOf the 34 study participants, 33 had a sustained virologic response at post-treatment weeks 12 and 24, for a rate of 97% (95% confidence interval, 85 to 100). The most common adverse events were fatigue, headache, and cough. Five patients (15%) required erythropoietin; no patient required blood transfusion. One patient discontinued the study drugs owing to adverse events after week 18 but had a sustained virologic response. Blood levels of calcineurin inhibitors were monitored, and dosages were modified to maintain therapeutic levels; no episode of graft rejection was observed during the study.ConclusionsTreatment with the multitargeted regimen of ombitasvir–ABT-450/r and dasabuvir with ribavirin was associated with a low rate of serious adverse events and a high rate of sustained virologic response among liver-transplant recipients with recurrent HCV genotype 1 infection, a historically difficult-to-treat population. (Funded by AbbVie; CORAL-I ClinicalTrials.gov number, NCT01782495.)

HCV cirrhosis at the edge of decompensation: Will paritaprevir with ritonavir, ombitasvir, dasabuvir, and ribavirin solve the need for treatment?

BACKGROUND: The interferon-free combination of the protease inhibitor ABT-450 with ritonavir (ABT-450/r) and the NS5A inhibitor ombitasvir (also known as ABT-267) plus the nonnucleoside polymerase inhibitor dasabuvir (also known as ABT-333) and ribavirin has shown efficacy against the hepatitis C virus (HCV) in patients with HCV genotype 1 infection. In this phase 3 trial, we evaluated this regimen in previously untreated patients with HCV genotype 1 infection and no cirrhosis. METHODS: In this multicenter, randomized, double-blind, placebocontrolled trial, we assigned previously untreated patients with HCV genotype 1 infection, in a 3:1 ratio, to an active regimen consisting of a single-tablet coformulation of ABT-450/r-ombitasvir (at a once-daily dose of 150 mg of ABT-450, 100 mg of ritonavir, and 25 mg of ombitasvir), and dasabuvir (250 mg twice daily) with ribavirin (in doses determined according to body weight) (group A) or matching placebos (group B). The patients received the study treatment during a 12-week double-blind period. The primary end point was sustained virologic response at 12 weeks after the end of Open access under CC BY-NC-ND license. Journal of Hepatology 20

Intracellular accumulation of atazanavir/ritonavir according to plasma concentrations and OATP1B1, ABCB1 and PXR genetic polymorphisms.

The rate of accumulation of atazanavir and ritonavir within cells is still debated due to methodological limitations. Our aim was to measure peripheral blood mononuclear cell (PBMC) concentrations of atazanavir and ritonavir and investigate whether single-nucleotide polymorphisms of OATP, ABCB1, CYP3A4 and PXR genes are involved in intracellular drug penetration. HIV-positive patients administered 300 mg of atazanavir/100 mg of ritonavir were enrolled. Blood sampling was performed at the end of the dosing interval (Ctrough). PBMC-associated and plasma atazanavir and ritonavir concentrations were measured by validated HPLC coupled with a single mass detector (HPLC-MS) and HPLC-photodiode array (PDA) methods, respectively. Cell count and mean cellular volume were determined using a Coulter counter. Genotyping was conducted using real-time PCR. Thirty-five patients were enrolled. Median atazanavir and ritonavir intracellular concentrations were 1844 and 716 ng/mL, respectively. Median plasma concentrations were 645 ng/mL for atazanavir and 75 ng/mL for ritonavir, while median intracellular/plasma concentration ratios were 2.4 and 9.2, respectively. Median ritonavir intracellular concentrations were higher for OATP1B1 521 T→C TC or CC carriers and for PXR 44477 A→G AG or GG carriers. Atazanavir intracellular/plasma concentration ratios were higher in patients GG for the ABCB1 2677 G→T single-nucleotide polymorphism (SNP) compared with GT and TT groups. Our study showed a higher intracellular ritonavir accumulation than previously reported. Ritonavir intracellular concentrations were associated with OATP1B1 521 and PXR 44477 SNPs while intracellular atazanavir exposure was associated with the ABCB1 2677 SNP. Further clinical studies are necessary in order to confirm these data.

ABT-450/r–Ombitasvir and Dasabuvir with or without Ribavirin for HCV

BackgroundThe interferon-free regimen of ABT-450 with ritonavir (ABT-450/r), ombitasvir, and dasabuvir with or without ribavirin has shown efficacy in inducing a sustained virologic response in a phase 2 study involving patients with hepatitis C virus (HCV) genotype 1 infection. We conducted two phase 3 trials to examine the efficacy and safety of this regimen in previously untreated patients with HCV genotype 1 infection and no cirrhosis.MethodsWe randomly assigned 419 patients with HCV genotype 1b infection (PEARL-III study) and 305 patients with genotype 1a infection (PEARL-IV study) to 12 weeks of ABT-450/r–ombitasvir (at a once-daily dose of 150 mg of ABT-450, 100 mg of ritonavir, and 25 mg of ombitasvir), dasabuvir (250 mg twice daily), and ribavirin administered according to body weight or to matching placebo for ribavirin. The primary efficacy end point was a sustained virologic response (an HCV RNA level of <25 IU per milliliter) 12 weeks after the end of treatment.ResultsThe study regimen resulted in high rates of sustained virologic response among patients with HCV genotype 1b infection (99.5% with ribavirin and 99.0% without ribavirin) and among those with genotype 1a infection (97.0% and 90.2%, respectively). Of patients with genotype 1b infection, 1 had virologic failure, and 2 did not have data available at post-treatment week 12. Among patients with genotype 1a infection, the rate of virologic failure was higher in the ribavirin-free group than in the ribavirin group (7.8% vs. 2.0%). In both studies, decreases in the hemoglobin level were significantly more common in patients receiving ribavirin. Two patients (0.3%) discontinued the study drugs owing to adverse events. The most common adverse events were fatigue, headache, and nausea.ConclusionsTwelve weeks of treatment with ABT-450/r–ombitasvir and dasabuvir without ribavirin was associated with high rates of sustained virologic response among previously untreated patients with HCV genotype 1 infection. Rates of virologic failure were higher without ribavirin than with ribavirin among patients with genotype 1a infection but not among those with genotype 1b infection. (Funded by AbbVie; PEARL-III and PEARL-IV ClinicalTrials.gov numbers, NCT01767116 and NCT01833533.)