Evaluation of BMS-986142, a reversible Bruton's tyrosine kinase inhibitor, for the treatment of rheumatoid arthritis: a phase 2, randomised, double-blind, dose-ranging, placebo-controlled, adaptive design study

BACKGROUND

Bruton's tyrosine kinase (BTK) is a promising biological target for rheumatoid arthritis treatment. This study examined safety, efficacy, and pharmacokinetics of BMS-986142, an oral, reversible BTK inhibitor. The aim was to compare the efficacy of BMS-986142 with placebo on a background of methotrexate in patients with moderate-to-severe rheumatoid arthritis and inadequate response to methotrexate.

METHODS

This phase 2, randomised, double-blind, dose-ranging, placebo-controlled, adaptive design study was conducted across 14 countries and 79 clinical sites. We recruited people aged 18 years or older with a documented diagnosis of rheumatoid arthritis at least 16 weeks before screening with an inadequate response to methotrexate with or without inadequate response to up to two tumour necrosis factor inhibitors. Participants were randomly assigned (1:1:1:1) to oral BMS-986142 (100 mg, 200 mg, or 350 mg) or placebo once daily for 12 weeks. Randomisation was done using an interactive voice response system and stratified by prior treatment status and geographical region. All participants, care providers, investigators, and outcome assessors were masked to treatment allocation. Co-primary endpoints were 20% and 70% improvement in American College of Rheumatology criteria (ACR20 and ACR70) at week 12. Primary endpoints were assessed in the efficacy analysis population (all randomised patients who received at least one dose of the study drug and did not discontinue the study). Safety endpoints were analysed in the as-treated analysis population, which included all patients who received at least one dose of the study drug (patients were grouped according to the treatment they actually received vs the treatment to which they were randomised). This trial was registered with ClinicalTrials.gov, number NCT02638948.

FINDINGS

Between Feb 24, 2016 and May 3, 2018, 248 patients were randomised (73 in the BMS-986142 100 mg group, 73 in the 200 mg group, 26 in the 350 mg group, and 75 in the placebo group; one post-randomisation exclusion); mean age was 56·7 years (SD 12·7); 214 (87%) of 247 were women, 33 (13%) were men, and 188 (76%) were White. Pre-specified interim analysis resulted in discontinuation of the 350 mg BMS-986142 dose due to elevated liver enzymes and absence of benefit versus placebo. Co-primary endpoints were not met. Response rates for ACR20 (placebo: 23 [31%] of 75; 100 mg: 26 [36%] of 73; 200 mg: 31 [42%] of 73) and ACR70 (placebo: three [4%] of 75; 100 mg: three [4%] of 73; 200 mg: seven [10%] of 73) were not significantly different to placebo; estimate of difference versus placebo for ACR20 was 4·9 (95% CI -10·2 to 20·1; p=0·52) for 100 mg and 11·8 (-3·6 to 27·2; p=0·14) for 200 mg, and for ACR70 the estimate of difference was 0·1 (-16·0 to 16·5; nominal p=1·00) for 100 mg and 5·6 (-10·5 to 21·9; nominal p=0·21) for 200 mg. Six patients experienced serious adverse events (four in the placebo group [mouth ulceration, open globe injury, rheumatoid arthritis flare, and endometrial adenocarcinoma] and two in the BMS-986142 100 mg group [angina pectoris and intestinal obstruction]); there were no deaths.

INTERPRETATION

Further investigation of BMS-986142 in people with rheumatoid arthritis is not warranted. An absence of clinical benefit in this study, together with other study results, highlights the need for additional research on the extent of BTK inhibition, treatment duration, and adequacy of drug distribution to inflammation sites, to understand the potential utility of BTK inhibition as a therapeutic strategy for rheumatoid arthritis.

FUNDING

Bristol Myers Squibb.

Safety, pharmacokinetics and pharmacodynamics of branebrutinib (BMS-986195), a covalent, irreversible inhibitor of Bruton's tyrosine kinase: Randomised phase I, placebo-controlled trial in healthy participants

Aims

Branebrutinib (BMS‐986195) is a potent, highly selective, oral, small‐molecule, covalent inhibitor of Bruton's tyrosine kinase (BTK). This study evaluated safety, pharmacokinetics and pharmacodynamics of branebrutinib in healthy participants.

Methods

This double‐blind, placebo‐controlled, single‐ and multiple‐ascending dose (SAD; MAD) Phase I study (NCT02705989) enrolled participants into 3 parts: SAD, MAD and JMAD (MAD in first‐generation Japanese participants). In each part, participants were randomised 3:1 to receive branebrutinib (SAD: 0.3–30 mg; [J]MAD: 0.3–10 mg) or placebo. Participants in the MAD parts received branebrutinib daily for 14 days and were followed for 14 days postdosing. Safety was assessed by monitoring, laboratory and physical examinations, vital signs, and recording adverse events (AEs). Pharmacodynamics were assessed with a mass spectrometry assay that measured drug‐occupied and free BTK.

Results

The SAD, MAD and JMAD parts of the study included 40, 32 and 24 participants. Branebrutinib was well tolerated and AEs were mild/moderate, except for 1 serious AE that led to discontinuation. Branebrutinib was rapidly absorbed, with maximum plasma concentration occurring within 1 hour and a half‐life of 1.2—1.7 hours, dropping to undetectable levels within 24 hours. BTK occupancy was rapid, with 100% occupancy reached after a single 10‐mg dose. BTK occupancy decayed predictably over time (mean half‐life in MAD panels: 115–154 hours), such that pharmacodynamic effects were maintained after branebrutinib plasma levels fell below the lower limit of quantification.

Conclusion

Rapid and high occupancy of BTK and the lack of notable safety findings support further clinical development of branebrutinib.

Immune checkpoint inhibition in sepsis: a Phase 1b randomized study to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of nivolumab

PURPOSE

Sepsis-associated immunosuppression increases hospital-acquired infection and viral reactivation risk. A key underlying mechanism is programmed cell death protein-1 (PD-1)-mediated T-cell function impairment. This is one of the first clinical safety and pharmacokinetics (PK) assessments of the anti-PD-1 antibody nivolumab and its effect on immune biomarkers in sepsis.

METHODS

Randomized, double-blind, parallel-group, Phase 1b study in 31 adults at 10 US hospital ICUs with sepsis diagnosed ≥ 24 h before study treatment, ≥ 1 organ dysfunction, and absolute lymphocyte count ≤ 1.1 × 10³ cells/μL. Participants received one nivolumab dose [480 mg (n = 15) or 960 mg (n = 16)]; follow-up was 90 days. Primary endpoints were safety and PK parameters.

RESULTS

Twelve deaths occurred [n = 6 per study arm; 40% (480 mg) and 37.5% (960 mg)]. Serious AEs occurred in eight participants [n = 1, 6.7% (480 mg); n = 7, 43.8% (960 mg)]. AEs considered by the investigator to be possibly drug-related and immune-mediated occurred in five participants [n = 2, 13.3% (480 mg); n = 3, 18.8% (960 mg)]. Mean ± SD terminal half-life was 14.7 ± 5.3 (480 mg) and 15.8 ± 7.9 (960 mg) days. All participants maintained > 90% receptor occupancy (RO) 28 days post-infusion. Median (Q1, Q3) mHLA-DR levels increased to 11,531 (6528, 19,495) and 11,449 (6225, 16,698) mAbs/cell in the 480- and 960-mg arms by day 14, respectively. Pro-inflammatory cytokine levels did not increase.

CONCLUSIONS

In this sepsis population, nivolumab administration did not result in unexpected safety findings or indicate any 'cytokine storm'. The PK profile maintained RO > 90% for ≥ 28 days. Further efficacy and safety studies are warranted. TRIAL REGISTRATION NUMBER (CLINICALTRIALS.GOV): NCT02960854.

Inhibitors of HIV-1 Attachment: The Discovery and Development of Temsavir and its Prodrug Fostemsavir

Human immunodeficiency virus-1 (HIV-1) infection currently requires lifelong therapy with drugs that are used in combination to control viremia. The indole-3-glyoxamide 6 was discovered as an inhibitor of HIV-1 infectivity using a phenotypic screen and derivatives of this compound were found to interfere with the HIV-1 entry process by stabilizing a conformation of the virus gp120 protein not recognized by the host cell CD4 receptor. An extensive optimization program led to the identification of temsavir (31), which exhibited an improved antiviral and pharmacokinetic profile compared to 6 and was explored in phase 3 clinical trials as the phosphonooxymethyl derivative fostemsavir (35), a prodrug designed to address dissolution- and solubility-limited absorption issues. In this drug annotation, we summarize the structure-activity and structure-liability studies leading to the discovery of 31 and the clinical studies conducted with 35 that entailed the development of an extended release formulation suitable for phase 3 clinical trials.

Clinical Trial of the Anti-PD-L1 Antibody BMS-936559 in HIV-1 Infected Participants on Suppressive Antiretroviral Therapy

Background

Reversing immune exhaustion with an anti-PD-L1 antibody may improve human immunodeficiency virus type 1 (HIV-1)-specific immunity and increase clearance of HIV-1-expressing cells.

Methods

We conducted a phase I, randomized, double-blind, placebo-controlled, dose-escalating study of BMS-936559, including HIV-1-infected adults aged >18 to <70 years on suppressive antiretroviral therapy with CD4+ counts >350 cells/μL and detectable plasma HIV-1 RNA by single-copy assay. Data on single infusions of BMS-936559 (0.3 mg/kg) versus placebo are described. The primary outcomes were safety defined as any grade 3 or greater or immune-related adverse event (AE) and the change in HIV-1 Gag-specific CD8+ T cell responses from baseline to day 28 after infusion.

Results

Eight men enrolled: 6 received 0.3 mg/kg of BMS-936559, and 2 received placebo infusions. There were no BMS-936559-related grade 3 or greater AEs. In 1 participant, asymptomatic hypophysitis (a protocol-defined immune-related AE) was identified 266 days after BMS-936559 infusion; it resolved over time. The mean percentage of HIV-1 Gag-specific CD8+ T cells expressing interferon γ increased from baseline (0.09%) through day 28 (0.20%; P = .14), driven by substantial increases in 2 participants who received BMS-936559.

Conclusions

In this first evaluation of an immunologic checkpoint inhibitor in healthy HIV-1-infected persons, single low-dose BMS-936559 infusions appeared to enhance HIV-1-specific immunity in a subset of participants.

Clinical Trials Registration

NCT02028403.

Discovery of a Hepatitis C Virus NS5B Replicase Palm Site Allosteric Inhibitor (BMS-929075) Advanced to Phase 1 Clinical Studies

The hepatitis C virus (HCV) NS5B replicase is a prime target for the development of direct-acting antiviral drugs for the treatment of chronic HCV infection. Inspired by the overlay of bound structures of three structurally distinct NS5B palm site allosteric inhibitors, the high-throughput screening hit anthranilic acid 4, the known benzofuran analogue 5, and the benzothiadiazine derivative 6, an optimization process utilizing the simple benzofuran template 7 as a starting point for a fragment growing approach was pursued. A delicate balance of molecular properties achieved via disciplined lipophilicity changes was essential to achieve both high affinity binding and a stringent targeted absorption, distribution, metabolism, and excretion profile. These efforts led to the discovery of BMS-929075 (37), which maintained ligand efficiency relative to early leads, demonstrated efficacy in a triple combination regimen in HCV replicon cells, and exhibited consistently high oral bioavailability and pharmacokinetic parameters across preclinical animal species. The human PK properties from the Phase I clinical studies of 37 were better than anticipated and suggest promising potential for QD administration.

Discovery of a Potent Acyclic, Tripeptidic, Acyl Sulfonamide Inhibitor of Hepatitis C Virus NS3 Protease as a Back-up to Asunaprevir with the Potential for Once-Daily Dosing

The discovery of a back-up to the hepatitis C virus NS3 protease inhibitor asunaprevir (2) is described. The objective of this work was the identification of a drug with antiviral properties and toxicology parameters similar to 2, but with a preclinical pharmacokinetic (PK) profile that was predictive of once-daily dosing. Critical to this discovery process was the employment of an ex vivo cardiovascular (CV) model which served to identify compounds that, like 2, were free of the CV liabilities that resulted in the discontinuation of BMS-605339 (1) from clinical trials. Structure-activity relationships (SARs) at each of the structural subsites in 2 were explored with substantial improvement in PK through modifications at the P1 site, while potency gains were found with small, but rationally designed structural changes to P4. Additional modifications at P3 were required to optimize the CV profile, and these combined SARs led to the discovery of BMS-890068 (29).

Daclatasvir + asunaprevir + beclabuvir ± ribavirin for chronic HCV genotype 1-infected treatment-naive patients

BACKGROUND AND AIMS

This phase-2b study examined the safety and efficacy of an all-oral, interferon-free combination of the NS5A replication complex inhibitor daclatasvir (DCV), the NS3 protease inhibitor asunaprevir (ASV), and the nonnucleoside NS5B polymerase inhibitor beclabuvir (BCV) with or without ribavirin in patients with HCV genotype (GT) 1 infection.

METHODS

A total of 187 patients received 12 weeks of DCV 30 mg BID plus ASV 200 mg BID and BCV 150 mg BID (n = 86) or 75 mg BID with (n = 21) or without (n = 80) weight-based ribavirin BID. The primary endpoint was HCV RNA <25 IU/ml at post-treatment week 12 (SVR12).

RESULTS

Overall, 90% of patients (169/187) in the combined treatment groups achieved SVR on or after post-treatment week 12. SVR rates were similar across subgroups (by mITT analysis), i.e. patients with cirrhosis (88%, 14/16), HCV GT-1a (90%, 137/155), and IL28B non-CC genotype (90%, 115/128). There were no drug-related serious AEs or grade 4 AEs. The most frequently reported AEs were headache, diarrhoea, fatigue and nausea. Addition of ribavirin to DCV+ASV+BCV was associated with decreased haemoglobin, compared with DCV+ASV+BCV alone. There were six grade 3/4 laboratory abnormalities noted, all unrelated to the study drugs. Viral breakthrough occurred in 2.5-4.8% of patients across groups and appeared unrelated to BCV dose or ribavirin inclusion.

CONCLUSIONS

Results support phase 3 evaluation of a twice-daily, fixed-dose formulation of this DCV+ASV+BCV regimen with or without ribavirin in HCV GT-1-infected patients.

The pharmacokinetics of daclatasvir and asunaprevir administered in combination in studies in healthy subjects and patients infected with hepatitis C virus

BACKGROUND AND OBJECTIVES

The combination of direct-acting antiviral agents in patients with chronic hepatitis C virus (HCV) infection has demonstrated clinical benefit; however, evaluation of potential drug-drug interactions is required prior to therapy.

METHODS

An open-label study assessed the pharmacokinetics and tolerability of the HCV NS5A replication complex inhibitor daclatasvir and the HCV NS3 protease inhibitor asunaprevir when co-administered in healthy subjects. Daclatasvir 60 mg once daily and asunaprevir 600 mg twice daily were dosed for 7 days alone followed by combination dosing for 14 days at 30 mg once daily and 200 mg twice daily, respectively. Further assessments were provided comparing exposures from the current study with those from studies in HCV-infected patients receiving either the same or higher doses of daclatasvir or asunaprevir administered alone or together.

RESULTS

Dose-normalized daclatasvir and asunaprevir morning exposures were comparable with control in healthy subjects, with geometric mean area under the concentration-time curve ratios of 1.202 (90 % CI 1.113-1.298) and 0.868 (90 % CI 0.726-1.038), respectively. In HCV patients daclatasvir and asunaprevir exposures were largely comparable, when administered together or alone.

CONCLUSIONS

Additional data support the conclusion that there is no clinically meaningful interaction between daclatasvir and asunaprevir in either healthy subjects or HCV-infected patients, including those also receiving peginterferon-α/ribavirin, and that the combination of daclatasvir 60 mg once daily and asunaprevir 200 mg twice daily is generally well-tolerated.

The discovery of asunaprevir (BMS-650032), an orally efficacious NS3 protease inhibitor for the treatment of hepatitis C virus infection

The discovery of asunaprevir (BMS-650032, 24) is described. This tripeptidic acylsulfonamide inhibitor of the NS3/4A enzyme is currently in phase III clinical trials for the treatment of hepatitis C virus infection. The discovery of 24 was enabled by employing an isolated rabbit heart model to screen for the cardiovascular (CV) liabilities (changes to HR and SNRT) that were responsible for the discontinuation of an earlier lead from this chemical series, BMS-605339 (1), from clinical trials. The structure-activity relationships (SARs) developed with respect to CV effects established that small structural changes to the P2* subsite of the molecule had a significant impact on the CV profile of a given compound. The antiviral activity, preclincial PK profile, and toxicology studies in rat and dog supported clinical development of BMS-650032 (24).

Randomized trial of daclatasvir and asunaprevir with or without PegIFN/RBV for hepatitis C virus genotype 1 null responders

BACKGROUND & AIMS

Patients with chronic hepatitis C virus (HCV) infection and prior null response (<2 log HCV RNA decline after ⩾ 12 weeks of PegIFN/RBV) have limited options. We evaluated daclatasvir plus once- or twice-daily asunaprevir in non-cirrhotic genotype 1 null responders.

METHODS

In this randomized, phase 2a, open-label, 24-week treatment study, 101 patients received daclatasvir (60 mg) once-daily. In addition, 38 genotype 1b patients received asunaprevir (200mg) twice- (DUAL A1) or once-daily (DUAL A2); 36 genotype 1a and 5 genotype 1b patients received asunaprevir twice- (QUAD B1) or once-daily (QUAD B2) plus PegIFN/RBV; and 18 genotype 1a and 4 genotype 1b patients received asunaprevir twice-daily plus ribavirin (TRIPLE B3). The primary endpoint was undetectable HCV RNA 12 weeks post-treatment (sustained virologic response, SVR12).

RESULTS

Across all groups, mean HCV RNA was ⩾ 6 log IU/ml, and 99% of patients had a non-CC IL28B genotype. SVR12 rates were 78% (A1), 65% (A2), 95% (B1), and 95% (B2). In B3, most genotype 1a patients experienced virologic breakthrough. The most common adverse events were headache, diarrhea, and asthenia. Grade 3-4 aminotransferase elevations were infrequent and not treatment-limiting.

CONCLUSIONS

In genotype 1 null responders, daclatasvir plus twice-daily asunaprevir DUAL therapy is effective for most genotype 1b patients, and daclatasvir, asunaprevir, and PegIFN/RBV QUAD therapy is effective for nearly all genotype 1a and 1b patients; but neither DUAL nor TRIPLE therapy is effective for genotype 1a patients. Interferon-free regimens including daclatasvir and twice-daily asunaprevir for genotype 1 null responders should be tailored to subtype.

Efficacy of an interferon- and ribavirin-free regimen of daclatasvir, asunaprevir, and BMS-791325 in treatment-naive patients with HCV genotype 1 infection

BACKGROUND & AIMS

The combination of peginterferon and ribavirin with telaprevir or boceprevir is the standard treatment of hepatitis C virus (HCV) genotype 1 infection. However, these drugs are not well tolerated because of their side effects and suboptimal virologic responses. In a phase 2a, open-label study, we examined the safety and efficacy of an interferon-free, ribavirin-free regimen of direct-acting antivirals, comprising daclatasvir (an NS5A replication complex inhibitor), asunaprevir (an NS3 protease inhibitor), and BMS-791325 (a non-nucleoside NS5B inhibitor), in patients with chronic HCV infection.

METHODS

We analyzed data from 66 treatment-naive patients with HCV genotype 1 infection without cirrhosis who were assigned randomly to groups given daclatasvir (60 mg, once daily), asunaprevir (200 mg, twice daily), and BMS-791325 (75 or 150 mg, twice daily) for 12 or 24 weeks. The primary end point was an HCV-RNA level less than 25 IU/mL at 12 weeks after treatment (sustained virologic response at 12 weeks [SVR12]).

RESULTS

In 64 patients, HCV-RNA levels were less than 25 IU/mL by week 4 of treatment (including 48 of 49 patients with HCV genotype 1a infection and 45 of 46 patients with the non-CC interleukin 28B genotype). Sixty-one patients (92%) achieved SVR12, based on a modified intention-to-treat analysis. Virologic responses were similar between 12 and 24 weeks of treatment. During the study, 2 patients experienced viral breakthrough and 1 patient relapsed. There were no grade 3-4 increases in levels of alanine or aspartate aminotransferases or bilirubin; there were no deaths or discontinuations resulting from serious adverse events or adverse events related to the treatment regimen. The most common adverse events were headache, asthenia, and gastrointestinal symptoms.

CONCLUSIONS

In a phase 2a study, the all-oral, interferon-free, and ribavirin-free regimen of daclatasvir, asunaprevir, and BMS-791325 was well tolerated and achieved high rates of SVR12 in patients with HCV genotype 1 infection. Further studies of this regimen are warranted. ClinicalTrials.gov, number NCT01455090.

Daclatasvir plus sofosbuvir for previously treated or untreated chronic HCV infection

BACKGROUND

All-oral combination therapy is desirable for patients with chronic hepatitis C virus (HCV) infection. We evaluated daclatasvir (an HCV NS5A replication complex inhibitor) plus sofosbuvir (a nucleotide analogue HCV NS5B polymerase inhibitor) in patients infected with HCV genotype 1, 2, or 3.

METHODS

In this open-label study, we initially randomly assigned 44 previously untreated patients with HCV genotype 1 infection and 44 patients infected with HCV genotype 2 or 3 to daclatasvir at a dose of 60 mg orally once daily plus sofosbuvir at a dose of 400 mg orally once daily, with or without ribavirin, for 24 weeks. The study was expanded to include 123 additional patients with genotype 1 infection who were randomly assigned to daclatasvir plus sofosbuvir, with or without ribavirin, for 12 weeks (82 previously untreated patients) or 24 weeks (41 patients who had previous virologic failure with telaprevir or boceprevir plus peginterferon alfa-ribavirin). The primary end point was a sustained virologic response (an HCV RNA level of <25 IU per milliliter) at week 12 after the end of therapy.

RESULTS

Overall, 211 patients received treatment. Among patients with genotype 1 infection, 98% of 126 previously untreated patients and 98% of 41 patients who did not have a sustained virologic response with HCV protease inhibitors had a sustained virologic response at week 12 after the end of therapy. A total of 92% of 26 patients with genotype 2 infection and 89% of 18 patients with genotype 3 infection had a sustained virologic response at week 12. High rates of sustained virologic response at week 12 were observed among patients with HCV subtypes 1a and 1b (98% and 100%, respectively) and those with CC and non-CC IL28B genotypes (93% and 98%, respectively), as well as among patients who received ribavirin and those who did not (94% and 98%, respectively). The most common adverse events were fatigue, headache, and nausea.

CONCLUSIONS

Once-daily oral daclatasvir plus sofosbuvir was associated with high rates of sustained virologic response among patients infected with HCV genotype 1, 2, or 3, including patients with no response to prior therapy with telaprevir or boceprevir. (Funded by Bristol-Myers Squibb and Pharmasset (Gilead); A1444040 ClinicalTrials.gov number, NCT01359644.).

Pharmacokinetics of the NS3 Protease Inhibitor, Asunaprevir (ASV, BMS-650032), in Phase I Studies in Subjects With or Without Chronic Hepatitis C

Asunaprevir (BMS-650032, ASV) is a potent, selective hepatitis C virus (HCV) NS3 protease inhibitor in clinical evaluation for chronic hepatitis C treatment. ASV pharmacokinetics were evaluated in four single- and multiple-ascending-dose studies in healthy subjects or subjects with HCV genotype 1 infection and in human mass balance and food-effect studies. Median Tmax was 2-4 hours. Although T½ was 14-23 hours, oral clearance was high (302-668 L/h at doses ≥100 mg). Steady state was achieved by Day 7. The ASV dose-exposure relationship was disproportionate at doses <200 mg but largely proportional for Cmax and AUC at clinically relevant doses of 200-600 mg (capsule). Following multiple doses, the accumulation index for AUC[TAU] and Cmin was lower at doses ≥200 mg, suggestive of possible auto-induction. ASV exposure increased when administered as a solution (vs. suspension) or with a high-fat meal; the effect was greater for Cmax than AUC, suggesting a saturable first-pass process, the mechanism of which remains to be defined. The apparent complexities of ASV pharmacokinetics will be further explored; nevertheless, data from these studies and antiviral activity in phase 2a/2b studies support further development. Clinical studies are ongoing with ASV in combination with other antivirals.

Phase I dose escalation study of nivolumab (Anti-PD-1; BMS-936558; ONO-4538) in patients (pts) with advanced hepatocellular carcinoma (HCC) with or without chronic viral hepatitis

TPS3111

Background: Pts with advanced HCC have limited treatment options. Sorafenib, the current standard of care, achieves only modest overall survival improvements. There is a clear etiologic association between HCC and prior/concurrent hepatitis B (HBV) or C (HCV) infection. Programmed death-1 (PD-1) is an immune checkpoint receptor that inhibits T-cell activation when bound by ligands including PD-L1/L2. PD-L1 overexpression has been noted on HCC tumors, and PD-1/PD-L1 interaction may contribute to viral hepatitis induced T-cell exhaustion. Nivolumab, a PD-1 receptor blocking antibody, has shown efficacy against various solid tumor types in Ph 1 trials. We hypothesized that blockade of PD-1/PD-L1 interaction could enhance T-cell activation and mediate antitumor and/or antiviral activity in HCC pts. We describe a phase I, dose-escalation study of nivolumab in advanced HCC pts. Methods: Successive pt cohorts with histologically confirmed advanced HCC with/without HBV or HCV infection (N=72 max) will be treated on 3 distinct arms with IV nivolumab at 0.3, 1 and 3.0 mg/kg (uninfected or HCV-infected pts) or 0.1, 0.3, 1 and 3.0 mg/kg (HBV-infected pts) every 2 weeks using a 3+3 escalation scheme. Pts must have progressive disease or intolerance after ≥1 line of therapy or have refused sorafenib treatment, and a Child-Pugh class A. HBV-infected pts must be receiving antiviral therapy (viral DNA <100 IU/mL) for ≥3 months. Pts with brain metastasis, encephalopathy, prior/current ascites requiring paracentesis, history of recent variceal bleeding, active coinfection with HIV, or both HBV and HCV, or concurrent hepatitis D and HBV infection will be excluded. Primary endpoints include characterization of safety, tolerability, dose-limiting toxicities and maximum tolerated dose of nivolumab. Secondary endpoints include assessment of the preliminary antitumor activity (per modified RECIST for HCC), PK and immunogenicity. Exploratory endpoints include evaluation of the relationship between tumor PD-L1 expression and clinical outcome, and nivolumab’s antiviral and immunoregulatory activity in peripheral blood and/or tumor specimens. Clinical trial information: NCT01658878.

The Effect of Ravuconazole on the Pharmacokinetics of Nelfinavir in Healthy Male Volunteers

An open-label, nonrandomized study was conducted to assess the effect of ravuconazole on the pharmacokinetics of concomitantly administered nelfinavir. Healthy volunteers received 750 mg nelfinavir on day 1, 750 mg nelfinavir and 400 mg ravuconazole on day 2, 400 mg ravuconazole on days 3 to 28, and 750 mg nelfinavir and 400 mg ravuconazole on day 29. The geometric means of C(max) and area under the curve of nelfinavir coadministered with ravuconazole were 30.7% and 31.9% higher on day 2 and 7.9% and 16.2% lower on day 29, respectively, compared to the corresponding values on day 1. These findings are consistent with the potential for ravuconazole to both inhibit and induce CYP3A isozymes. The alterations in the systemic exposure to nelfinavir were within the range defined by the 90% confidence interval. The study data indicate that coadministration of ravuconazole did not result in a clinically significant change in the plasma levels of nelfinavir.

Absence of a Pharmacokinetic Interaction Between Entecavir and Adefovir

This study evaluated the effect of entecavir on the pharmacokinetics of adefovir and the effect of adefovir on the pharmacokinetics of entecavir using a fixed-sequence crossover design in healthy adult subjects. Subjects received 10 mg of adefovir once daily on days 1 to 4, 1 mg of entecavir on days 5 to 14, and 1 mg of entecavir plus 10 mg of adefovir on days 15 to 24. Pharmacokinetic assessments were performed on days 4 and 24 for adefovir and on days 14 and 24 for entecavir. The geometric mean ratios (90% confidence interval) for area under the plasma concentration-time curve in 1 dosing interval, peak plasma concentration, and 24-hour postdose plasma concentration of entecavir when coadministered with adefovir and of adefovir when coadministered with entecavir were within the prespecified 0.80 to 1.25 no-effect range. Entecavir and adefovir were well tolerated when administered in combination. Therefore, the pharmacokinetic data generated in this study indicate that entecavir and adefovir can be coadministered without the need for dosage adjustment.

The Influence of Renal Function on Hydroxyurea Pharmacokinetics in Adults With Sickle Cell Disease

This was an open-label, nonrandomized, 2-center study conducted to assess the influence of renal function on the pharmacokinetics of hydroxyurea in adults with sickle cell disease (SCD). Seventeen patients were divided into 5 groups: normal renal function (n = 7), mild renal impairment (n = 2), moderate renal impairment (n = 3), severe renal impairment (n = 2), and end-stage renal disease (ESRD, n = 3). Except for patients with ESRD, all the patients received a 15-mg/kg single oral dose of hydroxyurea. Patients with ESRD received a 15-mg/kg oral dose of hydroxyurea on 2 occasions. Blood and urine samples were collected for the assessment of hydroxyurea pharmacokinetics. The results indicate that the systemic exposure increases and the urinary recovery decreases as the degree of renal insufficiency worsens. On the basis of the exposure and the apparent clearance from the current and 2 historical studies, the authors have proposed an initial dosing regimen of hydroxyurea (7.5 mg/kg/day) for SCD patients with CL(cr) <60 mL/min. This dosing strategy is anticipated to provide a safe dose for SCD patients with renal impairment.

Inhibitors of human immunodeficiency virus type 1 (HIV-1) attachment. 12. Structure-activity relationships associated with 4-fluoro-6-azaindole derivatives leading to the identification of 1-(4-benzoylpiperazin-1-yl)-2-(4-fluoro-7-[1,2,3]triazol-1-yl-1h-pyrrolo[2,3-c]pyridin-3-yl)ethane-1,2-dione (BMS-585248)

A series of highly potent HIV-1 attachment inhibitors with 4-fluoro-6-azaindole core heterocycles that target the viral envelope protein gp120 has been prepared. Substitution in the 7-position of the azaindole core with amides (12a,b), C-linked heterocycles (12c-l), and N-linked heterocycles (12m-u) provided compounds with subnanomolar potency in a pseudotype infectivity assay and good pharmacokinetic profiles in vivo. A predictive model was developed from the initial SAR in which the potency of the analogues correlated with the ability of the substituent in the 7-position of the azaindole to adopt a coplanar conformation by either forming internal hydrogen bonds or avoiding repulsive substitution patterns. 1-(4-Benzoylpiperazin-1-yl)-2-(4-fluoro-7-[1,2,3]triazol-1-yl-1H-pyrrolo[2,3-c]pyridin-3-yl)ethane-1,2-dione (BMS-585248, 12m) exhibited much improved in vitro potency and pharmacokinetic properties than the previous clinical candidate BMS-488043 (1). The predicted low clearance in humans, modest protein binding, and good potency in the presence of 40% human serum for 12m led to its selection for human clinical studies.

Preliminary study of two antiviral agents for hepatitis C genotype 1

BACKGROUND

Patients with chronic hepatitis C virus (HCV) infection who have not had a response to therapy with peginterferon and ribavirin may benefit from the addition of multiple direct-acting antiviral agents to their treatment regimen.

METHODS

This open-label, phase 2a study included an exploratory cohort of 21 patients with chronic HCV genotype 1 infection who had not had a response to previous therapy (i.e., had not had ≥2 log(10) decline in HCV RNA after ≥12 weeks of treatment with peginterferon and ribavirin). We randomly assigned patients to receive the NS5A replication complex inhibitor daclatasvir (60 mg once daily) and the NS3 protease inhibitor asunaprevir (600 mg twice daily) alone (group A, 11 patients) or in combination with peginterferon alfa-2a and ribavirin (group B, 10 patients) for 24 weeks. The primary end point was the percentage of patients with a sustained virologic response 12 weeks after the end of the treatment period.

RESULTS

A total of 4 patients in group A (36%; 2 of 9 with HCV genotype 1a and 2 of 2 with genotype 1b) had a sustained virologic response at 12 weeks after treatment and also at 24 weeks after treatment.. Six patients (all with HCV genotype 1a) had viral breakthrough while receiving therapy, and resistance mutations to both antiviral agents were found in all cases; 1 patient had a viral response at the end of treatment but had a relapse after the treatment period. All 10 patients in group B had a sustained virologic response at 12 weeks after treatment, and 9 had a sustained virologic response at 24 weeks after treatment. Diarrhea was the most common adverse event in both groups. Six patients had transient elevations of alanine aminotransferase levels to more than 3 times the upper limit of the normal range.

CONCLUSIONS

This preliminary study involving patients with HCV genotype 1 infection who had not had a response to prior therapy showed that a sustained virologic response can be achieved with two direct-acting antiviral agents only. In addition, a high rate of sustained virologic response was achieved when the two direct-acting antiviral agents were combined with peginterferon alfa-2a and ribavirin. (Funded by Bristol-Myers Squibb; ClinicalTrials.gov number, NCT01012895.).

Multiple ascending dose study of BMS-790052, a nonstructural protein 5A replication complex inhibitor, in patients infected with hepatitis C virus genotype 1

The antiviral activity, resistance profile, pharmacokinetics (PK), safety, and tolerability of BMS-790052, a nonstructural protein 5A (NS5A) replication complex inhibitor, were evaluated in a double-blind, placebo-controlled, sequential panel, multiple ascending dose study. Thirty patients with chronic hepatitis C virus (HCV) genotype 1 infection were randomized to receive a 14-day course of BMS-790052 (1, 10, 30, 60, or 100 mg once daily or 30 mg twice daily) or placebo in a ratio of 4:1. The mean maximum decline from baseline in HCV RNA ranged from 2.8 to 4.1 log(10) IU/mL; the placebo group showed no evidence of antiviral activity. Most patients experienced viral rebound on or before day 7 of treatment with BMS-790052 monotherapy; viral rebound was associated with viral variants that had been previously implicated in resistance development in the in vitro replicon system. The PK profile was supportive of once-daily dosing with median peak plasma concentrations at 1-2 hours postdose and mean terminal half-life of 12-15 hours. Steady state was achieved following 3-4 days of daily dosing. BMS-790052 was well tolerated in all dose groups, with adverse events occurring with a similar frequency in BMS-790052- and placebo-treated groups. There were no clinically relevant changes in vital signs, laboratory, or electrocardiogram parameters.

CONCLUSION

BMS-7590052 is the first NS5A replication complex inhibitor with multiple dose proof-of-concept in clinic. At doses of 1-100 mg daily, BMS-790052 was well tolerated, had a PK profile supportive of once-daily dosing, and produced a rapid and substantial decrease in HCV-RNA levels in patients chronically infected with HCV genotype 1.

Model-based drug development survey finds pharmacometrics impacting decision making in the pharmaceutical industry

During the past decade, the pharmaceutical industry has seen the increasing application of pharmacometrics approaches in drug development. However, the full potential of incorporating model-based approaches in drug development and its impact on decision making has not been fully realized to date. In 2009, a survey on model-based drug development (MBDD) was conducted (1) to further understand the current state of MBDD in the pharmaceutical industry and (2) to identify opportunities to realize the full potential of MBDD. Ten large and mid-sized pharmaceutical companies provided responses to this survey. The results indicate that MBDD is achieving broad application in early and late development and is positively affecting both internal and regulatory decisions. Senior leadership (vice president and higher) within the companies indicated widely accepted utility for dose selection and gaining acceptance for study design and regulatory interactions but limited acceptance in discovery and commercial/pipeline decisions. Mounting appreciation for the impact of MBDD on internal and regulatory decision-making bodes well for the future of the pharmacometric discipline and the growth of opportunities to realize the full potential of MBDD.

Model-based drug development: strengths, weaknesses, opportunities, and threats for broad application of pharmacometrics in drug development

Systematic implementation of model-based drug development (MBDD) to drug discovery and development has the potential to significantly increase the rate of medical breakthroughs and make available new and better treatments to patients. An analysis of the strengths, weaknesses, opportunities, and threats (ie, SWOT) was conducted through focus group discussions that included 24 members representing 8 pharmaceutical companies to systematically assess the challenges to implementing MBDD into the drug development decision-making process. The application of the SWOT analysis to the successful implementation of MBDD yielded 19 strengths, 27 weaknesses, 34 opportunities, and 22 threats, which support the following conclusions. The shift from empirical drug development to MBDD requires a question-based mentality; early, proactive planning; dynamic access to multisource data; quantitative knowledge integration; multidisciplinary collaboration; effective communication and leadership skills; and innovative, impactful application of pharmacometrics focused on enhancing quantitative decision making. The ultimate goal of MBDD is to streamline discovery and development of innovative medicines to benefit patients.

Pharmacometrics and the transition to model-based development

As the transition to model-based drug development continues, pharmacometric analysis will have an increasingly important role across the entire life cycle of drug discovery, development, regulatory approval, and commercialization. For this reason, pharmacometrics can--and should--have an integrating function in the transformation to model-based development. This essay describes an approach for formalizing the pharmacometrics process using the disciplines encompassed by enterprise engineering.

Pharmacokinetics and pharmacodynamics of gatifloxacin in children with recurrent otitis media: application of sparse sampling in clinical development

Gatifloxacin is a 4th-generation fluoroquinolone previously under investigation for the treatment of otitis media in infants and children. These analyses were designed to evaluate the extent of drug exposure relative to adult populations and to examine the relationship between drug exposure and response to therapy in children with recurrent otitis media or early treatment failures of acute otitis media. The patient population included 187 patients from an open-label, multicenter, noncomparative study using gatifloxacin 10 mg/kg once daily. Gatifloxacin exposure was estimated using a single steady-state blood sample in conjunction with a pharmacostatistical model developed using a separate pediatric data set. Gatifloxacin exposure was equivalent to that in adults given 400 mg daily. Of the 41 patients who had Streptococcus pneumoniae from middle ear culture, there were only 3 bacteriologic failures; there was no relationship between plasma fu AUC(0-24):MIC ratio and outcome. In conclusion, population pharmacokinetic/pharmacodynamic methods allowed estimation of drug exposure using one sample per patient.

Effect of an Aluminum- and Magnesium-Containing Antacid on the Bioavailability of Garenoxacin in Healthy Volunteers

STUDY OBJECTIVE

To evaluate the effect of an aluminum- and magnesium-containing antacid (Al-Mg antacid), which contains a high concentration of cations, on the pharmacokinetics of garenoxacin.

DESIGN

Prospective, randomized, open-label, control-balanced, residual-effects-design study.

SETTING

Pharmaceutical company-affiliated study clinic.

SUBJECTS

Twenty healthy volunteers who were garenoxacin naïve.

INTERVENTION

Subjects were randomly assigned to receive three of six oral treatments, each separated by a 7-day washout period: garenoxacin 600 mg administered alone, with concomitant Al-Mg antacid, 2 or 4 hours before Al-Mg antacid, or 2 or 4 hours after Al-Mg antacid. The Al-Mg antacid dose was 20 ml, which contained aluminum hydroxide 900 mg and magnesium hydroxide 800 mg.

MEASUREMENTS AND MAIN RESULTS

The pharmacokinetics and safety of garenoxacin were assessed. For each treatment, serial blood samples for pharmacokinetic analysis of garenoxacin were collected before and up to 72 hours after garenoxacin dosing. Absence of effect of Al-Mg antacid on garenoxacin area under the concentration-time curve from time zero extrapolated to infinity (AUC(0-infinity)) and maximum observed plasma concentration (C(max)) were concluded if the 90% confidence interval of the adjusted geometric mean ratios with and without the antacid were contained within 0.80-1.25 and 0.70-1.43, respectively. Exposure to garenoxacin measured by AUC(0-infinity), a parameter well correlated with efficacy, was reduced by 58% when coadministered with Al-Mg antacid and reduced by 22% and 16% when administered 2 and 4 hours after the antacid, respectively. Administration of garenoxacin 4 hours before Al-Mg antacid had no effect on AUC(0-infinity) or C(max) of garenoxacin, whereas administration 2 hours before the antacid resulted in a nonclinically relevant (12%) reduction in AUC(0-infinity) of garenoxacin.

CONCLUSION

Exposure to garenoxacin was significantly decreased when garenoxacin was coadministered with Al-Mg antacid or within 2 hours after the antacid. The magnitude of the changes in garenoxacin exposure suggests that garenoxacin should be administered at least 2 hours before or 4 hours after administration of Al-Mg antacid or other cation-containing products.

Retrospective analysis of electrocardiographic changes after administration of oral or intravenous garenoxacin in five phase I, placebo-controlled studies in healthy volunteers

BACKGROUND

Certain fluoroquinolones and macrolide antibiotics have been associated with prolongation of the corrected QT (QTc) interval or QT dispersion, leading to cardiac arrhythmias. Garenoxacin is a des-F(6)-quinolone with broad-spectrum antimicrobial activity and a favorable pharmacokinetic/pharmacodynamic profile. Its effects on electrocardiographic (ECG) parameters in healthy volunteers have not been reported.

OBJECTIVE

The cardiac safety profile of garenoxacin was further examined using data from healthy volunteers enrolled in 5 dose-ranging and comparative Phase I clinical studies.

METHODS

This was a retrospective analysis of 5 randomized, double-blind, placebo-controlled studies in which 224 healthy volunteers received oral or intravenous garenoxacin (50-1200 mg/d) for 1 to 28 days' dosing duration (<or=14 days' therapeutic duration). The effects of garenoxacin on the QT interval corrected using Bazett's formula (QTcB) and Fridericia's formula (QTcF) and the PR interval were assessed by counts of outliers, linear regressions, and exposure-response plots. Absence of a concentration-dependent effect of garenoxacin on changes from baseline ECG parameters was concluded if the 95% CI for the linear regression slopes of derived QTc- or PR-interval parameters relative to Cmax and C(avg0-12) (average garenoxacin plasma concentration from 0-12 hours after dosing) values for garenoxacin contained zero.

RESULTS

No clinically relevant changes in the QTc or PR intervals were observed over a range of garenoxacin plasma concentrations (Cmax: 0.5-38.6 microg/mL, oral dose range; 3.36-21.4 microg/mL, intravenous dose range). No volunteer had a prolongation from baseline that exceeded established thresholds for the QTcB or QTcF interval (>450 milliseconds for men, >470 milliseconds for women) or the PR interval (>250 milliseconds). One subject had a change in QTcB of 67 milliseconds 4 hours after administration of garenoxacin 400 mg PO on day 7, but the actual value was 418 milliseconds (baseline, 351 milliseconds); the corresponding change in QTcF was 49 milliseconds (actual, 408 milliseconds; baseline, 359 milliseconds). The means for other derived ECG parameters were generally similar between garenoxacin-treated volunteers and placebo controls.

CONCLUSION

In this retrospective analysis of data from healthy volunteers, garenoxacin had no clinically relevant dose-, route-of-administration-, or concentration-dependent effects on the QTc or PR interval across a dose range from 50 to 1200 mg/d.

The Effect of Omeprazole on the Bioavailability and Safety of Garenoxacin in Healthy Volunteers

The effect of coadministration of omeprazole on the bioavailability of oral garenoxacin was evaluated in an open-label study in 14 healthy subjects. Single-dose pharmacokinetics of garenoxacin were determined with and without steady-state omeprazole. Following an oral dose of garenoxacin 600 mg on day 1, serial blood samples were obtained over the next 72 hours. Omeprazole 40 mg once daily was administered from days 4 to 10. A second pharmacokinetic assessment of garenoxacin was conducted on day 8. Geometric means for the maximum observed concentration and area under the concentration-time curve from time 0 extrapolated to infinity were 9.6 microg/mL (18.2%) and 132.0 microg.h/mL (18.9%), respectively, for garenoxacin alone and 9.3 microg/mL (21.6%) and 140.4 microg.h/mL (22.1%), respectively, for coadministered garenoxacin and omeprazole. The 90% confidence interval for the ratio of geometric means (with/without omeprazole) for both variables was contained within 0.80 to 1.25, and the bioavailability of garenoxacin was not affected by the concomitant administration of omeprazole.

Garenoxacin pharmacokinetics in subjects with renal impairment

OBJECTIVE

This open-label, parallel-group study determined the pharmacokinetics of garenoxacin in subjects with severe renal impairment, including subjects maintained on dialysis.

RESEARCH DESIGN AND METHODS

Subjects were assigned to one of four groups according to their underlying renal function: creatinine clearance (CL(cr)) > 80 mL/min, CL(cr) < 30 mL/min, hemodialysis (HD), and continuous ambulatory peritoneal dialysis (CAPD). Subjects received a single oral 600-mg dose of garenoxacin. Administration of garenoxacin to subjects receiving hemodialysis was completed in two phases separated by 14 days: 3 h before HD (phase 1) and immediately after HD (phase 2).

MAIN OUTCOME MEASURES

Plasma and urine or dialysate samples were analyzed for garenoxacin, and single-dose pharmacokinetic parameters were estimated. Safety was assessed.

RESULTS

Twenty-five subjects received garenoxacin. Compared with healthy controls, garenoxacin area under the concentration-time curve (AUC) and maximum plasma concentration were increased by 51% and lowered by 20%, respectively, in subjects with severe renal impairment. The terminal half-life was prolonged in subjects with severe renal impairment compared with healthy controls (26.5 +/- 7 h vs 14.4 +/- 3 h, respectively). In subjects receiving HD or CAPD, removal of garenoxacin from systemic circulation was relatively inefficient (HD, 1.5-11.5%; CAPD, 3%), suggesting no need for a supplemental dose of garenoxacin after dialysis. Garenoxacin was well tolerated.

CONCLUSIONS

Based on the broad therapeutic index of garenoxacin, the effects of renal impairment on garenoxacin exposure are not considered clinically significant. There was a modest increase in AUC in subjects with severe renal impairment and the magnitude of the changes was not considered clinically relevant.

Entecavir pharmacokinetics, safety, and tolerability after multiple ascending doses in healthy subjects

A double-blind, placebo-controlled, multiple oral dose escalation study was conducted to investigate the pharmacokinetics, safety, and tolerability of entecavir in healthy subjects. Eight subjects were assigned to each of the 3 dose panels (0.1 mg, 0.5 mg, and 1 mg or matched placebo once daily for 14 days). Blood and urine samples were collected for pharmacokinetic analyses. Entecavir was rapidly absorbed, with peak plasma concentration occurring within 1 hour of dosing. Steady-state plasma concentrations of entecavir were achieved by 10 days following the initial dose. At steady state, the mean area under the plasma concentration-time curve over 1 dosing interval, increased approximately proportional to dose. Entecavir had a mean terminal half-life ranging from 128 to 149 hours and an effective half-life of approximately 24 hours. Elimination was predominantly through renal excretion, with mean urinary recovery ranging from 62% to 73%. Entecavir was safe and well tolerated when administered at doses ranging from 0.1 mg to 1 mg/d for 14 days.

Population pharmacokinetic model for gatifloxacin in pediatric patients

The broad spectrum of antimicrobial activity, oral bioavailability, extensive tissue distribution, and once-daily intravenous or oral dosing of gatifloxacin, an expanded-spectrum 8-methoxy fluoroquinolone, make it a potentially useful agent for the treatment of pediatric infections. A population pharmacokinetic model was developed to describe the pharmacokinetics of gatifloxacin in children. Data for analysis were obtained from a single-dose safety/pharmacokinetic study utilizing intensive blood sampling in patients aged 6 months to 16 years. Each subject received a single oral dose of gatifloxacin as a suspension, at doses of 5, 10, or 15 mg/kg of body weight. A total of 845 samples were obtained from 82 patients. A one-compartment model with first-order absorption and elimination was the most appropriate to describe the gatifloxacin concentrations. Covariate analysis using forward selection and backward elimination found that apparent clearance was related to body surface area, and apparent volume of distribution was related to body weight. No effect of age on drug clearance could be identified once clearance was corrected for body surface area. Based on pharmacokinetic simulations, the 10-mg/kg (maximum, 400 mg) once-daily dose of gatifloxacin is expected to provide drug exposure similar to that in healthy adults. The population pharmacokinetic model described herein will be used for Bayesian analyses of sparse pharmacokinetic sampling in phase II/III clinical trials and for Monte Carlo simulation experiments. The success of this strategy provides a model for future pediatric drug development programs.

Pharmacokinetics of gatifloxacin in infants and children

Gatifloxacin is an 8-methoxy fluoroquinolone effective against a broad spectrum of pathogens common in pediatric infections. The safety and pharmacokinetics of a single dose of gatifloxacin were studied in pediatric patients from 6 months to 16 years of age. Seventy-six pediatric patients (average age, 6.7 +/- 5.0 years) were administered a single oral dose of gatifloxacin suspension (5, 10, or 15 mg/kg of body weight; 600-mg maximum) in a dose-escalating manner. Subjects were stratified by age into 4 groups. An additional 12 children, greater than 6 years of age, received gatifloxacin as the tablet formulation at a dose of approximately 10 mg/kg. Gatifloxacin's apparent clearance and half-life were 5.5 +/- 2.1 ml/min/kg and 5.1 +/- 1.4 h. The maximum concentration of drug in plasma and area under the concentration-time curve (AUC) increased in a manner approximately proportional to the dose. At the 10-mg/kg dose, the bioavailability was similar between the suspension and tablet formulation. The apparent oral clearance of gatifloxacin, normalized for body weight, exhibited a small but statistically significant decrease with increasing age. In all subjects receiving gatifloxacin at 10 mg/kg, the AUC exceeded 20 microg . h/ml (estimated free AUC/MIC ratio of > or =34 for MIC of < or =0.5 microg/ml). These data suggest that gatifloxacin at a dose of 10 mg/kg every 24 h will achieve therapeutic concentrations in plasma in infants and children.

Population pharmacokinetics and pharmacodynamics of garenoxacin in patients with community-acquired respiratory tract infections

Garenoxacin (T-3811ME, BMS-284756) is a novel, broad-spectrum des-F(6) quinolone currently under study for the treatment of community-acquired respiratory tract infections. This analysis assessed garenoxacin population pharmacokinetics and exposure-response relationships for safety (adverse effects [AE]) and antimicrobial activity (clinical cure and bacteriologic eradication of Streptococcus pneumoniae and the grouping of Haemophilus influenzae, Haemophilus parainfluenzae, and Moraxella catarrhalis). Data were obtained from three phase II clinical trials of garenoxacin administered orally as 400 mg once daily for 5 to 10 days for the treatment of community-acquired pneumonia, acute exacerbation of chronic bronchitis, and sinusitis. Samples were taken from each patient before drug administration, 2 h following administration of the first dose, and on the day 3 to 5 visit. Individual Bayesian estimates of the fu (fraction unbound), the Cmax, and the fu for the area under the concentration-time curve from 0 to 24 h (fu AUC(0-24)) were calculated as measurements of drug exposure by using an ex vivo assessment of average protein binding. Regression analysis was performed to examine the following relationships: treatment-emergent AE incidence and AUC(0-24), Cmax, or patient factors; clinical response or bacterial eradication and drug exposure (fu Cmax/MIC, fu AUC(0-24)/MIC, and other exposure covariates); or disease and patient factors. Garenoxacin pharmacokinetics were described by a one-compartment model with first-order absorption and elimination. Clearance was dependent on creatinine clearance, ideal body weight, age, obesity, and concomitant use of pseudoephedrine. The volume of distribution was dependent on weight and gender. Patients with mild or moderate renal dysfunction had, on average, approximately a 16 or 26% decrease in clearance, respectively, compared to patients of the same gender and obesity classification with normal renal function. AE occurrence was not related to garenoxacin exposure. Overall, clinical cure and bacterial eradication rates were 91 and 90%, respectively, for S. pneumoniae and 93 and 92%, respectively, for the grouping of H. influenzae, H. parainfluenzae, and M. catarrhalis. The fu AUC(0-24)/MIC ratios were high (>90% were >200), and none of the pharmacokinetic-pharmacodynamic exposure measurements indexed to the MIC or other factors were significant predictors of clinical or bacteriologic response. Garenoxacin clearance was primarily related to creatinine clearance and ideal body weight. Although garenoxacin exposure was approximately 25% higher for patients with moderate renal dysfunction, this increase does not appear to be clinically significant as exposures in this patient population were not significant predictors of AE occurrence. Garenoxacin exposures were at the upper end of the exposure-response curves for measurements of antimicrobial activity, suggesting that 400 mg of garenoxacin once daily is a safe and adequate dose for the treatment of the specified community-acquired respiratory tract infections.

The effects of HIV protease inhibitors atazanavir and lopinavir/ritonavir on insulin sensitivity in HIV-seronegative healthy adults

BACKGROUND

Therapy with some HIV protease inhibitors (PI) contributes to insulin resistance and type 2 diabetes mellitus, by inhibition of insulin-sensitive glucose transporters. Atazanavir (ATV) is a new PI with substantially less in vitro effect on glucose transport than observed with other PI, including lopinavir (LPV) or ritonavir (RTV).

METHODS

Randomized, double-blind, crossover study of the effect of 5 days of administering ATV, lopinavir/ritonavir (LPV/r) or placebo on insulin-stimulated glucose disposal in 30 healthy HIV-negative subjects. Each subject was studied on two of three possible treatments with a wash-out period between treatments.

RESULTS

The mean insulin-stimulated glucose disposal (mg/min per kg body weight) per unit insulin (microU/ml) (M/I) was 9.88, 9.80 and 7.52 for placebo, ATV and LPV/r, respectively (SEM, 0.84 for all). There was no significant difference between ATV and placebo. The M/I for LPV/r was 23% lower than that for ATV (P = 0.010) and 24% lower than that for placebo (P = 0.008). The mean glycogen storage rates were 3.85, 4.00 and 2.54 mg/min per kg for placebo, ATV and LPV/r, respectively (SEM, 0.39 for all). There was no significant difference between ATV and placebo. The glycogen storage rate for LPV/r was 36% lower than ATV (P = 0.003) and 34% lower than placebo (P = 0.006).

CONCLUSIONS

ATV given to healthy subjects for 5 days did not affect insulin sensitivity, while LPV/r induced insulin resistance. This observation is consistent with differential in vitro effects of these PI on glucose transport. Further data are needed to assess clinical implications for body composition.

Multiple-dose safety and pharmacokinetics of oral garenoxacin in healthy subjects

Garenoxacin (T-3811ME, BMS-284756) is a novel des-F(6) quinolone that has been shown to be effective in vitro against a wide range of clinically important pathogens, including gram-positive and gram-negative aerobes and anaerobes. This study was conducted to evaluate the safety and tolerability of multiple oral doses (100 to 1200 mg/day) of garenoxacin in healthy subjects and to determine its multiple-dose pharmacokinetics. Forty healthy male and female subjects (18 to 45 years of age) were enrolled in this randomized, double-blind, placebo-controlled, sequential, multiple- and ascending-dose study. Each subject received a once-daily oral dose of garenoxacin (100, 200, 400, 800, or 1200 mg) or a placebo for 14 days. Blood and urine samples were collected for measurements of garenoxacin by validated liquid chromatography with dual mass spectrometry, and plasma garenoxacin concentration-time data were analyzed by noncompartmental methods. The effects of garenoxacin on Helicobacter pylori, psychometric test performance, and electrocardiograms were assessed, as was drug safety. Over the 14 days of dosing, geometric mean peak concentrations of garenoxacin in plasma (C(max)) at the 100- and 1200-mg doses were within the ranges of 1.2 to 1.6 and 16.3 to 24 microg/ml, respectively. The corresponding values for the geometric mean area under the concentration-time curve over the dosing interval (AUC(tau)) for garenoxacin in plasma at the 100- and 1200-mg doses were within the ranges of 11.5 to 15.7 and 180 to 307 microg. h/ml, respectively. Increases in systemic exposure to garenoxacin in terms of AUC and C(max) were approximately dose proportional over the 100- to 400-mg dose range but demonstrated increases that were somewhat greater than the dose increments at the 800- and 1200-mg doses. Median values for the time to achieve C(max) were in the range of 1.13 to 2.50 h for all doses. The mean elimination half-life for garenoxacin in plasma appeared to be independent of dose and ranged from 13.3 to 17.8 h (day 14). Approximately 30 to 50% of an administered garenoxacin dose was excreted unchanged in the urine. At doses of 100 to 400 mg, steady-state concentrations of garenoxacin in plasma appeared to be attained by the fourth dose. Multiple oral doses of garenoxacin were well tolerated and did not demonstrate clinically significant effects on QT(c) or psychometric test results. Garenoxacin administered alone for 14 days at doses of >or=400 mg demonstrated activity against H. pylori. These results suggest that multiple once-daily oral doses of garenoxacin of up to 1200 mg are safe and well tolerated and that the pharmacokinetics of garenoxacin support once-daily administration.

Effect of garenoxacin on eubacteria in the normal intestinal microflora when administered concomitantly with digoxin

Garenoxacin is a new des-F(6)-quinolone with a broad antimicrobial spectrum. It has been reported that antibiotics may raise digoxin concentrations in the plasma of patients who are taking these agents concurrently, possibly due to the effect on the digoxin-metabolizing intestinal microflora. Sixteen healthy subjects were given a loading dose of digoxin (0.25 mg orally, q 6 h) on Day 1 followed by once-daily doses of 0.25 mg on Days 2 through 14. The subjects also received garenoxacin 600 mg orally, q 24 h, on Days 8 through 14. The number of enterococci, bacilli, corynebacteria, enterobacteria, bifidobacteria, lactobacilli, clostridia and bacteroides decreased whereas the number of eubacteria increased in the intestinal microflora. Eubacterium lentum strains increased during the administration of garenoxacin and returned towards normal levels within 14 days after the last dose of garenoxacin. The fecal concentrations of garenoxacin varied between 14.0-310.0 mg/kg. The minimum inhibitory concentrations of garenoxacin against the isolated E. lentum strains were >64 mg/L. There was no degradation of digoxin by the E. lentum strains.

Ecological impact of the des-F(6)-quinolone, BMS-284756, on the normal intestinal microflora

OBJECTIVE

BMS-284756 (T-3811ME) is a novel des-F(6)-quinolone effective against a broad spectrum of aerobic and anaerobic pathogens. The aim of this study was to investigate the ecological effect of BMS-284756 on the intestinal microflora.

METHODS

Forty healthy subjects participated in the trial. Eight subjects were assigned to each of five dose panels (100, 200, 400, 800 and 1200 mg BMS-284756) and received daily oral dosing with either BMS-284756 (n = 6) or placebo (n = 2) for 14 days. Fecal samples were collected before (days -2 and -1), during (days 7 and 14), and after (days 21, 28, and 45) completion of the administration period.

RESULTS

In subjects receiving 100 or 200 mg BMS-284756, no significant changes in the intestinal aerobic and anaerobic microflora occurred. The number of enterococci, bacilli, corynebacteria, bifidobacteria, lactobacilli, clostridia and bacteroides decreased in subjects receiving 400 or 800 mg BMS-284756, whereas the number of eubacteria increased. Subjects who received 1200 mg BMS-284756 had significant changes in the microflora: enterococci, bacilli, corynebacteria, enterobacteria, bifidobacteria, lactobacilli, clostridia and bacteroides were suppressed, whereas eubacteria and yeasts were increased. Regardless of dose, the microflora returned to normal levels at day 28 (2 weeks after the administration of BMS-284756 was discontinued). Fecal concentrations of BMS-284756 increased with the higher doses, from 35.7 mg/kg (100 mg) to 262.8 mg/kg (1200 mg). These ecological findings should be considered if 800- or 1200-mg doses of BMS-284756 are to be used for longer periods than 14 days.

CONCLUSION

The ecological impact of BMS-284756 is selective, with results similar to those described for other quinolones.

Effect of a high-fat meal on the pharmacokinetics of the des-F(6)-quinolone BMS-284756

STUDY OBJECTIVE

To evaluate the effects of a high-fat meal on the systemic exposure of oral BMS-284756.

DESIGN

Open-label, randomized, two-way crossover study.

SETTING

Clinical research facility.

SUBJECTS

Fourteen healthy individuals.

INTERVENTIONS

Participants received two single 400-mg doses of BMS-284756, separated by at least 1 week. One dose was given while participants were fasting, and one dose was given within 5 minutes of consumption of a high-fat meal.

MEASUREMENTS AND MAIN RESULTS

Serial blood samples were collected, and plasma samples were analyzed for BMS-284756 using a validated liquid chromatography with tandem mass spectrometry detection method. Maximum plasma concentration and area under the plasma concentration-time curve (AUC) after the high-fat meal were 19% and 11% lower, respectively, than those in the fasted state. The 90% confidence intervals for the ratios of means (0.71-0.94 and 0.85-0.93, respectively) satisfied predefined equivalence criteria. Equivalence of the AUC values for BMS-284756 in fed and fasted individuals indicates that the presence of food should not affect the efficacy of this drug.

CONCLUSION

Single doses of BMS-284756 were safe and well tolerated and may be taken without regard to meals.

Pharmacodynamics of fluoroquinolones against Streptococcus pneumoniae in patients with community-acquired respiratory tract infections

Fluoroquinolone antibiotic agents have demonstrated efficacy in the treatment of respiratory tract infections. This analysis was designed to examine the relationship between drug exposure, as measured by the free-drug area under the concentration-time curve at 24 h (AUC(24))/MIC ratio, and clinical and microbiological responses in patients with community-acquired respiratory tract infections involving Streptococcus pneumoniae. The study population included 58 adult patients (34 males, 24 females) who were enrolled in either of two phase III, randomized, multicenter, double-blind studies of levofloxacin versus gatifloxacin for the treatment of community-acquired pneumonia or acute exacerbation of chronic bronchitis. Clearance equations from previously published population pharmacokinetic models were used in conjunction with dose and adjusted for protein binding to estimate individual patient free-drug AUC(24)s. In vitro susceptibility was determined in a central laboratory by broth microdilution in accordance with NCCLS guidelines. Pharmacodynamic analyses were performed on data from all evaluable patients with documented S. pneumoniae infection using univariate and multivariable logistic regression; pharmacodynamic breakpoints were estimated using Classification and Regression Tree analysis. A statistically significant (P = 0.013) relationship between microbiological response and the free-drug AUC(24)/MIC ratio was detected. At a free-drug AUC(24)/MIC ratio of <33.7, the probability of a microbiological response was 64%, and at a free-drug AUC(24)/MIC ratio of >33.7, it was 100% (P < 0.01). These findings may provide a minimum target free-drug AUC(24)/MIC ratio for the treatment of infections involving S. pneumoniae with fluoroquinolone antibiotics and provide a paradigm for the selection of fluoroquinolones to be brought forward from drug discovery into clinical development and dose selection for clinical trials. Further, when target free-drug AUC(24)/MIC ratios are used in conjunction with stochastic modeling techniques, these findings may be used to support susceptibility breakpoints for fluoroquinolone antibiotics and S. pneumoniae.

The use of Monte Carlo simulation to examine pharmacodynamic variance of drugs: fluoroquinolone pharmacodynamics against Streptococcus pneumoniae

BACKGROUND

For fluoroquinolones, AUC:MIC ratios correlate with maximal bacterial eradication in in vitro models of infection and favorable cure rates in humans with respiratory tract infection. Inter-subject pharmacokinetic and MIC variability may impact the probability of attaining optimal AUC:MIC ratios and hence favorable clinical outcome.

METHODS

Monte Carlo simulation was utilized to estimate the probability of attaining AUC:MIC ratios of 30, 40, 50, 60, 70, 80, 90, 100, 110 and 120 using AUC values from patients treated with either gatifloxacin or levofloxacin and microbiologic activity against S. pneumoniae observed in 1997 SENTRY Antimicrobial Surveillance Program.

RESULTS

The probability curves for 5000 patient simulations were plotted. The median AUC:MIC ratios were 120 for gatifloxacin and 50.5 for levofloxacin. The probability of attaining AUC:MIC ratios of 30, 50, 70 and 100 for gatifloxacin were 94%, 86%, 78% and 62%, and for levofloxacin were 80%, 51%, 31% and 17%, respectively.

CONCLUSION

Gatifloxacin has a higher probability of achieving target AUC:MIC ratios than levofloxacin. Monte Carlo simulation, using patient-based AUC and MIC distributions, may have implications for selection of optimal antibiotics for the empiric treatment of infections. Moreover, Monte Carlo simulation may have utility in the determination of MIC breakpoints.

Pharmacokinetics of single-dose oral stavudine in subjects with renal impairment and in subjects requiring hemodialysis

Two open-label studies assessed the pharmacokinetics of single orally administered doses of 40 mg of stavudine in subjects with renal impairment. In one study (study I), 15 subjects with selected degrees of renal impairment, but not requiring hemodialysis, were stratified into three groups of five subjects each according to creatinine clearance (CL(CR)) normalized by body surface area (ml/min/1.73 m(2)): mild (CL(CR), 60 to 80), moderate (30 to 50), and severe (/= 90) were also enrolled. The stavudine area under the curve from 0 h to infinity (AUC(0-infinity)) increased nonlinearly with declining renal function: 1,864, 2,215, 3,609, and 5,928 ng. h/ml for normal renal function and for mild, moderate, and severe renal impairment, respectively (P = 0.0001 between renal impairment groups). The following stavudine dosage recommendations for renal impairment were proposed for subjects weighing >/=60 kg: CL(CR) of >50 ml/min/1.73 m(2), 40 mg every 12 h; CL(CR) of 21 to 50 ml/min/1. 73 m(2), 20 mg every 12 h; and CL(CR) of 10 to 20 ml/min/1.73 m(2), 20 mg every 24 h. For subjects weighing <60 kg, the proposed doses were 30, 15, and 15 mg, respectively, with the same dosing intervals specified above. In a second study (study II), 12 subjects with end-stage renal disease requiring hemodialysis three times a week were enrolled in a randomized, open-label crossover study (dialysis 2 h after dosing and lasting 4 h or dosing without dialysis). There were no statistically significant differences for AUC(0-infinity), AUC(2-6), time to maximum concentration of drug in serum, half-life, or apparent oral clearance when the two treatment dosage regimens were compared. As a result of study II, the recommended dosing rate for subjects requiring hemodialysis was the same as that proposed for those with severe renal impairment not requiring hemodialysis; however, dosing was recommended to follow hemodialysis and to occur at the same time each day.

Clinical pharmacology of gatifloxacin, a new fluoroquinolone

Gatifloxacin is an advanced-generation, 8-methoxy fluoroquinolone that is active against a broad spectrum of pathogens, including antibiotic-resistant Streptococcus pneumoniae. The drug has high oral bioavailability (96%), and, therefore, oral and intravenous formulations are bioequivalent and interchangeable. Gatifloxacin has a large volume of distribution ( approximately 1.8 L/kg), low protein binding ( approximately 20%), and broad tissue distribution and is primarily excreted unchanged in the urine (>80%). Gatifloxacin can be administered without dose modification in patients with hepatic impairment, in women, and in the elderly. In vitro experiments and clinical studies indicate that gatifloxacin does not interact with drugs metabolized by the cytochrome P450 enzyme family. At therapeutically relevant doses, gatifloxacin's pharmacodynamically linked parameters (the ratio of maximum serum concentration to minimum inhibitory concentration and the ratio of the area under the curve to minimum inhibitory concentration) are similar to or better than those of other fluoroquinolones. Clinical studies show that gatifloxacin has limited potential to prolong the QT interval on the electrocardiogram and lacks the potential to cause photosensitivity reactions, to alter oral glucose tolerance, or to cause crystalluria.

Safety and pharmacokinetics of a single oral dose of gatifloxacin in patients with moderate to severe hepatic impairment

STUDY OBJECTIVES

To assess the safety and pharmacokinetics of oral gatifloxacin 400 mg in subjects with and without hepatic impairment, and the need to modify doses in patients with hepatic dysfunction.

DESIGN

Single-dose, nonrandomized, open-label, parallel-group study.

SETTING

Clinical Research Center, New Orleans, Louisiana.

PATIENTS

Eight subjects with grade B or C hepatic dysfunction (Child-Pugh classification) and eight age-, weight-, and gender-matched subjects with normal hepatic function.

INTERVENTIONS

After a single oral dose of gatifloxacin 400 mg, blood and urine samples were collected at specified times or intervals over 48 hours to determine drug concentrations.

MEASUREMENTS AND MAIN RESULTS

All 16 subjects (7 with grade B and 1 with grade C hepatic impairment, 8 with normal hepatic function) completed the study. Peak plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC0-infinity) for gatifloxacin were 32% and 22% higher, respectively, in subjects with hepatic impairment. Except for Cmax, the ratio of means for AUC satisfied the specified criterion (0.67-1.50) for lack of effect. There were no statistically significant differences in any other pharmacokinetic values except apparent oral clearance (ClT/F). All treatment-emergent adverse events were mild or moderate in intensity and resolved before subjects were discharged from the study.

CONCLUSION

Modest increases in Cmax and AUC0-infinity are not anticipated to have a negative effect on the outcome of therapy in hepatically impaired subjects, nor are they anticipated to result in adverse drug reactions. Patients with moderate to severe (Child-Pugh grade B or C) hepatic dysfunction do not require gatifloxacin dose adjustments. In addition, the similarity in half-life (t1/2) for the groups (8.9 hrs for hepatically impaired subjects, 9.3 hrs for controls) suggests that no difference would be anticipated in the extent of drug accumulation after multiple doses. The overall safety and tolerability of a single oral dose of gatifloxacin 400 mg were excellent in both healthy subjects and those with hepatic impairment.

Effect of multiple-dose gatifloxacin or ciprofloxacin on glucose homeostasis and insulin production in patients with noninsulin-dependent diabetes mellitus maintained with diet and exercise

STUDY OBJECTIVES

To compare the effects of gatifloxacin and ciprofloxacin on glucose homeostasis, including glucose tolerance test (GTT), pancreatic beta-cell function, and insulin production and secretion in patients with noninsulin-dependent (type 2) diabetes mellitus (NIDDM) maintained with diet and exercise; and to evaluate the pharmacokinetics, safety, and tolerability of gatifloxacin.

DESIGN

Randomized, double-blind, placebo-controlled, multiple-dose study.

SETTING

GFI Pharmaceutical Services, Inc., Evansville, Indiana; Chicago Center for Clinical Research, Chicago, Illinois; and New Orleans Center for Clinical Research, New Orleans, Louisiana, USA.

PATIENTS

Forty-eight men and women with NIDDM.

INTERVENTIONS

Patients were assigned sequentially at enrollment to receive gatifloxacin 400 mg/day orally, ciprofloxacin 500 mg twice/day orally, or placebo for 10 days. Oral GTTs were performed on specific days throughout the study, as well as measurements of serum glucose, serum insulin, and C-peptide levels. Physical examinations, electrocardiograms, spirometry, and clinical laboratory tests were performed before dosing and on selected dosing days.

MEASUREMENTS AND MAIN RESULTS

Gatifloxacin had no significant effect on glucose tolerance and pancreatic beta-cell function, as shown by oral GTT results and insulin and C-peptide levels. Fasting glucose levels 0-6 hours after gatifloxacin administration on days 1 and 10 showed a downward trend, but it was not significant compared with placebo; results were similar with ciprofloxacin. Gatifloxacin also lacked a long-term effect on fasting insulin levels, but this was not shown for a short-term effect, suggesting a modest, transient effect on insulin release. On the other hand, ciprofloxacin had no short-term effect but produced a more sustained effect on insulin release and production. The pharmacokinetics of gatifloxacin in patients with NIDDM were similar to those in healthy subjects. Overall, subjects tolerated treatment well. All reported drug-related adverse events were mild to moderate in intensity. The frequency of adverse events was similar in gatifloxacin- and ciprofloxacin-treated patients, and only slightly higher than in placebo-treated patients.

CONCLUSION

Gatifloxacin was well tolerated in patients with NIDDM controlled by diet and exercise. It had no significant effect on glucose homeostasis, beta-cell function, or long-term fasting serum glucose levels, but it did cause a brief increase in serum insulin levels.

Interchangeability of 400-mg intravenous and oral gatifloxacin in healthy adults

STUDY OBJECTIVE

To evaluate the interchangeability of 400-mg intravenous and oral doses of gatifloxacin.

DESIGN

Randomized, open-label, crossover study.

SETTING

GFI Pharmaceutical Services, Inc., Evansville, Indiana, USA.

SUBJECTS

Twenty-four healthy men and women (12 of each gender), aged 18-42 years.

INTERVENTIONS

Subjects received single doses of gatifloxacin 400 mg either by intravenous infusion over 1 hour or a 400-mg tablet orally with 240 ml of water, each dose separated by a 1-week washout. Plasma concentrations of gatifloxacin were determined by a validated high-performance liquid chromatography; pharmacokinetic parameters were calculated using noncompartmental methods. Distributions of pharmacokinetic parameter values were summarized by route of administration and gender. Effects of treatment on pharmacokinetic parameter values of gatifloxacin were assessed by an analysis of variance model suitable for a two-way, two-treatment, crossover design. Clinical evaluations were performed to assess drug safety and tolerability.

MEASUREMENTS AND MAIN RESULTS

Intravenous and oral gatifloxacin were considered interchangeable because both routes were bioequivalent with respect to area under the curve (AUC; 90% confidence interval for the ratio of geometric means contained within 0.8-1.25). The plasma concentration-time profile after intravenous administration was similar and comparable in extent of exposure (AUC0-infinity) with that for the oral route when equal doses were administered to men and women. The absolute bioavailability of gatifloxacin after oral administration was 96%, consistent with bioequivalence of the 400-mg intravenous and oral doses. The drug was well tolerated; the frequency of adverse events was comparable after intravenous and oral administration.

CONCLUSION

Intravenous and tablet formulations of gatifloxacin are bioequivalent and therefore interchangeable. This permits greater flexibility in choosing oral or parenteral therapy, with the possibility of avoiding hospitalization based on knowledge that oral administration will deliver therapeutic exposure to the drug, or abbreviating hospital stay due to ease of switching from intravenous to oral therapy.