Pharmacokinetics and safety of coformulated bictegravir, emtricitabine, and tenofovir alafenamide in children aged 2 years and older with virologically suppressed HIV: a phase 2/3, open-label, single-arm study

BACKGROUND

Coformulated bictegravir, emtricitabine, and tenofovir alafenamide is a single-tablet regimen and was efficacious and well tolerated in children and adolescents with HIV (aged 6 years to <18 years) in a 48-week phase 2/3 trial. In this study, we report data from children aged at least 2 years and weighing 14 kg to less than 25 kg.

METHODS

We conducted this open-label, multicentre, multicohort, single-arm study in South Africa, Thailand, Uganda, and the USA. Participants were virologically suppressed children with HIV, aged at least 2 years, weighing 14 kg to less than 25 kg. Participants received bictegravir (30 mg), emtricitabine (120 mg), and tenofovir alafenamide (15 mg) once daily, switching to bictegravir (50 mg), emtricitabine (200 mg), and tenofovir alafenamide (25 mg) upon attaining a bodyweight of at least 25 kg. The study included pharmacokinetic evaluation at week 2 to confirm the dose of coformulated bictegravir, emtricitabine, and tenofovir alafenamide for this weight band by comparing with previous adult data. Primary outcomes were bictegravir area under the curve over the dosing interval (AUCtau) and concentration at the end of the dosing interval (Ctau) at week 2, and incidence of treatment-emergent adverse events and laboratory abnormalities until the end of week 24 in all participants who received at least one dose of bictegravir, emtricitabine, and tenofovir alafenamide. This study is registered with ClinicalTrials.gov, NCT02881320.

FINDINGS

Overall, 22 participants were screened (from Nov 14, 2018, to Jan 11, 2020), completed treatment with bictegravir, emtricitabine, and tenofovir alafenamide (until week 48), and entered an extension phase. The geometric least squares mean (GLSM) ratio for AUCtau for bictegravir was 7·6% higher than adults (GLSM ratio 107·6%, 90% CI 96·7-119·7); Ctau was 34·6% lower than adults (65·4%, 49·1-87·2). Both parameters were within the target exposure range previously found in adults, children, or both". Grade 3-4 laboratory abnormalities occurred in four (18%) participants by the end week 24 and six (27%) by the end of week 48. Drug-related adverse events occurred in three participants (14%) by the end of week 24 and week 48; none were severe. No Grade 3-4 adverse events, serious adverse events, or adverse events leading to discontinuation occurred by the end of week 24 and week 48.

INTERPRETATION

Data support the use of single-tablet coformulated bictegravir (30 mg), emtricitabine (120 mg), and tenofovir alafenamide (15 mg) for treatment of HIV in children aged at least 2 years and weighing 14 kg to less than 25 kg.

FUNDING

Gilead Sciences.

Sofosbuvir-velpatasvir in children 3-17 years old with hepatitis C virus infection

BACKGROUND

The safety and efficacy of sofosbuvir-velpatasvir in children aged 3-17 years with chronic hepatitis C virus (HCV) infection of any genotype were evaluated.

METHODS

In this Phase 2, multicenter, open-label study, patients received once daily for 12 weeks either sofosbuvir-velpatasvir 400/100 mg tablet (12-17 years), 200/50 mg low dose tablet or oral granules (3-11 years and ≥17 kg), or 150/37.5 mg oral granules (3-5 years and <17 kg). The efficacy endpoint was sustained virologic response 12 weeks after therapy (SVR12). Dose appropriateness was confirmed by intensive pharmacokinetics in each age group.

FINDINGS

Among 216 patients treated, 76% had HCV genotype 1% and 12% had genotype 3. Rates of SVR12 were 83% (34/41) among 3-5-year-olds, 93% (68/73) among 6-11-year-olds, and 95% (97/102) among 12-17-year-olds. Only two patients experienced virologic failure. The most common adverse events were headache, fatigue, and nausea in 12-17-year-olds; vomiting, cough, and headache in 6-11-year-olds; and vomiting in 3-5-year-olds. Three patients discontinued treatment because of adverse events. Four patients had serious adverse events; all except auditory hallucination (n = 1) were considered unrelated to study drug. Exposures of sofosbuvir, its metabolite GS-331007, and velpatasvir were comparable to those in adults in prior Phase 2/3 studies. Population pharmacokinetic simulations supported weight-based dosing for children in this age range.

INTERPRETATION

The pangenotypic regimen of sofosbuvir-velpatasvir is highly effective and safe in treating children 3-17 years with chronic HCV infection.

Remdesivir for COVID-19 in Hospitalized Children: A Phase 2/3 Study

OBJECTIVES

Remdesivir decreases the risk of SARS-CoV-2 infection progressing to severe disease in adults. This study evaluated remdesivir safety and pharmacokinetics in infants and children.

METHODS

This was a phase 2/3, open-label trial in children aged 28 days to 17 years hospitalized for polymerase chain reaction-confirmed SARS-CoV-2 infection. Participants received for ≤10 days once-daily intravenous remdesivir doses defined using physiologically based pharmacokinetic modeling (for ≥40 kg, 200 mg day 1, then 100 mg/day; for age ≥28 days and ≥3 to <40 kg, 5 mg/kg day 1, then 2.5 mg/kg/day). Sparse pharmacokinetic samples were analyzed using population-pharmacokinetic approaches for remdesivir and metabolites GS-704277 and GS-441524.

RESULTS

Among 53 participants, at enrollment the median (Q1, Q3) number of days of COVID-19 symptoms was 5 (3, 7) and hospitalization was 1 (1, 3). Underlying conditions included obesity in 19 (37%), asthma in 11 (21%), and cardiac disorders in 11 (21%). Median duration of remdesivir treatment was 5 days (range, 1-10). Remdesivir treatment had no new apparent safety trends. Two participants discontinued treatment because of adverse events including elevated transaminases; both had elevated transaminases at baseline. Three deaths occurred during treatment (and 1 after). When compared with phase 3 adult data, estimated mean pediatric parameters (area under the concentration-time curve over 1 dosing interval, AUCτ, Cmax, and Cτ) were largely overlapping but modestly increased (remdesivir, 33%-129%; GS-704277, 37%-124%; GS-441524, 0%-60%). Recovery occurred for 62% of participants on day 10 and 83% at last assessment.

CONCLUSIONS

In infants and children with COVID-19, the doses of remdesivir evaluated provided drug exposure similar to adult dosing. In this study with a small sample size, no new safety concerns were observed.

Performance of Noninvasive Tests of Fibrosis Among Asians, Hispanic, and non-Hispanic Whites in the STELLAR Trials

BACKGROUND & AIMS

The effect of race on routinely available noninvasive tests of fibrosis is incompletely understood. This study evaluated the performance of noninvasive tests among white and Asian patients in the STELLAR trials (NCT03053050 and NCT03053063), which evaluated selonsertib in patients with advanced (F3-F4) fibrosis due to nonalcoholic steatohepatitis (NASH).

METHODS

Baseline liver biopsies were centrally read using the NASH Clinical Research Network system, and 4 noninvasive tests (Nonalcoholic fatty liver disease fibrosis score [NFS], Fibrosis-4 index [FIB-4], Enhanced Liver Fibrosis test [ELF], and liver stiffness by vibration-controlled transient elastography) were measured. The performance of these tests to discriminate advanced fibrosis was evaluated using areas under the receiver operating characteristics curves with 5-fold cross-validation repeated 100 times.

RESULTS

Among 3207 patients screened with evaluable liver histology, 2281 were whites and 762 were Asians. Seventy-two percent of whites and 67% of Asians had advanced fibrosis. The areas under the receiver operating characteristics curves of the noninvasive tests for advanced fibrosis were similar in whites and Asians: 0.73 and 0.75 for NFS, 0.78 and 0.80 for FIB-4, 0.79 and 0.81 for ELF, and 0.80 and 0.83 for liver stiffness, respectively. At the published cutoffs, the tests had similar sensitivities and specificities in the 2 groups. However, the sensitivities of NFS, FIB-4, and ELF were low in both white and Asian patients younger than 40 years.

CONCLUSIONS

In the global phase III STELLAR trials, the diagnostic performance of routinely available noninvasive tests for the detection of advanced fibrosis due to NASH was acceptable and similar between white and Asian patients.

Sofosbuvir-velpatasvir-voxilaprevir in adolescents 12 to 17 years old with HCV infection

BACKGROUND AND AIMS

Sofosbuvir-velpatasvir-voxilaprevir is a pangenotypic regimen for chronic HCV infection. In the USA and Europe, sofosbuvir-velpatasvir-voxilaprevir once daily for 12 weeks is indicated for adults who previously received an HCV NS5A inhibitor. In Europe, sofosbuvir-velpatasvir-voxilaprevir is also indicated in the absence of prior HCV direct-acting antiviral (DAA) therapy as an 8-week or 12-week regimen. In an open-label study, we evaluated the safety, efficacy, and pharmacokinetics of sofosbuvir-velpatasvir-voxilaprevir in adolescents 12 to 17 years with chronic HCV of any genotype.

METHODS

In this Phase 2, multicenter study, sofosbuvir-velpatasvir-voxilaprevir 400/100/100 mg daily was administered to adolescents for 8 weeks if DAA-naïve or for 12 weeks for cirrhosis or prior DAA failure. The key efficacy endpoint was sustained virologic response 12 weeks after therapy (SVR12). Intensive pharmacokinetic sampling was done in 14 patients at week 2 or 4, and samples for population pharmacokinetics were collected in all patients.

RESULTS

All patients (n = 21) were naïve to HCV DAAs, and none had cirrhosis. HCV genotype 3a infection was most common, occurring in 43% of patients. Overall, 100% of patients (21 of 21) reached SVR12. The most common adverse events were abdominal pain and headache (24% each) and nausea (19%); no adverse events led to discontinuation. The only serious adverse event, hypotension, was considered related to study drug and resolved the same day without interruption of treatment. Sofosbuvir-velpatasvir-voxilaprevir exposures were similar to those observed in adults.

CONCLUSIONS

The pangenotypic regimen of sofosbuvir-velpatasvir-voxilaprevir is highly efficacious and well-tolerated in treating chronic HCV infection in adolescents.

Ledipasvir-sofosbuvir in Adolescents With Chronic Hepatitis C and Hematological Malignancies Undergoing Chemotherapy

OBJECTIVES

In children with hematological malignancies, chronic hepatitis C virus (HCV) infection has been associated with more rapid liver disease progression and higher risk of malignancy relapse due to chemotherapy interruption. We evaluated the safety and efficacy of ledipasvir-sofosbuvir for 12weeks in these patients.

METHODS

In a phase 2, open-label study, at one site in Egypt, patients ages 12-<18years with chronic HCV genotype 1 or 4 infection undergoing maintenance chemotherapy for hematological malignancies received ledipasvir-sofosbuvir (90 mg/400 mg) once daily for 12weeks. The efficacy endpoint was sustained virologic response 12 weeks after treatment (SVR12). Safety was assessed by the incidence of adverse events and clinical and laboratory data, including HCV flares defined as alanine aminotransferase >3-fold increase from Day 1 and HCV RNA elevation >1 × log10 from Day 1.

RESULTS

Of the 19 adolescents enrolled and treated, median age was 14 years (range 12-17), 84% (16/19) were male, and all had HCV genotype 4 and were HCV treatment naive. All patients completed treatment and achieved SVR12 (19/19, 100%, 95% confidence interval, 82-100). Common adverse events were pyrexia (5/19, 26%), diarrhea (4/19, 21%), and headache (4/19, 21%). Three patients experienced serious adverse events of pneumonia (two patients), and osteoarthritis and diarrhea (one patient); none were considered related to study drug. No patient experienced HCV flares.

CONCLUSIONS

Ledipasvir-sofosbuvir was well-tolerated and efficacious in adolescents with chronic HCV genotype 4 and leukemia undergoing maintenance chemotherapy. These data support the use of this interferon and ribavirin-free regimen in adolescents with hematological malignancies.

The Association of Histologic and Noninvasive Tests With Adverse Clinical and Patient-Reported Outcomes in Patients With Advanced Fibrosis Due to Nonalcoholic Steatohepatitis

BACKGROUND & AIM

Fibrosis is an independent predictor of death in nonalcoholic steatohepatitis (NASH). We assessed the associations between histologic and noninvasive tests (NITs) for fibrosis with clinical and patient-reported outcomes (PROs) in advanced NASH.

METHODS

Patients with advanced NASH (NASH Clinical Research Network stage F3 or F4) were enrolled in 4 multinational clinical trials of simtuzumab and selonsertib. Liver biopsy samples, NIT results, and PROs (Short Form-36, Chronic Liver Disease Questionnaire-NASH, EuroQol-5D, and Work Productivity and Activity Impairment) were prospectively collected.

RESULTS

A total of 2154 patients with advanced NASH were included: 52.5% with F4 NASH, 40% male, 72% with type 2 diabetes, baseline liver stiffness of 24.1 ± 14.2 kPa in F4 disease and 14.6 ± 8.0 kPa in F3 disease, baseline mean Enhanced Liver Fibrosis score of 11.4 ± 1.2 in F4 disease and 10.3 ± 1.0 in F3 disease, and a median follow-up of 16 months. Of those with baseline F3 disease, 16.7% experienced disease progression to cirrhosis, whereas for those with F4 disease, 7.3% experienced clinical events (39% ascites, 24% hepatic encephalopathy); patients who progressed had higher baseline NIT scores (all P < .0001). Adjusted for baseline levels, increases in NIT scores were also associated with increased risk of disease progression in both the F3 and F4 groups (P < .01 for all NITs in F3 and for ELF, NAFLD Fibrosis Score, Fibrosis-4 (FIB-4), and liver stiffness in F4). Higher NIT scores were found to be associated with impairment in PROs: ELF, ≥10.43; Nonalcoholic Fatty Liver Disease Fibrosis Score, ≥1.80; Fibrotest score, ≥0.54; liver stiffness, ≥23.4 kPa. During treatment, patients with decreases in NIT scores experienced improvement of their PRO scores, whereas those with increase in NIT scores had their PRO scores worsen (P < .05).

CONCLUSIONS

Baseline NIT scores and their changes over time are predictors of adverse clinical and PROs in patients with advanced NASH. (ClinicalTrials.gov, Numbers NCT01672866, NCT01672879, NCT03053050, and NCT03053063).

Fatigue and Pruritus in Patients with Advanced Fibrosis Due to Nonalcoholic Steatohepatitis: The Impact on Patient-Reported Outcomes

Fatigue and pruritus are common in patients with chronic liver diseases of all etiologies, but clinical awareness is mostly restricted to those with cholestatic liver diseases. We assessed the impact of fatigue and pruritus on patient‐reported outcomes (PROs) of patients with advanced nonalcoholic steatohepatitis (NASH). Specifically, PROs (Short Form–36, Chronic Liver Disease Questionnaire–NASH, Euro‐Qol 5 Dimension, and Work Productivity and Activity Impairment instruments) were assessed at baseline in patients with histologically confirmed bridging fibrosis (F3) or compensated cirrhosis (F4) due to NASH enrolled in STELLAR 3 and 4. Presence of fatigue and pruritus were indicated by a score of 4 or less on the respective items of the Chronic Liver Disease Questionnaire–NASH (scale range, 1‐7). Among the included 1,669 patients with advanced NASH (mean age = 58 ± 9 years, 48% F3, 42% with psychiatric comorbidities), 33% and 27% had fatigue and pruritus, respectively. Patients with NASH with fatigue were younger, more likely to be female, cirrhotic, and diabetic, and had higher body mass index and more comorbidities (all P < 0.05). All PRO scores of patients with fatigue were significantly impaired (mean up to −31% of a PRO range size in comparison to patients without fatigue). In multivariate analysis, predictors of fatigue included diabetes, history of depression or nervous system comorbidities, and lower serum albumin (P < 0.05). Patients with pruritus had demographic characteristics similar to those with fatigue, but a higher prevalence of dermatologic comorbidities. All PROs were impaired (by up to −19% of a range size, all P < 0.01) in patients with NASH with pruritus. Female gender, lower serum albumin, and a history of depression, nervous system, and dermatologic comorbidities were associated with increased risk of pruritus (P < 0.05). Conclusion: Clinically significant fatigue and pruritus are common in patients with advanced NASH, and these symptoms negatively affect PROs.

Selonsertib for patients with bridging fibrosis or compensated cirrhosis due to NASH: Results from randomized phase III STELLAR trials

BACKGROUND & AIMS

Apoptosis signal-regulating kinase 1 (ASK1) plays a key role in hepatocyte injury, inflammation, and fibrosis in non-alcoholic steatohepatitis (NASH). We evaluated the safety and antifibrotic effect of selonsertib, a selective inhibitor of ASK1, in patients with advanced fibrosis due to NASH.

METHODS

We conducted 2 randomized, double-blind, placebo-controlled, phase III trials of selonsertib in patients with NASH and bridging fibrosis (F3, STELLAR-3) or compensated cirrhosis (F4, STELLAR-4). Patients were randomized 2:2:1 to receive selonsertib 18 mg, selonsertib 6 mg, or placebo once daily for 48 weeks. Liver biopsies were performed at screening and week 48 and non-invasive tests of fibrosis (NITs) were evaluated. The primary efficacy endpoint was the proportion of patients with ≥1-stage improvement in fibrosis without worsening of NASH at week 48. Additional endpoints included changes in NITs, progression to cirrhosis (in STELLAR-3), and liver-related clinical events.

RESULTS

Neither trial met the primary efficacy endpoint. In STELLAR-3, fibrosis improvement without worsening of NASH was observed in 10% (31/322, p = 0.49 vs. placebo), 12% (39/321, p = 0.93 vs. placebo), and 13% (21/159) of patients in the selonsertib 18 mg, selonsertib 6 mg, and placebo groups, respectively. In STELLAR-4, the primary endpoint was achieved in 14% (51/354; p = 0.56), 13% (45/351; p = 0.93), and 13% (22/172) of patients, respectively. Although selonsertib led to dose-dependent reductions in hepatic phospho-p38 expression indicative of pharmacodynamic activity, it had no significant effect on liver biochemistry, NITs, progression to cirrhosis, or adjudicated clinical events. The rates and types of adverse events were similar among selonsertib and placebo groups.

CONCLUSIONS

Forty-eight weeks of selonsertib monotherapy had no antifibrotic effect in patients with bridging fibrosis or compensated cirrhosis due to NASH.

LAY SUMMARY

Patients with non-alcoholic steatohepatitis (NASH) can develop scarring of the liver (fibrosis), including cirrhosis, which increases the risks of liver failure and liver cancer. We tested whether 48 weeks of treatment with selonsertib reduced fibrosis in patients with NASH and advanced liver scarring. We did not find that selonsertib reduced fibrosis in these patients.

TRIAL REGISTRATION DETAILS

Clinicaltrials.gov numbers NCT03053050 and NCT03053063.

Pharmacokinetics, Safety, and Tolerability of Ledipasvir/Sofosbuvir and Sofosbuvir/Velpatasvir in Healthy Chinese Subjects

PURPOSE

Ledipasvir/sofosbuvir and sofosbuvir/velpatasvir have been approved worldwide for the treatment of chronic hepatitis C virus (HCV) infection. Although both have been approved in China, there are currently no data on their pharmacokinetic profiles in Chinese individuals. Two studies investigated the pharmacokinetic properties, safety, and tolerability of ledipasvir/sofosbuvir and sofosbuvir/velpatasvir, respectively, in healthy Chinese subjects.

METHODS

Two Phase I, open-label, single- and multiple-dose studies were conducted in healthy Chinese subjects. Ledipasvir/sofosbuvir (90/400 mg) or sofosbuvir/velpatasvir (400/100 mg), respectively, was administered orally once daily under fasted conditions. Subjects received a single dose (day 1) and multiple doses (days 8-17 [ledipasvir/sofosbuvir]; days 8-14 [sofosbuvir/velpatasvir]). Plasma pharmacokinetic parameters were estimated by using noncompartmental models, and safety was assessed through clinical evaluation and monitoring of adverse events.

FINDINGS

Fourteen subjects were enrolled in each study (7 men, 7 women each; mean age, 30 years [ledipasvir/sofosbuvir] and 29 years [sofosbuvir/velpatasvir]). The pharmacokinetic parameters for sofosbuvir, GS-566500, GS-331007, and ledipasvir or velpatasvir were similar to historical values in non-Chinese subjects. Consistent with the t_1/2 of ledipasvir relative to 24-h dosing, accumulation of 177% (AUC) and 107% (C_max) was observed. There was no significant accumulation of velpatasvir, sofosbuvir, GS-566500, or GS-331007. Both drugs were generally well tolerated; no serious adverse events or discontinuations due to adverse events were reported.

IMPLICATIONS

Overall, ledipasvir/sofosbuvir and sofosbuvir/velpatasvir exhibited pharmacokinetic and safety profiles in healthy Chinese subjects similar to those in non-Chinese subjects in historical studies, supporting their use in the Chinese population with HCV infection. ChinaDrugTrials.org.cn identifiers: CTR20160149 (ledipasvir/sofosbuvir); CTR20160602 (sofosbuvir/velpatasvir).

Reduced Patient-Reported Outcome Scores Associate With Level of Fibrosis in Patients With Nonalcoholic Steatohepatitis

BACKGROUND

Patient-reported outcomes (PROs) are used to measure patients' experience with their disease. However, there are few PRO data from patients with NASH. We collected data from the STELLAR clinical trials to assess PROs for NASH and advanced fibrosis.

METHODS

We analyzed data from 1667 patients (58 ± 9 years, 40% male, 52% with cirrhosis, 74% with diabetes) with NASH and bridging fibrosis or compensated cirrhosis (metavir scores, F3 or F4) enrolled in the phase 3 STELLAR trials of selonsertib (NCT03053050 and NCT03053063) who completed PRO questionnaires (SF-36, CLDQ-NASH, EQ-5D, or WPAI:SHP) before treatment initiation.

RESULTS

Compared with patients with F3 fibrosis, higher proportions of patients with F4 fibrosis were female, were white, had more hematologic and gastrointestinal comorbidities, and had type 2 diabetes (P ≤ .01). Mean physical health-related PRO scores were significantly lower than those of the general population: patients with F4 fibrosis had score reductions of 4.4% to 12.9% in 6/8 SF-36 domains and patients with F3 fibrosis had score reductions of 3.9% to 11.7% in 4/8 domains (P < .01). Compared to patients with F3 fibrosis, those with F4 fibrosis had lower scores in all but 1 domains of CLDQ-NASH, Role Physical, Bodily Pain, and Social Functioning domains of the SF-36, and EQ-5D (P ≤ 01). In multivariate regression analysis, factors independently associated with lower PRO scores included having cirrhosis, female sex, higher body mass index, history of smoking, and diabetes or other comorbidities (P < .01).

CONCLUSIONS

PROs are significantly lower in patients with NASH with advanced fibrosis who participated in the STELLAR clinical trials. Treatment of patients with NASH should focus on improving not only clinical outcomes but also quantifiable symptom burden and health-related quality of life.

Noninvasive Tests Accurately Identify Advanced Fibrosis due to NASH: Baseline Data From the STELLAR Trials

Accurate noninvasive tests (NITs) are needed to replace liver biopsy for identifying advanced fibrosis caused by nonalcoholic steatohepatitis (NASH). We analyzed screening data from two phase 3 trials of selonsertib to assess the ability of NITs to discriminate advanced fibrosis. Centrally read biopsies from the STELLAR studies, which enrolled patients with bridging fibrosis and compensated cirrhosis, were staged according to the NASH Clinical Research Network classification. We explored associations between fibrosis stage and NITs, including the nonalcoholic fatty liver disease fibrosis score (NFS), fibrosis-4 (FIB-4) index, Enhanced Liver Fibrosis (ELF) test, and liver stiffness by vibration-controlled transient elastography (LS by VCTE). The performance of these tests to discriminate advanced fibrosis, either alone or in combinations, was evaluated using areas under the receiver operating characteristic curve (AUROCs) with 5-fold cross-validation repeated 100 times. Of the 4,404 patients screened for these trials, 3,202 had evaluable biopsy data: 940 with F0-F2 fibrosis and 2,262 with F3-F4 fibrosis. Significant differences between median values of NITs for patients with F0-F2 versus F3-F4 fibrosis were observed: -0.972 versus 0.318 for NFS, 1.18 versus 2.20 for FIB-4, 9.22 versus 10.39 for ELF, and 8.8 versus 16.5 kPa for LS by VCTE (all P < 0.001). AUROCs ranged from 0.75 to 0.80 to discriminate advanced fibrosis. FIB-4 followed by an LS by VCTE or ELF test in those with indeterminate values (FIB-4 between 1.3 and 2.67) maintained an acceptable performance while reducing the rate of indeterminate results. Conclusion: Among patients being considered for enrollment into clinical trials, NITs alone or in combination can reduce the need for liver biopsy to discriminate advanced fibrosis caused by NASH. The predictive value of these tests for general screening will require confirmation in a real-world population.

Ledipasvir/sofosbuvir with or without ribavirin for 8 or 12 weeks for the treatment of HCV genotype 4 infection: results from a randomised phase III study in Egypt

OBJECTIVE

We evaluated the efficacy and safety of ledipasvir/sofosbuvir alone and with ribavirin for 8 and 12 weeks in Egyptian patients with and without cirrhosis, who were infected with hepatitis C virus (HCV) genotype 4, including those who had failed previous treatment with sofosbuvir regimens.

DESIGN

In this open-label, multicentre, phase III study, treatment-naive patients were randomised to receive 8 or 12 weeks of ledipasvir/sofosbuvir±ribavirin. Interferon treatment-experienced patients were randomised to receive 12 weeks of ledipasvir/sofosbuvir±ribavirin, while sofosbuvir-experienced or ledipasvir/sofosbuvir-experienced patients received 12 weeks of ledipasvir/sofosbuvir+ribavirin. Randomisation was stratified by cirrhosis status. The primary endpoint was sustained virological response 12 weeks post-treatment (SVR12).

RESULTS

We enrolled 255 patients from four centres in Egypt. Among treatment-naive patients, SVR12 rates were 95% and 90% for those receiving 8 weeks of ledipasvir/sofosbuvir alone and with ribavirin, respectively, and 98% for those receiving 12 weeks of ledipasvir/sofosbuvir both alone and with ribavirin. Among interferon-experienced patients, SVR rates were 94% for those receiving 12 weeks of ledipasvir/sofosbuvir and 100% for those receiving 12 weeks of ledipasvir/sofosbuvir plus ribavirin. All patients previously treated with sofosbuvir regimens who received ledipasvir/sofosbuvir plus ribavirin achieved SVR12. The most common adverse events, headache and fatigue, were more common among patients receiving ribavirin.

CONCLUSION

Among non-cirrhotic treatment-naive patients with HCV genotype 4, 8 weeks of ledipasvir/sofosbuvir±ribavirin was highly effective. Twelve weeks of ledipasvir/sofosbuvir±ribavirin was highly effective regardless of presence of cirrhosis or prior treatment experience, including previous treatment with sofosbuvir or ledipasvir/sofosbuvir.

TRIAL REGISTRATION NUMBER

NCT02487030.

Safety and Efficacy of Ledipasvir-Sofosbuvir With or Without Ribavirin for Chronic Hepatitis C in Children Ages 6-11

Currently, there are no interferon-free treatments available for hepatitis C virus (HCV)-infected patients younger than 12 years. We evaluated the safety and effectiveness of the all-oral regimen ledipasvir-sofosbuvir ± ribavirin in HCV-infected children aged 6 to <12 years. In an open-label study, patients aged 6 to <12 years received ledipasvir 45 mg-sofosbuvir 200 mg as two fixed-dose combination tablets 22.5/100 mg once daily, with or without ribavirin, for 12 or 24 weeks, depending on HCV genotype and cirrhosis status. The primary efficacy endpoint was sustained virologic response 12 weeks after therapy (SVR12). Twelve patients underwent intensive pharmacokinetic sampling to confirm the appropriateness of the ledipasvir and sofosbuvir dosages. Ninety-two patients were enrolled (88 genotype 1, 2 genotype 3, and 2 genotype 4), with a median age of 9 years (range, 6-11). Most were perinatally infected (97%) and treatment-naive (78%). Two were confirmed to have cirrhosis, while the degree of fibrosis was unknown in 55 patients. The overall SVR12 rate was 99% (91/92; 95% confidence interval, 94%-100%). The single patient not reaching SVR relapsed 4 weeks after completing 12 weeks of treatment. The most common adverse events were headache and pyrexia. One patient had three serious adverse events, which were considered to be not related to study treatment: tooth abscess, abdominal pain, and gastroenteritis. The area under the concentration-time curve and maximum concentration values for sofosbuvir, its primary metabolite GS-331007, and ledipasvir were within predefined pharmacokinetic equivalence boundaries (50%-200%) compared to values in adults in phase 2/3 of the ledipasvir and sofosbuvir studies. Conclusion: Ledipasvir-sofosbuvir was well tolerated and highly effective in children 6 to <12 years old with chronic HCV.

Sofosbuvir plus ribavirin with or without peginterferon for the treatment of hepatitis C virus: Results from a phase 3b study in China

BACKGROUND AND AIM

Sofosbuvir is a nucleotide analog inhibitor of the hepatitis C virus (HCV) NS5B RNA polymerase with pangenotypic potency. This phase 3b study evaluated the safety and efficacy of sofosbuvir + ribavirin ± peginterferon in Chinese patients infected with HCV genotype 1, 2, 3, or 6.

METHODS

Patients with genotype 1 or 6 received sofosbuvir + peginterferon/ribavirin for 12 weeks or sofosbuvir + ribavirin for 24 weeks, depending on prior treatment and interferon eligibility. Patients with genotype 2 or 3 received sofosbuvir + ribavirin for 12 or 24 weeks, respectively. The primary endpoint was sustained virologic response at 12 weeks after the end of treatment (SVR12).

RESULTS

Of 389 patients, 42% had genotype 1, 16% genotype 2, 32% genotype 3, and 9% genotype 6. Half were male, 58% were treatment-naïve, and 15% had cirrhosis. SVR12 rates for patients receiving 12 weeks of sofosbuvir + peginterferon/ribavirin were 94% (95% confidence interval [CI], 87-98%) for HCV genotype 1 and 97% (95% CI, 84-100%) for genotype 6. SVR12 rates for those receiving sofosbuvir + ribavirin for 24 weeks were 95% (95% CI, 87-99%) for genotype 1, 100% (95% CI, 40-100%) for genotype 6, and 95% (95% CI, 90-98%) for genotype 3. For genotype 2 patients receiving sofosbuvir + ribavirin for 12 weeks, the SVR12 rate was 92% (95% CI, 83-97%). Twenty patients (5%) relapsed. Ten (3%) experienced serious adverse events. Three (< 1%) discontinued treatment because of adverse events, of whom one died because of treatment-unrelated adverse events.

CONCLUSIONS

Sofosbuvir-based regimens were highly effective and safe in Chinese patients with HCV genotype 1, 2, 3, or 6, suggesting sofosbuvir could serve as the backbone for HCV treatment in China irrespective of genotype.

Efficacy of sofosbuvir plus ribavirin in treatment-naive patients with genotype-1 and -3 HCV infection: results from a Russian Phase IIIb study

BACKGROUND

In this Phase IIIb study, we evaluated the efficacy and safety of the oral nucleotide analogue inhibitor sofosbuvir plus ribavirin, with special attention given to viral resistance, in Russian patients with HCV genotype-1 or -3.

METHODS

Treatment-naive patients with and without compensated cirrhosis were randomized (1:1) to receive 16 or 24 weeks of once-daily sofosbuvir 400 mg plus twice-daily oral ribavirin 1,000 or 1,200 mg/day. The primary efficacy end point was the proportion of patients with sustained viral response 12 weeks after the end of treatment (SVR12). Viral resistance testing was performed by deep sequencing on all baseline samples and for patients who experienced virological failure.

RESULTS

SVR12 rates for patients with genotype-1 HCV were 50% and 76% for those in the 16-week and 24-week groups, respectively, and for patients with genotype-3 HCV, SVR12 rates were 87% and 90% for patients in the 16-week and 24-weeks groups, respectively. Genotype-1 patients with the L159F resistance-associated variant who received 16 weeks of treatment had lower SVR12 rates than those without, but in patients who received 24 weeks of treatment, response rates were similar in those with and without L159F (80% versus 74%). Sofosbuvir plus ribavirin was well tolerated with no deaths, adverse event-related study drug discontinuations, or grade 3 or 4 adverse events, and few grade 3 or 4 laboratory abnormalities.

CONCLUSIONS

Sofosbuvir plus ribavirin for 16 or 24 weeks was associated with a high SVR rate in patients with HCV genotype-3. Among HCV genotype-1b patients, the presence of the L159F variant at baseline was associated with a lower SVR rate in those treated for 16 weeks but not in those treated for 24 weeks. Sofosbuvir plus ribavirin was safe and well tolerated regardless of treatment duration. Clinicaltrials.gov number NCT01896193.

Resistance characterization of ledipasvir and velpatasvir in hepatitis C virus genotype 4

HCV genotype 4 (GT4) has often been overlooked in drug development, even though it infects ~20 million people worldwide. Ledipasvir/sofosbuvir and sofosbuvir/velpatasvir were highly efficacious in GT4 HCV-infected patients from GS-US-337-1119 and GS-US-342-1138. Here, we characterize the resistance profile of ledipasvir (LDV) and velpatasvir (VEL) in patients with GT4 HCV infection. NS5A deep-sequencing was performed for 454 patients infected with HCV GT4 at baseline, including 44 patients enrolled in GS-US-337-1119 and 116 patients enrolled in GS-US-342-1138, and at relapse for patients with virologic failure. LDV and VEL susceptibilities of 56 patient isolates were determined. In GS-US-337-1119, SVR12 rates were 100% for all subtypes except 4b and 4r. Phenotypic assessment of 56 HCV NS5A patient isolates from various GT4 subtypes indicated that LDV had high potency for the common subtypes 4a/d, and subtypes 4c/f/k/l/m/n/o/p/r/t despite the presence of resistance-associated substitutions (RASs). For the rare GT4b, LDV median EC₅₀ was higher, but with a broad range of individual values. Importantly, all GT4b isolates tested had 2-4 NS5A RASs, some including Y93H. Similarly, the 2 GT4r infected patients who had virologic relapse had rare triple RASs. Reversion of these substitutions to the consensus residue significantly increased LDV susceptibility. In GS-US-342-1138, all patients achieved SVR12, regardless of their subtype or presence of RASs. In vitro data confirmed that VEL is potent against all GT4 isolates tested. LDV and VEL are potent antiviral drugs, estimated to be effective against >95% and >99%, respectively, of GT4 HCV isolates.

Sofosbuvir and ribavirin in adolescents 12-17 years old with hepatitis C virus genotype 2 or 3 infection

Children with chronic hepatitis C virus infection have limited treatment options. We evaluated the all-oral combination of sofosbuvir and ribavirin in adolescents aged 12-17 with hepatitis C virus genotype 2 or 3 (ClinicalTrials.gov NCT02175758). Fifty-two patients received sofosbuvir 400 mg once daily and weight-based ribavirin twice daily for 12 (genotype 2) or 24 (genotype 3) weeks. The pharmacokinetics of sofosbuvir and its metabolite GS-331007 were evaluated by intensive plasma sampling at day 7 in the first 10 patients enrolled and by sparse sampling in all patients throughout treatment. The primary efficacy endpoint was the percentage of patients with a sustained virologic response 12 weeks after treatment (SVR12). The median age of patients was 15 years, and 75% had genotype 3. Eighty-three percent of patients were treatment-naive, and 73% were infected by vertical transmission. Forty percent were assessed as not having cirrhosis; the remainder did not have a cirrhosis determination. Overall, SVR12 was achieved by 98% of patients (51/52; 95% confidence interval, 90%-100%). SVR12 rates were 100% (13/13) for patients with genotype 2 and 97% (38/39) for those with genotype 3. The single patient who did not achieve SVR12 was lost to follow-up after achieving SVR4. The most commonly reported adverse events were nausea (27%) and headache (23%). When compared with the exposure in adults treated in phase 2 and 3 sofosbuvir studies, the area under the curve and maximum concentration for sofosbuvir and GS-331007 in adolescents were within predefined pharmacokinetic equivalence boundaries of 50%-200%.

CONCLUSION

Sofosbuvir and ribavirin was safe and highly effective in adolescents with chronic hepatitis C virus genotype 2 or 3 infection. (Hepatology 2017;66:1102-1110).

The safety and effectiveness of ledipasvir-sofosbuvir in adolescents 12-17 years old with hepatitis C virus genotype 1 infection

No all-oral, direct-acting antiviral regimens have been approved for children with chronic hepatitis C virus (HCV) infection. We conducted a phase 2, multicenter, open-label study to evaluate the efficacy and safety of ledipasvir-sofosbuvir in adolescents with chronic HCV genotype 1 infection. One hundred patients aged 12-17 years received a combination tablet of 90 mg ledipasvir and 400 mg sofosbuvir once daily for 12 weeks. On the tenth day following initiation of dosing, 10 patients underwent an intensive pharmacokinetic evaluation of the concentrations of sofosbuvir, ledipasvir, and the sofosbuvir metabolite GS-331007. The primary efficacy endpoint was the percentage of patients with a sustained virologic response at 12 weeks posttreatment. Median age of patients was 15 years (range 12-17). A majority (80%) were HCV treatment-naive, and 84% were infected through perinatal transmission. One patient had cirrhosis, and 42 did not; in 57 patients the degree of fibrosis was unknown. Overall, 98% (98/100; 95% confidence interval 93%-100%) of patients reached sustained virologic response at 12 weeks. No patient had virologic failure. The 2 patients who did not achieve sustained virologic response at 12 weeks were lost to follow-up either during or after treatment. The three most commonly reported adverse events were headache (27% of patients), diarrhea (14%), and fatigue (13%). No serious adverse events were reported. Area under the concentration-time curve (tau) and maximum concentration values for sofosbuvir, ledipasvir, and GS-331007 were within the predefined pharmacokinetic equivalence boundaries of 50%-200% when compared with adults from phase 2 and 3 studies of ledipasvir and sofosbuvir.

CONCLUSION

Ledipasvir-sofosbuvir was highly effective at treating adolescents with chronic HCV genotype 1 infection; the dose of ledipasvir-sofosbuvir currently used in adults was well tolerated in adolescents and had an appropriate pharmacokinetic profile. (Hepatology 2017;66:371-378).

Sofosbuvir plus ribavirin in treatment-naïve patients with chronic hepatitis C virus genotype 1 or 3 infection in India

Until 2014, pegylated interferon plus ribavirin was the recommended standard of care for the treatment of chronic hepatitis C virus (HCV) infection in India. This open-label phase 3b study, conducted across 14 sites in India between 31 March 2014 and 30 November 2015, evaluated the efficacy and safety of sofosbuvir plus ribavirin therapy among treatment-naïve patients with chronic genotype 1 or 3 HCV infection. A total of 117 patients with genotype 1 or 3 HCV infection were randomized 1:1 to receive sofosbuvir 400 mg and weight-based ribavirin (1000 or 1200 mg) daily for 16 or 24 weeks. Among those with genotype 1 infection, the primary efficacy endpoint of sustained virologic response at 12 weeks post-treatment (SVR12) was reported in 90% (95% confidence intervals [CI], 73-98) and 96% (95% CI, 82-100) of patients following 16 and 24 weeks of treatment, respectively. For patients with genotype 3 infection, SVR12 rates were 100% (95% CI, 88-100) and 93% (95% CI, 78-99) after 16 and 24 weeks of therapy, respectively. Adverse events, most of which were mild or moderate in severity, occurred in 69% and 57% of patients receiving 16 and 24 weeks of treatment, respectively. The most common treatment-emergent adverse events were asthenia, headache and cough. Only one patient in the 24-week group discontinued treatment with sofosbuvir during this study. Overall, sofosbuvir plus ribavirin therapy achieved SVR12 rates ≥90% and was well tolerated among treatment-naïve patients with chronic genotype 1 or 3 HCV infection in India.

Ledipasvir plus sofosbuvir for 12 weeks in patients with hepatitis C genotype 4 infection

Genotype 4 hepatitis C virus (HCV) was considered difficult to treat in the era of pegylated interferon-alpha (Peg-IFN-α) and ribavirin regimens. We evaluated the efficacy and safety of therapy with the nonstructural (NS) 5A inhibitor, ledipasvir, combined with the NS5B polymerase inhibitor, sofosbuvir, in patients with HCV genotype 4. In this phase 2, open-label study, 44 patients (22 treatment naïve and 22 treatment experienced) received a fixed-dose combination tablet of 90 mg of ledipasvir and 400 mg of sofosbuvir orally once-daily for 12 weeks. The primary endpoint was the percentage of patients with HCV RNA <15 IU/mL 12 weeks after stopping therapy (SVR12). Among study participants, HCV genotype 4 subtypes were well represented (4a, n = 25; 4d, n = 10; other subtypes, n = 9). Ten patients (23%) had compensated cirrhosis. Of the 22 treatment-experienced patients, 21 (95%) had a non-CC IL-28B genotype. All 44 patients completed the full 12 weeks of dosing. The SVR12 rate was 93% (41 of 44; 95% confidence interval, 81-99). SVR12 rates were similar between treatment-naïve (95%; 21 of 22) and treatment-experienced (91%; 20 of 22) patients. All 3 patients who did not achieve SVR12 had virological relapse within 4 weeks of the end of treatment; all 3 had baseline HCV RNA ≥800,000 IU/mL, a non-CC IL-28B genotype, and pretreatment NS5A resistance-associated variants. None of the patients who relapsed had cirrhosis. The most common adverse events were asthenia, headache, and fatigue. No patients experienced a serious adverse event.

CONCLUSION

The all-oral regimen of ledipasvir and sofosbuvir is an effective and safe treatment for a wide range of HCV 4 subtypes in both treatment-naïve and -experienced patients, including those with compensated cirrhosis. (EudraCT number: 2013-003978-27; Clinicaltrials.gov NCT02081079) (Hepatology 2016;64:1049-1056).

Ledipasvir-sofosbuvir in patients with hepatitis C virus genotype 5 infection: an open-label, multicentre, single-arm, phase 2 study

BACKGROUND

Data about the response of hepatitis C virus (HCV) genotype 5 to approved and experimental treatment regimens are scarce. We assessed the efficacy and safety of combination therapy with the NS5A inhibitor ledipasvir and the NS5B polymerase inhibitor sofosbuvir in patients with HCV genotype 5.

METHODS

We did this open-label, multicentre, single-arm, phase 2 trial at five hospitals in France. Eligible patients were at least 18 years old and had chronic infection with HCV genotype 5, with plasma HCV RNA of at least 10,000 IU/mL. We used BLAST analyses of NS5B partial sequences to establish the genotype and subtype at screening. Patients were given a fixed-dose combination tablet of 90 mg ledipasvir and 400 mg sofosbuvir orally once per day for 12 weeks. The primary endpoint was the proportion of patients with a sustained viral response, defined as HCV RNA concentration less than 15 IU/mL at 12 weeks after the end of treatment (SVR12). We analysed efficacy and safety in all patients who received at least one dose of ledipasvir-sofosbuvir. This trial is registered with EudraCT, number 2013-003978-27, and with ClinicalTrials.gov, number NCT02081079.

FINDINGS

From March 7 to June 10, 2014, we recruited 41 patients, including 21 who were treatment naive and 20 who were treatment experienced. All patients were of white ethnic origins. All 41 patients who started treatment completed the full 12 weeks of treatment and had undetectable HCV RNA at their final treatment visit. In the overall study population, 39 (95%, 95% CI 83-99) of 41 patients achieved SVR12. SVR12 was achieved by 20 (95%, 76-100) of the 21 patients who were treatment naive and 19 (95%, 75-100) of the 20 patients who were treatment experienced. Eight (89%) of nine patients with cirrhosis achieved SVR12, whereas 31 (97%) of the 32 patients without cirrhosis achieved SVR12. The two patients who did not reach SVR12 both had IL28B TT genotype and had viral relapse within 4 weeks of the end of treatment. The most common adverse events were asthenia (16 [39%] patients), headache (11 [27%] patients), and fatigue (four [10%] patients). One patient had a serious adverse event, worsening depression, which we judged to be unrelated to study treatment.

INTERPRETATION

The oral regimen of ledipasvir-sofosbuvir is an effective and well-tolerated treatment for patients with HCV genotype 5 infection who are treatment naive or treatment experienced.

FUNDING

Gilead Sciences.

Sofosbuvir plus ribavirin for treating Egyptian patients with hepatitis C genotype 4

BACKGROUND & AIMS

Egypt has the highest prevalence of chronic hepatitis C virus (HCV) infection in the world, and more than 90% of patients are infected with genotype 4 virus. We evaluated the efficacy and safety of the HCV polymerase inhibitor sofosbuvir in combination with ribavirin in HCV genotype 4 patients in Egypt.

METHODS

Treatment-naïve or treatment-experienced patients with genotype 4 HCV infection (n=103) were randomly assigned to receive either 12 or 24 weeks of sofosbuvir 400 mg and ribavirin 1000-1200 mg daily. Randomization was stratified by prior treatment experience and by presence or absence of cirrhosis. The primary endpoint was the percentage of patients with HCV RNA <25 IU/ml 12 weeks after therapy (SVR12).

RESULTS

Among all patients, 52% had received prior HCV treatment and 17% had cirrhosis at baseline. SVR12 rates were 90% (46/51) with 24 weeks and 77% (40/52) with 12 weeks of sofosbuvir and ribavirin therapy. Patients with cirrhosis at baseline had lower rates of SVR12 (63% 12 weeks, 78% 24 weeks) than those without cirrhosis (80% 12 weeks, 93% 24 weeks). The most common adverse events were fatigue, headache, insomnia, and anemia. Two patients experienced serious adverse events (cerebral ischemia, dyspnea). No adverse events resulted in treatment discontinuation.

CONCLUSION

Sofosbuvir plus ribavirin for 12 or 24 weeks is effective in treating both treatment-naïve and treatment-experienced Egyptian patients with genotype 4 HCV.

Sofosbuvir plus ribavirin for the treatment of chronic genotype 4 hepatitis C virus infection in patients of Egyptian ancestry

BACKGROUND & AIMS

We conducted an open-label phase 2 study to assess the efficacy and safety of the oral nucleotide polymerase inhibitor sofosbuvir in combination with ribavirin in patients of Egyptian ancestry, chronically infected with genotype 4 hepatitis C virus (HCV).

METHODS

Treatment-naive and previously treated patients with genotype 4 HCV were randomly allocated in a 1:1 ratio to receive sofosbuvir 400mg and weight-based ribavirin, for 12 or 24 weeks. The primary efficacy endpoint was the proportion of patients with sustained virologic response (HCV RNA <25IU/ml) 12 weeks after cessation of therapy (SVR12).

RESULTS

Thirty treatment-naive and thirty previously treated patients were enrolled and treated for 12 weeks (n=31) or 24 weeks (n=29). Overall, 23% of patients had cirrhosis and 38% had diabetes. 14% of treatment-naive patients were interferon ineligible and 63% of treatment-experienced patients had prior non-response. SVR12 was achieved by 68% of patients (95% CI, 49-83%) in the 12-week group, and by 93% of patients (95% CI, 77-99%) in the 24-week group. The most common adverse events were headache, insomnia, and fatigue. No patient discontinued treatment due to an adverse event.

CONCLUSIONS

The findings from the present study suggest that 24 weeks of sofosbuvir plus ribavirin is an efficacious and well tolerated treatment in patients with HCV genotype 4 infection.

An in vitro investigation of the cardiovascular effects of the 5-HT(4) receptor selective agonists, velusetrag and TD-8954

The 5-HT(4) receptor agonists, and gastrointestinal (GI) prokinetic agents, cisapride and tegaserod, lack selectivity for the 5-HT(4) receptor. Cisapride is a potent human ether-à-go-go-related gene (hERG) potassium channel inhibitor while cisapride and tegaserod have significant affinity for 5-HT(1) and 5-HT(2) receptor subtypes. Marketing of both compounds was discontinued due to cardiovascular concerns (cardiac arrhythmias with cisapride and ischemic events with tegaserod). The reported association of tegaserod with ischemia has been postulated to involve coronary artery constriction or augmentation of platelet aggregation. This in vitro study investigated the effects of two of the new generation of highly selective 5-HT(4) receptor agonists, velusetrag and TD-8954, on canine, porcine and human coronary artery tone, human platelet aggregation and hERG potassium channel conductance. No significant off-target actions of velusetrag or TD-8954 were identified in these, and prior, studies. While cisapride inhibited potently the hERG channel currents, tegaserod failed to affect platelet aggregation, and had only a small contractile effect on the canine coronary artery at high concentrations. Tegaserod inhibited the 5-HT-induced contractile response in the porcine coronary artery. New generation 5-HT(4) receptor agonists hold promise for the treatment of patients suffering from GI motility disorders with a reduced cardiovascular risk.

The Pharmacology of TD-8954, a Potent and Selective 5-HT(4) Receptor Agonist with Gastrointestinal Prokinetic Properties

This study evaluated the in vitro and in vivo pharmacological properties of TD-8954, a potent and selective 5-HT(4) receptor agonist. TD-8954 had high affinity (pK(i) = 9.4) for human recombinant 5-HT(4(c)) (h5-HT(4(c))) receptors, and selectivity (>2,000-fold) over all other 5-hydroxytryptamine (5-HT) receptors and non-5-HT receptors, ion channels, enzymes and transporters tested (n = 78). TD-8954 produced an elevation of cAMP in HEK-293 cells expressing the h5-HT(4(c)) receptor (pEC(50) = 9.3), and contracted the guinea pig colonic longitudinal muscle/myenteric plexus preparation (pEC(50) = 8.6). TD-8954 had moderate intrinsic activity in the in vitro assays. In conscious guinea pigs, subcutaneous administration of TD-8954 (0.03-3 mg/kg) increased the colonic transit of carmine red dye, reducing the time taken for its excretion. Following intraduodenal dosing to anesthetized rats, TD-8954 (0.03-10 mg/kg) evoked a dose-dependent relaxation of the esophagus. Following oral administration to conscious dogs, TD-8954 (10 and 30 μg/kg) produced an increase in contractility of the antrum, duodenum, and jejunum. In a single ascending oral dose study in healthy human subjects, TD-8954 (0.1-20 mg) increased bowel movement frequency and reduced the time to first stool. It is concluded that TD-8954 is a potent and selective 5-HT(4) receptor agonist in vitro, with robust in vivo stimulatory activity in the gastrointestinal (GI) tract of guinea pigs, rats, dogs, and humans. TD-8954 may have clinical utility in patients with disorders of reduced GI motility.

Clinical trial: the efficacy and tolerability of velusetrag, a selective 5-HT4 agonist with high intrinsic activity, in chronic idiopathic constipation - a 4-week, randomized, double-blind, placebo-controlled, dose-response study

BACKGROUND

Velusetrag is an orally active 5-HT(4) receptor agonist of potential benefit in treating chronic idiopathic constipation.

AIM

To evaluate the efficacy, safety and tolerability of velusetrag in chronic idiopathic constipation.

METHODS

After a 2-week baseline period, patients [<3 spontaneous bowel movements (SBM)/week] received placebo or velusetrag (15, 30 or 50 mg) daily for 4 weeks in a randomized, double-blind design, followed by a 1-week follow-up period. The primary endpoint was the change from baseline in weekly SBM frequency averaged over the 4-week treatment period.

RESULTS

Patients receiving velusetrag (15, 30 and 50 mg) achieved statistically and clinically significant increases in weekly SBM frequency relative to those receiving placebo. Mean increases were 3.6, 3.3 and 3.5 SBM/week respectively, compared with 1.4 SBM/week for placebo (P < 0.0001). Statistically significant increases in the weekly frequency of complete SBM (CSBM) were also reported (mean increases of 2.3, 1.8 and 2.3 for 15, 30 and 50 mg velusetrag respectively, compared with 0.6 for placebo). Common adverse events associated with velusetrag were diarrhoea, headache, nausea and vomiting, generally occurring during the initial days of dosing.

CONCLUSION

Velusetrag was efficacious and well tolerated in patients with chronic idiopathic constipation (ClinicalTrials.gov identifier NCT00391820).

Phase I study of the heat shock protein 90 inhibitor alvespimycin (KOS-1022, 17-DMAG) administered intravenously twice weekly to patients with acute myeloid leukemia

Heat shock protein 90 (Hsp90) is a molecular chaperone with many oncogenic client proteins. The small-molecule Hsp90 inhibitor alvespimycin, a geldanamycin derivative, is being developed for various malignancies. This phase 1 study examined the maximum-tolerated dose (MTD), safety and pharmacokinetic/pharmacodynamic profiles of alvespimycin in patients with advanced acute myeloid leukemia (AML). Patients with advanced AML received escalating doses of intravenous alvespimycin (8-32 mg/m(2)), twice weekly, for 2 of 3 weeks. Dose-limiting toxicities (DLTs) were assessed during cycle 1. A total of 24 enrolled patients were evaluable for toxicity. Alvespimycin was well tolerated; the MTD was 24 mg/m(2) twice weekly. Common toxicities included neutropenic fever, fatigue, nausea and diarrhea. Cardiac DLTs occurred at 32 mg/m(2) (elevated troponin and myocardial infarction). Pharmacokinetics revealed linear increases in C(max) and area under the curve (AUC) from 8 to 32 mg/m(2) and minor accumulation upon repeated doses. Pharmacodynamic analyses on day 15 revealed increased apoptosis and Hsp70 levels when compared with baseline within marrow blasts. Antileukemia activity occurred in 3 of 17 evaluable patients (complete remission with incomplete blood count recovery). The twice-weekly administered alvespimycin was well tolerated in patients with advanced AML, showing linear pharmacokinetics, target inhibition and signs of clinical activity. We determined a recommended phase 2 dose of 24 mg/m(2).

Phase I trial of alvespimycin (KOS-1022; 17-DMAG) and trastuzumab (T)

1115

Background: Alvespimycin (A) inhibits the activity of Hsp90, resulting in degradation of client proteins, such as the HER2 receptor. In vivo, Hsp90 inhibition induces rapid degradation of HER2 with loss of pAKT, cyclin D2 and tumor growth inhibition. Methods: Pts receive standard weekly doses of T followed by A in escalating doses via IV doses over 1 hr. Define the recommended dose (RP2D), toxicity and signs of activity of T+A in pts with solid tumors. PK: assessed after the 1st and 4th infusion. PBLs: purified to investigate changes in intracellular signaling proteins by immunoblot. The RP2D will produce DLT in no more than 1/6 evaluable pts. Results: 21 pts enrolled in 3 cohorts (60, 80 and 100 mg/m2). Median age 53 yrs, range 31–75; median KPS 90; prior regimens not including hormonal therapy: median 6, range 1–13; prior T-regimens for MBC pts: median 3, range 0–9. Diagnoses: HER2+ MBC (n=18), ovarian (n=3). DLT was observed at the highest dose, consisting of 1 pt with hypoxia and ↓LVEF; an additional pt at this dose had Grade 3 ↑AST, however ↑hepatic metastases and ascites were observed. Drug-related toxicity: diarrhea (60%), fatigue, headache (both 45%), nausea, arthralgias (both 40%), dry eye and pain in extremity (both 25%); all Grade 1–2 severity except 1 episode of Gr3 fatigue and Gr3 diarrhea. PK (n=18): t½ 17.7 hr (32%CV); Clearance 18.1 L/hr (46%CV); Vz 438L (42%CV); no change upon weekly dosing. AUCinf/Cmax (100 mg/m2): 14268 ng*hr/mL (60%CV) and 2233 ng/mL (23.5%CV). HER2+ MBC activity: 1 pt (13 prior regimens; 3x T and 1x lapatanib) with evaluable disease showed near complete resolution of lung metastases by CT/PET with significant improvement in dyspnea; 3 pts with HER2+ MBC with SD (4, 5 and 7+ months). Ovarian CA activity: 1 pt (HER2 unknown; 13 prior regimens; 11+ months on-study) with evaluable disease showed near complete resolution of ascites and pleural effusion at end of Cycle 2 with ↓83% CA125. Dose-dependent increase in Hsp70 in PBLs; at 80 and 100 mg/m2, Hsp70 induction was maintained prior to successive weekly doses. Conclusions: Combination of T+A has signs of activity in H-refractory HER2+ MBC and refractory ovarian cancer. Definition of RP2D dose is pending. Toxicity has been manageable.

No significant financial relationships to disclose.

Phase I trial of a novel epothilone, KOS-1584, using a weekly dosing schedule

2041

Background: Several epothilones are progressing through phase 1–3 clinical trials treating solid tumor malignancies. KOS-1584 is a 3rd generation epothilone with 3–12 fold increased potency compared to Epothilone D (as measured by in vitro cytotoxicity, in vivo xenografts or induction of G2/M arrest by flow cytometry) and improved pharmacologic/pharmacokinetic profile (enhanced tumor tissue penetration and reduced exposure to the CNS). This dose-escalation trial explores a weekly administration schedule of KOS-1584. Methods: Define the MTD, toxicity profile and PK of KOS-1584 when administered to patients with advanced solid malignancies via 1-hour infusion on Days 1, 8 and 15 every 4 weeks. Plasma PK and pharmacodynamics (serial sampling of PBMCs for soluble and polymerized microtubules by immunoblot) were assessed. Results: 12 pts (7 F; median age 60; median ECOG PS 1; median prior regimens 4, range 2–13) enrolled in 5 dose levels (0.8, 1.5, 2.5, 5.0 and 7.5 mg/m2). To date, no Cycle 1 DLT has been seen; one Grade 3 episode of arthritis occurred in Cycle 2. Drug-related toxicities, all Grade 1 or 2 in severity: fatigue (n=3), anorexia (n=2) and individual patients with constipation, nausea, mucositis, dehydration, headache and pruritus. Neurotoxicity has not been observed. PK/parent (n=8): t½ 18.5 ± 6.8h, Vz 504 ± 234 L and CL 19.7 ± 6.1 L/h (none of these parameters showed evidence of dose dependency). 5.0 mg/m2 Cmax 122.4 ± 60.6 ng/mL; AUCtot 688.2 ± 212 ng/mL*h. Dose proportional increase in exposure and Cmax was observed over the dose range tested to date. At 5.0 mg/m2 the1-hr infusion Cmax is 3-fold higher and AUCtot 50% higher than for the same dose delivered over 3 hours. As predicted by allometric scaling from animals, Vz is ∼4-fold and t½ 2-fold higher than that of Epothilone D. Activity consisted of extended stable disease (a patient with colon cancer for 3 cycles). Dose-dependent increases in polymerized microtubules were observed: prior to infusion ∼10% of tubulin was in its polymerized form; this increased to 20%, 30%, 35% and 48% for the 1st 4 dose levels at infusion end. Conclusions: Accrual is continuing in order to define the optimal dose on this regimen. Exposure and Cmax remain linear within this dose range; slower clearance is observed for the same dose administered over 1 hour compared to 3 hours.

[Table: see text]

The effects of the 5-HT3 antagonist, alosetron, on brain serotonin synthesis in patients with irritable bowel syndrome

Serotonin (5-HT) plays an important role in the pathophysiology of irritable bowel syndrome (IBS). Using alpha-[(11)C]methyl-L-tryptophan-positron emission tomography (PET), it was demonstrated that brain 5-HT synthesis is increased in patients with IBS, in a gender-specific manner. The aims of the study were to evaluate the effects of alosetron on brain 5-HT synthesis in patients with IBS. Six male and five female non-constipation-predominant IBS patients were enrolled. The subjects received alosetron or a placebo for 14 days, separated by a 2-week washout period. On day 14, rectal distensions commenced just prior to the PET scan (which was performed for 80 min), and continued for 20-min periods. The functional images were analysed with SPM99. Alosetron vs placebo treatments, in a randomized, double-blinded, crossover manner, were studied. 5-HT synthesis was greater in several regions in the males than in the females during the alosetron treatment, whereas there was no region in which the females had greater synthesis. There were significant gender-treatment interactions of synthesis in the cingulate gyrus, caudate nucleus, globus pallidus, and cerebellum. The gender differences in the effect of alosetron on brain 5-HT synthesis may be related to the gender differences in the efficacy of alosetron.

Sex differences of brain serotonin synthesis in patients with irritable bowel syndrome using alpha-[11C]methyl-L-tryptophan, positron emission tomography and statistical parametric mapping

BACKGROUND

Irritable bowel syndrome (IBS) is the most common functional bowel disorder and has a strong predominance in women. Recent data suggest that the brain may play an important role in the pathophysiology of IBS in the brain-gut axis. It is strongly suspected that serotonin (5-HT), a neurotransmitter found in the brain and gut, may be related to the pathophysiology of IBS. It is reported that a 5-HT3 antagonist is effective only in female patients with diarrhea-predominant IBS.

OBJECTIVE

In the present study, 5-HT synthesis was measured using positron emission tomography, with alpha-[11C]methyl-L-tryptophan as the tracer, in patients with IBS. The aim of the present study was to compare 5-HT synthesis in the IBS patients with that in the controls, and to compare 5-HT synthesis between male and female IBS patients.

METHODS

Six male and six female nonconstipated IBS patients were scanned. Age-matched healthy volunteers were scanned as controls. Eighty minute dynamic scans were performed. Functional 5-HT synthesis images were analyzed using statistical parametric mapping.

RESULTS

5-HT synthesis was greater only in the female IBS patients in the right medial temporal gyrus (multimodal sensory association cortex) compared with the female controls (P<0.001).

CONCLUSIONS

The greater brain 5-HT synthesis in the female IBS patients than in the controls may be related to the pathological visceral pain processing of the IBS patients, a larger female predominance of the disorder, and the sex difference of the efficacy of the 5-HT3 antagonist in treatment.

Effect of ranitidine on the pharmacokinetics of triazolam and alpha-hydroxytriazolam in both young (19-60 years) and older (61-78 years) people

OBJECTIVE

This study evaluated the effect of oral ranitidine (75 mg and 150 mg) on the pharmacokinetics of triazolam (0.25 mg) and its major metabolite, alpha-hydroxytriazolam, in both young and older people. Metabolite data were used to distinguish the mechanism of this interaction.

METHOD

This was a randomized, open-label, 3-way crossover study. Eighteen young (19-60 years) and 12 older (61-78 years) men and women were randomly assigned to receive evening doses of triazolam 0.25 mg (1) alone, (2) on the third day of dosing ranitidine 75 mg twice daily for 4 days, and (3) on the third day of dosing ranitidine 150 mg twice daily for 4 days.

RESULTS

In the young group, mean triazolam area under the concentration-time curve from time zero to infinity [AUC(0-infinity)] was 10% and 28% higher after treatment with 75 mg and 150 mg ranitidine, respectively. In the older group, mean triazolam AUC(0-infinity) was 31% and 28% higher after treatment with 75 mg and 150 mg ranitidine, respectively. There was no change in the alpha-hydroxytriazolam/triazolam AUC(0-infinity) ratio in either age group, indicating that neither formation nor elimination of alpha-hydroxytriazolam was affected by ranitidine. There were no changes in the half-life of triazolam or alpha-hydroxytriazolam.

CONCLUSION

Ranitidine increases oral absorption of triazolam in both young and older people. This effect is likely caused by elevation of gastrointestinal pH, allowing for greater absorption of acid-labile triazolam. The difference in this effect between age groups at the lower 75-mg dose of ranitidine suggests that older people may be more sensitive to the antisecretory effect of ranitidine.

Proteosomes, emulsomes, and cholera toxin B improve nasal immunogenicity of human immunodeficiency virus gp160 in mice: induction of serum, intestinal, vaginal, and lung IgA and IgG

Intranasal immunization of mice with human immunodeficiency virus (HIV) rgp160 complexed to proteosomes improved anti-gp160 serum IgA and IgG titers, increased the number of gp160 peptides recognized, and stimulated anti-gp160 intestinal IgA compared with immunization with uncomplexed rgp160 in saline. These enhanced responses were especially evident when either a bioadhesive nanoemulsion (emulsomes) or cholera toxin B subunit (CTB) was added to the proteosome-rgp160 vaccine. Furthermore, anti-gp160 IgG and IgA in vaginal secretions and fecal extracts were induced after intranasal immunization with proteosome-rgp160 delivered either in saline or with emulsomes. Formulation of uncomplexed rgp160 with emulsomes or CTB also enhanced serum and selected mucosal IgA responses. Induction of serum, vaginal, bronchial, intestinal, and fecal IgA and IgG by intranasal proteosome-rgp160 vaccines delivered in saline or with emulsomes or CTB is encouraging for mucosal vaccine development to help control the spread of HIV transmission and AIDS.

Effervescent and standard formulations of ranitidine--a comparison of their pharmacokinetics and pharmacology

BACKGROUND

An effervescent formulation of ranitidine may be absorbed faster and achieve a faster onset of action than conventional tablet form. The aim of this study was to compare the effects of effervescent formulations of ranitidine with equivalent dose standard tablets, in terms of intragastric pH and plasma pharmacokinetics in the initial 6 h following dosing.

METHODS

Fifteen fasting healthy males, aged 18-31 (mean 29) years, were each randomly given, at weekly intervals, 150 mg standard and effervescent ranitidine and 300 mg standard and effervescent ranitidine. Ambulatory gastric pH was performed and plasma drug levels measured at regular intervals.

RESULTS

Plasma ranitidine levels increased more rapidly with both effervescent formulations compared with standard tablets as indicated by mean area under curve (AUC) at 1 h (P < 0.001). However, the pH profiles produced by all four treatments were similar with a steep rise in pH at 40-60 min to give a sustained level of pH 7 for the following 5 h. The effervescent formulations produced a transient rise in pH immediately following dosing, and for 300 mg this rise was significantly different at 10-20 min compared with the standard tablet (median pH 4.75 vs. 2.3, P < 0.05).

CONCLUSIONS

Plasma drug levels increase more rapidly following effervescent ranitidine. Effervescent and standard formulations of 150 and 300 mg are all equally effective in producing gastric pH 7 after 1 h. However, effervescent formulations produce an early transient rise in pH which may be of clinical benefit.

Effect of intravenous infusion of ranitidine on intragastric acidity in fasting subjects: comparison with bolus or Gastrojet (pH-stat-adjusted) infusion

This study was undertaken in nine fasting healthy volunteers to compare the effect of intravenous continuous infusion versus bolus injection of ranitidine on 12-h intragastric pH, and to compare the efficacy of these two modes of administration of pH-stat-adjusted infusion of ranitidine using the Gastrojet. Each volunteer had three study sessions with 12-h pH measurements. In the ranitidine infusion treatment arm (RAN-INF), ranitidine was continually infused intravenously using an IVAC-pump at a dose of 0.125 mg mg.kg over a 12-h period. In the ranitidine bolus treatment arm (RAN-BOL), ranitidine bolus 50 mg was given over 10 min, every 6 h. When ranitidine infusion was given by the pH stat method using the Gastrojet (RAN-JET), sufficient ranitidine was given to maintain a present value of pH > or = 5. The study was analysed with a 3 x 3 Latin square cross-over design with multiple measurements of each phase of the cross-over. No difference was found between RAN-INF and RAN-BOL in 12-h or in daytime (10.00-18.00 h) mean pH, median pH, or percentage of pH > or = 5. Using RAN-JET, 89.5% of the pH values were > or = 5., compared with 39.7% and 40.0% with RAN-INF or RAN-BOL. RAN-JET also gave higher (P < 0.05) mean and median 12-h or daytime pH values, as compared with RAN-INF or RAN-BOL. The mean doses of ranitidine given in the 12-h infusion periods were 100 mg, 109 mg and 112 mg (RAN-BOL, RAN-INF and RAN-JET, respectively). Thus, this superior inhibition of acid inhibition achieved with Gastrojet does not require higher mean doses of ranitidine. These findings cannot necessarily be applied to persons with duodenal ulcer disease or to patients in an intensive-care unit setting. However, the data do raise the possibility that much greater inhibition of acid inhibition can be achieved by individualizing the dose of ranitidine using the Gastrojet.

Evidence that changes in tonic luteinizing hormone secretion determine the growth of preovulatory follicles in the rat

Physiological concentrations of progesterone (20-100 ng/ml), maintained by the insertion of implants into 30-day-old rats, delayed first ovulation, and withdrawal of progesterone on day 47 of age synchronized first ovulation in rats. Inhibition of ovulation involved negative feedback regulation of tonic LH and FSH secretion, blockage of gonadotropin surges, and suppression of preovulatory, but not antral, follicular growth. Removal of implants resulted in a rapid decline in serum progestrone from 100 to 5 ng/ml within 0-12 h. Between 0-36 h there were progressive increases in serum concentrations of LH and FSH, enhanced accumulation of estradiol by individual follicles incubated in vitro with or without exogenous substrate, and marked progressive increases in the content of LH (but not FSH) receptors in both thecal and granulosa cells. These events were followed by gonadotropin surges at 48 h (1800 h on day 49), ovulation, and morphological and biochemical signs of luteinization, including decreases in follicular gonadotropin receptor content and estradiol accumulation, evident by 60 h. With the exception of changes in basal LH, this sequence of events is remarkably similar in time and pattern to that after the decline of progesterone on diestrous day 2 and ovulation on proestrus of a 5-day cycle. Although a direct effect of progesterone on ovarian follicular cell function cannot be excluded, the data suggest that subtle but sustained increases in LH (and possibly FSH) are required for the enhanced follicular accumulation of estradiol and LH-binding activity occurring between diestrus and proestrus of the rat estrous cycle. Thus, perhaps some of the mystery surrounding the endocrine events between diestrus and proestrus can be ascribed to changes in serum LH that have been too small and/or variable for current nonserial sampling methods and RIAs to detect reliably.