Determination of the Optimal Single Dose Treatment for Acoziborole, a Novel Drug for the Treatment of Human African Trypanosomiasis: First-in-Human Study.

BACKGROUND AND OBJECTIVES: Acoziborole is a novel boron-containing candidate developed as an oral drug for the treatment of human African trypanosomiasis (HAT). Results from preclinical studies allowed progression to Phase 1 trials. We aimed to determine the best dose regimen for all stages of HAT. METHODS: Acoziborole was assessed in 128 healthy adult males of sub-Saharan African origin living in France. The study included a single oral administration of a 20- to 1200-mg dose in a randomised double-blind study in cohorts of 8 (6 active, 2 placebo) to assess safety, tolerability, and pharmacokinetics. In three additional open cohorts of 6 participants, the effect of activated charcoal was evaluated, bioequivalence of capsules versus tablets was assessed, and safety in the 960-mg tablet cohorts was monitored. RESULTS: Acoziborole was well tolerated at all doses tested; no dose-related adverse events were observed. The drug appeared rapidly in plasma (at 1 h), reached tmax between 24 and 72 h, and remained stable for up to 96 h, after which a slow decrease was quantifiable until 14 weeks after dosing. Charcoal had little impact on the enterohepatic recirculation effect, except for the 20-mg dose. Bioequivalence between capsule and tablet formulations was demonstrated. The therapeutic single dose for administration under fasted conditions was fixed to 960 mg. The maximum administered dose was 1200 mg. CONCLUSIONS: This study showed that acoziborole could be safely assessed in patients as a potential single-dose oral cure for both stages of gambiense HAT. TRIAL REGISTRATION: The study was registered with ClinicalTrials.gov: NCT01533961.

Efficacy and safety of acoziborole in patients with human African trypanosomiasis caused by Trypanosoma brucei gambiense: a multicentre, open-label, single-arm, phase 2/3 trial.

BACKGROUND: Human African trypanosomiasis caused by Trypanosoma brucei gambiense (gambiense HAT) in patients with late-stage disease requires hospital admission to receive nifurtimox-eflornithine combination therapy (NECT). Fexinidazole, the latest treatment that has been recommended by WHO, also requires systematic admission to hospital, which is problematic in areas with few health-care resources. We aim to assess the safety and efficacy of acoziborole in adult and adolescent patients with gambiense HAT. METHODS: This multicentre, prospective, open-label, single-arm, phase 2/3 study recruited patients aged 15 years or older with confirmed gambiense HAT infection from ten hospitals in the Democratic Republic of the Congo and Guinea. Inclusion criteria included a Karnofsky score greater than 50, ability to swallow tablets, a permanent address or traceability, ability to comply with follow-up visits and study requirements, and agreement to hospital admission during treatment. Oral acoziborole was administered as a single 960 mg dose (3 × 320 mg tablets) to fasted patients. Patients were observed in hospital until day 15 after treatment administration then for 18 months as outpatients with visits at 3, 6, 12, and 18 months. The primary efficacy endpoint was the success rate of acoziborole treatment at 18 months in patients with late-stage gambiense HAT (modified intention-to-treat [mITT] population), based on modified WHO criteria. A complementary post-hoc analysis comparing the 18-month success rates for acoziborole and NECT (using historical data) was performed. This study is registered at ClinicalTrials.gov, NCT03087955. FINDINGS: Between Oct 11, 2016, and March 25, 2019, 260 patients were screened, of whom 52 were ineligible and 208 were enrolled (167 with late-stage and 41 with early-stage or intermediate-stage gambiense HAT; primary efficacy analysis set). All 41 (100%) patients with early-stage or intermediate-stage and 160 (96%) of 167 with late-stage disease completed the last 18-month follow-up visit. The mean age of participants was 34·0 years (SD 12·4), including 117 (56%) men and 91 (44%) women. Treatment success rate at 18 months was 95·2% (95% CI 91·2-97·7) reached in 159 of 167 patients with late-stage gambiense HAT (mITT population) and 98·1% (95·1-99·5) reached in 159 of 162 patients (evaluable population). Overall, 155 (75%) of 208 patients had 600 treatment-emergent adverse events. A total of 38 drug-related treatment-emergent adverse events occurred in 29 (14%) patients; all were mild or moderate and most common were pyrexia and asthenia. Four deaths occurred during the study; none were considered treatment related. The post-hoc analysis showed similar results to the estimated historical success rate for NECT of 94%. INTERPRETATION: Given the high efficacy and favourable safety profile, acoziborole holds promise in the efforts to reach the WHO goal of interrupting HAT transmission by 2030. FUNDING: Bill & Melinda Gates Foundation, UK Aid, Federal Ministry of Education and Research, Swiss Agency for Development and Cooperation, Médecins Sans Frontières, Dutch Ministry of Foreign Affairs, Norwegian Agency for Development Cooperation, Norwegian Ministry of Foreign Affairs, the Stavros Niarchos Foundation, Spanish Agency for International Development Cooperation, and the Banco Bilbao Vizcaya Argentaria Foundation. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Trypanosome spliced leader RNA for diagnosis of acoziborole treatment outcome in gambiense human African trypanosomiasis: A longitudinal follow-up study.

BACKGROUND: Detection of spliced leader (SL)-RNA allows sensitive diagnosis of gambiense human African trypanosomiasis (HAT). We investigated its diagnostic performance for treatment outcome assessment. METHODS: Blood and cerebrospinal fluid (CSF) from a consecutive series of 97 HAT patients, originating from the Democratic Republic of the Congo, were prospectively collected before treatment with acoziborole, and during 18 months of longitudinal follow-up after treatment. For treatment outcome assessment, SL-RNA detection was compared with microscopic trypanosome detection and CSF white blood cell count. The trial was registered under NCT03112655 in clinicaltrials.gov. FINDINGS: Before treatment, respectively 94.9% (92/97; CI 88.5-97.8%) and 67.7% (65/96; CI 57.8-76.2%) HAT patients were SL-RNA positive in blood or CSF. During follow-up, one patient relapsed with trypanosomes observed at 18 months, and was SL-RNA positive in blood and CSF at 12 months, and CSF positive at 18 months. Among cured patients, one individual tested SL-RNA positive in blood at month 12 (Specificity 98.9%; 90/91; CI 94.0-99.8%) and 18 (Specificity 98.9%; 88/89; CI 93.9-99.8%). INTERPRETATION: SL-RNA detection for HAT treatment outcome assessment shows ≥98.9% specificity in blood and 100% in CSF, and may detect relapses without lumbar puncture. FUNDING: The DiTECT-HAT project is part of the EDCTP2 programme, supported by Horizon 2020, the European Union Funding for Research and Innovation (grant number DRIA-2014-306-DiTECT-HAT).

Safety and efficacy of oral fexinidazole in children with gambiense human African trypanosomiasis: a multicentre, single-arm, open-label, phase 2-3 trial.

BACKGROUND: Fexinidazole has been reported as an effective oral monotherapy against non-severe gambiense human African trypanosomiasis in a recent trial in adults. We aimed to assess the safety and efficacy of fexinidazole in children across all disease stages of gambiense human African trypanosomiasis. METHODS: We did a multicentre, single-arm, open-label, phase 2-3 trial at eight district hospitals in the Democratic Republic of the Congo. We recruited children with a Karnofsky score of more than 50, those aged 6 years to younger than 15 years, weighing 20 kg or more, and with confirmed gambiense human African trypanosomiasis (any stage). Children weighing 20 kg or more and less than 35 kg received oral fexinidazole of 1200 mg (two × 600 mg tablets) once per day for 4 days (days 1-4) followed by 600 mg (one × 600 mg tablet) once per day for 6 days (days 5-10). Children weighing 35 kg or more received oral fexinidazole of 1800 mg (three × 600 mg tablets) once per day for 4 days (days 1-4), followed by 1200 mg (two × 600 mg tablets) once per day for 6 days (days 5-10). The primary endpoint was fexinidazole treatment success rate 12 months after end of treatment. A rate greater than 80% was deemed acceptable and a target value of 92% was aimed for. Safety was assessed through routine monitoring. This study is completed and registered with ClinicalTrials.gov, number NCT02184689. FINDINGS: Between May 3, 2014, and Nov 22, 2016, we screened a total of 130 paediatric patients, of whom 125 (96%) received at least one dose of fexinidazole. All 125 patients (69 [55%] patients with stage 1, 19 [15%] with early stage 2, and 37 [30%] with late stage 2 gambiense human African trypanosomiasis) completed the 10-day treatment. Treatment success rate at 12 months was 97·6% (95% CI 93·1-99·5; 122 of 125 patients). The primary endpoint was met and the targeted value of 92% was exceeded. Treatment success at 12 months was elevated across all disease stages: 98·6% (95% CI 92·2-99·9; 68 of 69 patients) in stage 1, 94·7% (74·0-99·9; 18 of 19 patients) in early stage 2, and 97·3% (85·8-99·9; 36 of 37 patients) in late stage 2 gambiense human African trypanosomiasis. No new safety issues were observed beyond those found in adult trials. Overall, 116 (93%) of 125 patients reported 586 treatment-emergent adverse events, mainly mild or moderate. The most frequently reported treatment-emergent adverse events of interest during hospital admission were vomiting (86 [69%] of 125) and headache (41 [33%]). Seven (6%) of 125 patients had severe malaria, which was often accompanied by anaemia that was unrelated to fexinidazole. One patient died following dyspnoea and injury due to traumatic aggression 172 days after end of treatment, which was considered unrelated to fexinidazole or gambiense human African trypanosomiasis. INTERPRETATION: Oral fexinidazole is a safe and effective first-line treatment option across all gambiense human African trypanosomiasis disease stages in paediatric patients. FUNDING: Through the Drugs for Neglected Diseases initiative: the Bill & Melinda Gates Foundation (USA), the Republic and Canton of Geneva (Switzerland), the Dutch Ministry of Foreign Affairs (Netherlands), the Norwegian Agency for Development Cooperation (Norway), the Federal Ministry of Education and Research through KfW (Germany), the Brian Mercer Charitable Trust (UK), and other private foundations and individuals from the human African trypanosomiasis campaign. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Development and Introduction of Fexinidazole into the Global Human African Trypanosomiasis Program.

In this article, the authors show the strategy used to streamline the introduction of fexinidazole, the first all oral treatment of human African trypanosomiasis (HAT) caused by Trypanosoma brucei gambiense. The dose range was determined in phase 1 studies and a significant food effect was observed, which was tested with field-adapted meals. The pharmacokinetic profile required definition of a higher loading dosage for the first 4 days and administration of the daily dose together with a typical local meal to optimize product absorption and rapidly achieve drug steady state. This allowed for a combined phase II/III pivotal study directly after phase I trials. Partnerships with highly engaged actors from endemic country control programs and international research institutions started early through the HAT platform, building on an agreed target product profile (TPP), establishing a regulatory plan early and transparently including endemic countries in the research and data flow. A key element that enabled a quick start to access activities was preparing for World Health Organization guidelines early and starting the process prior to registration. Distribution plans were identified and supply was established from the start, by taking advantage of the existing supply agreement between the producers of all HAT drugs (Sanofi and Bayer) and the WHO. Pharmacovigilance and phase 4 studies were nested into wider implementation activities. Targeted sequential introduction into national programs was prioritized, based on medical need and epidemiologically updated information.

Trypanosome SL-RNA detection in blood and cerebrospinal fluid to demonstrate active gambiense human African trypanosomiasis infection.

BACKGROUND: Spliced Leader (SL) trypanosome RNA is detectable only in the presence of live trypanosomes, is abundant and the Trypanozoon subgenus has a unique sequence. As previously shown in blood from Guinean human African trypanosomiasis (HAT) patients, SL-RNA is an accurate target for diagnosis. Detection of SL-RNA in the cerebrospinal fluid (CSF) has never been attempted. In a large group of Congolese gambiense HAT patients, the present study aims i) to confirm the sensitivity of SL-RNA detection in the blood and; ii) to assess the diagnostic performance of SL-RNA compared to trypanosome detection in CSF. METHODOLOGY/PRINCIPAL FINDINGS: Blood and CSF from 97 confirmed gambiense HAT patients from the Democratic Republic of Congo were collected using PAXgene blood RNA Tubes. Before RNA extraction, specimens were supplemented with internal extraction control RNA to monitor the extraction, which was performed with a PAXgene Blood RNA Kit. SL-RNA qPCR was carried out with and without reverse transcriptase to monitor DNA contamination. In blood, 92/97 (94.8%) HAT patients tested SL-RNA positive, which was significantly more than combined trypanosome detection in lymph and blood (78/97 positive, 80.4%, p = 0.001). Of 96 CSF RNA specimens, 65 (67.7%) were SL-RNA positive, but there was no significant difference between sensitivity of SL-RNA and trypanosome detection in CSF. The contribution of DNA to the Cq values was negligible. In CSF with normal cell counts, a fraction of SL-RNA might have been lost during extraction as indicated by higher internal extraction control Cq values. CONCLUSIONS/SIGNIFICANCE: Detection of SL-RNA in blood and CSF allows sensitive demonstration of active gambiense HAT infection, even if trypanosomes remain undetectable in blood or lymph. As this condition often occurs in treatment failures, SL-RNA detection in blood and CSF for early detection of relapses after treatment deserves further investigation. TRIAL REGISTRATION: This study was an integral part of the diagnostic trial "New Diagnostic Tools for Elimination of Sleeping Sickness and Clinical Trials: Early tests of Cure" (DiTECT-HAT-WP4, ClinicalTrials.gov Identifier: NCT03112655).

Oral fexinidazole for stage 1 or early stage 2 African Trypanosoma brucei gambiense trypanosomiasis: a prospective, multicentre, open-label, cohort study.

BACKGROUND: Staging and treatment of human African trypanosomiasis caused by Trypanosoma brucei gambiense (g-HAT) required lumbar puncture to assess cerebrospinal fluid (CSF) and intravenous drugs that cross the blood-brain barrier for late-stage infection. These procedures are inconvenient in rural health systems of disease-endemic countries. A pivotal study established fexinidazole as the first oral monotherapy to be effective against non-severe stage 2 g-HAT. We aimed to assess the safety and efficacy of fexinidazole in early g-HAT. METHODS: In this prospective, multicentre, open-label, single-arm cohort study, patients with stage 1 or early stage 2 g-HAT were recruited from eight treatment centres in the Democratic Republic of the Congo. Primary inclusion criteria included being older than 15 years, being able to ingest at least one complete meal per day (or at least one sachet of Plumpy'Nut®), a Karnofsky score higher than 50, evidence of trypanosomes in the blood or lymph but no evidence of trypanosomes in the CSF, willingness to be admitted to hospital to receive treatment, having a permanent address, and being able to comply with the follow-up visit schedule. Exclusion criteria included severe malnutrition, inability to take medication orally, pregnant or breastfeeding women, any clinically important medical condition that could jeopardise patient safety or participation in the study, severely deteriorated general status, any contraindication to imidazole drugs, HAT treatment in the past 2 years, previous enrolment in the study or previous intake of fexinidazole, abnormalities on electrocardiogram that did not return to normal in pretreatment repeated assessments or were considered clinically important, QT interval corrected using Fridericia's formula of at least 450 ms, and patients not tested for malaria or not having received appropriate treatment for malaria or for soil-transmitted helminthiasis. Patients were classified into stage 1 or early stage 2 g-HAT groups following evidence of trypanosomes in the blood, lymph, and absence in CSF, and using white-blood-cell count in CSF. Patients received 1800 mg fexinidazole once per day on days 1-4 then 1200 mg fexinidazole on days 5-10. Patients were observed for approximately 19 months in total. Study participants were followed up on day 5 and day 8 during treatment, at end of treatment on day 11, at end of hospitalisation on days 11-18, at week 9 for a subset of patients, and after 6 months, 12 months, and 18 months. The primary endpoint was treatment success at 12 months. Safety was assessed through routine monitoring. Analyses were done in the intention-to-treat population. The acceptable success rate was defined as treatment efficacy in more than 80% of patients. This study is completed and registered with ClinicalTrials.gov (NCT02169557). FINDINGS: Patients were enrolled between April 30, 2014, and April 25, 2017. 238 patients were recruited: 195 (82%) patients with stage 1 g-HAT and 43 (18%) with early stage 2 g-HAT. 189 (97%) of 195 patients with stage 1 g-HAT and 41 (95%) of 43 patients with early stage 2 g-HAT were finally included and completed the 10 day treatment period. Three patients with stage 1 g-HAT died after the 10 day treatment period and before the 12 month primary follow-up visit, considered as treatment failure and were withdrawn from the study. Treatment was effective at 12 months for 227 (99%) of 230 patients (95% CI 96·2-99·7): 186 (98%) of 189 patients (95·4-99·7) with stage 1 and 41 (100%) of 41 patients (91·4-100·0) with early stage 2, indicating that the primary study endpoint was met. No new safety issues were observed. The most frequent adverse events were headache and vomiting. In total, 214 (93%) of 230 patients had treatment-emergent adverse events, mainly common-terminology criteria for adverse events grades 1 to 3. None led to treatment discontinuation. INTERPRETATION: Fexinidazole is a valuable first-line treatment option in the early stages of g-HAT. FUNDING: Through the Drugs for Neglected Diseases initiative: the Bill & Melinda Gates Foundation, the Republic and Canton of Geneva (Switzerland), the Dutch Ministry of Foreign Affairs (also known as DGIS; Netherlands), the Norwegian Agency for Development Cooperation (also known as Norad; Norway), the Federal Ministry of Education and Research (also known as BMBF) through KfW (Germany), the Brian Mercer Charitable Trust (UK), and other private foundations and individuals from the HAT campaign. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Implications of asymptomatic infection for the natural history of selected parasitic tropical diseases.

Progress has been made in the control or elimination of tropical diseases, with a significant reduction of incidence. However, there is a risk of re-emergence if the factors fueling transmission are not dealt with. Although it is essential to understand these underlying factors for each disease, asymptomatic carriers are a common element that may promote resurgence; their impact in terms of proportion in the population and role in transmission needs to be determined. In this paper, we review the current evidence on whether or not to treat asymptomatic carriers given the relevance of their role in the transmission of a specific disease, the efficacy and toxicity of existing drugs, the Public Health interest, and the benefit at an individual level, for example, in Chagas disease, to prevent irreversible organ damage. In the absence of other control tools such as vaccines, there is a need for safer drugs with good risk/benefit profiles in order to change the paradigm so that it addresses the complete infectious process beyond manifest disease to include treatment of non-symptomatic infected persons.

Pharmacokinetic-Pharmacodynamic Assessment of the Hepatic and Bone Marrow Toxicities of the New Trypanoside Fexinidazole.

Fexinidazole is a novel oral treatment for human African trypanosomiasis caused by Trypanosoma brucei gambiense (g-HAT). Fexinidazole also has activity against T. cruzi, the causative agent of Chagas disease. During the course of a dose ranging assessment in patients with chronic indeterminate Chagas disease, delayed neutropenia and significant increases in hepatic transaminases were observed and clinical investigations were suspended. We retrospectively analyzed all available pharmacokinetic and pharmacodynamic data on fexinidazole in normal healthy volunteers and in patients with Chagas disease and g-HAT to assess the determinants of toxicity. A population pharmacokinetic model was fitted to plasma concentrations (n = 4,549) of the bioactive fexinidazole sulfone metabolite, accounting for the majority of the bioactive exposure, from three phase 1 studies, two g-HAT phase 2/3 field trials, and one Chagas disease phase 2 field trial (n = 462 individuals in total). Bayesian exposure-response models were then fitted to hematological and liver-related pharmacodynamic outcomes in Chagas disease patients. Neutropenia, reductions in platelet counts, and elevations in liver transaminases were all found to be exposure dependent and, thus, dose dependent in patients with Chagas disease. Clinically insignificant transient reductions in neutrophil and platelet counts consistent with these exposure-response relationships were observed in patients with g-HAT. In contrast, no evidence of hepatotoxicity was observed in patients with g-HAT. Fexinidazole treatment results in a dose-dependent liver toxicity and transient bone marrow suppression in Chagas disease patients. Regimens of shorter duration should be evaluated in clinical trials with patients with Chagas disease. The currently recommended regimen for sleeping sickness provides exposures within a satisfactory safety margin for bone marrow suppression and does not cause hepatotoxicity.

Oral fexinidazole for late-stage African Trypanosoma brucei gambiense trypanosomiasis: a pivotal multicentre, randomised, non-inferiority trial.

BACKGROUND: Few therapeutic options are available to treat the late-stage of human African trypanosomiasis, a neglected tropical disease, caused by Trypanosoma brucei gambiense (g-HAT). The firstline treatment is a combination therapy of oral nifurtimox and intravenous eflornithine that needs to be administered in a hospital setting by trained personnel, which is not optimal given that patients often live in remote areas with few health resources. Therefore, we aimed to assess the safety and efficacy of an oral regimen of fexinidazole (a 2-substituted 5-nitroimidazole with proven trypanocidal activity) versus nifurtimox eflornithine combination therapy in patients with late-stage g-HAT. METHODS: In this randomised, phase 2/3, open-label, non-inferiority trial, we recruited patients aged 15 years and older with late-stage g-HAT from g-HAT treatment centres in the Democratic Republic of the Congo (n=9) and the Central African Republic (n=1). Patients were randomly assigned (2:1) to receive either fexinidazole or nifurtimox eflornithine combination therapy according to a predefined randomisation list (block size six). The funder, data management personnel, and study statisticians were masked to treatment. Oral fexinidazole was given once a day (days 1-4: 1800 mg, days 5-10: 1200 mg). Oral nifurtimox was given three times a day (days 1-10: 15 mg/kg per day) with eflornithine twice a day as 2 h infusions (days 1-7: 400 mg/kg per day). The primary endpoint was success at 18 months (ie, deemed as patients being alive, having no evidence of trypanosomes in any body fluid, not requiring rescue medication, and having a cerebrospinal fluid white blood cell count ≤20 cells per µL). Safety was assessed through routine monitoring. Primary efficacy analysis was done in the modified intention-to-treat population and safety analyses in the intention-to-treat population. The acceptable margin for the difference in success rates was defined as 13%. This study has been completed and is registered with ClinicalTrials.gov, number NCT01685827. FINDINGS: Between October, 2012, and November, 2016, 419 patients were pre-screened. Of the 409 eligible patients, 14 were not included because they did not meet all inclusion criteria (n=12) or for another reason (n=2). Therefore, 394 patients were randomly assigned, 264 to receive fexinidazole and 130 to receive nifurtimox eflornithine combination therapy. Success at 18 months was recorded in 239 (91%) patients given fexinidazole and 124 (98%) patients given nifurtimox eflornithine combination therapy, within the margin of acceptable difference of -6·4% (97·06% CI -11·2 to -1·6; p=0·0029). We noted no difference in the proportion of patients who experienced treatment-related adverse events (215 [81%] in the fexinidazole group vs 102 [79%] in the nifurtimox eflornithine combination therapy group). Treatment discontinuations were unrelated to treatment (n=2 [1%] in the fexinidazole group). Temporary nifurtimox eflornithine combination therapy interruption occurred in three (2%) patients. 11 patients died during the study (nine [3%] in the fexinidazole group vs two [2%] in the nifurtimox eflornithine combination therapy group). INTERPRETATION: Our findings show that oral fexinidazole is effective and safe for the treatment of T b gambiense infection compared with nifurtimox eflornithine combination therapy in late-stage HAT patients. Fexinidazole could be a key asset in the elimination of this fatal neglected disease. FUNDING: Drugs for Neglected Diseases initiative.

Phase 1 Study Assessing the Pharmacokinetic Profile and Safety of Avibactam in Patients With Renal Impairment.

Avibactam is a non-ß-lactam ß-lactamase inhibitor intended for use as a fixed-dose combination with ceftazidime for the treatment of certain serious Gram-negative infections. As avibactam is primarily excreted unchanged in the urine, renal impairment may affect its pharmacokinetics. This phase 1 study investigated the effect of renal impairment and hemodialysis on avibactam pharmacokinetics and safety. Healthy controls and subjects with increasing degrees of renal impairment received a single 30-minute intravenous (IV) infusion of avibactam (100 mg). Anuric subjects requiring hemodialysis received the same infusion pre- and posthemodialysis, separated by a 7- to 14-day washout. Blood and urine samples were collected, and pharmacokinetics were analyzed using noncompartmental methods. The relationships between avibactam total plasma clearance (CL) or renal clearance (CLR ) and creatinine clearance (CrCL) were evaluated by linear correlation analysis. Safety was also monitored. Increasing severity of renal impairment was associated with decreasing CL and CLR and increasing exposure and terminal half-life (t1/2 ). Avibactam CL and CLR demonstrated an approximately linear relationship with CrCL comparable to that previously observed for ceftazidime. In patients requiring hemodialysis, >50% of the administered avibactam was removed during a 4-hour hemodialysis session, demonstrating that avibactam should be administered after hemodialysis. No new safety findings were reported. To conclude, avibactam dose adjustment is warranted in patients with renal impairment based on the severity of impairment. Because the slope of the linear relationship between avibactam total plasma CL and CrCL is similar to that of ceftazidime, renal impairment dose adjustments should maintain the currently advised 4:1 ratio of ceftazidime:avibactam.

Safety and pharmacokinetics of single and multiple ascending doses of avibactam alone and in combination with ceftazidime in healthy male volunteers: results of two randomized, placebo-controlled studies.

BACKGROUND AND OBJECTIVE: Avibactam is a novel non-ß-lactam ß-lactamase inhibitor effective against Ambler class A, C and some class D ß-lactamases that is currently in clinical development in combination with ceftazidime for the treatment of serious Gram-negative infections. It restores the in vitro activity of a range of ß-lactams, including ceftazidime, against extended-spectrum ß-lactamase-producing pathogens. Two phase I studies assessed the safety and pharmacokinetics of avibactam in healthy subjects when administered alone or with ceftazidime. METHODS: The first study (NXL104-1001) was a placebo-controlled, single-ascending dose study assessing avibactam 50, 100, 250, 500, 1000, 1500 or 2000 mg given as a 30-min intravenous infusion. After a 7-day washout, subjects in the 250 and 500 mg dosing groups received a second avibactam dose with concomitant ceftazidime 1000 or 2000 mg, respectively. The second study (NXL104-1002) was performed in two parts. Part 1 assessed multiple-ascending doses of avibactam. Subjects were randomized to receive avibactam 500, 750 or 1000 mg every 8 h (q8 h) over 5 days, or ceftazidime-avibactam 2000-500 mg q8 h over 10 days. Part 2 assessed bioavailability of avibactam after a single oral dose (500 mg) relative to a single 30-min intravenous infusion (500 mg). RESULTS: No serious or severe adverse events were reported in either study. Avibactam exposure generally increased proportionally to dose and there was no trend for accumulation after multiple doses. Almost all avibactam was excreted largely unchanged in the urine within the first 6 h. Concomitant ceftazidime did not affect avibactam's safety and pharmacokinetic profile. Avibactam exposure after oral dosing was very low at 6.2 % of that observed after intravenous infusion. CONCLUSION: Avibactam was generally well tolerated across all dosing regimens, when given alone or with ceftazidime. Avibactam exposure was dose related in both studies, and avibactam pharmacokinetics were linear and not affected by ceftazidime.

Effect of age and sex on the pharmacokinetics and safety of avibactam in healthy volunteers.

PURPOSE: Avibactam is a novel non-ß-lactam ß-lactamase inhibitor currently being assessed in combination with ceftazidime, ceftaroline fosamil, and aztreonam. The objectives of this study were to investigate the pharmacokinetics, safety, and tolerability of avibactam in healthy young (aged 18-45 years) and elderly (aged ≥65 years) volunteers of both sexes. METHODS: This was a Phase I, open-label study in which healthy volunteers aged ≥18 years were enrolled into 4 cohorts: young male, young female, elderly male, and elderly female (n = 8 in each group). Subjects were excluded if they had any condition requiring regular medication or any other relevant conditions. All subjects received a single dose of avibactam 500 mg/100 mL given intravenously over 30 minutes. Pharmacokinetic measurements included Cmax, Tmax, AUC0-∞, plasma clearance, and t½. FINDINGS: Within the two age categories the mean age across male and female subjects was well matched. The majority of subjects in the young cohort were black (≥62.5%), whilst the majority of those in the elderly cohorts were white (≥75%). Mean avibactam plasma clearance was similar between the young male, young female, and elderly male cohorts (10.16, 10.34, and 9.82 L/h, respectively), and slightly lower in elderly women (7.98 L/h). Mean Cmax was similar in young male, young female, and elderly female subjects (33.8, 36.9, and 38.4 µg/mL) but lower in elderly male subjects (26.5 µg/mL). Point estimates comparing the ratio of Cmax in male and female subjects over all age groups suggested that Cmax values were 18% lower (90% CI, 30%-5% lower) in male subjects compared with female subjects. Mean AUC0-∞ data were similar between the young male, young female, and elderly male cohorts (49.86, 49.75, and 52.40 µg·h/mL) but higher in elderly women (66.23 µg·h/mL). Point estimates comparing the ratio of AUC0-∞ in elderly and young subjects across both sexes suggested that AUC0-∞ values were 17% higher (90% CI, 5%-31%) in elderly subjects compared with young subjects. The t½ was slightly longer for elderly subjects compared with younger subjects. The most common adverse event was administration/venipuncture site bruising (6 events); all adverse events were mild. IMPLICATIONS: No notable differences in pharmacokinetics were observed between the male and female cohorts. The generalizability of the study is limited due to its small sample size. However, the small differences observed between the young and elderly cohorts are not sufficient to warrant dosing adjustments based on age.

Improving the Quality of Host Country Ethical Oversight of International Research: The Use of a Collaborative 'Pre-Review' Mechanism for a Study of Fexinidazole for Human African Trypanosomiasis.

Developing countries face numerous barriers to conducting effective and efficient ethics reviews of international collaborative research. In addition to potentially overlooking important scientific and ethical considerations, inadequate or insufficiently trained ethics committees may insist on unwarranted changes to protocols that can impair a study's scientific or ethical validity. Moreover, poorly functioning review systems can impose substantial delays on the commencement of research, which needlessly undermine the development of new interventions for urgent medical needs. In response to these concerns, the Drugs for Neglected Diseases Initiative (DNDi), an independent nonprofit organization founded by a coalition of public sector and international organizations, developed a mechanism to facilitate more effective and efficient host country ethics review for a study of the use of fexinidazole for the treatment of late stage African Trypanosomiasis (HAT). The project involved the implementation of a novel 'pre-review' process of ethical oversight, conducted by an ad hoc committee of ethics committee representatives from African and European countries, in collaboration with internationally recognized scientific experts. This article examines the process and outcomes of this collaborative process.

Determination of an optimal dosing regimen for fexinidazole, a novel oral drug for the treatment of human African trypanosomiasis: first-in-human studies.

BACKGROUND AND OBJECTIVES: Fexinidazole is a 5-nitroimidazole recently included in a clinical efficacy trial as an oral drug for the treatment of human African trypanosomiasis (HAT). Preclinical studies showed it acts as a pharmacologically active pro-drug with two key active metabolites: sulfoxide and sulfone (the most active metabolite). The present studies aimed to determine the best dose regimen for the treatment of stage 2 sleeping sickness patients, which could eventually also treat stage 1 patients. METHODS: Fexinidazole was assessed in 154 healthy adult male subjects of sub-Saharan African origin. Three initial first-in-human studies and two additional studies assessed a single ascending dose and multiple ascending doses (both under fasted conditions), tablet versus suspension formulation and food effect (fasted vs. high-fat meal and field-adapted food), and multiple ascending doses with a loading dose regimen under fed conditions. RESULTS: Fexinidazole was well-tolerated in a single dose from 100 to 3,600 mg, with quick absorption of the parent drug and rapid metabolism into sulfoxide [time to maximum concentration (t max) 2-5 h] and sulfone (t max 18-24 h). The tablet formulation was approximately 25 % less bioavailable than the suspension, and food intake increased drug absorption and plasma concentrations of fexinidazole and its two metabolites by approximately 200 %. Fourteen-day multiple ascending dosing administered up to 3,600 mg/day in fasted conditions showed that fexinidazole was generally well-tolerated (mild to moderate, spontaneously reversible drug-related adverse events). Following the high-fat food effect finding, another study was conducted to evaluate the impact of a low-fat regimen closer to that of the target population, showing that the type of meal does not influence fexinidazole absorption. The last study showed that a loading dose of 1,800 mg/day for 4 days followed by a 1,200 mg/day regimen for 6 days with a normal meal provided the desired exposure of fexinidazole and its metabolites, particularly sulfone, with good tolerability. Based on preclinical evidence from a chronic infection mouse model, systemic drug concentrations obtained are expected to be clinically effective in stage 2 HAT. CONCLUSIONS: These studies show that fexinidazole can be safely assessed in patients as a potential oral cure for both stages of HAT.

Single and multiple ascending dose studies of a novel tissue-selective oestrogen receptor modulator, CHF 4227, in healthy postmenopausal women.

AIMS: We evaluated the tolerability, adverse events profile, pharmacokinetics, and pharmacodynamics of CHF 4227, a new selective oestrogen receptor modulator (SERM), in healthy postmenopausal women. METHODS: Two phase I studies were conducted according to a double-bind, placebo-controlled design. Subjects were randomized to receive six single (5-400 mg) or five multiple oral doses of CHF 4227 for 28 days (5-100 mg). RESULTS: No vaginal bleeding and no changes in either endometrial thickness or the placenta protein 14 marker were found after 4 weeks of treatment. The compound did not induce negative effects on the fibrinolytic system. After 28 days of treatment, CHF 4227 decreased both total and LDL cholesterol concentrations (maximum decreases from baseline of 17.4% (95% CI 7.0, 27.7) and 27.6% (95% CI 9.0, 46.3), respectively). Decreases in both serum and urinary type-I C-terminal collagen telopeptide were also observed producing maximum changes of 40.6% (95% CI 29.5, 51.7), and 41.7% (95% CI 20.3, 56.8), respectively. CHF4227 (5 and 10 mg) induced near maximal oestrogen-like effects on bone markers and serum lipids without causing hot flushes. The pharmacokinetics of CHF 4227 were characterized by a slow absorption, a long elimination half-life (31-42 h after single administration) and dose linearity with respect to C(max) and AUC up to 100 mg. CONCLUSIONS: CHF 4227 is a well-tolerated SERM when administered once daily for 28 days. It is potentially active on bone resorption and serum lipids, without affecting the endometrium and without worsening hot flushes. CHF 4227 is a promising agent for the treatment of several conditions in postmenopausal women.

Steady-state pharmacokinetics and pharmacodynamics of CHF3381, a novel antineuropathic pain agent, in healthy subjects.

AIMS: To evaluate the safety, tolerability, pharmacokinetic and pharmacodynamic profiles of CHF3381, a dual NMDA and MAO-A inhibitor, after multiple oral doses in healthy subjects. METHODS: Forty-eight young males received CHF3381 at doses of 100 mg twice daily, 200 mg twice daily, 400 mg twice daily or placebo for 2 weeks according to a double-blind, randomized, parallel group design. Plasma and urine concentrations of the parent drug and of two major metabolites (CHF3567 and 2-aminoindane) were measured over time. MAO-A activity in plasma was estimated by measuring plasma concentrations of 3,4-dihydroxyphenylglycol. Sustained attention, memory and sedation were assessed throughout the study with standard psychometric tests. RESULTS: Most of the adverse events were mild in intensity, with dose regimens of 100 mg twice daily and 200 mg twice daily being indistinguishable from placebo. After 400 mg twice daily, the most frequent adverse events were mild dizziness, asthenia and insomnia. At steady-state, 400 mg twice daily slightly increased supine heart rate (+ 9 +/- 2 beats min(-1)) and diastolic blood pressure (+6 +/- 2 mmHg) compared with placebo. There were no dose-dependent or consistent effects of CHF3381 on attention, motor co-ordination or memory, but 400 mg twice daily significantly decreased alertness compared with placebo. Plasma concentrations of CHF3381 peaked at around 3 h and were dose-proportional. The elimination half-life of CHF3381 was estimated to be 4-6 h. At steady-state, significant CHF3381 plasma concentrations were detected at predose with a modest accumulation (1.3-1.5 times), showing that the drug given twice daily is active over the entire 24 h period. Plasma concentrations of CHF3567 and of 2-aminoindane were also proportional to the dose of CHF3381. CHF3381 dose-dependently inhibited MAO-A activity with peak effects at steady-state of 27 +/- 4%, 46 +/- 2% and 65 +/- 5% after 100 mg twice daily, 200 mg twice daily and 400 mg twice daily, respectively. There were no significant effects of CHF3381 on attention (rapid visual information processing), motor co-ordination (body sway) or memory (learning memory task) at any of the doses. At steady-state, there was a significant decrease in alertness (Bond & Lader visual analogue scale) in the 400 mg twice daily group compared with placebo. CONCLUSIONS: A twice daily regimen of CHF3381 appears to be adequate from a pharmacokinetic and pharmacodynamic perspective. Plasma concentrations reached with 400 mg twice daily exceeded those observed in animals receiving pharmacologically active doses in chronic pain models.

Safety, pharmacokinetics, and pharmacodynamics of CHF 3381, a novel N-methyl-D-aspartate antagonist, after single oral doses in healthy subjects.

A double-blind, randomized, placebo-controlled study was performed to assess the safety, tolerability, and pharmacokinetics of single oral doses of CHF 3381 in 56 young healthy male volunteers. The central nervous system effects of CHF 3381 were also evaluated, as well as the effect of food on the rate and extent of CHF 3381 absorption. Seven doses of CHF 3381 (25, 50, 100, 200, 300, 450, and 600 mg) were evaluated in an escalating order. At each dose level, 6 subjects were given CHF 3381, and 2 subjects were given placebo. Safety and tolerability evaluation included adverse events, physical examination, vital functions, electrocardiogram, laboratory tests, and 24-hour Holter (100-mg and 450-mg dose panels). Plasma and urinary concentrations of CHF 3381 and its two main metabolites (CHF 3567 and 2-aminoindane) were measured with a validated high-performance liquid chromatography method. Central nervous system effects were evaluated with the simple reaction time (SRT); learning memory task (LMT); Bond & Lader Visual Analog Scale for alertness, contentedness, and calmness; Addiction Research Center Inventory (ARCI); and electroencephalogram. There were no serious adverse events; the most frequent adverse events were dizziness, abnormal thinking, and asthenia. The number of adverse events with moderate intensity increased sharply with the dose, with no or few events up to 450 mg and 17 events with 600 mg. Therefore, 600 mg was defined as the maximum tolerated dose. There were no significant treatment effects on cardiovascular function and electrocardiogram parameters at any CHF 3381 dose or on oral temperature or laboratory tests. There were no clinically significant changes in laboratory variables. CHF 3381 was absorbed rapidly (tmax = 0.5-2 h) and cleared from plasma with a half-life of 3 to 4 hours. Plasma levels of CHF 3381 and its two major metabolites were found to be proportional to the dose. 2-Aminoindane formed slowly and reached much lower concentrations compared to the parent compound and the other metabolite (CHF 3567). Within 48 hours after dosing, 2% to 6% of the administered dose was found in the urine as unchanged drug, about 50% to 55% as the acid derivative (CHF 3567), and 2% to 3% as 2-aminoindane. Ingestion of food did not affect the extent of absorption of the drug, while the rate of absorption was considerably reduced (tmax = 4 h). No significant effects of CHF 3381 were observed on attention (SRT) or memory (LMT). Visual analog scales revealed a decreasing effect of CHF 3381 on alertness at 1 hour that reached statistical significance at 300 and 600 mg. EEG spectral analysis revealed minor decreasing effects of the 200-mg dose on total electric power measured at 2 hours. A stimulant effect was detected by the ARCI scale 24 hours after the 300-mg dose and might be related to the slow formation of the 2-aminoindane metabolite. In conclusion, this study has shown that the maximum tolerated dose of CHF 3381 after single oral administration in young healthy male volunteers is 600 mg. CHF 3381 displays linear pharmacokinetics in the dose range of 25 to 600 mg. The compound is rapidly absorbed and cleared from plasma with a half-life of 3 to 4 hours. The ingestion of food seems to not affect the extent of absorption of the drug. Minor effects on the central nervous system were detected at doses equal to or greater than 300 mg.

Effects on postural oscillation and memory functions of a single dose of zolpidem 5 mg, zopiclone 3.75 mg and lormetazepam 1 mg in elderly healthy subjects. A randomized, cross-over, double-blind study versus placebo.

OBJECTIVE: In elderly patients, both falls and impaired memory are considerable medical problems. Hypnotics, which are frequently administered to this patient group for the treatment of insomnia, should ideally not impair equilibrium or memory functions. This double-blind, randomised, four-way, cross-over study investigated the effects of frequently prescribed hypnotics from different classes on postural oscillation and memory under real life conditions. Zolpidem 5 mg, zopiclone 3.75 mg, lormetazepam 1 mg (i.e. usual starting doses in elderly) or placebo were administered at night to 48 healthy elderly volunteers aged 65 years or more. The study included four treatment periods separated by wash-out periods of at least 1 week. METHODS: Psychomotor tests up to 9 h or 10 h after drug intake included, for attention and body sway, clinical stabilometric platform (CSP) tests, simple reaction time (SRT), and the critical tracking test (CTT); for memory, the learning memory tasks (LMT) and the Sternberg memory scanning test (mean reaction time [MRT] and percentage of correct answers) were used. For subjective sleep evaluation the Leeds sleep evaluation questionnaire (LSEQ) and for sedation a visual analogue scale (VAS) were used. For safety evaluations, adverse events (AEs) were recorded. RESULTS: The results demonstrate that compared with placebo, the active drugs increased body sway (area eyes open and closed in the CSP); however, this effect disappeared after 5 h with zolpidem, while it disappeared only after 8 h with lormetazepam and zopiclone. All three drugs did not affect attention assessed by the SRT and CTT. Concerning memory, Sternberg MRT at 9 h was not significantly different up to 5 digits for all groups in comparison with placebo, while for 6 digits it was significantly increased with lormetazepam and zopiclone. In the LMT, an impairment of performance was observed with lormetazepam relative to both zolpidem and placebo. CONCLUSION: The safest compared drug with regard to body sway was zolpidem, because of its short-lasting effect. In addition, zolpidem did not show any significant effect on memory functions, in the present dose comparison.