An Observational Study on the Pharmacokinetics of Oseltamivir in Lactating Influenza Patients.

Influenza infection may lead to serious complications in the postpartum period, therefore, oseltamivir treatment in these patients and their breastfed infants is of great importance. However, the pharmacokinetics of oseltamivir in postpartum lactating women with acute influenza infection, and the consequent infant exposure to oseltamivir are still unknown, and these data would help in assessing risk and the need for dose adjustment in breastfed infants. Six lactating women with influenza-like symptoms, at a standard dose of 75 mg oral oseltamivir twice daily for 5 days, were recruited in this phase IV clinical study during the 2011/2012 H1N1 pandemic seasons. Breast milk/colostrum and venous blood samples were taken at multiple timepoints, maternal urine samples were obtained from total output within the 12-hour observational period following the seventh dose of oseltamivir. Oseltamivir phosphate (OP) reached a maximum 69.5 ± 29.4 ng/mL concentration in breast milk, higher than that found in the plasma, and showed elimination within ~ 8 hours. Oseltamivir carboxylate (active metabolite of OP) showed a lower, nearly steady-state concentration in breast milk during the observational period (maximum plasma concentration (Cmax ) = 38.4 ± 12.9 ng/mL). Based on estimated daily milk consumption of exclusively breastfed infants, their calculated daily exposure is < 0.1% of the infant dose of oseltamivir for treatment of influenza as per marketing authorization. Here, we provide the first maternal breast milk pharmacokinetic data for oral multiple-dose oseltamivir in lactating patients with influenza and showed that its concentration in the breast milk is not sufficient to reach a therapeutic dose for breastfed infants.

Safety and efficacy of AK0529 in respiratory syncytial virus-infected infant patients: A phase 2 proof-of-concept trial.

Background: Respiratory syncytial virus (RSV) infection is a cause of substantial morbidity and mortality in young children. There is currently no effective therapy available. Methods: This was a Phase 2 study of the oral RSV fusion protein inhibitor AK0529 in infants aged 1-24 months, hospitalized with RSV infection. In Part 1, patients (n = 24) were randomized 2:1 to receive a single dose of AK0529 up to 4 mg/kg or placebo. In Part 2, patients (n = 48) were randomized 2:1 to receive AK0529 at 0.5, 1, or 2 mg/kg bid or placebo for 5 days. Sparse pharmacokinetic samples were assessed using population pharmacokinetics modelling. Safety, tolerability, viral load, and respiratory signs and symptoms were assessed daily during treatment. Results: No safety or tolerability signals were detected for AK0529: grade ≥3 treatment-emergent adverse events occurring in 4.1% of patients in AK0529 and 4.2% in placebo groups, respectively, and none led to death or withdrawal from the study. In Part 2, targeted drug exposure was reached with 2 mg/kg bid. A numerically greater reduction in median viral load with 2 mg/kg bid AK0529 than with placebo at 96 h was observed. A -4.0 (95% CI: -4.51, -2.03) median reduction in Wang Respiratory Score from baseline to 96 h was observed in the 2 mg/kg group compared with -2.0 (95% CI: -3.42, -1.82) in the placebo group. Conclusions: AK0529 was well tolerated in hospitalized RSV-infected infant patients. Treatment with AK0529 2 mg/kg bid was observed to reduce viral load and Wang Respiratory Score. Clinical Trials Registration: NCT02654171.

Cognitive and other neuropsychiatric symptoms in COVID-19: analysis of person-generated longitudinal health data from a community-based registry.

OBJECTIVE: To describe cognitive symptoms in people not hospitalised at study enrolment for SARS-CoV-2 infection and associated demographics, medical history, other neuropsychiatric symptoms and SARS-CoV-2 vaccination. DESIGN: Longitudinal observational study. SETTING: Direct-to-participant registry with community-based recruitment via email and social media including Google, Facebook and Reddit, targeting adult US residents. Demographics, medical history, COVID-19-like symptoms, tests and vaccinations were collected through enrolment and follow-up surveys. PARTICIPANTS: Participants who reported positive COVID-19 test results between 15 December 2020 and 13 December 2021. Those with cognitive symptoms were compared with those not reporting such symptoms. MAIN OUTCOME MEASURE: Self-reported cognitive symptoms (defined as 'feeling disoriented or having trouble thinking' from listed options or related written-in symptoms) RESULTS: Of 3908 participants with a positive COVID-19 test result, 1014 (25.9%) reported cognitive symptoms at any time point during enrolment or follow-up, with approximately half reporting moderate/severe symptoms. Cognitive symptoms were associated with other neuropsychiatric symptoms, including dysgeusia, anosmia, trouble waking up, insomnia, headache, anxiety and depression. In multivariate analyses, female sex (OR, 95% CI): 1.7 (1.3 to 2.2), age (40-49 years (OR: 1.5 (1.2-1.9) compared with 18-29 years), history of autoimmune disease (OR: 1.5 (1.2-2.1)), lung disease (OR: 1.7 (1.3-2.2)) and depression (OR: 1.4 (1.1-1.7)) were associated with cognitive symptoms. Conversely, black race (OR: 0.6 (0.5-0.9)) and COVID-19 vaccination before infection (OR: 0.6 (0.4-0.7)) were associated with reduced occurrence of cognitive symptoms. CONCLUSIONS: In this study, cognitive symptoms among COVID-19-positive participants were associated with female gender, age, autoimmune disorders, lung disease and depression. Vaccination and black race were associated with lower occurrence of cognitive symptoms. A constellation of neuropsychiatric and psychological symptoms occurred with cognitive symptoms. Our findings suggest COVID-19's full health and economic burden may be underestimated. TRIAL REGISTRATION NUMBER: NCT04368065.

Evaluating real-world COVID-19 vaccine effectiveness using a test-negative case-control design.

Aim: It is important to assess if clinical trial efficacy translates into real-world effectiveness for COVID-19 vaccines. Materials & methods: We conducted a modified test-negative design (TND) to evaluate the real-world effectiveness of three COVID-19 vaccines. We defined cases in two ways: self-reported COVID-19-positive tests, and self-reported positive tests with ≥1 moderate/severe COVID-19 symptom. Results: Any vaccination was associated with a 95% reduction in subsequently reporting a positive COVID-19 test, and a 71% reduction in reporting a positive test and ≥1 moderate/severe symptom. Conclusion: We observed high effectiveness across all three marketed vaccines, both for self-reported positive COVID-19 tests and moderate/severe COVID-19 symptoms. This innovative TND approach can be implemented in future COVID-19 vaccine and treatment real-world effectiveness studies. Clinicaltrials.gov identifier: NCT04368065.

COVID-19 Vaccination Breakthrough Infections in a Real-World Setting: Using Community Reporters to Evaluate Vaccine Effectiveness.

Purpose: Coronavirus disease 2019 (COVID-19) has highlighted the need for new methods of pharmacovigilance. Here, we use adult community volunteers to obtain systematic information on vaccine effectiveness and the nature and severity of breakthrough infections. Methods: Between December 15, 2020 and September 16, 2021, 11,826 unpaid community-based volunteers reported the following information to an on-line registry: COVID-19 test results, vaccination (Pfizer, Moderna, or Johnson & Johnson) and COVID-19 symptoms. COVID-19 infections were described based on vaccination status at the time of infection: 1) fully vaccinated, 2) partially vaccinated (received first of two-dose vaccines or were <14 days post-final dose), or 3) unvaccinated. Results: Among 8554 participants who received any COVID-19 vaccine, COVID-19 infections were reported by 74 (1.0%) of those who were fully vaccinated and 198 (2.3%) of those who were partially vaccinated at the time of infection. Among the 74 participants who reported a breakthrough infection after full vaccination, the median time from vaccination to reported positive test result was 104.5 days (interquartile range: 77-135 days), with no difference among vaccine manufacturers. One quarter (25.7%) of breakthrough infections in the fully vaccinated cases were asymptomatic and most (>97%) fully vaccinated participants reported no symptoms or only mild symptoms compared to 89.3% of the unvaccinated cases. Only 1.4% of fully vaccinated participants reported experiencing at least 3 moderate-to-severe symptoms compared to 7.8% in the unvaccinated. Conclusion: Person-generated health data, also referred to as patient-reported outcomes, is a useful approach for quantifying breakthrough infections and their severity and for comparing vaccines. Trial Registration: Clinicaltrials.gov NCT04368065, EU PAS Register EUPAS36240.

COVID-19 Vaccinations in Pregnancy: Comparative Evaluation of Acute Side Effects and Self-Reported Impact on Quality of Life between Pregnant and Nonpregnant Women in the United States.

OBJECTIVE: The objective of this study was to describe the acute side effects experienced by pregnant women who received a coronavirus disease 2019 (COVID-19) vaccine in the United States and to compare their experience to nonpregnant women of similar age. STUDY DESIGN: Adults who received a COVID-19 vaccine in the United States were invited via social media to enroll in an online, longitudinal, community-based registry ( www.helpstopCOVID19.com ). Participants self-reported pregnancy status, vaccination dates, manufacturer, acute side effects, impact on work and self-care, medical consultation, and hospitalization. This analysis was restricted to women aged 20 to 39 at the time of vaccination. Side effects reported by pregnant women were compared to those reported by nonpregnant women. RESULTS: This analysis included 946 pregnant women, with 572 (60%) receiving at least one dose of Pfizer, 321 (34%) Moderna, and 53 (6%) J&J, and 1,178 nonpregnant women. Demographic and medical history were similar across manufacturers for both cohorts.Overall, pregnant women reported similar side effects as nonpregnant women, with the most common being injection site reactions (83 vs. 87%), fatigue (72 vs.78%), and headache (45 vs. 59%). Pregnant women reported fewer side effects (median: 3 vs. 4, respectively). In both cohorts, very few reported seeking medical care (<5%) or being hospitalized (<0.3%) after vaccination. Fewer pregnant women reported working less after vaccination than nonpregnant women (32 vs. 40%) or trouble with self-care (32 vs. 46%), respectively. CONCLUSION: Pregnant women reported similar COVID-19 vaccine side effects as nonpregnant women, although fewer total side effects; pregnant women judged these side effects to have less impact on work and self-care. While these results do not address pregnancy outcomes or long-term effects, findings about acute side effects and impact offer reassurance for all three vaccines in terms of tolerability. KEY POINTS: · COVID vaccines were well tolerated by pregnant women.. · Pregnant women reported fewer total side effects.. · Pregnant women reported less impact on work and self-care..

How frequent are acute reactions to COVID-19 vaccination and who is at risk?

INTRODUCTION: Our objective was to describe and compare self-reported side effects ofCOVID-19 vaccinesin theUSA. METHODS: Aweb-basedregistry enrolled volunteers who received a COVID-19 vaccine between March 19-July 15, 2021. We collected self-reported short-term side effects, medical consultation, hospitalization, and quality of life impact following completed vaccination regimens (Pfizer, Moderna, J&J). RESULTS: We recruited 6,966 volunteers who completed their full course of vaccination (median age 48 years, IQR 35.0-62.0; 83.6% female): Pfizer 3,486; Moderna 2,857; J&J 623. Few (3.1%) sought medical care for post-vaccination side effects. Hospitalization (n = 17; 0.3%) and severe allergic reactions (n = 39; 0.6%) also were rare. Those with autoimmune disease or lung disease were approximately twice as likely to seek medical care (adjusted odds ratio (aOR) 2.01, 95% CI:1.39; 2.92 and aOR 1.70, 95% CI: 1.12; .58 respectively). 92.4% of participantsreported ≥ 1side effect (median 3), with injection site reactions (78.9%), fatigue (70.3%), headache (49.0%) reported most frequently. More side effects were reported after the second dose of two-dose vaccines (medians: 1 vs. 2 for Pfizer and 1 vs. 3 for Moderna for first and second doses respectively) versus 3 for J&J's single-dose vaccine. For the employed, the median number of workdays missed was one. Diabetics and those vaccinated against influenza were substantially less likely to report 3 or more symptoms (aOR 0.68, 95% CI: 0.56;0.82] and aOR 0.82, 95% CI: 0.73;0.93, respectively). DISCUSSION: The total side effect burden was, not unexpectedly, greater with two-dose regimens but all three vaccines appear relatively safe. Very few subjects reported side effects serious enough to warrant medical care or reported post-vaccination hospitalization. While these findings do not address possible long-term effects, they do inform on their short-term safety and tolerability and will hopefully provide some reassurance and positively inform the benefit-risk and pharmacoeconomic assessment for all three vaccines. See Clinicaltrials.gov NCT04368065.

Identification of a Vulnerable Group for Post-Acute Sequelae of SARS-CoV-2 (PASC): People with Autoimmune Diseases Recover More Slowly from COVID-19.

PURPOSE: Evidence is emerging that a significant percentage of COVID-19 cases experience symptom persistence beyond 30 days and go on to develop post-acute sequelae. Our objective was to compare the risk for COVID-19 symptom persistence by self-reported use of medications for autoimmune disease among participants of an on-line COVID-19 registry. PATIENTS AND METHODS: A community-based online survey collected weekly data on COVID-19 symptom presentation. Participants who completed informed consent online, reported a positive COVID-19 test result within 14 days prior to enrollment and also reported demographics, underlying illnesses, and medication use were included. Symptom presence and severity were evaluated weekly after enrollment and compared between participants reporting use of medications for autoimmune conditions and all others. Logistic regression was used to evaluate the odds of more severe acute illness and symptom persistence approximately 30 days after enrollment. RESULTS: A total of 1,518 COVID-19-positive participants were included. Participants reporting use of medications for autoimmune disease (n=70) were more likely to have experienced symptoms at all time points over a 30-day time period and were more likely to report more severe presentation of COVID-19 during acute illness (adjusted OR (95% CI)=1.32 (0.76-2.29)) compared to those reporting not taking medications for autoimmune disease. At about 30 days after enrollment, users of medications for autoimmune disease were more than twice as likely to report three or more symptoms (adjusted OR (95% CI)=2.53 (1.21-5.29)). In particular, their risk of persistent shortness of breath and fatigue was elevated (adjusted OR (95% CI)=2.66 (1.15-6.18) and 4.73 (2.17-10.34), respectively). CONCLUSION: Individuals with underlying autoimmune conditions appear to be particularly vulnerable to post-acute sequelae from COVID-19; early intervention might be considered.

Self-reported symptoms from exposure to Covid-19 provide support to clinical diagnosis, triage and prognosis: An exploratory analysis.

BACKGROUND: Symptomatic COVID-19 is prevalent in the community. We identify factors indicating COVID-19 positivity in non-hospitalized patients and prognosticators of moderate-to-severe disease. METHODS: Appeals conducted in April-June 2020 in social media, collaborating medical societies and patient advocacy groups recruited 20,476 participants ≥18 years who believed they had COVID-19 exposure. Volunteers consented on-line and reported height, weight, concomitant illnesses, medication and supplement use, residential, occupational or community COVID-19 exposure, symptoms and symptom severity on a 4-point scale. Of the 12,117 curated analytic population 2279 reported a COVID-19 viral test result: 865 positive (COVID+) and 1414 negative (COVID-). RESULTS: The triad of anosmia, ageusia and fever best distinguished COVID+ from COVID-participants (OR 6.07, 95% CI: 4.39 to 8.47). COVID + subjects with BMI≥30, concomitant respiratory disorders or an organ transplant had increased risk of moderate-to- severe dyspnoea. Race and anti-autoimmunity medication did not affect moderate-to-severe dyspnea risk. CONCLUSIONS: The triad of anosmia, ageusia and fever differentiates COVID-19. Elevated risks of severe symptoms outside the hospital were most evident among the obese and those with pulmonary comorbidity. Race and use of medication for autoimmune disease did not predict severe disease. These findings should facilitate rapid COVID-19 diagnosis and triage in settings without testing.

Neurological and psychiatric safety of tafenoquine in Plasmodium vivax relapse prevention: a review.

BACKGROUND: Tafenoquine is an 8-aminoquinoline anti-malarial drug recently approved as a single-dose (300 mg) therapy for Plasmodium vivax relapse prevention, when co-administered with 3-days of chloroquine or other blood schizonticide. Tafenoquine 200 mg weekly after a loading dose is also approved as travellers' prophylaxis. The development of tafenoquine has been conducted over many years, using various dosing regimens in diverse populations. METHODS: This review brings together all the preclinical and clinical data concerning tafenoquine central nervous system safety. Data were assembled from published sources. The risk of neuropsychiatric adverse events (NPAEs) with single-dose tafenoquine (300 mg) in combination with chloroquine to achieve P. vivax relapse prevention is particularly examined. RESULTS: There was no evidence of neurotoxicity with tafenoquine in preclinical animal models. In clinical studies in P. vivax relapse prevention, nervous system adverse events, mainly headache and dizziness, occurred in 11.4% (36/317) of patients with tafenoquine (300 mg)/chloroquine versus 10.2% (19/187) with placebo/chloroquine; and in 15.5% (75/483) of patients with tafenoquine/chloroquine versus 13.3% (35/264) with primaquine (15 mg/day for 14 days)/chloroquine. Psychiatric adverse events, mainly insomnia, occurred in 3.8% (12/317) of patients with tafenoquine/chloroquine versus 2.7% (5/187) with placebo/chloroquine; and in 2.9% (14/483) of patients with tafenoquine/chloroquine versus 3.4% (9/264) for primaquine/chloroquine. There were no serious or severe NPAEs observed with tafenoquine (300 mg)/chloroquine in these studies. CONCLUSIONS: The risk:benefit of single-dose tafenoquine/chloroquine in P. vivax relapse prevention is favourable in the presence of malaria, with a low risk of NPAEs, similar to that seen with chloroquine alone or primaquine/chloroquine.

Development of a physiologically based pharmacokinetic model for mefloquine and its application alongside a clinical effectiveness model to select an optimal dose for prevention of malaria in young Caucasian children.

AIMS: To predict the optimal chemoprophylactic dose of mefloquine in infants of 5-10 kg using physiologically based pharmacokinetic (PBPK) and clinical effectiveness models. METHODS: The PBPK model was developed in Simcyp version 14.1 and verified against clinical pharmacokinetic data in adults; the final model, accounting for developmental physiology and enzyme ontogeny was then applied in the paediatric population. The clinical effectiveness model utilized real-world chemoprophylaxis data with stratification of output by age and including infant data from the UK population. RESULTS: PBPK simulations in infant populations depend on the assumed fraction of mefloquine metabolized by CYP3A4 (0.47, 0.95) and on the associated CYP3A4 ontogeny (Salem, Upreti). However, all scenarios suggest that a dose of 62.5 mg weekly achieves or exceeds the exposure in adults following a 250 mg weekly dose and results in a minimum plasma concentration of 620 ng ml-1 , which is considered necessary to achieve 95% prophylactic efficacy. The clinical effectiveness model predicts a 96% protective efficacy from mefloquine chemoprophylaxis at 62.5 mg weekly. CONCLUSIONS: The PBPK and clinical effectiveness models are mutually supportive and suggest a prophylactic dose of 62.5 mg weekly in the Caucasian 5-10 kg infant population travelling to endemic countries. This dual approach offers a novel route to dose selection in a vulnerable population, where clinical trials would be difficult to conduct.

Tafenoquine and primaquine do not exhibit clinical neurologic signs associated with central nervous system lesions in the same manner as earlier 8-aminoquinolines.

BACKGROUND: Tafenoquine was recently approved for Plasmodium vivax radical cure (KRINTAFEL™) and malaria prevention (ARAKODA™). METHODS: A review of the non-clinical and clinical literature was conducted to assess whether tafenoquine (and primaquine) exhibit the same neurologic lesions and associated clinical signs as earlier 8-aminoquinolines, as has been alleged in recent opinion pieces. RESULTS: Plasmocid, pamaquine and pentaquine damage specific neuro-anatomical structures in Rhesus monkeys and humans leading to corresponding deficits in neurologic function. Neurologic therapeutic indices for these 3 drugs calculated based on monkey data were well correlated with human data. Despite 60 years of use, there is no evidence that primaquine exhibits similar neurotoxicity in humans. DISCUSSION/CONCLUSIONS: Extrapolation of data from Rhesus monkeys to humans, and the available clinical data, suggest that tafenoquine also does not exhibit pamaquine, pentaquine or plasmocid-like clinical neurologic signs in humans.

Comparison of antiviral resistance across acute and chronic viral infections.

Antiviral therapy can lead to drug resistance, but multiple factors determine the frequency of drug resistance mutations and the clinical consequences. When chronic infections caused by Human Immunodeficiency Virus (HIV), Hepatitis C Virus (HCV) and Hepatitis B Virus (HBV) are compared with acute infections such as influenza virus, respiratory syncytial virus (RSV), and other respiratory viruses, there are similarities in how and why antiviral resistance substitutions occur, but the clinical significance can be quite different. Emergence of resistant variants has implications for design of new therapeutics, treatment guidelines, clinical trial design, resistance monitoring, reporting, and interpretation. In this discussion paper, we consider the molecular factors contributing to antiviral drug resistance substitutions, and a comparison is made between chronic and acute infections. The implications of resistance are considered for clinical trial endpoints and public health, as well as the requirements for therapeutic monitoring in clinical practice with acute viral infections.

Antimalarial activity of single-dose DSM265, a novel plasmodium dihydroorotate dehydrogenase inhibitor, in patients with uncomplicated Plasmodium falciparum or Plasmodium vivax malaria infection: a proof-of-concept, open-label, phase 2a study.

BACKGROUND: DSM265 is a novel, long-duration inhibitor of plasmodium dihydroorotate dehydrogenase (DHODH) with excellent selectivity over human DHODH and activity against blood and liver stages of Plasmodium falciparum. This study aimed to assess the efficacy of DSM265 in patients with P falciparum or Plasmodium vivax malaria infection. METHODS: This proof-of-concept, open-label, phase 2a study was conducted at the Asociación Civil Selva Amazónica in Iquitos, Peru. Patients aged 18-70 years, weighing 45-90 kg, who had clinical malaria (P falciparum or P vivax monoinfection) and fever within the previous 24 h were eligible. Exclusion criteria were clinical or laboratory signs of severe malaria, inability to take oral medicine, and use of other antimalarial treatment in the preceding 14 days. Patients were divided into cohorts of those with P falciparum (cohort a) or P vivax (cohort b) infection. Two initial cohorts received single oral doses of 400 mg DSM265. Patients were followed up for efficacy for 28 days and safety for 35 days. Further cohorts received escalated or de-escalated doses of DSM265, after safety and efficacy assessment of the initial dose. The primary endpoints were the proportion of patients achieving PCR-adjusted adequate clinical and parasitological response (ACPR) by day 14 for patients infected with P falciparum and the proportion of patients achieving a crude cure by day 14 for those infected with P vivax. Cohort success, the criteria for dose escalation, was defined as ACPR (P falciparum) or crude cure (P vivax) in at least 80% of patients in the cohort. The primary analysis was done in the intention-to-treat population (ITT) and the per-protocol population, and safety analyses were done in all patients who received the study drug. This study is registered at ClinicalTrials.gov (NCT02123290). FINDINGS: Between Jan 12, 2015, and Dec 2, 2015, 45 Peruvian patients (24 with P falciparum [cohort a] and 21 with P vivax [cohort b] infection) were sequentially enrolled. For patients with P falciparum malaria in the per-protocol population, all 11 (100%) in the 400 mg group and eight (80%) of ten in the 250 mg group achieved ACPR on day 14. In the ITT analysis, 11 (85%) of 13 in the 400 mg group and eight (73%) of 11 in the 250 mg group achieved ACPR at day 14. For the patients with P vivax malaria, the primary endpoint was not met. In the per-protocol analysis, none of four patients who had 400 mg, three (50%) of six who had 600 mg, and one (25%) of four who had 800 mg DSM265 achieved crude cure at day 14. In the ITT analysis, none of five in the 400 mg group, three (33%) of nine in the 600 mg group, and one (14%) of seven in the 800 mg group achieved crude cure at day 14. During the 28-day extended observation of P falciparum patients, a resistance-associated mutation in the gene encoding the DSM265 target DHODH was observed in two of four recurring patients. DSM265 was well tolerated. The most common adverse events were pyrexia (20 [44%] of 45) and headache (18 [40%] of 45), which are both common symptoms of malaria, and no patients had any treatment-related serious adverse events or adverse events leading to study discontinuation. INTERPRETATION: After a single dose of DSM265, P falciparum parasitaemia was rapidly cleared, whereas against P vivax, DSM265 showed less effective clearance kinetics. Its long duration of action provides the potential to prevent recurrence of P falciparum after treatment with a single dose, which should be further assessed in future combination studies. FUNDING: The Global Health Innovative Technology Fund, the Bill & Melinda Gates Foundation, the National Institutes of Health (R01 AI103058), the Wellcome Trust, and the UK Department of International Development.

Tafenoquine for malaria prophylaxis in adults: An integrated safety analysis.

BACKGROUND: Tafenoquine is a new prophylactic antimalarial drug. The current analysis presents an integrated safety assessment of the Tafenoquine Anticipated Clinical Regimen (Tafenoquine ACR) from 5 clinical trials, including 1 conducted in deployed military personnel and 4 in non-deployed residents, which also incorporated placebo and mefloquine comparator groups. METHODS: Adverse events (AEs) were coded according to the Medical Dictionary for Regulatory Activities (MedDRA®, Version 15.0) and summarized. Among all subjects who had received the Tafenoquine ACR, safety findings were compared for subjects who were deployed military personnel from the Australian Defence Force (Deployed ADF) versus non-deployed residents (Resident Non-ADF). RESULTS: The incidence of at least one AE was 80.6%, 64.1%, 67.6% and 94.9% in the mefloquine, placebo, tafenoquine Resident Non-ADF and tafenoquine Deployed ADF groups, respectively. The latter group had a higher incidence of AEs related to military deployment. AEs that occurred at ≥ 1% incidence in both tafenoquine sub-groups and at a higher frequency than placebo included diarrhea, nausea, vomiting, gastroenteritis, nasopharyngeal tract infections, and back/neck pain. CONCLUSIONS: Weekly administration of tafenoquine for up to six months increased the incidence of gastrointestinal AEs, certain infections, and back/neck pain, but not the overall incidence of AEs versus placebo. CLINICAL TRIAL REGISTRATION NUMBERS/CLINICALTRIALS. GOV IDENTIFIERS: NCT02491606; NCT02488980; NCT02488902.

Tafenoquine is not neurotoxic following supertherapeutic dosing in rats.

BACKGROUND: Tafenoquine is a new drug for malaria prevention. The goal of the present work was to conduct a specific neurobehavioral study in rats with histopathological assessment of the brain. METHODS: The clinical, hematological, behavioral, motor activity, and neurohistopathologic changes induced by different dose levels of tafenoquine were evaluated following single super-therapeutic dose administration. Toxicokinetic data were generated to allow extrapolation to clinical exposures. RESULTS: At the highest dose (500 mg/kg), two animals (of 12) died. Surviving animals showed clinical signs of toxicity and had reduced body weight 7-8 days after dosing. Decreases in motor activity were observed on more than one occasion at doses > 9-fold higher than the clinical exposure. No statistically significant changes were observed for other behavioral endpoints. No neurohistopathological changes were noted. Changes in hematological and clinical pathology endpoints were observed at the lowest dose level (125 mg/kg). For context, the human dosing regimen is a 10 mg/kg load followed by 3.3 mg/kg weekly (in a 60 kg person). CONCLUSIONS: As in humans, adverse events other than neurotoxicity were dose-limiting for tafenoquine in rats. This raises the prospect that a new weekly prophylactic, without neurologic liability, may become available in the near future.

Interdisciplinary pharmacometrics linking oseltamivir pharmacology, influenza epidemiology and health economics to inform antiviral use in pandemics.

AIMS: A modular interdisciplinary platform was developed to investigate the economic impact of oseltamivir treatment by dosage regimen under simulated influenza pandemic scenarios. METHODS: The pharmacology module consisted of a pharmacokinetic distribution of oseltamivir carboxylate daily area under the concentration-time curve at steady state (simulated for 75 mg and 150 mg twice daily regimens for 5 days) and a pharmacodynamic distribution of viral shedding duration obtained from phase II influenza inoculation data. The epidemiological module comprised a susceptible, exposed, infected, recovered (SEIR) model to which drug effect on the basic reproductive number (R0 ), a measure of transmissibility, was linked by reduction of viral shedding duration. The number of infected patients per population of 100 000 susceptible individuals was simulated for a series of pandemic scenarios, varying oseltamivir dose, R0 (1.9 vs. 2.7), and drug uptake (25%, 50%, and 80%). The number of infected patients for each scenario was entered into the health economics module, a decision analytic model populated with branch probabilities, disease utility, costs of hospitalized patients developing complications, and case-fatality rates. Change in quality-adjusted life years was determined relative to base case. RESULTS: Oseltamivir 75 mg relative to no treatment reduced the median number of infected patients, increased change in quality-adjusted life years by deaths averted, and was cost-saving under all scenarios; 150 mg relative to 75 mg was not cost effective in low transmissibility scenarios but was cost saving in high transmissibility scenarios. CONCLUSION: This methodological study demonstrates proof of concept that the disciplines of pharmacology, disease epidemiology and health economics can be linked in a single quantitative framework.