Patterns of antibiotic use, pathogens, and prediction of mortality in hospitalized neonates and young infants with sepsis: A global neonatal sepsis observational cohort study (NeoOBS).

BACKGROUND: There is limited data on antibiotic treatment in hospitalized neonates in low- and middle-income countries (LMICs). We aimed to describe patterns of antibiotic use, pathogens, and clinical outcomes, and to develop a severity score predicting mortality in neonatal sepsis to inform future clinical trial design. METHODS AND FINDINGS: Hospitalized infants <60 days with clinical sepsis were enrolled during 2018 to 2020 by 19 sites in 11 countries (mainly Asia and Africa). Prospective daily observational data was collected on clinical signs, supportive care, antibiotic treatment, microbiology, and 28-day mortality. Two prediction models were developed for (1) 28-day mortality from baseline variables (baseline NeoSep Severity Score); and (2) daily risk of death on IV antibiotics from daily updated assessments (NeoSep Recovery Score). Multivariable Cox regression models included a randomly selected 85% of infants, with 15% for validation. A total of 3,204 infants were enrolled, with median birth weight of 2,500 g (IQR 1,400 to 3,000) and postnatal age of 5 days (IQR 1 to 15). 206 different empiric antibiotic combinations were started in 3,141 infants, which were structured into 5 groups based on the World Health Organization (WHO) AWaRe classification. Approximately 25.9% (n = 814) of infants started WHO first line regimens (Group 1-Access) and 13.8% (n = 432) started WHO second-line cephalosporins (cefotaxime/ceftriaxone) (Group 2-"Low" Watch). The largest group (34.0%, n = 1,068) started a regimen providing partial extended-spectrum beta-lactamase (ESBL)/pseudomonal coverage (piperacillin-tazobactam, ceftazidime, or fluoroquinolone-based) (Group 3-"Medium" Watch), 18.0% (n = 566) started a carbapenem (Group 4-"High" Watch), and 1.8% (n = 57) a Reserve antibiotic (Group 5, largely colistin-based), and 728/2,880 (25.3%) of initial regimens in Groups 1 to 4 were escalated, mainly to carbapenems, usually for clinical deterioration (n = 480; 65.9%). A total of 564/3,195 infants (17.7%) were blood culture pathogen positive, of whom 62.9% (n = 355) had a gram-negative organism, predominantly Klebsiella pneumoniae (n = 132) or Acinetobacter spp. (n = 72). Both were commonly resistant to WHO-recommended regimens and to carbapenems in 43 (32.6%) and 50 (71.4%) of cases, respectively. MRSA accounted for 33 (61.1%) of 54 Staphylococcus aureus isolates. Overall, 350/3,204 infants died (11.3%; 95% CI 10.2% to 12.5%), 17.7% if blood cultures were positive for pathogens (95% CI 14.7% to 21.1%, n = 99/564). A baseline NeoSep Severity Score had a C-index of 0.76 (0.69 to 0.82) in the validation sample, with mortality of 1.6% (3/189; 95% CI: 0.5% to 4.6%), 11.0% (27/245; 7.7% to 15.6%), and 27.3% (12/44; 16.3% to 41.8%) in low (score 0 to 4), medium (5 to 8), and high (9 to 16) risk groups, respectively, with similar performance across subgroups. A related NeoSep Recovery Score had an area under the receiver operating curve for predicting death the next day between 0.8 and 0.9 over the first week. There was significant variation in outcomes between sites and external validation would strengthen score applicability. CONCLUSION: Antibiotic regimens used in neonatal sepsis commonly diverge from WHO guidelines, and trials of novel empiric regimens are urgently needed in the context of increasing antimicrobial resistance (AMR). The baseline NeoSep Severity Score identifies high mortality risk criteria for trial entry, while the NeoSep Recovery Score can help guide decisions on regimen change. NeoOBS data informed the NeoSep1 antibiotic trial (ISRCTN48721236), which aims to identify novel first- and second-line empiric antibiotic regimens for neonatal sepsis. TRIAL REGISTRATION: ClinicalTrials.gov, (NCT03721302).

A Nonprofit Drug Development Model Is Part of the Antimicrobial Resistance (AMR) Solution.

Antibiotics underpin modern medicine and are critical for pandemic preparedness. Push funding has revitalized the preclinical antimicrobial resistance (AMR) pipeline and government funding via CARB-X and BARDA, as well as private sector-led investment via the AMR Action Fund, will help several new antibiotics obtain regulatory approval. Nevertheless, revenues generated by new antibiotics are not considered sufficiently profitable by commercial developers to address unmet need. The question remains: Who could viably fund development and secure global equitable access for new antibiotics? Public health need should be the primary driver for antibiotic development. Improved prioritization and government oversight by funders who allocate public resources are a needed first step. In this framework, nonprofit research and development organizations, with support from public funders, and unconstrained by commercial profitability requirements are well positioned to work with public and private actors to viably provide new antibiotics to all in need.

Antibiotics needed to treat multidrug-resistant infections in neonates.

Infections remain a leading cause of death in neonates. The sparse antibiotic development pipeline and challenges in conducting neonatal research have resulted in few effective antibiotics being adequately studied to treat multidrug-resistant (MDR) infections in neonates, despite the increasing global mortality burden caused by antimicrobial resistance. Of 40 antibiotics approved for use in adults since 2000, only four have included dosing information for neonates in their labelling. Currently, 43 adult antibiotic clinical trials are recruiting patients, compared with only six trials recruiting neonates. We review the World Health Organization (WHO) priority pathogens list relevant to neonatal sepsis and propose a WHO multiexpert stakeholder meeting to promote the development of a neonatal priority antibiotic development list. The goal is to develop international, interdisciplinary consensus for an accelerated neonatal antibiotic development programme. This programme would enable focused research on identified priority antibiotics for neonates to reduce the excess morbidity and mortality caused by MDR infections in this vulnerable population.

Les infections demeurent l'une des principales causes de décès chez les nouveau-nés. Les rares projets de développement d'antibiotiques et les défis posés par la recherche néonatale ont entraîné une pénurie d'antibiotiques efficaces spécialement étudiés pour traiter les infections multirésistantes (MR) chez les nouveau-nés, en dépit d'une mortalité galopante due à une résistance accrue aux antimicrobiens. Sur 40 antibiotiques autorisés pour les adultes depuis 2000, quatre à peine sont munis d'un étiquetage indiquant la posologie adaptée aux nouveau-nés. Actuellement, 43 essais cliniques portant sur des antibiotiques recrutent des patients du côté des adultes, contre six seulement du côté des nouveau-nés. Dans le présent document, nous passons en revue la liste prioritaire d'agents pathogènes établie par l'Organisation mondiale de la Santé (OMS) pour soigner la septicémie néonatale et proposons de réunir, sous l'égide de l'OMS, des parties prenantes issues de plusieurs domaines d'expertise afin de promouvoir la création d'une liste prioritaire de développement d'antibiotiques destinés aux nouveau-nés. Objectif: parvenir à un consensus international et interdisciplinaire visant à accélérer le programme de mise au point d'antibiotiques à usage néonatal. Ce programme permettrait d'orienter les recherches vers des antibiotiques identifiés comme prioritaires pour les nouveau-nés, en vue de faire baisser les taux de morbidité et de mortalité excessifs qu'engendrent les infections MR au sein de cette population vulnérable.

Las infecciones siguen siendo una de las principales causas de muerte en los recién nacidos. Debido al escaso desarrollo de los antibióticos y a las dificultades para llevar a cabo la investigación neonatal, son pocos los antibióticos eficaces que se estudian de manera adecuada para tratar las infecciones multirresistentes (MR) en los recién nacidos, a pesar de la creciente carga de mortalidad mundial causada por la resistencia a los antimicrobianos. De los 40 antibióticos aprobados para su uso en adultos desde el 2000, solo cuatro han incluido información sobre la dosis para recién nacidos en su etiquetado. En la actualidad, 43 ensayos clínicos con antibióticos para adultos están reclutando pacientes, en comparación con solo seis ensayos que reclutan recién nacidos. Se revisa la lista de patógenos prioritarios de la Organización Mundial de la Salud (OMS) relevantes para la sepsis neonatal y se propone una reunión de la OMS con múltiples expertos para promover el desarrollo de una lista de antibióticos prioritarios para los recién nacidos. El objetivo es desarrollar un consenso internacional e interdisciplinario para establecer un programa acelerado de desarrollo de antibióticos neonatales. Este programa permitiría centrar la investigación en los antibióticos prioritarios identificados para los recién nacidos con el fin de reducir el exceso de morbilidad y mortalidad causado por las infecciones MR en esta población vulnerable.

Antimicrobial resistance - moving forward?

BACKGROUND: When microorganisms (such as bacteria or viruses) are highly exposed to antimicrobial drugs, they can develop the capacity to defeat the drugs designed to eradicate them. Long-term accumulation of adaptations to survive drug exposure can lead to the development of antimicrobial resistance (AMR). The success of antibiotics has led to their widespread overuse and misuse in humans, animals and plants. MAIN TEXT: AMR is a global concern and solutions are not vertical actions in a single buy business model. Even if a transectoral approach is key, there is a lack of multi-disciplinary partnerships that allow for strategic cooperation between different sectors such as the pharmaceutical industry, agro-alimentary complex, patient care and education, NGOs and research and development. Global public health voices should lead this integration to align the progress of existing AMR successes. Maintaining the public's trust in preventive medicine, health systems and food production safety, together with public health driven, non-profit drug development, is a key factor. In its "Call for integrated action on AMR", signed by about 70 national and international organizations the World Federation of Public Health Associations (WFPHA) called "on all governments, the private sector, non-governmental organizations, health professionals, public and private research organizations, and all stakeholders to ensure that public health remains at the centre of all policy and scientific endeavours in the field of antimicrobial resistance". CONCLUSIONS: The "Global Charter for the Public's Health", developed by the WFPHA in association with WHO, is proposed in this article as a tool for implementation of complex public health actions such as AMR.

Diagnostic preparedness for infectious disease outbreaks.

Diagnostics are crucial in mitigating the effect of disease outbreaks. Because diagnostic development and validation are time consuming, they should be carried out in anticipation of epidemics rather than in response to them. The diagnostic response to the 2014-15 Ebola epidemic, although ultimately effective, was slow and expensive. If a focused mechanism had existed with the technical and financial resources to drive its development ahead of the outbreak, point-of-care Ebola tests supporting a less costly and more mobile response could have been available early on in the diagnosis process. A new partnering model could drive rapid development of tests and surveillance strategies for novel pathogens that emerge in future outbreaks. We look at lessons learned from the Ebola outbreak and propose specific solutions to improve the speed of new assay development and ensure their effective deployment.

An open source pharma roadmap.

In an Essay, Matthew Todd and colleagues discuss an open source approach to drug development.

Multidrug-resistant gonorrhea: A research and development roadmap to discover new medicines.

Emilie Alirol and colleagues discuss the development of new treatments for gonorrhea.

Maximising access to achieve appropriate human antimicrobial use in low-income and middle-income countries.

Access to quality-assured antimicrobials is regarded as part of the human right to health, yet universal access is often undermined in low-income and middle-income countries. Lack of access to the instruments necessary to make the correct diagnosis and prescribe antimicrobials appropriately, in addition to weak health systems, heightens the challenge faced by prescribers. Evidence-based interventions in community and health-care settings can increase access to appropriately prescribed antimicrobials. The key global enablers of sustainable financing, governance, and leadership will be necessary to achieve access while preventing excess antimicrobial use.

International cooperation to improve access to and sustain effectiveness of antimicrobials.

Securing access to effective antimicrobials is one of the greatest challenges today. Until now, efforts to address this issue have been isolated and uncoordinated, with little focus on sustainable and international solutions. Global collective action is necessary to improve access to life-saving antimicrobials, conserving them, and ensuring continued innovation. Access, conservation, and innovation are beneficial when achieved independently, but much more effective and sustainable if implemented in concert within and across countries. WHO alone will not be able to drive these actions. It will require a multisector response (including the health, agriculture, and veterinary sectors), global coordination, and financing mechanisms with sufficient mandates, authority, resources, and power. Fortunately, securing access to effective antimicrobials has finally gained a place on the global political agenda, and we call on policy makers to develop, endorse, and finance new global institutional arrangements that can ensure robust implementation and bold collective action.

Visceral leishmaniasis relapse hazard is linked to reduced miltefosine exposure in patients from Eastern Africa: a population pharmacokinetic/pharmacodynamic study.

BACKGROUND: Low efficacy of miltefosine in the treatment of visceral leishmaniasis was recently observed in Eastern Africa. OBJECTIVES: To describe the pharmacokinetics and establish a pharmacokinetic/pharmacodynamic relationship for miltefosine in Eastern African patients with visceral leishmaniasis, using a time-to-event approach to model relapse of disease. METHODS: Miltefosine plasma concentrations from 95 patients (48 monotherapy versus 47 combination therapy) were included in the population pharmacokinetic model using non-linear mixed effects modelling. Subsequently a time-to-event model was developed to model the time of clinical relapse. Various summary pharmacokinetic parameters (various AUCs, Time > EC50, Time > EC90), normalized within each treatment arm to allow simultaneous analysis, were evaluated as relapse hazard-changing covariates. RESULTS: A two-compartment population model with first-order absorption fitted the miltefosine pharmacokinetic data adequately. Relative bioavailability was reduced (-74%, relative standard error 4.7%) during the first week of treatment of the monotherapy arm but only the first day of the shorter combination regimen. Time to the relapse of infection could be described using a constant baseline hazard (baseline 1.8 relapses/year, relative standard error 72.7%). Miltefosine Time > EC90 improved the model significantly when added in a maximum effect function on the baseline hazard (half maximal effect with Time > EC90 6.97 days for monotherapy). CONCLUSIONS: Miltefosine drug exposure was found to be decreased in Eastern African patients with visceral leishmaniasis, due to a (transient) initial lower bioavailability. Relapse hazard was inversely linked to miltefosine exposure. Significantly lower miltefosine exposure was observed in children compared with adults, further urging the need for implementation of dose adaptations for children.

Systematic review of biomarkers to monitor therapeutic response in leishmaniasis.

Recently, there has been a renewed interest in the development of new drugs for the treatment of leishmaniasis. This has spurred the need for pharmacodynamic markers to monitor and compare therapies specifically for visceral leishmaniasis, in which the primary recrudescence of parasites is a particularly long-term event that remains difficult to predict. We performed a systematic review of studies evaluating biomarkers in human patients with visceral, cutaneous, and post-kala-azar dermal leishmaniasis, which yielded a total of 170 studies in which 53 potential pharmacodynamic biomarkers were identified. In conclusion, the large majority of these biomarkers constituted universal indirect markers of activation and subsequent waning of cellular immunity and therefore lacked specificity. Macrophage-related markers demonstrate favorable sensitivity and times to normalcy, but more evidence is required to establish a link between these markers and clinical outcome. Most promising are the markers directly related to the parasite burden, but future effort should be focused on optimization of molecular or antigenic targets to increase the sensitivity of these markers. In general, future research should focus on the longitudinal evaluation of the pharmacodynamic biomarkers during treatment, with an emphasis on the correlation of studied biomarkers and clinical parameters.

Principles for designing future regimens for multidrug-resistant tuberculosis.

Fewer than 20% of patients with multidrug-resistant (MDR) tuberculosis are receiving treatment and there is an urgent need to scale up treatment programmes. One of the biggest barriers to scale-up is the treatment regimen, which is lengthy, complex, ineffective, poorly tolerated and expensive. For the first time in over 50 years, new drugs have been developed specifically to treat tuberculosis, with bedaquiline and potentially delamanid expected to be available soon for treatment of MDR cases. However, if the new drugs are merely added to the current treatment regimen, the new regimen will be at least as lengthy, cumbersome and toxic as the existing one. There is an urgent need for strategy and evidence on how to maximize the potential of the new drugs to improve outcomes and shorten treatment. We devised eight key principles for designing future treatment regimens to ensure that, once they are proven safe in clinical trials, they will be clinically effective and programmatically practicable. Regimens should contain at least one new class of drug; be broadly applicable for use against MDR and extensively drug-resistant Mycobacterium tuberculosis complex strains; contain three to five effective drugs, each from a different drug class; be delivered orally; have a simple dosing schedule; have a good side-effect profile that allows limited monitoring; last a maximum of 6 months; and have minimal interaction with antiretrovirals. Following these principles will maximize the potential of new compounds and help to overcome the clinical and programmatic disadvantages and scale-up constraints that plague the current regimen.

Moins de 20% des patients atteints de tuberculose multirésistante (MDR) reçoivent actuellement un traitement et il est urgent de renforcer les programmes de traitement. Un des plus grands obstacles à ce renforcement est le schéma thérapeutique qui est long, complexe, inefficace, mal toléré et coûteux. Pour la première fois en plus de 50 ans, de nouveaux médicaments ont été développés spécifiquement pour traiter la tuberculose, dont la bedaquiline et potentiellement la delamanid qui devraient être bientôt disponibles pour traiter les cas de MDR. Cependant, si les nouveaux médicaments sont juste ajoutés au schéma thérapeutique actuel, le nouveau schéma thérapeutique sera au moins aussi long, lourd et toxique que celui qui existe déjà. Il est urgent d'élaborer une stratégie et d'obtenir des preuves concernant la façon de maximiser le potentiel des nouveaux médicaments pour améliorer les résultats et raccourcir la durée du traitement. Nous avons mis au point huit principes clés pour la conception des futurs schémas thérapeutiques afin de s'assurer que, une fois qu'ils aient été éprouvés comme sûrs dans des essais cliniques, ils soient cliniquement efficaces et utilisables dans le cadre d'un programme. Les schémas thérapeutiques doivent comprendre au moins une nouvelle classe de médicament; être généralement applicables pour une utilisation contre les MDR et plus largement contre les souches complexes de Mycobacterium tuberculosis multirésistantes; comprendre trois des cinq médicaments efficaces, chacun provenant d'une classe de médicament différent; être administré par voie orale; avoir un schéma posologique simple; avoir un bon profil d'effets secondaires permettant un suivi limité; durer au moins 6 mois et avoir le moins d'interaction possible avec les antirétroviraux. Suivre ces principes maximisera le potentiel des nouveaux composés et permettra de surmonter les inconvénients cliniques et programmatiques, ainsi que les contraintes qui plombent le schéma thérapeutique actuel.

Menos del 20 % de los pacientes con tuberculosis multirresistente (MDR) recibe tratamiento, al tiempo que existe una necesidad apremiante de ampliar los programas de tratamiento. Uno de los mayores obstáculos para la ampliación es el propio programa de tratamiento, el cual resulta largo, complejo, ineficaz, caro y no se tolera bien. Por primera vez en más de 50 años se han desarrollado fármacos nuevos específicos para tratar la tuberculosis y se espera que la bedaquilina y, potencialmente, la delamanida estén disponibles pronto para tratar los casos de tuberculosis multirresistente. Sin embargo, si se limitan a introducir los fármacos nuevos al programa de tratamiento actual, el programa nuevo será, como mínimo, tan largo, complicado y tóxico como el presente. Es, por tanto, muy urgente diseñar una estrategia y reunir pruebas sobre cómo maximizar el potencial de los fármacos nuevos para mejorar los resultados y acortar el tratamiento. Hemos establecido ocho principios esenciales para el diseño de los programas de tratamiento futuros a fin de garantizar que, una vez que se hayan probado en ensayos clínicos, sean eficaces desde el punto de vista clínico y viables mediante programación. Los programas deben contener, al menos, un tipo nuevo de fármaco, poder aplicarse de forma amplia para su uso contra la tuberculosis multirresistente y las cepas complejas de Mycobacterium tuberculosis ultrarresistentes, contener de tres a cinco medicamentos eficaces, cada uno de una clase de fármaco diferente; suministrarse por vía oral, tener un horario de dosificación simple y un perfil adecuado de efectos secundarios que permita una supervisión restringida, durar un máximo de 6 meses y tener una interacción mínima con antirretrovirales. Si se siguen estos principios, se maximizará el potencial de los compuestos nuevos y será más fácil superar los inconvenientes clínicos y programáticos, así como las barreras a la ampliación que abundan en el programa actual.

Improving equitable access for effective antibacterials: an ecosystem approach.

BACKGROUND: Antibiotics are indispensable to modern healthcare, yet their equitable access remains a pressing global challenge. Factors contributing to inequities include insufficient evidence for optimal clinical use, limited registration, pricing for Reserve antibiotics, and supply chain challenges. These issues disproportionately affect low- and middle-income countries (LMICs), exacerbating antimicrobial resistance (AMR) burdens. OBJECTIVES: This paper explores the multifaceted dimensions of inequitable antibiotic access and proposes a comprehensive framework to address the crisis. SOURCES: Published articles, grey literature analysis, and the authors' own expertise contributed to this article. CONTENT: While much attention has been paid to push and pull incentives for antibiotic development, these interventions are inadequate to reach sustainable and equitable access to antibiotics. Improving equitable antibiotic access requires an ecosystem approach, involving multiple stakeholders and including public-private partnerships. The paper advocates for initiatives spanning research and development (R&D), regulatory pathways, procurement strategies, and financing mechanisms and suggests concrete interventions in each of these areas. The specific interventions and mix of public and private actors may vary according to antibiotic, market, and health system context, but must be designed to meet public health needs while also supporting a market that will sustain quality-assured production and delivery of antibiotics. IMPLICATIONS: Addressing the challenge of equitable antibiotic access requires coordinated efforts across sectors and regions. By embracing an ecosystem approach centred on public health priorities, stakeholders can pave the way for a sustainable supply of antibiotics, and equitable access, safeguarding the future of global healthcare amidst the growing threat of AMR.

Comparison of short-course multidrug treatment with standard therapy for visceral leishmaniasis in India: an open-label, non-inferiority, randomised controlled trial.

BACKGROUND: Improved treatment approaches are needed for visceral leishmaniasis. We assessed the efficacy and safety of three potential short-course combination treatments compared with the standard monotherapy in India. METHODS: Standard treatment (1 mg/kg amphotericin B infusion on alternate days for 30 days, total dose 15 mg/kg) was compared with three drug combinations (single injection of 5 mg/kg liposomal amphotericin B and 7-day 50 mg oral miltefosine or single 10-day 11 mg/kg intramuscular paromomycin; or 10 days each of miltefosine and paromomycin) in an open-label, parallel-group, non-inferiority, randomised controlled trial in two hospital sites in Bihar, India. Patients aged 5-60 years with parasitologically confirmed visceral leishmaniasis were randomly assigned one of the four treatments by the trial statistician by use of a computer-generated list. Clinical assessments were done at the end of treatment (15 days on combination treatment; 31 days for standard treatment) and after 45 days and 6 months. The primary endpoint was definitive cure (defined as no sign or symptom of visceral leishmaniasis and parasitologically cured to the last follow-up). Analyses were done both by intention to treat and per protocol. This trial is registered with ClinicalTrials.gov, number NCT00696969. FINDINGS: Between June, 2008, and July, 2009, 634 patients were assigned amphotericin B (n=157), liposomal amphotericin B with miltefosine (n=160) or paromomycin (n=158), or miltefosine and paromomycin (n=159). 618 patients were in the per-protocol population. There were two relapses in each group. The numbers with definitive cure at 6 months for the intention-to-treat population were 146 (cure rate 93·0%; CI 87·5-96·3) for amphotericin B, 156 (97·5%; 93·3-99·2) for liposomal amphotericin B and miltefosine, 154 (97·5%; 93·24-99·2) for liposomal amphotericin B and paromomycin, and 157 (98·7%; 95·1-99·8) for miltefosine and paromomycin. All combinations were non-inferior to the standard treatment, in both the intention-to-treat and per-protocol populations. Patients in the combination groups had fewer adverse events than did those assigned standard treatment. INTERPRETATION: Combination treatments for visceral leishmaniasis are efficacious and safe, and decrease the duration of therapy, thereby encouraging adherence and reducing emergence of drug-resistant parasites. FUNDING: Drugs for Neglected Diseases initiative and the Indian Council of Medical Research.

Miltefosine: a review of its pharmacology and therapeutic efficacy in the treatment of leishmaniasis.

Miltefosine is an alkylphosphocholine drug with demonstrated activity against various parasite species and cancer cells as well as some pathogenic bacteria and fungi. For 10 years it has been licensed in India for the treatment of visceral leishmaniasis (VL), a fatal neglected parasitic disease. It is the first and still the only oral drug that can be used to treat VL and cutaneous leishmaniasis (CL). The standard 28 day miltefosine monotherapy regimen is well tolerated, except for mild gastrointestinal side effects, although its teratogenic potential severely hampers its general use in the clinic and roll-out in national elimination programmes. The pharmacokinetics of miltefosine are mainly characterized by its long residence time in the body, resulting in extensive drug accumulation during treatment and long elimination half-lives. At the moment, different combination therapy strategies encompassing miltefosine are being tested in multiple controlled clinical trials in various geographical areas of endemicity, both in South Asia and East Africa. We here review the most salient pre-clinical and clinical pharmacological aspects of miltefosine, its mechanism of action against Leishmania parasites and other pathogens, and provide a systematic overview of the efficacy and safety data from all clinical trials of miltefosine, either alone or in combination, in the treatment of VL and CL.

Translational pharmacokinetic modelling and simulation for the assessment of duration of contraceptive use after treatment with miltefosine.

OBJECTIVES: Use of miltefosine in the treatment of visceral leishmaniasis (VL) is hampered by its potential teratogenicity. The duration of adequate contraceptive cover in females of child-bearing potential after cessation of a potentially teratogenic drug therapy remains debated. The objective of this study was to provide a rational approach to suggest durations of contraceptive cover for various miltefosine regimens. METHODS: A human reproductive safety threshold exposure limit was derived using animal-to-human dose conversion. Pharmacokinetic (PK) data for miltefosine in females are lacking; a previously developed population PK model and a comprehensive anthropometric dataset were used to simulate PK data for Indian female VL patients receiving miltefosine for 5, 7, 10 or 28 days. Probability of supra-threshold miltefosine exposure was used to evaluate adequate durations of post-treatment contraceptive cover for the various regimens. RESULTS: PK data were simulated for 465 treated Indian female VL patients of child-bearing potential with a median age of 25 years (IQR 16-31 years) and median weight of 38 kg (IQR 34-42 kg). From animal reproductive toxicity studies, a human reproductive safety threshold exposure limit was derived of 24.5 µg ·â€Šday/mL. Probability of 'unprotected' supra-threshold miltefosine exposure was very low (<0.2%) for a post-treatment contraceptive cover period of 4 months for the standard 28 day regimen, and of 2 months for the shorter regimens. CONCLUSIONS: To our knowledge, this is the first study providing rational suggestions for contraceptive cover for a teratogenic drug based on animal-to-human dose conversion. For the 28 day miltefosine regimen, post-treatment contraceptive cover may be extended to 4 months, whereas for all shorter regimens 2 months may be adequate.