Introduction Post-kala-azar dermal leishmaniasis (PKDL) arises as a dermal complication following a visceral leishmaniasis (VL) infection. Current treatment options for PKDL are unsatisfactory, and there is a knowledge gap regarding the distribution of antileishmanial compounds within human skin. The present study investigated the skin distribution of miltefosine in PKDL patients, with the aim to improve the understanding of the pharmacokinetics at the skin target site in PKDL.Methods Fifty-two PKDL patients underwent treatment with liposomal amphotericin B (20 mg/kg) plus miltefosine (allometric dosing) for 21 days. Plasma concentrations of miltefosine were measured on study days 8, 15, 22 and 30, while a punch skin biopsy was taken on day 22. A physiologically based pharmacokinetic (PBPK) model was developed to evaluate the distribution of miltefosine into the skin.Results Following the allometric weight-based dosing regimen, median miltefosine concentrations on day 22 were 43.73 mu g/g (IQR: 21.94-60.65 mu g/g) in skin and 33.29 mu g/mL (IQR: 25.9-42.58 mu g/mL) in plasma. The median individual concentration ratio of skin to plasma was 1.19 (IQR: 0.79-1.9). In 87% (45/52) of patients, skin exposure was above the suggested EC90 PK target of 10.6 mg/L associated with in vitro susceptibility. Simulations indicated that the residence time of miltefosine in the skin would be more than 2-fold longer than in plasma, estimated by a mean residence time of 604 versus 266 hours, respectively.Conclusion This study provides the first accurate measurements of miltefosine penetration into the skin, demonstrating substantial exposure and prolonged retention of miltefosine within the skin. These findings support the use of miltefosine in cutaneous manifestations of leishmaniasis. In combination with parasitological and clinical data, these results are critical for the future optimization of combination therapies with miltefosine in the treatment of PKDL.

INTRODUCTION Treatment options for the highly neglected fungal tropical disease eumycetoma are limited and poorly adapted to patients’ contexts, with surgery often required. The first-line treatment, itraconazole, thought to be 40% effective, must be taken twice daily for ≥12 months with food, making adherence difficult. An effective, affordable, context-appropriate treatment is urgently needed. The Drugs for Neglected Diseases Initiative (DNDi) repurposed the broad-spectrum antifungal agent fosravuconazole, developed by Eisai Ltd for onychomycosis. We aimed to compare two different doses of weekly fosravuconazole with standard-of-care daily itraconazole in patients with eumycetoma. METHODS This phase 2, randomised, double-blind, active-controlled, superiority trial was done at the Mycetoma Research Centre, Soba University Hospital, Sudan. Patients aged ≥15 years with a small-to-medium lesion (≥2 to <16 cm) caused by M mycetomatis requiring surgery were randomly assigned (1:1:1) to receive either 300 mg fosravuconazole weekly (group 1), 200 mg fosravuconazole weekly (group 2), or 400 mg itraconazole daily (group 3), for 12 months, together with surgery at 6 months in all groups. The primary efficacy endpoint, assessed in all patients receiving at least one dose of study drug (modified intention to treat), was complete cure at 12 months (absence of eumycetoma mass and sinuses and discharge with normal imaging; or a negative fungal culture if mass present). Safety was assessed in patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov (NCT03086226). RESULTS Between 9 May, 2017, and 10 June, 2021, 104 patients were randomised (34 to group 1, 34 to group 2, and 36 to group 3).Median age was 29.0 (IQR22.0–33.0), 23.0 (20.0–29.0) and 24.5 (19.5–33.0) years for Groups 1, 2, and 3 respectively. Complete cure rates at end of treatment were 50.0% (95% CI 32.4–67.6), 64.7% (46.5–80.3), and 75.0% (57.8–87.9) with Groups 1, 2 and 3, respectively, showing no superiority of fosravuconazole over the standard-of-care (p=0.030 for Group 2 vs Group 3; and p=0.347 for Group 1 vs Group 3; with significance level set at 0.022). Treatment-emergent adverse drug reactions were reported in one (3%) of 34 patients in group 2 (nausea or vomiting) and three (8%) of 36 patients in group 3 (cortisol decreased, QT prolonged). CONCLUSION Although not superior, fosravuconazole 200 mg seemed to have similar efficacy to itraconazole, coupled with advantages such as a weekly, not daily, administration, no food effect, and low risk for drug-drug interactions. An early access programme is under review by authorities in Sudan and a regulatory dossier and global access plan are under preparation.

The CRUCIAL trial (NCT04217421) is investigating the effect of postnatal and perioperative administration of allopurinol on postoperative brain injury in neonates with critical congenital heart disease (CCHD) undergoing cardiac surgery with cardiopulmonary bypass (CPB) shortly after birth. This study aimed to characterize the pharmacokinetics (PK) of allopurinol and oxypurinol during the preoperative, intraoperative, and postoperative phases in this population, and to evaluate target attainment of the current dosing strategy. Nonlinear mixed-effects modeling was used to develop population PK models in 14 neonates from the CRUCIAL trial who received up to five intravenous allopurinol administrations throughout the postnatal and perioperative periods. Target attainment was defined as achieving an allopurinol concentration >2 mg/L in at least two-thirds of the patients during the first 24 h after birth and between the start and 36 h after cardiac surgery with CPB. A two-compartment model for allopurinol was connected to a one-compartment model for oxypurinol with an auto-inhibition effect on the conversion, which best described the PK. In a typical neonate weighing 3.5 kg who underwent cardiac surgery at a postnatal age (PNA) of 5.6 days, the clearance (CL) of allopurinol and oxypurinol at birth was 0.95 L/h (95

Treatment regimens for post-kala-azar dermal leishmaniasis (PKDL) are usually extrapolated from those for visceral leishmaniasis (VL), but drug pharmacokinetics (PK) can differ due to disease-specific variations in absorption, distribution, and elimination. This study characterized PK differences in paromomycin and miltefosine between 109 PKDL and 264 VL patients from Eastern Africa. VL patients showed 0.55-fold (95% confidence interval [CI], .41-.74) lower capacity for paromomycin saturable reabsorption in renal tubules, and required a 1.44-fold (95% CI, 1.23-1.71) adjustment when relating renal clearance to creatinine-based estimated glomerular filtration rate. Miltefosine bioavailability in VL patients was lowered by 69% (95% CI, 62%-76%) at treatment start. Comparing PKDL to VL patients on the same regimen, paromomycin plasma exposures were 0.74- to 0.87-fold, while miltefosine exposure until the end of treatment day was 1.4-fold. These pronounced PK differences between PKDL and VL patients in Eastern Africa highlight the challenges of directly extrapolating dosing regimens from one leishmaniasis presentation to another.

BackgroundWith the current treatment options for visceral leishmaniasis (VL), recrudescence of the parasite is seen in a proportion of patients. Understanding parasite dynamics is crucial to improving treatment efficacy and predicting patient relapse in cases of VL. This study aimed to characterize the kinetics of circulatingLeishmaniaparasites in the blood, during and after different antileishmanial therapies, and to find predictors for clinical relapse of disease.MethodsData from three clinical trials, in which Eastern African VL patients received various antileishmanial regimens, were combined in this study.Leishmaniakinetoplast DNA was quantified in whole blood with real-time quantitative PCR (qPCR) before, during, and up to six months after treatment. An integrated population pharmacokinetic-pharmacodynamic model was developed using non-linear mixed effects modelling.ResultsParasite proliferation was best described by an exponential growth model, with anin vivoparasite doubling time of 7.8 days (RSE 12%). Parasite killing by fexinidazole, liposomal amphotericin B, sodium stibogluconate, and miltefosine was best described by linear models directly relating drug concentrations to the parasite elimination rate. After treatment, parasite growth was assumed to be suppressed by the host immune system, described by an Emaxmodel driven by the time after treatment. No predictors for the high variability in onset and magnitude of the immune response could be identified. Model-based individual predictions of blood parasite load on Day 28 and Day 56 after start of treatment were predictive for clinical relapse of disease.ConclusionThis semi-mechanistic pharmacokinetic-pharmacodynamic model adequately captured the blood parasite dynamics during and after treatment, and revealed that high blood parasite loads on Day 28 and Day 56 after start of treatment are an early indication for VL relapse, which could be a useful biomarker to assess treatment efficacy of a treatment regimen in a clinical trial setting.

Pharmacotherapy: The Journal of Human Pharmacology and Drug TherapyVolume 43, Issue 9 p. 992-992 LETTER TO THE EDITOR Response to comment on “Dosing implications for liposomal amphotericin B in pregnancy” Niamh O'Grady, Corresponding Author Niamh O'Grady [email protected] orcid.org/0000-0001-8050-0408 Department of Pharmacy, Yale-New Haven Hospital, New Haven, Connecticut, USA Correspondence Niamh O'Grady, Department of Pharmacy, Boston Medical Center, One Boston Medical Center Pl, Boston, MA 02118, USA. Email: [email protected]Search for more papers by this authorMatthew Davis, Matthew Davis orcid.org/0000-0002-6509-0487 Department of Pharmacy, Yale-New Haven Hospital, New Haven, Connecticut, USASearch for more papers by this authorDayna McManus, Dayna McManus orcid.org/0000-0002-8153-3284 Department of Pharmacy, Yale-New Haven Hospital, New Haven, Connecticut, USASearch for more papers by this authorJeffrey Topal, Jeffrey Topal Infectious Disease Section, Department of Internal Medicine, Yale-New Haven Hospital, New Haven, Connecticut, USASearch for more papers by this authorMarwan M. Azar, Marwan M. Azar orcid.org/0000-0001-5498-5042 Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorNeima Briggs, Neima Briggs orcid.org/0000-0002-5583-7057 Infectious Disease Section, Department of Internal Medicine, Yale-New Haven Hospital, New Haven, Connecticut, USASearch for more papers by this author Niamh O'Grady, Corresponding Author Niamh O'Grady [email protected] orcid.org/0000-0001-8050-0408 Department of Pharmacy, Yale-New Haven Hospital, New Haven, Connecticut, USA Correspondence Niamh O'Grady, Department of Pharmacy, Boston Medical Center, One Boston Medical Center Pl, Boston, MA 02118, USA. Email: [email protected]Search for more papers by this authorMatthew Davis, Matthew Davis orcid.org/0000-0002-6509-0487 Department of Pharmacy, Yale-New Haven Hospital, New Haven, Connecticut, USASearch for more papers by this authorDayna McManus, Dayna McManus orcid.org/0000-0002-8153-3284 Department of Pharmacy, Yale-New Haven Hospital, New Haven, Connecticut, USASearch for more papers by this authorJeffrey Topal, Jeffrey Topal Infectious Disease Section, Department of Internal Medicine, Yale-New Haven Hospital, New Haven, Connecticut, USASearch for more papers by this authorMarwan M. Azar, Marwan M. Azar orcid.org/0000-0001-5498-5042 Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, USASearch for more papers by this authorNeima Briggs, Neima Briggs orcid.org/0000-0002-5583-7057 Infectious Disease Section, Department of Internal Medicine, Yale-New Haven Hospital, New Haven, Connecticut, USASearch for more papers by this author First published: 13 September 2023 https://doi.org/10.1002/phar.2864Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. REFERENCES 1Aronson N, Herwaldt BL, Libman M, et al. Diagnosis and treatment of leishmaniasis: clinical practice guidelines by the Infectious Diseases Society of America (IDSA) and the American Society of Tropical Medicine and Hygiene (ASTMH). Clin Infect Dis. 2016; 63(12): 1539-1557. doi:10.1093/cid/ciw742 10.1093/cid/ciw742 CASPubMedWeb of Science®Google Scholar 2Cornely OA, Maertens J, Bresnik M, et al. Liposomal amphotericin B as initial therapy for invasive mold infection: a randomized trial comparing a high-loading dose regimen with standard dosing (AmBiLoad trial). Clin Infect Dis. 2007; 44(10): 1289-1297. doi:10.1086/514341 10.1086/514341 CASPubMedWeb of Science®Google Scholar Volume43, Issue9September 2023Pages 992-992 ReferencesRelatedInformation

Pyronaridine-artesunate was recently strongly recommended in the 2022 update of the WHO Guidelines for the Treatment of Malaria, becoming the newest artemisinin-based combination therapy (ACT) for both uncomplicated Plasmodium falciparum and Plasmodium vivax malaria. Pyronaridine-artesunate, available as a tablet and paediatric granule formulations, is being adopted in regions where malaria treatment outcome is challenged by increasing chloroquine resistance. Pyronaridine is an old antimalarial agent that has been used for more than 50 years as a blood schizonticide, which exerts its antimalarial activity by interfering with the synthesis of the haemozoin pigment within the Plasmodium digestive vacuole. Pyronaridine exhibits a high blood-to-plasma distribution ratio due to its tendency to accumulate in blood cells. This feature is believed to play a crucial role in its pharmacokinetic (PK) properties and pharmacological activity. The PK characteristics of pyronaridine include rapid oral absorption, large volumes of distribution and low total body clearance, resulting in a long terminal apparent half-life. Moreover, differences in PK profiles have been observed between healthy volunteers and malaria-infected patients, indicating a potential disease-related impact on PK properties. Despite a long history, there is only limited knowledge of the clinical PK and pharmacodynamics of pyronaridine, particularly in special populations such as children and pregnant women. We here provide a comprehensive overview of the clinical pharmacology of pyronaridine in the treatment of malaria.

Background Treatment for post-kala-azar dermal leishmaniasis (PKDL) in Sudan is currently recommended only for patients with persistent or severe disease, mainly because of the limitations of current therapies, namely toxicity and long hospitalization. We assessed the safety and efficacy of miltefosine combined with paromomycin and liposomal amphotericin B (LAmB) for the treatment of PKDL in Sudan. Methodology/principal findings An open-label, phase II, randomized, parallel-arm, non-comparative trial was conducted in patients with persistent (stable or progressive disease for ≥ 6 months) or grade 3 PKDL, aged 6 to ≤ 60 years in Sudan. The median age was 9.0 years (IQR 7.0–10.0y) and 87% of patients were ≤12 years old. Patients were randomly assigned to either daily intra-muscular paromomycin (20mg/kg, 14 days) plus oral miltefosine (allometric dose, 42 days)–PM/MF–or LAmB (total dose of 20mg/kg, administered in four injections in week one) and oral miltefosine (allometric dose, 28 days)–LAmB/MF. The primary endpoint was a definitive cure at 12 months after treatment onset, defined as clinical cure (100% lesion resolution) and no additional PKDL treatment between end of therapy and 12-month follow-up assessment. 104/110 patients completed the trial. Definitive cure at 12 months was achieved in 54/55 (98.2%, 95% CI 90.3–100) and 44/55 (80.0%, 95% CI 70.2–91.9) of patients in the PM/MF and AmB/MF arms, respectively, in the mITT set (all randomized patients receiving at least one dose of treatment; in case of error of treatment allocation, the actual treatment received was used in the analysis). No SAEs or deaths were reported, and most AEs were mild or moderate. At least one adverse drug reaction (ADR) was reported in 13/55 (23.6%) patients in PM/MF arm and 28/55 (50.9%) in LAmB/MF arm, the most frequent being miltefosine-related vomiting and nausea, and LAmB-related hypokalaemia; no ocular or auditory ADRs were reported. Conclusions/significance The PM/MF regimen requires shorter hospitalization than the currently recommended 60-90-day treatment, and is safe and highly efficacious, even for patients with moderate and severe PKDL. It can be administered at primary health care facilities, with LAmB/MF as a good alternative. For future VL elimination, we need new, safe oral therapies for all patients with PKDL. Trial registration ClinicalTrials.gov NCT03399955, https://clinicaltrials.gov/study/NCT03399955 ClinicalTrials.gov ClinicalTrials.gov

Abstract Objectives To improve visceral leishmaniasis (VL) treatment in Eastern Africa, 14- and 28-day combination regimens of paromomycin plus allometrically dosed miltefosine were evaluated. As the majority of patients affected by VL are children, adequate paediatric exposure to miltefosine and paromomycin is key to ensuring good treatment response. Methods Pharmacokinetic data were collected in a multicentre randomized controlled trial in VL patients from Kenya, Sudan, Ethiopia and Uganda. Patients received paromomycin (20 mg/kg/day for 14 days) plus miltefosine (allometric dose for 14 or 28 days). Population pharmacokinetic models were developed. Adequacy of exposure and target attainment of paromomycin and miltefosine were evaluated in children and adults. Results Data from 265 patients (59% ≤12 years) were available for this pharmacokinetic analysis. Paromomycin exposure was lower in paediatric patients compared with adults [median (IQR) end-of-treatment AUC0–24h 187 (162–203) and 242 (217–328) µg·h/mL, respectively], but were both within the IQR of end-of-treatment exposure in Kenyan and Sudanese adult patients from a previous study. Cumulative miltefosine end-of-treatment exposure in paediatric patients and adults [AUCD0–28 517 (464–552) and 524 (456–567) µg·day/mL, respectively] and target attainment [time above the in vitro susceptibility value EC90 27 (25–28) and 30 (28–32) days, respectively] were comparable to previously observed values in adults. Conclusions Paromomycin and miltefosine exposure in this new combination regimen corresponded to the desirable levels of exposure, supporting the implementation of the shortened 14 day combination regimen. Moreover, the lack of a clear exposure–response and exposure–toxicity relationship indicated adequate exposure within the therapeutic range in the studied population, including paediatric patients.

Previously, we developed a pharmacokinetic-pharmacodynamic model of allopurinol, oxypurinol, and biomarkers, hypoxanthine, xanthine, and uric acid, in neonates with hypoxic-ischemic encephalopathy, in which high initial biomarker levels were observed suggesting an impact of hypoxia. However, the full pharmacodynamics could not be elucidated in our previous study. The current study included additional data from the ALBINO study (NCT03162653) placebo group, aiming to characterize the dynamics of hypoxanthine, xanthine, and uric acid in neonates with hypoxic-ischemic encephalopathy. Neonates from the ALBINO study who received allopurinol or placebo mannitol were included. An extended population pharmacokinetic-pharmacodynamic model was developed based on the mechanism of purine metabolism, where synthesis, salvage, and degradation via xanthine oxidoreductase pathways were described. The initial level of the biomarkers was a combination of endogenous turnover and high disease-related amounts. Model development was accomplished by nonlinear mixed-effects modeling (NONMEM®, version 7.5). In total, 20 neonates treated with allopurinol and 17 neonates treated with mannitol were included in this analysis. Endogenous synthesis of the biomarkers reduced with 0.43

Vincristine, a chemotherapeutic agent that extensively binds to β-tubulin, is commonly dosed at 1.4–2.0 mg/m2 capped at 2 mg. For infants, doses vary from 0.025–0.05 mg/kg or 50–80% of the mg/m2 dose. However, evidence for lower doses in infants compared to older children is lacking. This study was conducted to unravel the complex pharmacokinetics of vincristine, including the effects of age, to assist optimal dosing in this population. 206 patients (0.04–33.9 years; 25 patients < 1 years), receiving vincristine, with 1297 plasma concentrations were included. Semi-mechanistic population pharmacokinetic analyses were performed using non-linear mixed effects modelling. A three-compartment model, with one saturable compartment resembling saturable binding to β-tubulin and thus, saturable distribution, best described vincristine pharmacokinetics. Body weight and age were covariates significantly influencing the maximal binding capacity to β-tubulin, which increased with increasing body weight and decreased with increasing age. Vincristine clearance (CL) was estimated as 30.6 L/h (95% confidence interval (CI) 27.6–33.0), intercompartmental CL (Q) as 63.2 L/h (95%CI 57.2–70.1), volume of distribution of the central compartment as 5.39 L (95%CI 4.23–6.46) and of the peripheral compartment as 400 L (95%CI 357–463) (all parameters correspond to a patient of 70 kg). The maximal binding capacity was 0.525 mg (95%CI 0.479–0.602) (for an 18 year old patient of 70 kg), with a high association rate constant, fixed at 1300 /h and a dissociation constant of 11.5 /h. A decrease of vincristine β-tubulin binding capacity with increasing age suggests that young children tolerate higher doses of vincristine.

Allopurinol, an xanthine oxidase (XO) inhibitor, is a promising intervention that may provide neuroprotection for neonates with hypoxic-ischemic encephalopathy (HIE). Currently, a double-blind, placebo-controlled study (ALBINO, NCT03162653) is investigating the neuroprotective effect of allopurinol in HIE neonates. The aim of the current study was to establish the pharmacokinetics (PK) of allopurinol and oxypurinol, and the pharmacodynamics (PD) of both compounds on hypoxanthine, xanthine, and uric acid in HIE neonates. The dosage used and the effect of allopurinol in this population, either or not undergoing therapeutic hypothermia (TH), were evaluated. Forty-six neonates from the ALBINO study and two historical clinical studies were included. All doses were administered on the first day of life. In the ALBINO study (n = 20), neonates received a first dose of allopurinol 20 mg/kg, and, in the case of TH (n = 13), a second dose of allopurinol 10 mg/kg. In the historical cohorts (n = 26), neonates (all without TH) received two doses of allopurinol 20 mg/kg in total. Allopurinol and oxypurinol population PK, and their effects on inhibiting conversions of hypoxanthine and xanthine to uric acid, were assessed using nonlinear mixed-effects modelling. Allopurinol and oxypurinol PK were described by two sequential one-compartment models with an autoinhibition effect on allopurinol metabolism by oxypurinol. For allopurinol, clearance (CL) was 0.83 L/h (95% confidence interval [CI] 0.62–1.09) and volume of distribution (Vd) was 2.43 L (95% CI 2.25–2.63). For metabolite oxypurinol, CL and Vd relative to a formation fraction (fm) were 0.26 L/h (95% CI 0.23–0.3) and 11 L (95% CI 9.9–12.2), respectively. No difference in allopurinol and oxypurinol CL was found between TH and non-TH patients. The effect of allopurinol and oxypurinol on XO inhibition was described by a turnover model of hypoxanthine with sequential metabolites xanthine and uric acid. The combined allopurinol and oxypurinol concentration at the half-maximal XO inhibition was 0.36 mg/L (95% CI 0.31–0.42). The PK and PD of allopurinol, oxypurinol, hypoxanthine, xanthine, and uric acid in neonates with HIE were described. The dosing regimen applied in the ALBINO trial leads to the targeted XO inhibition in neonates treated with or without TH.