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%CI: 0.41-0.74) lower capacity for paromomycin saturable reabsorption in renal tubules, and required a 1.44-fold (1.23-1.71) adjustment when relating renal clearance to creatinine-based eGFR. Miltefosine bioavailability in VL patients was lowered by 69% (62-76) at treatment start. Comparing PKDL to VL patients on the same regimen, paromomycin plasma exposures were 0.74-0.87-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.
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.
The parasitic disease visceral leishmaniasis (VL) is most commonly caused by Leishmania donovani in eastern Africa, currently the region with highest burden worldwide. Current treatment for VL comprises the combination of sodium stibogluconate and paromomycin, SSG/PM; this is toxic, painful, and requires hospitalisation and daily injections. Treatments are urgently needed that are safe, effective, and appropriate for use in remote areas.
METHODS
We conducted a phase III open-label randomised non-inferiority trial in Ethiopia, Kenya, Sudan, and Uganda. The trial used a parallel-arm design with two arms, comparing the combination regimen of 20 mg/kg/day paromomycin and allometric miltefosine (MF) for 14 days with the current 17-day standard of care, 20 mg/kg/day SSG and 15 mg/kg/day PM. We enrolled adults and children aged 4-50 years with primary VL, without HIV or severe concomitant disease co-infection. The primary endpoint was definitive cure at 6 months’ follow-up.
ETHICS
This study was approved by the MSF Ethics Review Board and by ethics committees at the Institute of Endemic Diseases, Khartoum, Sudan; Kenya Medical Research Institute, Nairobi, Kenya; Makerere University, Uganda; and the University of Gondar, Ethiopia. Clinicaltrials.gov registry number, NCT03129646.
RESULTS
439 predominantly male (80%) patients aged 4 to 50 years were recruited over a period of 29 months. A similar proportion of patients in the PM/MF and the SSG/PM arms achieved definitive cure at 6-month follow-up in primary efficacy analysis using modified intention-to-treat; mITT; 91.2% cure for PM/MF (97.5% confidence interval, CI, 85-98.6) and 91.8% for SSG/PM (97.5% CI, 85.6-99.2). Non-inferiority was not demonstrated in the mITT population, with the upper limit of the 97.5% CI, 7.4%, slightly exceeding the non-inferiority margin of 7%. However, the per protocol analysis did show non-inferiority, with 92% (97.5% CI, 85-98.5) cure in the PM/MF arm, as compared to 91.7% (97.5% CI, 84.7-98.2) in the SSG/PM arm. Most adverse drug reactions (ADR’s) were mild to moderate. The most common expected ADR’s were MF-related vomiting, and PM-related injection site pain and hypoacusis. ADR’s suggesting SSG-related cardiac toxicity were reported in 6.5% (11/170) of patients in the SSG/PM arm. Eighteen serious adverse events were reported in 13 patients, four of which were considered related to study drugs. Fatality rate in the trial was 0.9% (4/439), with one death judged due to SSG-related cardiotoxicity.
CONCLUSION
The results of this study demonstrate that the 14-day PM/MF regimen achieved a clinically meaningful rate of cure with very similar efficacy to the standard of care, SSG/PM. It was generally well tolerated, with ADR’s as expected, based on the known safety profiles of study drugs. The PM/MF regimen has one fewer painful injection per day, a 3-day shorter treatment duration, and with no risk of SSG-associated life threating cardiotoxicity, as compared to SSG/PM. This regimen may therefore provide a more patient-friendly alternative for adults and children with VL in eastern Africa.
CONFLICTS OF INTEREST
None declared
This study aimed to determine whether paromomycin plus miltefosine (PM/MF) is noninferior to sodium stibogluconate plus paromomycin (SSG/PM) for treatment of primary visceral leishmaniasis in eastern Africa.
METHODS
An open-label, phase 3, randomized, controlled trial was conducted in adult and pediatric patients at 7 sites in eastern Africa. Patients were randomly assigned to either 20 mg/kg paromomycin plus allometric dose of miltefosine (14 days), or 20 mg/kg sodium stibogluconate plus 15 mg/kg paromomycin (17 days). The primary endpoint was definitive cure after 6 months.
RESULTS
Of 439 randomized patients, 424 completed the trial. Definitive cure at 6 months was 91.2% (155 of 170) and 91.8% (156 of 170) in the PM/MF and SSG/PM arms in primary efficacy modified intention-to-treat analysis (difference, 0.6%; 97.5% confidence interval [CI], -6.2 to 7.4), narrowly missing the noninferiority margin of 7%. In the per-protocol analysis, efficacy was 92% (149 of 162) and 91.7% (155 of 169) in the PM/MF and SSG/PM arms (difference, -0.3%; 97.5% CI, –7.0 to 6.5), demonstrating noninferiority. Treatments were well tolerated. Four of 18 serious adverse events were study drug–related, and 1 death was SSG-related. Allometric dosing ensured similar MF exposure in children (< 12 years) and adults.
CONCLUSIONS
PM/MF and SSG/PM efficacies were similar, and adverse drug reactions were as expected given the drugs safety profiles. With 1 less injection each day, reduced treatment duration, and no risk of SSG-associated life-threatening cardiotoxicity, PM/MF is a more patient-friendly alternative for children and adults with primary visceral leishmaniasis in eastern Africa.
CLINICAL TRIALS REGISTRATION
NCT03129646.
The long-term treatment outcome of visceral leishmaniasis (VL) patients with HIV co-infection is complicated by a high rate of relapse, especially when the CD4 count is low. Although use of secondary prophylaxis is recommended, it is not routinely practiced and data on its effectiveness and safety are limited.
METHODS:
A prospective cohort study was conducted in Northwest Ethiopia from August 2014 to August 2017 (NCT02011958). HIV-VL patients were followed for up to 12 months. Patients with CD4 cell counts below 200/μL at the end of VL treatment received pentamidine prophylaxis starting one month after parasitological cure, while those with CD4 count ≥200 cells/μL were followed without secondary prophylaxis. Compliance, safety and relapse-free survival, using Kaplan-Meier analysis methods to account for variable time at risk, were summarised. Risk factors for relapse or death were analysed.
RESULTS:
Fifty-four HIV patients were followed. The probability of relapse-free survival at one year was 50% (95% confidence interval [CI]: 35-63%): 53% (30-71%) in 22 patients with CD4 ≥200 cells/μL without pentamidine prophylaxis and 46% (26-63%) in 29 with CD4 <200 cells/μL who started pentamidine. Three patients with CD4 <200 cells/μL did not start pentamidine. Amongst those with CD4 ≥200 cells/μL, VL relapse was an independent risk factor for subsequent relapse or death (adjusted rate ratio: 5.42, 95% CI: 1.1-25.8). Except for one case of renal failure which was considered possibly related to pentamidine, there were no drug-related safety concerns.
CONCLUSION:
The relapse-free survival rate for VL patients with HIV was low. Relapse-free survival of patients with CD4 count <200cells/μL given pentamidine secondary prophylaxis appeared to be comparable to patients with a CD4 count ≥200 cells/μL not given prophylaxis. Patients with relapsed VL are at higher risk for subsequent relapse and should be considered a priority for secondary prophylaxis, irrespective of their CD4 count.
Visceral leishmaniasis (VL) in human immunodeficiency virus (HIV) co-infected patients requires special case management. AmBisome monotherapy at 40 mg/kg is recommended by the World Health Organization. The objective of the study was to assess if a combination of a lower dose of AmBisome with miltefosine would show acceptable efficacy at the end of treatment.
METHODOLOGY/PRINCIPAL FINDINGS
An open-label, non-comparative randomized trial of AmBisome (30 mg/kg) with miltefosine (100 mg/day for 28 days), and AmBisome monotherapy (40 mg/kg) was conducted in Ethiopian VL patients co-infected with HIV (NCT02011958). A sequential design was used with a triangular continuation region. The primary outcome was parasite clearance at day 29, after the first round of treatment. Patients with clinical improvement but without parasite clearance at day 29 received a second round of the allocated treatment. Efficacy was evaluated again at day 58, after completion of treatment.
Recruitment was stopped after inclusion of 19 and 39 patients in monotherapy and combination arms respectively, as per pre-specified stopping rules. At D29, intention-to-treat efficacy in the AmBisome arm was 70% (95% CI 45–87%) in the unadjusted analysis, and 50% (95% CI 27–73%) in the adjusted analysis, while in the combination arm, it was 81% (95% CI 67–90%) and 67% (95% CI 48–82%) respectively. At D58, the adjusted efficacy was 55% (95% CI 32–78%) in the monotherapy arm, and 88% (95% CI 79–98%) in the combination arm.
No major safety concerns related to the study medication were identified. Ten SAEs were observed within the treatment period, and 4 deaths unrelated to the study medication.
CONCLUSIONS/SIGNIFICANCE
The extended treatment strategy with the combination regimen showed the highest documented efficacy in HIV-VL patients; these results support a recommendation of this regimen as first-line treatment strategy for HIV-VL patients in eastern Africa.
TRIAL REGISTRATION NUMBER
www.clinicaltrials.gov NCT02011958
In 2010, WHO recommended a new first-line treatment for visceral leishmaniasis (VL) in Eastern Africa. The new treatment, a combination of intravenous (IV) or intramuscular (IM) sodium stibogluconate (SSG) and IM paromomycin (PM) was an improvement over SSG monotherapy, the previous first-line VL treatment in the region. To monitor the new treatment's safety and effectiveness in routine clinical practice a pharmacovigilance (PV) programme was developed.
METHODS
A prospective PV cohort was developed. Regulatory approval was obtained in Sudan, Kenya, Uganda and Ethiopia. Twelve sentinel sites sponsored by the Ministries of Health, Médecins Sans Frontières (MSF) and Drugs for Neglected Diseases initiative (DNDi) participated. VL patients treated using the new treatment were consented and included in a common registry that collected demographics, baseline clinical characteristics, adverse events, serious adverse events and treatment outcomes. Six-monthly periodic safety update reports (PSUR) were prepared and reviewed by a PV steering committee.
RESULTS
Overall 3126 patients were enrolled: 1962 (62.7%) from Sudan, 652 (20.9%) from Kenya, 322 (10.3%) from Ethiopia and 190 (6.1%) from Uganda. Patients were mostly male children (68.1%, median age 11 years) with primary VL (97.8%). SSG-PM initial cure rate was 95.1%; no geographical differences were noted. HIV/VL co-infected patients and patients older than 50 years had initial cure rates of 56 and 81.4%, respectively, while 1063 (34%) patients had at least one adverse event (AE) during treatment and 1.92% (n = 60) had a serious adverse event (SAE) with a mortality of 1.0% (n = 32). There were no serious unexpected adverse drug reactions.
CONCLUSIONS
This first regional PV programme in VL supports SSG-PM combination as first-line treatment for primary VL in Eastern Africa. SSG-PM was effective and safe except in HIV/VL co-infected or older patients. Active PV surveillance of targeted safety, effectiveness and key VL outcomes such us VL relapse, PKDL and HIV/VL co-infection should continue and PV data integrated to national and WHO PV databases.