Safety and efficacy of paromomycin/miltefosine/liposomal amphotericin B combinations for the treatment of post-kala-azar dermal leishmaniasis in Sudan: A phase II, open label, randomized, parallel arm study

Abstract

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.

Fig 1

Patient disposition. AE = Adverse event; AmB = liposomal amphotericin B; EOT = End of treatment; mITT = Modified intention-to-treat; MF = Miltefosine; PM = Paromomycin; PP = Per-protocol. ¹ One patient discontinued the study treatment due to an AE but did not receive rescue treatment and completed the study. ² One patient had two major protocol deviations (exclusion criteria met and poor compliance). ³ Serum potassium <3.5 mmol/L, but within the normal laboratory range.

Fig 2. Kaplan-Meier curve of time to complete cure by treatment arm and overall–mITT set.

Fig 3. PKDL lesion distribution grade over time by treatment arm–mITT set.

AmB = liposomal amphotericin B; MF = Miltefosine; mITT = Modified intention-to-treat; PKDL = Post-kala-azar dermal leishmaniasis; PM = Paromomycin. Note: The grade “none” refers to the absence of lesions in the patients, i.e., the patients are cured.

Fig 4. Median plasma and skin concentrations of miltefosine on days 28 and 42, of paromomycin on day 14, and liposomal amphotericin B on day 7.

(A) Median plasma and skin concentration of miltefosine on day 28 (arm 2) were 28.5 μg/ml and 49 μg/g, respectively, with median skin to plasma concentration ratio calculated at 1.64 (IQR = 0.62–4.35); (B) Median plasma and skin concentration of miltefosine on day 42 (arm 1) were 32.9 μg/ml and 46.7 μg/g, respectively, with median skin to plasma concentration ratio calculated at 1.46 (IQR = 0.57–3.23); (C) Median plasma and skin concentration of paromomycin on day 14 (arm 1, intensive PK cohort) were 40.5 μg/ml and 17.3 μg/g, respectively, with median skin to plasma concentration ratio calculated at 0.44 (IQR = 0.2–1.05); (D) Median plasma and skin concentration of LAmB on day 7 (arm 2) were 55.8 μg/ml and 7.63 μg/g, respectively, with median skin to plasma concentration ratio calculated at 0.11 (IQR = 0.02–0.94).