Estimated distribution of malaria cases among children in sub-Saharan Africa by specified age categories using data from the Global Burden of Diseases 2019.

BACKGROUND: Children in sub-Saharan Africa (SSA) remain the most vulnerable to malaria and malaria mortality. This study estimated the disease burden and distribution of Plasmodium falciparum malaria among children with age categories (0 to < 2 years, 2 to < 6 years, 6 to < 12 years, ≥ 12 years) in SSA. METHODS: Data on the number of cases and incidence rates of P. falciparum malaria by age group from the Institute of Health Metrics and Evaluation (GBD 2019) for 11 countries in SSA was employed in this study. The best-fitting distribution of P. falciparum malaria cases by prespecified age categories was derived using a combination of a Log-normal and Weibull distribution. RESULTS: Plasmodium falciparum malaria was 15.4% for ages 0 to < 2 years, 30.5% for 2 to < 6 years, 17.6% for 6 to < 12 years, and 36.5% for ≥ 12 years based on data from countries in SSA. The results have important implications for the current drive by the FDA and EMA to ensure the representativeness of real-world populations in clinical trials evaluating the safety and efficacy of medication exposure. CONCLUSIONS: The theoretical distributions of P. falciparum malaria will help guide researchers in ensuring that children are appropriately represented in clinical trials and other interventions aiming to address the current burden of malaria in SSA.

Ganaplacide (KAF156) plus lumefantrine solid dispersion formulation combination for uncomplicated Plasmodium falciparum malaria: an open-label, multicentre, parallel-group, randomised, controlled, phase 2 trial.

BACKGROUND: Emergence of drug resistance demands novel antimalarial drugs with new mechanisms of action. We aimed to identify effective and well tolerated doses of ganaplacide plus lumefantrine solid dispersion formulation (SDF) in patients with uncomplicated Plasmodium falciparum malaria. METHODS: This open-label, multicentre, parallel-group, randomised, controlled, phase 2 trial was conducted at 13 research clinics and general hospitals in ten African and Asian countries. Patients had microscopically-confirmed uncomplicated P falciparum malaria (>1000 and <150 000 parasites per µL). Part A identified the optimal dose regimens in adults and adolescents (aged ≥12 years) and in part B, the selected doses were assessed in children (≥2 years and <12 years). In part A, patients were randomly assigned to one of seven groups (once a day ganaplacide 400 mg plus lumefantrine-SDF 960 mg for 1, 2, or 3 days; ganaplacide 800 mg plus lumefantrine-SDF 960 mg as a single dose; once a day ganaplacide 200 mg plus lumefantrine-SDF 480 mg for 3 days; once a day ganaplacide 400 mg plus lumefantrine-SDF 480 mg for 3 days; or twice a day artemether plus lumefantrine for 3 days [control]), with stratification by country (2:2:2:2:2:2:1) using randomisation blocks of 13. In part B, patients were randomly assigned to one of four groups (once a day ganaplacide 400 mg plus lumefantrine-SDF 960 mg for 1, 2, or 3 days, or twice a day artemether plus lumefantrine for 3 days) with stratification by country and age (2 to <6 years and 6 to <12 years; 2:2:2:1) using randomisation blocks of seven. The primary efficacy endpoint was PCR-corrected adequate clinical and parasitological response at day 29, analysed in the per protocol set. The null hypothesis was that the response was 80% or lower, rejected when the lower limit of two-sided 95% CI was higher than 80%. This study is registered with EudraCT (2020-003284-25) and ClinicalTrials.gov (NCT03167242). FINDINGS: Between Aug 2, 2017, and May 17, 2021, 1220 patients were screened and of those, 12 were included in the run-in cohort, 337 in part A, and 175 in part B. In part A, 337 adult or adolescent patients were randomly assigned, 326 completed the study, and 305 were included in the per protocol set. The lower limit of the 95% CI for PCR-corrected adequate clinical and parasitological response on day 29 was more than 80% for all treatment regimens in part A (46 of 50 patients [92%, 95% CI 81-98] with 1 day, 47 of 48 [98%, 89-100] with 2 days, and 42 of 43 [98%, 88-100] with 3 days of ganaplacide 400 mg plus lumefantrine-SDF 960 mg; 45 of 48 [94%, 83-99] with ganaplacide 800 mg plus lumefantrine-SDF 960 mg for 1 day; 47 of 47 [100%, 93-100] with ganaplacide 200 mg plus lumefantrine-SDF 480 mg for 3 days; 44 of 44 [100%, 92-100] with ganaplacide 400 mg plus lumefantrine-SDF 480 mg for 3 days; and 25 of 25 [100%, 86-100] with artemether plus lumefantrine). In part B, 351 children were screened, 175 randomly assigned (ganaplacide 400 mg plus lumefantrine-SDF 960 mg once a day for 1, 2, or 3 days), and 171 completed the study. Only the 3-day regimen met the prespecified primary endpoint in paediatric patients (38 of 40 patients [95%, 95% CI 83-99] vs 21 of 22 [96%, 77-100] with artemether plus lumefantrine). The most common adverse events were headache (in seven [14%] of 51 to 15 [28%] of 54 in the ganaplacide plus lumefantrine-SDF groups and five [19%] of 27 in the artemether plus lumefantrine group) in part A, and malaria (in 12 [27%] of 45 to 23 [44%] of 52 in the ganaplacide plus lumefantrine-SDF groups and 12 [50%] of 24 in the artemether plus lumefantrine group) in part B. No patients died during the study. INTERPRETATION: Ganaplacide plus lumefantrine-SDF was effective and well tolerated in patients, especially adults and adolescents, with uncomplicated P falciparum malaria. Ganaplacide 400 mg plus lumefantrine-SDF 960 mg once daily for 3 days was identified as the optimal treatment regimen for adults, adolescents, and children. This combination is being evaluated further in a phase 2 trial (NCT04546633). FUNDING: Novartis and Medicines for Malaria Venture.

Defining the Antimalarial Activity of Cipargamin in Healthy Volunteers Experimentally Infected with Blood-Stage Plasmodium falciparum.

The spiroindolone cipargamin, a new antimalarial compound that inhibits Plasmodium ATP4, is currently in clinical development. This study aimed to characterize the antimalarial activity of cipargamin in healthy volunteers experimentally infected with blood-stage Plasmodium falciparum Eight subjects were intravenously inoculated with parasite-infected erythrocytes and received a single oral dose of 10 mg cipargamin 7 days later. Blood samples were collected to monitor the development and clearance of parasitemia and plasma cipargamin concentrations. Parasite regrowth was treated with piperaquine monotherapy to clear asexual parasites, while allowing gametocyte transmissibility to mosquitoes to be investigated. An initial rapid decrease in parasitemia occurred in all participants following cipargamin dosing, with a parasite clearance half-life of 3.99 h. As anticipated from the dose selected, parasite regrowth occurred in all 8 subjects 3 to 8 days after dosing and allowed the pharmacokinetic/pharmacodynamic relationship to be determined. Based on the limited data from the single subtherapeutic dose cohort, a MIC of 11.6 ng/ml and minimum parasiticidal concentration that achieves 90% of maximum effect of 23.5 ng/ml were estimated, and a single 95-mg dose (95% confidence interval [CI], 50 to 270) was predicted to clear 109 parasites/ml. Low gametocyte densities were detected in all subjects following piperaquine treatment, which did not transmit to mosquitoes. Serious adverse liver function changes were observed in three subjects, which led to premature study termination. The antimalarial activity characterized in this study supports the further clinical development of cipargamin as a new treatment for P. falciparum malaria, although the hepatic safety profile of the compound warrants further evaluation. (This study has been registered at ClinicalTrials.gov under identifier NCT02543086.).

Liver Enzyme Elevations in Plasmodium falciparum Volunteer Infection Studies: Findings and Recommendations.

Malaria volunteer infection studies (VISs) accelerate new drug and vaccine development. In the induced blood-stage malaria (IBSM) model, volunteers are inoculated with erythrocytes infected with Plasmodium falciparum. Observations of elevated liver enzymes in the IBSM model with new chemical entities (NCEs) promoted an analysis of available data. Data were reviewed from eight IBSM studies of seven different NCEs, plus two studies with the registered antimalarial piperaquine conducted between June 2013 and January 2017 at QIMR Berghofer, Brisbane, Australia. Alanine aminotransferase (ALT) was elevated (> 2.5 times the upper limit of normal [×ULN]) in 20/114 (17.5%) participants. Of these, 8.9% (10/114) had moderate increases (> 2.5-5 × ULN), noted in seven studies of six different NCEs ± piperaquine or piperaquine alone, and 8.9% (10/114) had severe elevations (> 5 × ULN), occurring in six studies of six different NCEs ± piperaquine. Aspartate aminotransferase (AST) was elevated (> 2.5 × ULN) in 11.4% (13/114) of participants, across six of the 10 studies. Bilirubin was > 2 × ULN in one participant. Published data from other VIS models, using sporozoite inoculation by systemic administration or mosquito feeding, also showed moderate/severe liver enzyme elevations. In conclusion, liver enzyme elevations in IBSM studies are most likely multifactorial and could be caused by the model conditions, that is, malaria infection/parasite density and/or effective parasite clearance, or by participant-specific risk factors, acetaminophen administration, or direct hepatotoxicity of the test drug. We make recommendations that may mitigate the risk of liver enzyme elevations in future VISs and propose measures to assist their interpretation, should they occur.

Lung Deposition of Alpha1-Proteinase Inhibitor (Human) (A1-PI[H]) Inhalation Solution Using Two Inhalation Modes of the I-neb Adaptive Aerosol Delivery (AAD) System in Healthy Subjects and Subjects with Cystic Fibrosis.

BACKGROUND: In cystic fibrosis (CF) patients, inhalation of alpha1-proteinase inhibitor (A1-PI) can prevent or slow down persistent infections and reduce the massive ongoing inflammation and excessive levels of NE that destroy the airway epithelium, leading to progressive loss of pulmonary function and death. It is essential for an efficient treatment with inhaled A1-PI that an adequate and reproducible dose is deposited within all regions of the lung. The I-neb AAD System provides two inhalation modes: the Target Inhalation Mode (TIM) and the Tidal Breathing Mode (TBM). Both were compared in this study for their efficiency to deliver A1-PI to the lungs. METHODS: This was a randomized, open label, cross-over study to investigate the lung deposition of A1-PI in 6 healthy subjects (HS) and 15 CF subjects. The primary endpoint was to evaluate the total lung deposition relative to filling dose of A1-PI inhalation solution using the I-neb AAD System in TIM and in TBM. The main secondary endpoints were extra-thoracic deposition, exhaled drug fraction, nebulizer residue, C/P ratio, and variance of pixel counts. Additional exploratory endpoints were total treatment time and the inhalation time. Radiolabeling was performed considering GMP using a commercially available sterile labeling kit. Radiolabeling was validated using NGI data acquired by gamma scintillation and UV spectrometry. RESULTS AND CONCLUSIONS: The intrapulmonary deposition (mean ± SD) in CF subjects was 47.0% ± 6.6% and 46.7% ± 10.3% in TIM and TBM, respectively, and in healthy subjects, 50.0% ± 6.7% and 54.8% ± 7.0% in TIM and TBM, respectively. TIM resulted in an approximately 40% lower treatment time (HS 6.4 min vs. 10.3 min, CF 5.3 min vs. 10.7 min) and less extra-thoracic deposition compared to TBM, and showed a higher residue of drug in the nebulizer, compared to TBM. In both groups, inhalation of a single dose of 77 mg of A1-PI was efficient, safe, and well tolerated using TIM and TBM.

Pentamycin shows high efficacy against Trichomonas vaginalis.

Trichomonas vaginalis is the causative agent of the venereal disease trichomoniasis, which is the most frequent non-viral sexually transmitted disease worldwide. Since the 1960s, metronidazole has been the standard treatment, however an increasing number of cases with metronidazole-resistant strains is being reported. In this study, pentamycin, a polyene antibiotic, was tested for its in vitro efficacy against T. vaginalis using four strains with different metronidazole susceptibilities. It was shown that pentamycin is highly active against T. vaginalis and that the effect is prompt and independent of underlying metronidazole resistance. The effective concentrations (EC values) after 1 h of treatment were in the range 1.74-2.62 µg/mL (EC50) and 4.91-6.51 µg/mL (EC90). Total eradication of trichomonads (EC100) was achieved in all strains by treatment with 15 µg/mL (22 µM) for 1 h or with ≥1 µg/mL (≥1.5 µM) for 24 h. Long-term cultivation (12 months) under permanent drug pressure did not induce stable resistance against pentamycin in any of the strains tested. Pentamycin has been approved for intravaginal use and is a promising candidate for the topical treatment of trichomoniasis.