Efficacy and safety of the six-dose regimen of artemether-lumefantrine in pediatrics with uncomplicated Plasmodium falciparum malaria: a pooled analysis of individual patient data

Patient data from eight clinical trials were pooled and analyzed to study the efficacy and safety of the six-dose versus four-dose regimen of artemether-lumefantrine (coartemether; Coartem) in children weighing 5-25 kg. A total of 544 patients with uncomplicated P. falciparum malaria (six-dose: 343; four-dose: 201), matched for demographic and baseline characteristics and individual coartemether doses were included in the analysis. Analysis of day 28 cure rate based on the intention-to-treat and evaluable populations yielded corrected cure rates for the six-dose regimen of 93% and 96% compared with 61% and 76%, respectively, for the four-dose regimen (P < 0.0001 for both comparisons). Similarly high cure rates were achieved with the six-dose regimen in non-immune infants weighing as little as 5 kg. The six- and four-dose regimens were equally well tolerated. The main finding of this analysis is that the six-dose regimen of coartemether is safe and more efficacious than the four-dose regimen in children.     

Successful treatment of Plasmodium falciparum malaria with a six-dose regimen of artemether-lumefantrine versus quinine-doxycycline in the Western Amazon region of Brazil

This randomized, open-label study compared a three-day, six-dose regimen of artemether-lumefantrine with a five-day, 19-dose regimen of quinine-doxycycline for the treatment of Plasmodium falciparum malaria in the western Amazon region of Brazil. All patients remained hospitalized during their treatment and the study assessments were scheduled daily from the start of treatment (day 0) through day 6. By day 3, the percentage of infected patients was 0% in the artemether-lumefantrine group and 48.8% in the quinine-doxycycline group. Median parasite clearance time was significantly shorter in the artemether-lumefantrine group (two days) compared with the quinine-doxycycline group (three days) (P < 0.0001). Two patients in the quinine-doxycycline group left the study early because of treatment ineffectiveness or adverse event. Adverse events were reported by 91.5% of the study participants, most of which were mild in severity and/or not considered related to study treatment. Artemether-lumefantrine was shown to be an efficacious, safe, and convenient treatment for P. falciparum malaria in a highly drug-resistant region of South America.     

Therapeutic efficacy of artemether-lumefantrine for the treatment of uncomplicated Plasmodium falciparum malaria in Bangladesh

Bangladesh faces increasing levels of chloroquine resistance, and drug sensitivity to sulfadoxine-pyremethamine is already compromised. Therefore, the Ministry of Health recently changed the national treatment guidelines to artemisinin-based combination therapies. The purpose of this study was to determine the baseline therapeutic efficacy of artemether-lumefantrine used as a six-dose regimen for the treatment of uncomplicated Plasmodium falciparum malaria. Sixty-seven patients were enrolled in the study; the cure rate in a 42-day follow-up after an adjustment by polymerase chain reaction was 94.3%. The treatment led to rapid fever (mean +/- SD = 25.82 +/- 12.14 hours) and parasite (30.36 +/- 19.43 hours) clearance. These data suggest that artemether-lumefantrine is a highly efficacious and well-tolerated treatment for uncomplicated P. falciparum malaria in Bangladesh.     

Efficacy and safety of the six-dose regimen of artemether-lumefantrine for treatment of uncomplicated Plasmodium falciparum malaria in adolescents and adults: a pooled analysis of individual patient data from randomized clinical trials

To demonstrate the superiority of the six-dose over the four-dose regimen of artemether-lumefantrine (co-artemether, Coartem) in patients >12 years, data from 11 randomized clinical trials were pooled and analyzed. A total of 1368 patients with uncomplicated Plasmodium falciparum malaria (six-dose: 598; four-dose: 770) were included in the analysis, together with 717 patients treated with comparators. Analysis of the 28-day cure rate based on the ITT and evaluable populations yielded corrected cure rates for the six-dose regimen of 87% and 97% compared with 74% and 87%, respectively, with the four-dose regimen (P<0.0001, for both comparisons). For mefloquine/artesunate, the most frequently used comparator, cure rates were 87% and 99%, respectively. The six-dose regimen was well tolerated and not markedly different to the four-dose regimen. The main finding of our analysis is that the six-dose regimen of co-artemether is more effective than the four-dose regimen in adolescents and adults without compromising safety.     

A randomized trial of artesunate-mefloquine versus artemether-lumefantrine for treatment of uncomplicated Plasmodium falciparum malaria in Mali

The choice of appropriate artemisin-based combination therapy depends on several factors (cost, efficacy, safety, reinfection rate, and simplicity of administration). In this study, we tested the hypothesis that artesunate-mefloquine (Artequin) is as efficacious as artemether-lumefantrine (Coartem) in treatment of uncomplicated Plasmodium falciparum malaria. The study was carried out from August 2004 through February 2005 in Kambila, Mali. Subjects with weights >/= 10 kg and uncomplicated malaria were enrolled. Artesunate-mefloquine was given once a day for three days and artemether/lumefantrine twice a day for three days. A total of 470 (235 in each arm) patients were enrolled. The unadjusted 28-day cure rate was higher in artesunate-mefloquine arm than in the artemether-lumefantrine arm (79.7% versus 67.8%; P < 0.004). After correction for reinfection, the 28-day cure rates were similar in the two groups (96.04% versus 96.93%). Artesunate-mefloquine is well-tolerated and is as effective as artemether-lumefantrine for the treatment of P. falciparum malaria. Artesunate-mefloquine also prevented more new infections.     

The antischistosomal efficacies of artesunate-sulfamethoxypyrazine-pyrimethamine and artemether-lumefantrine administered as treatment for uncomplicated, Plasmodium falciparum malaria

Although artemisinin and its derivatives are widely used for the treatment of malaria, they also have antischistosomal activity. In a small study in eastern Sudan, the effects of the treatment of uncomplicated, Plasmodium falciparum malaria with artesunate-sulfamethoxypyrazine-pyrimethamine (AS-SMP) and artemether-lumefantrine (AT-LU) on co-infections with Schistosoma mansoni were therefore investigated. Faecal samples from 14 of the 306 patients screened on presentation, at the start of a clinical trial of antimalarial treatment, were found to contain Schistosoma mansoni eggs. For the treatment of their malaria, the 14 egg-positive cases, who were aged 6-40 years (mean = 13.7 years), were each subsequently treated with three tablets of a fixed combination of AS-SMP, with a 12-h (six patients) or 24-h interval (five patients) between each tablet, or with six doses of AT-LU given over 3 days. When checked 28 and 29 days after the initiation of treatment, all 14 patients were found stool-negative for schistosome eggs. These results indicate that AS-SMP and AT-LU are currently very effective treatments not only for uncomplicated, P. falciparum malaria but also for S. mansoni infections.     

A randomized trial of artesunate-sulfamethoxypyrazine-pyrimethamine versus artemether-lumefantrine for the treatment of uncomplicated Plasmodium falciparum malaria in Mali.

The choice of artemisinin-based combination that is being adopted for malaria treatment in sub-Saharan Africa may depend on several factors, including cost, efficacy, side effects, and simplicity of administration. We tested the hypothesis that artesunate-sulfamethoxypyrazine-pyrimethamine is as efficacious as the four-dose regimen of artemether-lumefantrine for treatment of Plasmodium falciparum malaria. The study was carried out during two transmission seasons (2003 and 2004) in Sotuba, Mali. Participants at least 6 months of age with uncomplicated P. falciparum malaria were randomly assigned to receive artesunate-sulfamethoxypyrazine-pyrimethamine or artemether-lumefantrine. Treatment efficacy was assessed using the World Health Organization 28-day protocol. A total of 606 (303 in each arm) patients were enrolled. The cure rate was higher for artesunate-sulfamethoxypyrazine-pyrimethamine than for artemether-lumefantrine (98.7% versus 89.6%; P < 0.0001). After correction for cases of re-infection, the cure rates were 100% and 99.0%, respectively (P = 0.08). No serious adverse events occurred. Artesunate-sulfamethoxypyrazine-pyrimethamine is well-tolerated and effective against P. falciparum malaria. It showed an additional benefit of preventing new infections.     

Efficacy of artemether-lumefantrine for the treatment of uncomplicated falciparum malaria in northwest Cambodia

OBJECTIVE: To determine the efficacy of artemether-lumefantrine malaria treatment, as an alternative to artesunate + mefloquine, which is becoming ineffective in some areas of the Thai-Cambodian border. METHODS: Two studies were conducted to monitor the efficacy of artemether-lumefantrine in Sampov Lun referral hospital, Battambang Province, in 2002 and 2003, and one study was conducted to assess the efficacy of mefloquine + artesunate in 2003 for comparison. The studies were performed according to the WHO standardized protocol with a follow-up of 28 days. The therapeutic efficacy tests were complemented with in vitro tests and in 2003, with the measurement of lumefantrine plasma concentration at day 7 for the patients treated with artemether-lumefantrine. RESULTS: A total of 190 patients were included: 55 were treated with artemether-lumefantrine in 2002 (AL2002), 80 with artemether-lumefantrine and food supplementation in 2003 (AL2003) and 55 with artesunate + mefloquine in 2003 (AM2003). With the per-protocol analysis, the cure rate was 71.1% in study AL2002, 86.5% in study AL2003 and 92.4% in study AM2003. All the data were PCR corrected. The artemether-lumefantrine cure rate was unexpectedly low in 2002, but it increased with food supplementation in 2003. There was a significant difference (P = 0.02) in lumefantrine plasma concentrations between adequate clinical and parasitological responses and treatment failure cases. In vitro susceptibility to lumefantrine was reduced for isolates sampled from patients presenting with treatment failure, but the difference was not statistically different from isolates sampled from patients who were successfully treated. CONCLUSION: Treatment failure cases of artemether-lumefantrine are most probably because of low levels of lumefantrine blood concentration. Further investigations are necessary to determine whether resistance of Plasmodium falciparum isolates to lumefantrine is present in the region.     

Efficacy and safety of artemether-lumefantrine in the treatment of acute, uncomplicated Plasmodium falciparum malaria: a pooled analysis

Randomized trials have confirmed the efficacy and safety of artemether-lumefantrine (AL) for treatment of uncomplicated Plasmodium falciparum malaria. Data from seven studies supported by Novartis (1996-2007), including 647 adults (> 16 years of age, 83.3% completed the study) and 1,332 children (≤ 16 years of age, 89.3% completed the study) with microscopically confirmed uncomplicated P. falciparum malaria and treated with the recommended regimen of AL, were pooled. The 28-day polymerase chain reaction-corrected parasitologic cure rate (primary efficacy endpoint) was 97.1% (495 of 510) in adults and 97.3% (792 of 814) in children (evaluable population). Gametocytemia prevalence after day was 4.2% (23 of 554) in adults and 0.9% (8 of 846) in children. No noteworthy safety signals were observed. Serious adverse events occurred in 1.4% of the adults and 1.3% of the children. This study is the largest data set to date assessing AL therapy for treatment of acute uncomplicated P. falciparum malaria. Artemether-lumefantrine showed high cure rates and rapid resolution of parasitemia, fever, and gametocytemia in adults and children, and showed an excellent safety and tolerability profile.     

Comparison of artemether-lumefantrine with sulfadoxine-pyrimethamine for the treatment of uncomplicated falciparum malaria in eastern Nepal

Because available data suggest that resistance of Plasmodium falciparum to sulfadoxine-pyrimethamine (SP) is increasing in Nepal, an open-label, parallel-group efficacy/safety study was conducted in 99 Nepalese patients with uncomplicated falciparum malaria randomized 2:1 to artemetherlumefantrine (AL) or SP. Efficacy was assessed from clinical and microscopic evidence of treatment failure. Four SP-treated patients (12.1%; 95% CI, 4.0-29.1%) redeveloped parasitemia during the 28-day follow-up versus 0% (95% CI, 0-6.9%) in the AL group (P = 0.011), a difference that was confirmed by polymerase chain reaction (PCR) analysis of parasite DNA. PCR detected an additional six patients (two SP and four AL) with sub-microscopic gametocytemia or breakthrough parasitemia between Days 14 and 28, suggesting that AL efficacy was lower than estimated by microscopy. Dhfr and dhps mutations were not associated with outcome. AL is more effective than SP for uncomplicated malaria in Nepal, but regular monitoring of its efficacy should be carried out if this combination therapy is introduced.     

Pyrimethamine-sulfadoxine treatment of uncomplicated Plasmodium falciparum malaria in Lao PDR

A 28-day in vivo treatment trial to evaluate the efficacy of pyrimethamine/sulfadoxine (Fansidar, PS) was conducted in 21 Lao patients with uncomplicated Plasmodium falciparum malaria. Sixteen patients (76%) were completely cured with PS without any reappearance of asexual stage parasitemia during the follow-up examination. On the other hand, 5 patients (24%) failed to respond to this trial medication, resulting in recrudescence of asexual stage P. falciparum malaria. PS resistance resulted in higher prevalence of post-treatment gametocytemia, 25% gametocyte carriers among PS sensitive cases versus 75% of the resistant cases. These findings suggest that although the level of PS resistance is still valid for treatment of malaria in the study area of Lao PDR, post-treatment induction of gametocytemia among resistant cases may result an increase in transmission rate of PS resistant falciparum malaria.     

Pharmacokinetic study of artemether-lumefantrine given once daily for the treatment of uncomplicated multidrug-resistant falciparum malaria

BACKGROUND: Adherence to antimalarial drug regimens is improved by simple dosing. If the fixed antimalarial drug combination artemether-lumefantrine (AL) could be given once daily, this should improve adherence and thus effectiveness and lower the risk of selecting for resistance. METHODS: In an open randomized study, 43 patients with uncomplicated falciparum malaria were given equivalent doses of AL with 200 ml flavoured milk either as the conventional twice-daily regimen or as a single daily dose for 3 days. The primary end point was a comparison of the areas under the plasma lumefantrine concentration-time curves (AUC). Secondary end points were the day 42 polymerase chain reaction (PCR)-adjusted cure rates and the tolerability profiles. RESULTS: Lumefantrine pharmacokinetic profiles were obtained for 36 patients. The AUC((0-->infinity)) of the once-daily regimen was 30% lower than that in the conventional regimen (P = 0.011) with a median (range) value of 306 (114-5781) microg/ml h, compared with 432 (308-992) microg/ml h. There was no significant difference in the peak plasma concentrations reached. PCR-adjusted cure rate estimates at day 42 of follow-up were 94% (95% CI: 84-100) in the six-dose arm and 85% (70-100) in the three-dose arm (P = 0.3). CONCLUSION: Artemether-lumefantrine efficacy is reduced by once-daily dosing, because absorption of lumefantrine is dose limited. At currently recommended doses, this antimalarial should be given twice daily in a 3-day regimen, with food containing fat.     

Therapeutic efficacy of artemether-lumefantrine and artesunate-mefloquine for treatment of uncomplicated Plasmodium falciparum malaria in Luang Namtha Province, Lao People's Democratic Republic

The efficacy of the six-dose regimen of artemether-lumefantrine was compared with the combination of artesunate and mefloquine in a randomised, comparative trial in Luang Namtha Province, Northern Laos. Of 1033 screened patients, 201 were positive for Plasmodium falciparum; 108 patients of all age groups (2-66 years) with acute, uncomplicated P. falciparum malaria were enrolled in the study, 100 of whom were followed-up for 42 days. Fifty-three patients received artemether-lumefantrine and 55 received artesunante-mefloquine. Both drug combinations induced rapid clearance of parasites and malaria symptoms; there was no significant difference in the initial therapeutic response parameters. Both regimes were well tolerated. After 42 days, cure rates were 93.6% (95% CI = 82.5-98.7%; 44 of 47 patients) for artemether-lumefantrine and 100% (95% CI = 93.3-100.0%; 53 of 53 patients) for artesunate-mefloquine. The results show the excellent efficacy and tolerability of both artemether-lumefantrine and artesunate-mefloquine in Northern Laos.     

Proguanil plus sulfamethoxazole in the treatment of uncomplicated Plasmodium falciparum malaria

In a malaria endemic area of Brazil where P. falciparum is highly resistant to chloroquine and Fansidar, we conducted an in vivo study to evaluate the therapeutic response of proguanil plus sulfametoxazole against Plasmodium falciparum malaria. Twenty-five adult subjects with uncomplicated P. falciparum malaria received supervised drug administration and were followed for 28 days in an inpatient hospital or in a malaria free-transmission area. The therapeutic regimen was proguanil 100 mg BID plus sulfamethoxazole 1,000 mg BID for 7 days. Of those who took all medications (n=21), 17 (81%) were cured. Recrudescent parasitemia during follow-up occurred in four (19%) patients on days 14, 19, 20 and 21 after beginning of treatment. The remaining four (16%) subjects did not complete their therapeutic regimen because the incidence of side effects. Considering the shortage of falciparum malaria therapeutic options and the urgent need for new regimens to deal with the spread of drug resistant P. falciparum, one might consider the study results as a lead to study analogous compounds, hopefully with fewer adverse reactions.     

Randomized comparison of amodiaquine plus sulfadoxine-pyrimethamine, artemether-lumefantrine, and dihydroartemisinin-piperaquine for the treatment of uncomplicated Plasmodium falciparum malaria in Burkina Faso.

BACKGROUND: Combination antimalarial therapy is advocated to improve treatment efficacy and limit selection of drug-resistant parasites. We compared the efficacies of 3 combination regimens in Bobo-Dioulasso, Burkina Faso: amodiaquine plus sulfadoxine-pyrimethamine, which was recently shown to be highly efficacious at this site; artemether-lumefantrine, the new national first-line antimalarial regimen; and dihydroartemisinin-piperaquine (DP), a newer regimen. METHODS: We enrolled 559 patients >or=6 months of age with uncomplicated Plasmodium falciparum malaria and randomized them to the 3 regimens. We analyzed the risk of recurrent parasitemia by day 28 and day 42, both unadjusted and adjusted by PCR methods to distinguish recrudescence and new infection. RESULTS: Complete data were available for 517 (92.5%) of the enrolled subjects. Early treatment failures occurred in 5 patients treated with amodiaquine plus sulfadoxine-pyrimethamine and in 2 patients each treated with the other regimens. The day 28 risk of recurrent parasitemia, unadjusted by genotyping, was significantly higher for patients receiving artemether-lumefantrine than for patients receiving amodiaquine plus sulfadoxine-pyrimethamine (20.1% vs. 6.2%; risk difference, 13.8%; 95% confidence interval, 7.0%-20.7%) or dihydroartemisinin-piperaquine (20.1% vs. 2.2%; risk difference, 17.9%; 95% confidence interval, 11.6%-24.1%). Similar differences were seen for children <5 years of age (54% of the study population) and when outcomes were extended to 42 days. Significant differences were not seen between outcomes for patients receiving amodiaquine plus sulfadoxine-pyrimethamine and outcomes for those receiving dihydroartemisinin-piperaquine. Recrudescences were uncommon (occurring in <5% of patients) in all treatment groups. No serious adverse events were noted. CONCLUSIONS: All regimens were highly efficacious in clearing infection, but considering the risks of recurrent malaria after therapy, the amodiaquine plus sulfadoxine-pyrimethamine and dihydroartemisinin-piperaquine regimens were more efficacious than the artemether-lumefantrine regimen (the new national regimen in Burkina Faso) for the treatment of uncomplicated P. falciparum malaria.     

Prolonged selection of pfmdr1 polymorphisms after treatment of falciparum malaria with artemether-lumefantrine in Uganda

We compared the prevalence of key pfmdr1 alleles between pretreatment Plasmodium falciparum parasite isolates and parasites that emerged after treatment of uncomplicated malaria in a longitudinal cohort of Ugandan children. The pfmdr1 86N, 184F, and 1246D alleles were selected after treatment with artemether-lumefantrine, but not after artesunate-amodiaquine or amodiaquine-sulfadoxine-pyrimethamine. Remarkably, selection persisted in infections presenting up to about 60 days after treatment with artemether-lumefantrine. Thus, parasites selected for decreased drug sensitivity can appear long after predicted exposure to antimalarial drugs. Continued surveillance of the clinical efficacy and in vitro activity of new combination therapies is warranted.     

Emergence and clearance of gametocytes in uncomplicated Plasmodium falciparum malaria

We reviewed the records of 1,175 patients with uncomplicated Plasmodium falciparum malaria to determine the prevalence of gametocytemia. All patients were admitted and received artemisinin combination therapy. Blood films were checked daily until discharge. Circulating gametocytes were observed in 240 (20.2%) of patients and in most cases (222 of 240, 92.5%) gametocytemia was detected during the first 24 hours after admission. Gametocytes were first seen in 174 cases on admission, in 24 cases at 12 hours, and in 24 cases at 24 hours. The longest interval between admission and first appearance of gametocytes was 192 hours. The median gametocyte clearance time was 163 hours (range = 12-806) in the 219 patients in whom gametocytemia resolved. However, 21 patients (9.8%) still had gametocytemia on discharge. Gametocytemia generally is present within the first 24 hours after admission, and emerges in only 1.9% of patients later on during treatment with artemisinin.     

Comparative efficacy of aminoquinoline-antifolate combinations for the treatment of uncomplicated falciparum malaria in Kampala,Uganda

Resistance to chloroquine (CQ) requires its replacement as first-line therapy for uncomplicated malaria in much of Africa. Combination therapy may improve efficacy and delay the selection of resistant malaria parasites. Combinations of sulfadoxine-pyrimethamine (SP) with 4-aminoquinolines offer affordable and available alternatives to CQ. We conducted a randomized, single-blinded trial to compare the efficacy of SP monotherapy with combinations of SP and either CQ or amodiaquine (AQ) for the treatment of uncomplicated falciparum malaria in patients over 6 months of age in Kampala, Uganda. Of the 448 patients enrolled, 428 (95%) completed follow-up. Clinical treatment failure after 14 days occurred in 21/140 (15.0%, 95% CI 9.5-22.0%) SP-treated, 11/152 (7.2%, 95% CI 3.7-12.6%) SP/CQ-treated, and 0/136 (0%, 95% CI 0-2.7%) SP/AQ-treated patients. Combination therapies were safe and offered superior efficacy to SP monotherapy. SP/AQ was the most efficacious. This low-cost combination regimen may provide an optimal alternative to CQ for the treatment of uncomplicated malaria in Uganda.