The initial pharmaceutical development of an artesunate/amodiaquine oral formulation for the treatment of malaria: a public-private partnership

Value regimes and pricing in the pharmaceutical industry: financial capital inflation (hepatitis C) versus innovation and production capital savings for malaria medicines

The idea of this paper is to draw a parallel between two diametrically opposed political economies of medicine that coexist today. The first is embodied in the invention, appropriation, and distribution of antivirals for hepatitis C, particularly sofosbuvir, which was commercialized at an initial price of $85,000 in the United States, €56,000 in France, and $8000 in Brazil. These prices destabilized payers in both the North and the South. The second economy encompasses the invention, industrialization and distribution of new therapeutic combinations for malaria that were commercialized by Sanofi from 2007 onwards at a price of $1 per treatment for public markets. This price was set by a contract negotiated with Médecins sans Frontières. In this paper, I examine the pricing of these 2 classes of drugs, and I argue that the prices synthesize these political economies: they summarize the policy of appropriation of these molecules, aimed at their monopolization or a model of common good; they are referred to economic value regimes designed to optimize the profitability of advanced capital or to increase the accessibility of drugs for public payers and patients; and they are justified or contested by moral economies.

Enhancing the antimalarial activity of artesunate

The global challenge to the treatment of malaria is mainly the occurrence of resistance of malaria parasites to conventionally used antimalarials. Artesunate, a semisynthetic artemisinin compound, and other artemisinin derivatives are currently used in combination with selected active antimalarial drugs in order to prevent or delay the emergence of resistance to artemisinin derivatives. Several methods, such as preparation of hybrid compounds, combination therapy, chemical modification and the use of synthetic materials to enhance solubility and delivery of artesunate, have been employed over the years to improve the antimalarial activity of artesunate. Each of these methods has advantages it bestows on the efficacy of artesunate. This review discussed the various methods employed in enhancing the antimalarial activity of artesunate and delaying the emergence of resistance of parasite to it.

Small volume method for drug release screening using ultrasonic agitation

Drug release testing plays a major role along all parts of the dosage form development and manufacturing process. However, official methods to perform this type of testing are often resource intensive and require highly specialized facilities. Affordable and accessible methods for studying drug release behavior are currently lacking. This work presents a small volume approach to solid dissolution and drug release testing of solid dosage forms using ultrasonic agitation. Cavitation and acoustic streaming were generated by a microprobe horn delivering a 40 kHz acoustic signal into a 50 mL test vessel. These two phenomena resulted in breakdown of and release of drug from tablet samples. Prednisone Performance Verification Tablets were used as model tablets to study the effect of system parameters on the drug release process. The effects of these parameters on the acousto-hydrodynamic environment were studied using streak photography and hydrophone measurements. Drug release behavior showed a slow/fast threshold transition separated by a highly variable regime as a function of the system parameters. Observations from drug release experiments and results from acoust-hydrodynamic characterization experiments suggested that this transition is dominated by acoustic streaming. This method represents a screening method to probe relative differences in dosage form composition and acts as a complimentary approach to official testing methods. The small volume format of this test has potential applications in the study of drug release properties from low-dose and novel solid dosage forms as well as reduced cost and increased accessibility of release testing for post-manufacturing tablet quality screening, a current need in low- and middle-income countries.

Adherence to treatment with artemether-lumefantrine or amodiaquine-artesunate for uncomplicated malaria in children in Sierra Leone: a randomized trial

BACKGROUND

Prompt, effective treatment of confirmed malaria cases with artemisinin-based combination therapy (ACT) is a cornerstone of malaria control. Maximizing adherence to ACT medicines is key to ensuring treatment effectiveness.

METHODS

This open-label, randomized trial evaluated caregiver adherence to co-formulated artemether-lumefantrine (AL) and fixed-dose amodiaquine-artesunate (AQAS) in Sierra Leone. Children aged 6-59 months diagnosed with malaria were recruited from two public clinics, randomized to receive AL or AQAS, and visited at home the day after completing treatment. Analyses were stratified by site, due to differences in participant characteristics and outcomes.

RESULTS

Of the 784 randomized children, 680 (85.6%) were included in the final per-protocol analysis (340 AL, 340 AQAS). Definite adherence (self-reported adherence plus empty package) was higher for AL than AQAS at both sites (Site 1: 79.4% AL vs 63.4% AQAS, odds ratio [OR] 2.16, compared to probable adherence plus probable or definite non-adherence, 95% confidence interval [CI] 1.34-3.49; p = 0.001; Site 2: 52.1% AL vs 37.5% AQAS, OR 1.53, 95% CI 1.00-2.33, p = 0.049). However, self-reported adherence (ignoring drug package inspection) was higher for both regimens at both sites and there was no strong evidence of variation by treatment (Site 1: 96.6% AL vs 95.9% AQAS, OR 1.19, 95% CI 0.39-3.63, p = 0.753; Site 2: 91.5% AL vs 96.4% AQAS, OR 0.40, 95% CI 0.15-1.07, p = 0.067). In Site 2, correct treatment (correct dose + timing + duration) was lower for AL than AQAS (75.8% vs 88.1%, OR 0.42, 95% CI 0.23-0.76, p = 0.004). In both sites, more caregivers in the AQAS arm reported adverse events (Site 1: 3.4% AL vs 15.7% AQAS, p < 0.001; Site 2: 15.2% AL vs 24.4% AQAS, p = 0.039).

CONCLUSIONS

Self-reported adherence was high for both AL and AQAS, but varied by site. These results suggest that each regimen has potential disadvantages that might affect adherence; AL was less likely to be taken correctly at one site, but was better tolerated than AQAS at both sites. Measuring adherence to anti-malarials remains challenging, but important. Future research should focus on comparative studies of new drug regimens, and improving the methodology of measuring adherence.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT01967472. Retrospectively registered 18 October 2013, https://clinicaltrials.gov/ct2/show/NCT01967472.

A New Handheld Device for the Detection of Falsified Medicines: Demonstration on Falsified Artemisinin-Based Therapies from the Field

Poor-quality medicines are a major problem for health-care systems in resource-poor settings as identifying falsified medicines requires a complex laboratory infrastructure such as a Medicines Quality Control Laboratory. We report here an evaluation of a low-cost, handheld near-infrared spectrometer (NIRS) device by analyzing a library of artemisinin-based combination therapy (ACT) medicines to determine its usefulness as a drug-screening tool. The “SCiO” research prototype device was used to collect NIR spectra of a library of ACT and artesunate monotherapy medicine samples previously collected in Bioko Island and Equatorial Guinea and Kintampo, Ghana. The quality of these samples had been categorized as falsified, substandard, and quality assured based on the amount of stated active pharmaceutical ingredients detected using high-performance liquid chromatography photodiode array. Numerical analyses were performed on the NIR spectra to assess the usefulness of NIR to identify falsified and substandard medicines. The NIRS device was successful at detecting falsified medicines in all cases where the library contained both quality assured and falsified medicines of the same stated brand of medicines. The NIRS device was successful at identifying substandard amounts of artesunate but not amodiaquine in the ACT samples (N = 15) of artesunate–amodiaquine. This work reveals that this low-cost, portable NIRS device is promising for screening ACTs for falsified samples and could enable widespread drug screening at all points of the health system.

Fixed-Dose Artesunate-Amodiaquine Combination vs Chloroquine for Treatment of Uncomplicated Blood Stage P. vivax Infection in the Brazilian Amazon: An Open-Label Randomized, Controlled Trial

In the Brazilian Amazon, the artesunate–amodiaquine combination was more effective in preventing Plasmodium vivax recurrence. With a favorable safety profile, this antimalarial treatment proved to be a good first-line alternative. Chloroquine resistance is probably underestimated in the area.

Background.

Despite increasing evidence of the development of Plasmodium vivax chloroquine (CQ) resistance, there have been no trials comparing its efficacy with that of artemisinin-based combination therapies (ACTs) in Latin America.

Methods.

This randomized controlled trial compared the antischizontocidal efficacy and safety of a 3-day supervised treatment of the fixed-dose combination artesunate-amodiaquine Winthrop^® (ASAQ) versus CQ for treatment of uncomplicated P. vivax infection in Manaus, Brazil. Patients were followed for 42 days. Primary endpoints were adequate clinical and parasitological responses (ACPR) rates at day 28. Genotype-adjustment was performed.

Results.

From 2012 to 2013, 380 patients were enrolled. In the per-protocol (PP) analysis, adjusted-ACPR was achieved in 100% (165/165) and 93.6% (161/172) of patients in the ASAQ and CQ arm (difference 6.4%, 95% CI 2.7%; 10.1%) at day 28 and in 97.4% (151/155) and 77.7% (129/166), respectively (difference 19.7%, 95% CI 12.9%; 26.5%), at day 42. Apart from ITT D28 assessment, superiority of ASAQ on ACPR was demonstrated. ASAQ presented faster clearance of parasitaemia and fever. Based on CQ blood level measurements, CQ resistance prevalence was estimated at 11.5% (95% CI: 7.5-17.3) up to day 42. At least one emergent adverse event (AE) was recorded for 79/190 (41x6%) in the ASAQ group and for 85/190 (44x7%) in the CQ group. Both treatments had similar safety profiles.

Conclusions.

ASAQ exhibited high efficacy against CQ resistant P. vivax and is an adequate alternative in the study area. Studies with an efficacious comparator, longer follow-up and genotype-adjustment can improve CQR characterization.

Clinical Trials Registration. NCT01378286.

Degradation of Artemisinin-Based Combination Therapies Under Tropical Conditions

Poor quality antimalarials, including falsified, substandard, and degraded drugs, are a serious health concern in malaria-endemic countries. Guidelines are lacking on how to distinguish between substandard and degraded drugs. “Forced degradation” in an oven was carried out on three common artemisinin-based combination therapy (ACT) brands to detect products of degradation using liquid chromatography mass spectrometry and help facilitate classification of degraded drugs. “Natural aging” of 2,880 tablets each of ACTs artemether/lumefantrine and artesunate/amodiaquine was undertaken to evaluate their long-term stability in tropical climates. Samples were aged in the presence and absence of light on-site in Ghana and in a stability chamber (London), removed at regular intervals, and analyzed to determine loss of the active pharmaceutical ingredients (APIs) over time and detect products of degradation. Loss of APIs in naturally aged tablets (both in Ghana and the pharmaceutical stability chamber) was 0–7% over 3 years (∼12 months beyond expiry) with low levels of degradation products detected. Using this developed methodology, it was found that a quarter of ACTs purchased in Enugu, Nigeria (concurrent study), that would have been classified as substandard, were in fact degraded. Presence of degradation products together with evidence of insufficient APIs can be used to classify drugs as degraded.

High adherence to malaria treatment: promising results of an adherence study in South Kivu, Democratic Republic of the Congo

BACKGROUND

In resource-poor settings, treatment adherence is a major determinant of response to anti-malarial drugs as most are taken at home without medical supervision. Evidence on adherence to artemisinin-based combination therapy (ACT) is limited. The study aimed to measure adherence and identify reasons for non-adherence to a 3-day, fixed-dose combination (FDC) of artesunate-amodiaquine (ASAQ), the first-line treatment for uncomplicated malaria in the Médecins Sans Frontières project in the Shabunda Health Zone, South Kivu, Democratic Republic of Congo, a highly malarious and conflict-affected area.

METHODS

The study took place in the health centres/outpatient departments of the Shabunda general hospital, the quarter Mbangayo, and participant households. Patients prescribed FDC ASAQ were visited at home on the day after their regimen finished and asked to complete an adherence questionnaire. Patients/caretakers were also interviewed when exiting the outpatient department to understand their attitude towards FDC ASAQ and assess the quality of the prescribing process.

RESULTS

148 patients/caretakers completed the adherence questionnaire: 11.5 % (17/148, 95 % CI 7-17) had ≥1 tablet left at the time of the home visit and were defined as certainly non-adherent; 13.5 % (20/148, 95 % CI 8-19) were probably non-adherent; thus total non-adherence was 25.0 % (37/148, 95 % CI 18-32). 75 % (111/148, 95 % CI 68-82) were defined as probably adherent. In exit interviews, 87.5 % (105/120) knew they had malaria or could name the correct signs/symptoms. 89 % (107/120) could identify FDC ASAQ as anti-malarials among all tablets given and correctly repeat the intake instructions given at the outpatient department.

CONCLUSIONS

This is the first study to assess adherence to an FDC of ACT under real treatment conditions in a context of high instability. High quality prescribing of anti-malarials at health centre level and patient adherence to the correct intake of ACT were possible in this setting. Adherence to treatment regimen requires careful and constant monitoring which might be better guaranteed at health centre rather than community level. It could, nevertheless, be a precondition to the successful introduction of home- or community based management of malaria.

The Pharmaceutical Commons: Sharing and Exclusion in Global Health Drug Development

In the last decade, the organization of pharmaceutical research on neglected tropical diseases has undergone transformative change. In a context of perceived "market failure," the development of new medicines is increasingly handled by public-private partnerships. This shift toward hybrid organizational models depends on a particular form of exchange: the sharing of proprietary assets in general and of intellectual property rights in particular. This article explores the paradoxical role of private property in this new configuration of global health research and development. Rather than a tool to block potential competitors, proprietary assets function as a lever to attract others into risky collaborative ventures; instead of demarcating public and private domains, the sharing of property rights is used to increase the porosity of that boundary. This reimagination of the value of property is connected to the peculiar timescape of global health drug development, a promissory orientation to the future that takes its clearest form in the centrality of "virtual" business models and the proliferation of strategies of deferral. Drawing on the anthropological literature on inalienable possessions, we reconsider property's traditional exclusionary role and discuss the possibility that the new pharmaceutical "commons" proclaimed by contemporary global health partnerships might be the precursor of future enclosures.

An enzymatic platform for the synthesis of isoprenoid precursors

The isoprenoid family of compounds is estimated to contain ∼65,000 unique structures including medicines, fragrances, and biofuels. Due to their structural complexity, many isoprenoids can only be obtained by extraction from natural sources, an inherently risky and costly process. Consequently, the biotechnology industry is attempting to genetically engineer microorganisms that can produce isoprenoid-based drugs and fuels on a commercial scale. Isoprenoid backbones are constructed from two, five-carbon building blocks, isopentenyl 5-pyrophosphate and dimethylallyl 5-pyrophosphate, which are end-products of either the mevalonate or non-mevalonate pathways. By linking the HMG-CoA reductase pathway (which produces mevalonate) to the mevalonate pathway, these building block can be synthesized enzymatically from acetate, ATP, NAD(P)H and CoA. Here, the enzymes in these pathways are used to produce pathway intermediates and end-products in single-pot reactions and in remarkably high yield, ∼85%. A strategy for the regio-specific incorporation of isotopes into isoprenoid backbones is developed and used to synthesize a series of isotopomers of diphosphomevalonate, the immediate end-product of the mevalonate pathway. The enzymatic system is shown to be robust and capable of producing quantities of product in aqueous solutions that meet or exceed the highest levels achieved using genetically engineered organisms in high-density fermentation.

Population pharmacokinetics of mefloquine, administered as a fixed-dose combination of artesunate-mefloquine in Indian patients for the treatment of acute uncomplicated Plasmodium falciparum malaria

Background

Fixed-dose combinations of artemisinin combination therapy are strongly recommended to facilitate drug administration and compliance. New fixed-dose combinations must nevertheless be evaluated in relevant populations in terms of efficacy and pharmacokinetics.

Methods

A single-arm, open-label, clinical trial was performed in Indian patients with acute uncomplicated Plasmodium falciparum malaria to investigate the efficacy and the pharmacokinetics of mefloquine when combined with artesunate in a fixed-dose combination (400/200 mg of mefloquine base/artesunate). The pharmacokinetic analysis was performed using a population approach.

Results

Seventy-seven patients were included in the study. Mefloquine pharmacokinetics obeys a two-compartment model with first-order absorption and elimination. Mean parameter estimates (% inter-individual variability) were as follows: 0.16 h^-1 (75%) for the absorption rate constant, 1.13 L/h (30%) for the apparent plasma clearance, 271 L (21%) for the apparent central distribution volume, 344 L (54%) for the apparent peripheral distribution volume, and 1.43 L/h for the apparent distribution clearance. These values were consistent with the pharmacokinetic results described in Thai patients. No significant covariate was found for clearance. Body weight explained the inter-individual variability of the apparent central and peripheral distribution volumes. The PCR-adjusted efficacy of the treatment was 100%.

Conclusions

The lack of significant covariate explaining the inter-individual variability of mefloquine clearance, combined with the excellent efficacy, supports the use of the standard 200/400 mg of artesunate-mefloquine fixed-dose combination in Indian patients with uncomplicated P. falciparum malaria.

Trial Registration

Clinical Trial Registration: ISRCTN70618692

The global pipeline of new medicines for the control and elimination of malaria

Over the past decade, there has been a transformation in the portfolio of medicines to combat malaria. New fixed-dose artemisinin combination therapy is available, with four different types having received approval from Stringent Regulatory Authorities or the World Health Organization (WHO). However, there is still scope for improvement. The Malaria Eradication Research agenda identified several gaps in the current portfolio. Simpler regimens, such as a single-dose cure are needed, compared with the current three-day treatment. In addition, new medicines that prevent transmission and also relapse are needed, but with better safety profiles than current medicines. There is also a big opportunity for new medicines to prevent reinfection and to provide chemoprotection. This study reviews the global portfolio of new medicines in development against malaria, as of the summer of 2012. Cell-based phenotypic screening, and 'fast followers' of clinically validated classes, mean that there are now many new classes of molecules starting in clinical development, especially for the blood stages of malaria. There remain significant gaps for medicines blocking transmission, preventing relapse, and long-duration molecules for chemoprotection. The nascent pipeline of new medicines is significantly stronger than five years ago. However, there are still risks ahead in clinical development and sustainable funding of clinical studies is vital if this early promise is going to be delivered.

Clinical tolerability of artesunate-amodiaquine versus comparator treatments for uncomplicated falciparum malaria: an individual-patient analysis of eight randomized controlled trials in sub-Saharan Africa

BACKGROUND

The widespread use of artesunate-amodiaquine (ASAQ) for treating uncomplicated malaria makes it important to gather and analyse information on its tolerability.

METHODS

An individual-patient tolerability analysis was conducted using data from eight randomized controlled clinical trials conducted at 17 sites in nine sub-Saharan countries comparing ASAQ to other anti-malarial treatments. All patients who received at least one dose of the study drug were included in the analysis. Differences in adverse event (AE) and treatment emergent adverse event (TEAE) were analysed by Day 28.

RESULTS

Of the 6,179 patients enrolled (74% <5 years of age), 50% (n = 3,113) received ASAQ, 20% (n = 1,217) another ACT, and 30% (n = 1,849) a non-ACT (combination or single-agent) treatment. Overall, 8,542 AEs were recorded. The proportion of patients experiencing at least one gastro-intestinal AE on ASAQ was 43% (and higher than that with artemether-lumefantrine and dihydroartemisinin-piperaquine at two sites), and was 23% for any other AEs (not different from other treatments). Specifically, the risk of diarrhoea, vomiting, cough and weakness was lower with artemether-lumefantrine; artemether-lumefantrine and dihydroartemisinin-piperaquine carried a higher risk of pruritus, chloroquine-SP had a higher risk of nausea. Parasitological recurrence increased the risk of occurrence of any AE. No other difference was detected. Comparing AE to TEAE in patients who had pre-treatment occurrence and grades of intensity recorded, AEs were significantly more related to the pre-treatment prevalence of the symptom (p = 0.001, Fisher test); AEs overestimated TEAEs by a factor ranging from none to five-fold. The overall incidence of serious AEs (SAEs) with ASAQ was nine per 1,000 (29/3,113) and mortality was one per 1,000 (three deaths, none drug-related); both were similar to other treatments.

CONCLUSION

ASAQ was comparatively well-tolerated. Safety information is important, and must be collected and analysed in a standardized way. TEAEs are a more objective measure of treatment-induced toxicity.

Capillary electrophoresis for the assay of fixed-dose combination tablets of artesunate and amodiaquine

Background

Quality control of drugs in formulations is still a major challenge in developing countries. For the quality control of artesunate and amodiaquine tablets in fixed-dose combination, only liquid chromatographic methods have been proposed in the literature. There are no capillary electrophoretic methods reported for the determination of these active substances, although this technique presents several advantages over liquid chromatography (long lifetime, low price of the capillary, low volumes of electrolyte consumption) in addition to simplicity. In this paper, a reliable capillary electrophoresis method has been developed and validated for the quality control of these drugs in commercial fixed-dose combination tablets.

Methods

Artesunate and amodiaquine hydrochloride in bilayer tablets were determined by micellar electrokinetic capillary chromatography (MEKC). Analytes were extracted from tablets by sonication with a solvent mixture phosphate buffer pH 7.0-acetonitrile containing benzoic acid as internal standard. Separation was carried out on Beckman capillary electrophoresis system equipped with fused silica capillary, 30 cm long (20 cm to detector) × 50 μm internal diameter, using a 25 mM borate buffer pH 9.2 containing 30 mM sodium dodecyl sulfate as background electrolyte, a 500 V cm⁻¹ electric field and a detection wavelength of 214 nm.

Results

Artesunate, amodiaquine and benzoic acid were separated in 6 min. The method was found to be reliable with respect to specificity,linearity of the calibration line (r² > 0.995), recovery from synthetic tablets (in the range 98–102%), repeatability (RSD 2–3%, n = 7 analytical procedures). Application to four batches of commercial formulations with different dosages gave content in good agreement with the declared content.

Conclusion

The MEKC method proposed is reliable for the determination of artesunate and amodiaquine hydrochloride in fixed-dose combination tablets. The method is well-suited for drug quality control and detection of counterfeit or substandard medicines.

Innovative public-private partnerships to maximize the delivery of anti-malarial medicines: lessons learned from the ASAQ Winthrop experience

Background

This case study describes how a public-private partnership initiated to develop a new anti-malarial combination, ASAQ Winthrop, has evolved over time to address issues posed by its effective deployment in the field.

Case description

In 2002, DNDi created the FACT project to develop two fixed-dose combinations, artesunate-amodiaquine and artesunate-mefloquine, to meet the WHO anti-malarial treatment recommendations and international regulatory agencies approval standards. In 2002, Sanofi-aventis had started a development programme for a fixed-dose combination of artesunate and amodiaquine, to replace its co-blister combination. DNDi and sanofi-aventis joined forces in 2004, with the objective of developing within the shortest possible time frame a non-patented, affordable and easy to use fixed-dose combination of artesunate and amodiaquine adapted to the needs of patients, in particular, those of children. The partners developed Coarsucam^®/Artesunate Amodiaquine Winthrop^® ("ASAQ Winthrop") which was prequalified by the WHO in 2008. Additional partnerships have since been established by DNDi and sanofi-aventis to ensure: 1) the adoption of this new medicine by malaria-endemic countries, 2) its appropriate usage through a broad range of information tools, and 3) the monitoring of its safety and efficacy in the field through an innovative Risk Management Plan.

Discussion and evaluation

The partnership between DNDi and sanofi-aventis has enabled the development and pre-qualification of ASAQ Winthrop in a short timeframe. As a result of the multiple collaborations established by the two partners, as of late 2010, ASAQ Winthrop was registered in 30 sub-Saharan African countries and in India, with over 80 million treatments distributed in 21 countries. To date, 10 clinical studies, involving 3432 patients with ASAQ Winthrop were completed to document efficacy and safety issues identified in the Risk Management Plan.

Conclusions

The speed at which ASAQ Winthrop was adopted in the field shows that this drug fits the needs of patients and health authorities. It also demonstrates the power of partnerships that combine different sets of strengths and skills, and that evolve to include additional actors to meet new global health challenges for poverty-related diseases.