Preclinical characterization and target validation of the antimalarial pantothenamide MMV693183

Recent Advances in Diagnostics and Therapeutic Interventions for Drug-Resistant Malaria

The emergence of drug-resistant malarial parasites has been a growing challenge to medical science to safeguard public health in the malaria-endemic regions of the globe. With time, the parasite develops newer resistance mechanisms to defunct the drug's action one after another. Genetic mutation is the prime weapon parasites rely upon to initiate the resistance mechanism in a case-specific manner, following various strategies such as structural changes in the target protein, metabolic alterations, and tweaking the drug-transported channels. In order to combat these resistances, different approaches have evolved among these developing inhibitors against critical parasite enzymes and metabolic pathways, combinatorial/hybrid drug therapies, exploring new drug targets and analogues of existing drugs, use of resistance-reversal agents, drug-repurposing, gene blocking/altering using RNA interference and CRISPR/Cas systems are prominent. However, the effectiveness of these approaches needs to be earnestly monitored for better management of the disease, which demands the development of a reliable diagnosis technique. Several methodologies have been investigated in search of a suitable diagnosis technique, such as in vivo, in vitro, ex vivo drug efficacy studies, and molecular techniques. A parallel effort to transform the efficient method into an inexpensive and portable diagnosis tool for rapid screening of drug resistance malaria among masses in the societal landscape is advocated. This review gives an insight into the historical perspectives of drug-resistant malaria and the recent developments in malaria diagnosis and antimalarial drug discovery. Efforts have been made to update recent strategies formulated to combat and diagnose drug-resistant malaria. Finally, a concluding remark with a future perspective on the subject has been forwarded.

Discovery and mechanism of a highly selective, antifungal acetyl CoA synthetase inhibitor

Acetyl CoA synthetases (ACS) have emerged as drug targets for the treatment of cancer, metabolic diseases as well as fungal and parasitic infections. Although a variety of small molecule ACS inhibitors have been discovered, the systematic optimization of these molecules has been slowed by a lack of structural information regarding their mechanism of inhibition. Through a chemical genetic-based, synthetic lethal screen of the human fungal pathogen Cryptococcus neoformans, we identified an isoxazole-based ACS inhibitor with antifungal activity and exquisite selectivity for the C. neoformans Acs1 relative to human ACSS2 as well as other fungal ACSs. Xray crystallographic characterization of the isoxazole-CnAcs1 complex revealed that the isoxazole functions as an acetyl CoA mimic and occupies both the acetyl- and CoA-binding sites of CnAcs1. Consistent with this novel mode of inhibition, the isoxazoles display uncompetitive inhibition kinetics that are similar to antimalarial ACS inhibitors also proposed to target the CoA binding site. Consequently, these data provide structural and mechanistic insights into the remarkable selectivity of Acetyl CoA pocket-targeting ACS inhibitors. In addition, these data provide strong proof-of-principle that targeting fungal and parasitic ACSs for the development of novel anti-infectives can be achieved with high selectivity and, thereby, low host toxicity.

Antimalarial Drug Discovery from Natural and Synthetic Sources

Malaria remains a significant global health threat despite extensive efforts aimed at its eradication. Numerous challenges persist in eliminating the disease, chief among them being the parasite's ability to mutate, resulting in drug resistance. The discovery of antimalarial drugs has relied on both phenotypic and target-based approaches. While phenotypic screening has identified promising candidates, target-based methods offer a more precise approach by leveraging chemically validated targets and computational tools. Analysis of Plasmodium spp . protein structures reveal druggable targets, offering opportunities for in silico screening. Combining compounds from natural and synthetic sources in a target-based approach accelerates the discovery of new antimalarial agents. This review explores previous breakthroughs in antimalarial drug discovery from natural products and synthetic origins, emphasizing their specific target proteins within Plasmodium species.

Chemical synthesis and enzymatic late-stage diversification of novel pantothenate analogues with antiplasmodial activity

The emergence of resistance to nearly every therapeutic agent directed against malaria-causing Plasmodium parasites emphasises the dire need for new antimalarials. Despite their high potency and low cytotoxicity in vitro, the clinical use of pantothenamides is hindered by pantetheinase-mediated hydrolysis in human serum. We herein report the chemical synthesis and biological activity of a new series of pantothenamide analogues in which the labile amide group is replaced with an isoxazole ring. In addition, we utilised, for the first time, enzymatic late-stage diversification to generate additional isoxazole-containing pantothenamide-mimics. Thirteen novel isoxazole-containing pantothenamide-mimics were generated, several of which display nanomolar antiplasmodial activity against Plasmodium falciparum and are non-toxic to human cells in vitro. Although the derivatives generated via late-stage diversification are less potent than the parent compounds, the most potent still exerted its activity via a mechanism that interferes with the pantothenate-utilising process and appears to be nontoxic to human cells. This increases the appeal of using late-stage diversification to modify pantothenamide-mimics, potentially leading to compounds with improved antiplasmodial and/or pharmacological properties.

MULTIPLE, REDUNDANT CARBOXYLIC ACID TRANSPORTERS SUPPORT MITOCHONDRIAL METABOLISM IN PLASMODIUM FALCIPARUM

The mitochondrion of the deadliest human malaria parasite, Plasmodium falciparum, is an essential source of cellular acetyl-CoA during the asexual blood-stage of the parasite life cycle. Blocking mitochondrial acetyl-CoA synthesis leads to a hypoacetylated proteome and parasite death. We previously determined that mitochondrial acetyl-CoA is primarily synthesized from glucose-derived pyruvate by α-ketoacid dehydrogenases. Here, we asked if inhibiting the import of glycolytic pyruvate across the mitochondrial inner membrane would affect acetyl-CoA production and, thus, could be a potential target for antimalarial drug development. We selected the two predicted mitochondrial pyruvate carrier proteins ( Pf MPC1 and Pf MPC2) for genetic knockout and isotopic metabolite tracing via HPLC-MS metabolomic analysis. Surprisingly, we observed that asexual blood-stage parasites could survive the loss of either or both Pf MPCs with only minor growth defects, despite a substantial reduction in the amount of glucose-derived isotopic labelling into acetyl-CoA. Furthermore, genetic deletion of two additional mitochondrial carboxylic acid transporters - DTC (di/tricarboxylic acid carrier) and YHM2 (a putative citrate/α-ketoglutarate carrier protein) - only mildly affected asexual blood-stage replication, even in the context of Pf MPC deficiency. Although we observed no added impact on the incorporation of glucose carbon into acetyl-CoA in these quadruple knockout mutants, we noted a large decrease in glutamine-derived label in tricarboxylic acid cycle metabolites, suggesting that DTC and YHM2 both import glutamine derivatives into the mitochondrion. Altogether, our results expose redundant routes used to fuel the blood-stage malaria parasite mitochondrion with imported carbon from two major sources - glucose and glutamine.

SIGNIFICANCE

The mitochondrion of malaria parasites generates key molecules, such as acetyl-CoA, that are required for numerous cellular processes. To support mitochondrial biosynthetic pathways, the parasites must transport carbon sources into this organelle. By studying how the mitochondrion obtains pyruvate, a molecule derived from glucose, we have uncovered redundant carbon transport systems that ensure parasite survival in red blood cells. This metabolic redundancy poses a challenge for drug development, as it enables the parasite to adapt and survive by relying on alternative pathways when one is disrupted.

Eliminating malaria transmission requires targeting immature and mature gametocytes through lipoidal uptake of antimalarials

Novel antimalarial compounds targeting both the pathogenic and transmissible stages of the human malaria parasite, Plasmodium falciparum, would greatly benefit malaria elimination strategies. However, most compounds affecting asexual blood stage parasites show severely reduced activity against gametocytes. The impact of this activity loss on a compound's transmission-blocking activity is unclear. Here, we report the systematic evaluation of the activity loss against gametocytes and investigate the confounding factors contributing to this. A threshold for acceptable activity loss between asexual blood stage parasites and gametocytes was defined, with near-equipotent compounds required to prevent continued gametocyte maturation and onward transmission. Target abundance is not predictive of gametocytocidal activity, but instead, lipoidal uptake is the main barrier of dual activity and is influenced by distinct physicochemical properties. This study provides guidelines for the required profiles of potential dual-active antimalarial agents and facilitates the development of effective transmission-blocking compounds.

Another decade of antimalarial drug discovery: New targets, tools and molecules

Malaria remains a devastating but preventable infectious disease that disproportionately affects the African continent. Emerging resistance to current frontline therapies means that not only are new treatments urgently required, but also novel validated antimalarial targets to circumvent cross-resistance. Fortunately, tremendous efforts have been made by the global drug discovery community over the past decade. In this chapter, we will highlight some of the antimalarial drug discovery and development programmes currently underway across the globe, charting progress in the identification of new targets and the development of new classes of drugs to prosecute them. These efforts have been complemented by the development of valuable tools to accelerate target validation such as the NOD scid gamma (NSG) humanized mouse efficacy model and progress in predictive modelling and open-source software. Among the medicinal chemistry programmes that have been conducted over the past decade are those targeting Plasmodium falciparum ATPase4 (ATP4) and acetyl-CoA synthetase (AcAS) as well as proteins disrupting parasite protein translation such as the aminoacyl-tRNA synthetases (aaRSs) and eukaryotic elongation factor 2 (eEF2). The benefits and challenges of targeting Plasmodium kinases will be examined, with a focus on Plasmodium cyclic GMP-dependent protein kinase (PKG), cyclin-dependent-like protein kinase 3 (CLK3) and phosphatidylinositol 4-kinase (PI4K). The chapter concludes with a survey of incipient drug discovery centres in Africa and acknowledges the value of recent international meetings in galvanizing and uniting the antimalarial drug discovery community.

Defining the next generation of severe malaria treatment: a target product profile

BACKGROUND

Severe malaria is a life-threatening infection, particularly affecting children under the age of 5 years in Africa. Current treatment with parenteral artemisinin derivatives is highly efficacious. However, artemisinin partial resistance is widespread in Southeast Asia, resulting in delayed parasite clearance after therapy, and has emerged independently in South America, Oceania, and Africa. Hence, new treatments for severe malaria are needed, and it is prudent to define their characteristics now. This manuscript focuses on the target product profile (TPP) for new treatments for severe malaria. It also highlights preparedness when considering ways of protecting the utility of artemisinin-based therapies.

TARGET PRODUCT PROFILE

Severe malaria treatments must be highly potent, with rapid onset of antiparasitic activity to clear the infection as quickly as possible to prevent complications. They should also have a low potential for drug resistance selection, given the high parasite burden in patients with severe malaria. Combination therapies are needed to deter resistance selection and dissemination. Partner drugs which are approved for uncomplicated malaria treatment would provide the most rapid development pathway for combinations, though new candidate molecules should be considered. Artemisinin combination approaches to severe malaria would extend the lifespan of current therapy, but ideally, completely novel, non-artemisinin-based combination therapies for severe malaria should be developed. These should be advanced to at least phase 2 clinical trials, enabling rapid progression to patient use should current treatment fail clinically. New drug combinations for severe malaria should be available as injectable formulations for rapid and effective treatment, or as rectal formulations for pre-referral intervention in resource-limited settings.

CONCLUSION

Defining the TPP is a key step to align responses across the community to proactively address the potential for clinical failure of artesunate in severe malaria. In the shorter term, artemisinin-based combination therapies should be developed using approved or novel drugs. In the longer term, novel combination treatments should be pursued. Thus, this TPP aims to direct efforts to preserve the efficacy of existing treatments while improving care and outcomes for individuals affected by this life-threatening disease.

Identification of an inhibitory pocket in falcilysin provides a new avenue for malaria drug development

Identification of new druggable protein targets remains the key challenge in the current antimalarial development efforts. Here we used mass-spectrometry-based cellular thermal shift assay (MS-CETSA) to identify potential targets of several antimalarials and drug candidates. We found that falcilysin (FLN) is a common binding partner for several drug candidates such as MK-4815, MMV000848, and MMV665806 but also interacts with quinoline drugs such as chloroquine and mefloquine. Enzymatic assays showed that these compounds can inhibit FLN proteolytic activity. Their interaction with FLN was explored systematically by isothermal titration calorimetry and X-ray crystallography, revealing a shared hydrophobic pocket in the catalytic chamber of the enzyme. Characterization of transgenic cell lines with lowered FLN expression demonstrated statistically significant increases in susceptibility toward MK-4815, MMV000848, and several quinolines. Importantly, the hydrophobic pocket of FLN appears amenable to inhibition and the structures reported here can guide the development of novel drugs against malaria.

Molecular mechanisms of mitochondria-mediated ferroptosis: a potential target for antimalarial interventions

Ferroptosis is an iron-dependent form of regulated cell death characterized by glutathione (GSH) depletion, glutathione peroxidase 4 (GPX4) inactivation, and the build-up of lipotoxic reactive species. Ferroptosis-targeted induction is a promising therapeutic approach for addressing antimalarial drug resistance. In addition to being the primary source of intracellular energy supply and reactive oxygen species (ROS) generation, mitochondria actively participate in diverse forms of regulated cell death, including ferroptosis. Altered mitochondrial morphology and functionality are attributed to ferroptosis. Diverse mitochondria-related proteins and metabolic activities have been implicated in fine-tuning the action of ferroptosis inducers. Herein, we review recent progress in this evolving field, elucidating the numerous mechanisms by which mitochondria regulate ferroptosis and giving an insight into the role of the organelle in ferroptosis. Additionally, we present an overview of how mitochondria contribute to ferroptosis in malaria. Furthermore, we attempt to shed light on an inclusive perspective on how targeting malaria parasites' mitochondrion and attacking redox homeostasis is anticipated to induce ferroptosis-mediated antiparasitic effects.

Highly Regioselective Protecting-Group-Free Synthesis of the Antimalarial Drug MMV693183

MMV693183 is a promising antimalarial drug candidate that works for uncomplicated malaria treatment and resistance management. Herein, we report an efficient and highly regioselective synthesis of MMV693183. This novel synthetic method highlights a three-step route with an overall yield of 46% from readily available starting materials. The key to the success lies in (1) utilizing the subtle difference of the two amino groups in the starting material (S)-propane-1,2-diamine dihydrochloride without amino protection and (2) identifying the L-(+)-tartaric acid as the counter acid for the organic salt formation, yielding the desired regioisomer up to 100:0. The efficient and scalable three-step protocol operates under mild conditions with a high chemo/regioselectivity, providing effective access to MMV693183.

High-throughput screening of compounds targeting RNA editing in Trypanosoma brucei: Novel molecular scaffolds with broad trypanocidal effects

Mitochondrial uridine insertion/deletion RNA editing, catalyzed by a multiprotein complex (editosome), is essential for gene expression in trypanosomes and Leishmania parasites. As this process is absent in the human host, a drug targeting this mechanism promises high selectivity and reduced toxicity. Here, we successfully miniaturized our FRET-based full-round RNA editing assay, which replicates the complete RNA editing process, adapting it into a 1536-well format. Leveraging this assay, we screened over 100,000 compounds against purified editosomes derived from Trypanosoma brucei, identifying seven confirmed primary hits. We sourced and evaluated various analogs to enhance the inhibitory and parasiticidal effects of these primary hits. In combination with secondary assays, our compounds marked inhibition of essential catalytic activities, including the RNA editing ligase and interactions of editosome proteins. Although the primary hits did not exhibit any growth inhibitory effect on parasites, we describe eight analog compounds capable of effectively killing T. brucei and/or Leishmania donovani parasites within a low micromolar concentration. Whether parasite killing is - at least in part - due to inhibition of RNA editing in vivo remains to be assessed. Our findings introduce novel molecular scaffolds with the potential for broad antitrypanosomal effects.

Antimalarial drug discovery: progress and approaches

Recent antimalarial drug discovery has been a race to produce new medicines that overcome emerging drug resistance, whilst considering safety and improving dosing convenience. Discovery efforts have yielded a variety of new molecules, many with novel modes of action, and the most advanced are in late-stage clinical development. These discoveries have led to a deeper understanding of how antimalarial drugs act, the identification of a new generation of drug targets, and multiple structure-based chemistry initiatives. The limited pool of funding means it is vital to prioritize new drug candidates. They should exhibit high potency, a low propensity for resistance, a pharmacokinetic profile that favours infrequent dosing, low cost, preclinical results that demonstrate safety and tolerability in women and infants, and preferably the ability to block Plasmodium transmission to Anopheles mosquito vectors. In this Review, we describe the approaches that have been successful, progress in preclinical and clinical development, and existing challenges. We illustrate how antimalarial drug discovery can serve as a model for drug discovery in diseases of poverty.

Starving the Beast: Limiting Coenzyme A Biosynthesis to Prevent Disease and Transmission in Malaria

Malaria parasites must acquire all necessary nutrients from the vertebrate and mosquito hosts to successfully complete their life cycle. Failure to acquire these nutrients can limit or even block parasite development and presents a novel target for malaria control. One such essential nutrient is pantothenate, also known as vitamin B5, which the parasite cannot synthesize de novo and is required for the synthesis of coenzyme A (CoA) in the parasite. This review examines pantothenate and the CoA biosynthesis pathway in the human-mosquito-malaria parasite triad and explores possible approaches to leverage the CoA biosynthesis pathway to limit malaria parasite development in both human and mosquito hosts. This includes a discussion of sources for pantothenate for the mosquito, human, and parasite, examining the diverse strategies used by the parasite to acquire substrates for CoA synthesis across life stages and host resource pools and a discussion of drugs and alternative approaches being studied to disrupt CoA biosynthesis in the parasite. The latter includes antimalarial pantothenate analogs, known as pantothenamides, that have been developed to target this pathway during the human erythrocytic stages. In addition to these parasite-targeted drugs, we review studies of mosquito-targeted allosteric enzymatic regulators known as pantazines as an approach to limit pantothenate availability in the mosquito and subsequently deprive the parasite of this essential nutrient.

Sermé S, Bolscher JM, T. G. Huijs T, S. Coulibaly A, Sombié S, Ouédraogo N, Diarra A, Zongo S, Guelbéogo WM, Nébié I, Sirima SB, Tiono AB, Pietro A, Collins KA, Dechering KJ, Bousema T. Assessment of the transmission blocking activity of antimalarial compounds by membrane feeding assays using natural Plasmodium falciparum gametocyte isolates from West-Africa

Antimalarial drugs that can block the transmission of Plasmodium gametocytes to mosquito vectors would be highly beneficial for malaria elimination efforts. Identifying transmission-blocking drugs currently relies on evaluation of their activity against gametocyte-producing laboratory parasite strains and would benefit from a testing pipeline with genetically diverse field isolates. The aims of this study were to develop a pipeline to test drugs against P. falciparum gametocyte field isolates and to evaluate the transmission-blocking activity of a set of novel compounds. Two assays were designed so they could identify both the overall transmission-blocking activity of a number of marketed and experimental drugs by direct membrane feeding assays (DMFA), and then also discriminate between those that are active against the gametocytes (gametocyte killing or sterilizing) or those that block development in the mosquito (sporontocidal). These DMFA assays used venous blood samples from naturally infected Plasmodium falciparum gametocyte carriers and locally reared Anopheles gambiae s.s. mosquitoes. Overall transmission-blocking activity was assessed following a 24 hour incubation of compound with gametocyte infected blood (TB-DMFA). Sporontocidal activity was evaluated following addition of compound directly prior to feeding, without incubation (SPORO-DMFA); Gametocyte viability was retained during 24-hour incubation at 37°C when gametocyte infected red blood cells were reconstituted in RPMI/serum. Methylene-blue, MMV693183, DDD107498, atovaquone and P218 showed potent transmission-blocking activity in the TB-DMFA, and both atovaquone and the novel antifolate P218 were potent inhibitors of sporogonic development in the SPORO-DMA. This work establishes a pipeline for the integral use of field isolates to assess the transmission-blocking capacity of antimalarial drugs to block transmission that should be validated in future studies.

A versatile Plasmodium falciparum reporter line expressing NanoLuc enables highly sensitive multi-stage drug assays

Transgenic luciferase-expressing Plasmodium falciparum parasites have been widely used for the evaluation of anti-malarial compounds. Here, to screen for anti-malarial drugs effective against multiple stages of the parasite, we generate a P. falciparum reporter parasite that constitutively expresses NanoLuciferase (NanoLuc) throughout its whole life cycle. The NanoLuc-expressing P. falciparum reporter parasite shows a quantitative NanoLuc signal in the asexual blood, gametocyte, mosquito, and liver stages. We also establish assay systems to evaluate the anti-malarial activity of compounds at the asexual blood, gametocyte, and liver stages, and then determine the 50% inhibitory concentration (IC₅₀) value of several anti-malarial compounds. Through the development of this robust high-throughput screening system, we identify an anti-malarial compound that kills the asexual blood stage parasites. Our study highlights the utility of the NanoLuc reporter line, which may advance anti-malarial drug development through the improved screening of compounds targeting the human malarial parasite at multiple stages.

Recent advances in measurement of metabolic clearance, metabolite profile and reaction phenotyping of low clearance compounds

INTRODUCTION

Low metabolic clearance is usually a highly desirable property of drug candidates in order to reduce dose and dosing frequency. However, measurement of low clearance can be challenging in drug discovery. A number of new tools have recently been developed to address the gaps in the measurement of intrinsic clearance, identification of metabolites, and reaction phenotyping of low clearance compounds.

AREAS COVERED

The new methodologies of low clearance measurements are discussed, including the hepatocyte relay, HepatoPac®, HμREL®, and spheroid systems. In addition, metabolite formation rate determination and in vivo allometric scaling approaches are covered as alternative methods for low clearance measurements. With these new methods, measurement of ~ 20-fold lower limit of intrinsic clearance can be achieved. The advantages and limitations of each approach are highlighted.

EXPERT OPINION

Although several novel methods have been developed in recent years to address the challenges of low clearance, these assays tend to be time and labor intensive and costly. Future innovations focusing on developing systems with high enzymatic activities, ultra-sensitive universal quantifiable detectors, and artificial intelligence will further enhance our ability to explore the low clearance space.

Susceptibility of Ugandan Plasmodium falciparum Isolates to the Antimalarial Drug Pipeline

Malaria, especially Plasmodium falciparum infection, remains an enormous problem, and its treatment and control are seriously challenged by drug resistance. New antimalarial drugs are needed. To characterize the Medicines for Malaria Venture pipeline of antimalarials under development, we assessed the ex vivo drug susceptibilities to 19 compounds targeting or potentially impacted by mutations in P. falciparum ABC transporter I family member 1, acetyl-CoA synthetase, cytochrome b, dihydroorotate dehydrogenase, elongation factor 2, lysyl-tRNA synthetase, phenylalanyl-tRNA synthetase, plasmepsin X, prodrug activation and resistance esterase, and V-type H+ ATPase of 998 fresh P. falciparum clinical isolates collected in eastern Uganda from 2015 to 2022. Drug susceptibilities were assessed by 72-h growth inhibition (half-maximum inhibitory concentration [IC50]) assays using SYBR green. Field isolates were highly susceptible to lead antimalarials, with low- to midnanomolar median IC50s, near values previously reported for laboratory strains, for all tested compounds. However, outliers with decreased susceptibilities were identified. Positive correlations between IC50 results were seen for compounds with shared targets. We sequenced genes encoding presumed targets to characterize sequence diversity, search for polymorphisms previously selected with in vitro drug pressure, and determine genotype-phenotype associations. We identified many polymorphisms in target genes, generally in <10% of isolates, but none were those previously selected in vitro with drug pressure, and none were associated with significantly decreased ex vivo drug susceptibility. Overall, Ugandan P. falciparum isolates were highly susceptible to 19 compounds under development as next-generation antimalarials, consistent with a lack of preexisting or novel resistance-conferring mutations in circulating Ugandan parasites. IMPORTANCE Drug resistance necessitates the development of new antimalarial drugs. It is important to assess the activities of compounds under development against parasites now causing disease in Africa, where most malaria cases occur, and to determine if mutations in these parasites may limit the efficacies of new agents. We found that African isolates were generally highly susceptible to the 19 studied lead antimalarials. Sequencing of the presumed drug targets identified multiple mutations in these genes, but these mutations were generally not associated with decreased antimalarial activity. These results offer confidence that the activities of the tested antimalarial compounds now under development will not be limited by preexisting resistance-mediating mutations in African malaria parasites.

Potent acyl-CoA synthetase 10 inhibitors kill Plasmodium falciparum by disrupting triglyceride formation

Identifying how small molecules act to kill malaria parasites can lead to new "chemically validated" targets. By pressuring Plasmodium falciparum asexual blood stage parasites with three novel structurally-unrelated antimalarial compounds (MMV665924, MMV019719 and MMV897615), and performing whole-genome sequence analysis on resistant parasite lines, we identify multiple mutations in the P. falciparum acyl-CoA synthetase (ACS) genes PfACS10 (PF3D7_0525100, M300I, A268D/V, F427L) and PfACS11 (PF3D7_1238800, F387V, D648Y, and E668K). Allelic replacement and thermal proteome profiling validates PfACS10 as a target of these compounds. We demonstrate that this protein is essential for parasite growth by conditional knockdown and observe increased compound susceptibility upon reduced expression. Inhibition of PfACS10 leads to a reduction in triacylglycerols and a buildup of its lipid precursors, providing key insights into its function. Analysis of the PfACS11 gene and its mutations point to a role in mediating resistance via decreased protein stability.

New targets for antimalarial drug discovery

Phenotypic screening methods have placed numerous preclinical candidates into the antimalarial drug-discovery pipeline. As more chemically validated targets become available, efforts are shifting to target-based drug discovery. Here, we briefly review some of the most attractive targets that have been identified in recent years.

Recent metabolomic developments for antimalarial drug discovery

Malaria is a parasitic disease that remains a global health issue, responsible for a significant death and morbidity toll. Various factors have impacted the use and delayed the development of antimalarial therapies, such as the associated financial cost and parasitic resistance. In order to discover new drugs and validate parasitic targets, a powerful omics tool, metabolomics, emerged as a reliable approach. However, as a fairly recent method in malaria, new findings are timely and original practices emerge frequently. This review aims to discuss recent research towards the development of new metabolomic methods in the context of uncovering antiplasmodial mechanisms of action in vitro and to point out innovative metabolic pathways that can revitalize the antimalarial pipeline.