Drug substances for the treatment and prevention of malaria

Abstract

The invention relates to the substances benfo-oxythiamine (B-OT) and / or oxythiamine (OT) as active ingredient of a medicament, in particular a human medicament, for the therapeutic treatment of infections with sporozoa of the genus Plasmodium and the resulting malaria disease in a patient or potential patient.

Description

[0001] The invention relates to substances for use as active ingredients of a medicament for the therapeutic treatment of infections with sporozoa of the genus Plasmodium and the resulting malaria disease in a patient or potential patient.

[0002] Malaria is one of the world's deadliest infectious diseases. According to WHO estimates, in 2021, almost half of the world's population was at risk from malaria, and more than 0.6 million deaths were attributed to malaria. Malaria is caused by parasites of the genus Plasmodium. The two species Plasmodium falciparum and Plasmodium vivax cause most malaria infections in humans. Children under 5 years of age and pregnant women in sub-Saharan Africa are most affected. Every two minutes, a child dies from the effects of malaria. Rapid diagnostic tests and improved prevention through drug prophylaxis had led to a decline in the number of malaria cases starting in 2010. A number of factors have now brought this positive trend of declining case numbers to a halt. A key reason for this is the increasing resistance of Plasmodium to drugs that were previously very effective.Combination therapy with the active ingredient artemisinin is an essential pillar of therapy, especially in severe cases. However, resistance to artemisinin combination therapies is increasingly being identified, and in these cases, no effective treatment options are available for affected malaria patients.

[0003] The increasing global spread of resistance to malaria drugs is hampering the rapid and effective treatment of malaria. Furthermore, climate change could lead to the expansion of malaria-affected areas. The invasion of the Anopheles stephensi mosquito, which can adapt very easily to urban environmental conditions, into previously unaffected or largely unaffected regions poses a major risk. A new anti-malaria drug would be extremely important, but it would also be like looking for a needle in a haystack.

[0004] There is therefore an urgent need to establish new antimalarial drugs. Drugs with novel mechanisms of action are particularly important.

[0005] Unfortunately, many active substances currently in preclinical development or clinical trials are derived from already known drugs and their mode of action, so there is a high risk that resistance to these new malaria drugs will emerge within a short period of time. It is therefore of utmost importance to utilize new chemical structures with new mechanisms of action to minimize the risk of emerging resistance (see also Wells, 2011).

[0006] A key property of a malaria drug is its ability to inhibit the proliferation of Plasmodium in the host organism. The development of human malaria drugs has been and continues to be significantly shaped by the therapeutic approach of finding active ingredients that target targets that are selectively found in Plasmodium but not in the human body. The strategy of developing vaccines against Plasmodium also uses epitopes specific to Plasmodium. This is intended to prevent the vaccination from triggering an autoimmune reaction in the patient's body.

[0007] The current state of malaria control is sobering and extremely dangerous because resistance has now developed against all malaria drugs and there is still no vaccine that provides comprehensive protection against malaria.

[0008] Plasmodium falciparum transketolase (PfTk) plays a crucial role in the proliferation and survival of the parasite. For this reason, and because the amino acid sequence of Plasmodium falciparum transketolase differs significantly from that of human transketolase, PfTk was considered a suitable target in the early 2000s for the development and establishment of inhibitors that specifically inhibit PfTk but not human transketolase. The latter was a mandatory feature of the sought-after inhibitors because human transketolase plays a crucial role in the proliferation and survival of human cells and of humans as a whole, and is particularly crucial for the formation of new immune cells, which are important for the immunological control of Plasmodium.A suitable inhibitor must exclusively inhibit Plasmodium transketolase, but not human transketolase, so that humans do not suffer general disadvantages from the inhibition of their transketolase, and especially from the inhibition of their immune system. To address this challenge, Joshi et al. expressed PfTk as a protein and biochemically investigated it. Based on this, a structural model of PfTk was created and differences in its kinetic properties compared to human (i.e., the host) transketolase were demonstrated. This enabled the authors to significantly facilitate the design of new inhibitors with the potential of an antimalarial drug that only inhibits Plasmodium falciparum transketolase.

[0009] Even more recent publications (see Hasan et al. 2015, Boateng et al. 2020) show that this approach is still relevant in the search for effective antimalarial drugs.

[0010] In a study by a Nigerian research group (Fadare et al. 2021), PfTk was also used to identify specific inhibitors against this transketolase that do not inhibit human transketolase. In this study, the active ingredient LAN, a dinitrophenylhydrazine derivative of lanosterol, was identified. LAN showed better binding to PfTk than its natural cofactor thiamine pyrophosphate (TPP). The active ingredient LAN was tested in vivo for its anti-malarial efficacy using a mouse model with the established anti-malarial drug chloroquine (trade name Resochin®) as a standard. It was found that LAN, at a concentration of 25 mg / kg, exhibited an activity comparable to that of chloroquine (at 10 mg / kg).Even 24 days after administration of the drug, no mortality was observed in the test animals, demonstrating that the active ingredient LAN, as an inhibitor of PfTk, indeed has the potential to be a future antimalarial drug.

[0011] In the 2023 study by Kaushik et al., the focus of research was also PfTk. This research group succeeded in producing PfTk as a recombinant protein. In their study, they investigated the antimalarial effect of extracts from the leaves of the plant Anacardium occidentale L., which are traditionally used to treat malaria. Various extracts were prepared and tested in vitro for their inhibitory effect against the recombinant PfTk enzyme. In addition, the growth-inhibiting activity against cultured P. falciparum parasites in the blood stage was investigated. An aqueous-alcoholic extract of the leaves of A. occidentale (HELA) was used, and different concentrations were initially tested for adverse effects (toxic effects) in mouse and fish embryos.The HELA extract showed very pronounced inhibition of Plasmodium transketolase (75%) and outstanding inhibition of the growth of intra-erythrocytic Plasmodium stages of over 99%. This result is strong evidence that inhibition of Plasmodium transketolase is a very promising approach for establishing a new anti-malarial drug.

[0012] In contrast to the aforementioned studies, the study by Chan et al. (2013) used an active ingredient that does not exhibit selectivity for Plasmodium transketolase, namely oxythiam (OT). Data on the in vivo effect of OT on Plasmodium proliferation were generated using a mouse model in which mice were infected with Plasmodium vinckei vinckei. OT was administered at a concentration of 400 mg per kilogram of body weight per day. On day 5 after infection, Plasmodium proliferation (parasitemia) was approximately 6-fold lower than in mice from the control group, which received water (i.e., no OT). However, OT treatment also led to significant weight loss in the mice. The survival time of the mice treated with OT was only extended from 6 to 8 days. After 8 days, all mice (with or without OT treatment) were dead.In discussing these results, the authors conclude that it is unlikely that oxythiamine will be developed as a standalone antimalarial. They suggest that it could serve as a starting point for the development of new antimalarials targeting the relevant metabolic pathway. They emphasize that new antimalarials, or their active ingredients, must be specific to Plasmodium, because otherwise, as in the case of OT, the host's (human) immune system will be inhibited.

[0013] The publication of this study by Chan et al., and in particular the death of all mice infected with Plasmodium and treated with oxythiamine, led to the discontinuation of the approach of using oxythiamine as an antimalarial drug since 2013. Instead, the research groups attempted to establish drugs that selectively inhibit Plasmodium transketolase. The study by Fadare et al. (loc. cit.), published in 2021 and also conducted in a mouse model, shows that this approach works: In contrast to oxythiamine, in which all Plasmodium-infected mice died or had to be sacrificed, all mice were rescued with the drug LAN, which selectively inhibits Plasmodium transketolase.

[0014] The present invention is based on the object of providing a new active ingredient for use in a medicament for the therapeutic treatment of malaria, preferably an active ingredient which has novel mechanisms of action against the pathogens.

[0015] One solution to this problem consists in the use of benfo-oxythiamine (B-OT) and / or oxythiamine (OT) as the active ingredient of a medicinal product, in particular a human medicinal product, for the therapeutic treatment of infections with sporozoa of the genus Plasmodium and the resulting malaria disease in a patient or potential patient.

[0016] The use of B-OT and / or OT is particularly suitable and intended for symptom-relieving and / or curative treatment, whereby B-OT and / or OT inhibits the development of plasmodia in the patient's host cells, namely the erythrocytes. As a result, the plasmodia remain in the affected erythrocytes (host cells), which, on the one hand, significantly reduces or prevents their spread (via mosquitoes) to other potential patients (host organisms), and, on the other hand, reduces or prevents the suppression of the patient's immune system caused by the plasmodia and / or the erythrocytes they infect.This reduction or removal of suppression results in the activation of the immune system to (i) develop an effective immunological defense reaction by which the plasmodia and / or the erythrocytes infected by them can be eliminated, and (ii) develop an immune response that counteracts the proliferation of plasmodia in the patient during subsequent reinfections with plasmodia. This means that it will elicit an immunological defense reaction or immune response that eliminates the plasmodia and / or the erythrocytes infected by them, or that is suitable and intended to eliminate the plasmodia and / or the erythrocytes infected by them, and that also counteracts the proliferation of plasmodia during subsequent reinfections of the patient.

[0017] The use according to the invention for the purpose of alleviating or curing a diagnosed plasmodia infection and / or malaria disease particularly produces one or more of the following effects in the potential patient, preferably a human: - Inhibiting or preventing the formation of extracellular forms of plasmodia; - cellular immune response against plasmodia; - Activation of the innate immune system, particularly macrophages (phagocytic cells) to eliminate plasmodia by phagocytosis; - humoral immune response (B cell response) against plasmodia antigens; - protective cellular immunity against infection by Plasmodium or against Plasmodium-induced pathology; - Reduction of the severity of symptoms of plasmodia infection and / or malaria; - Increasing the survival time of sick patients.

[0018] The use of B-OT and / or OT is particularly suitable and intended for the preventive (prophylactic, preventative) treatment of potential patients, especially mammals, especially humans. The preventive (preventive) administration of benfo-oxythiamine and / or oxythiamine ensures that, in the event of a plasmodia infection, the development of plasmodia in their host cells in the patient, especially in the erythrocytes, is prevented or greatly reduced, thereby inhibiting their proliferation and causing them to remain in their host cells. This significantly reduces or prevents their spread to other potential patients.As the plasmodia remain (or are essentially "fixed") in the erythrocytes / host cells and the active ingredient reduces immunosuppression, the plasmodia and / or the erythrocytes they infect are effectively presented to the patient's immune system and thus become recognizable. This activates the immune system to generate an immune response that eliminates the plasmodia and / or the erythrocytes they infect. This reduces or prevents the symptoms of a plasmodia infection and / or malaria disease.

[0019] The use of B-OT and / or OT as a preventive (prophylactic, preventative) treatment of potential plasmodia infection and / or malaria disease is also intended according to the invention to provide the patient with permanent immunity against plasmodia. For this purpose, the plasmodia that have penetrated the patient during a plasmodia infection are used and act as a quasi-live vaccine.

[0020] With the preventive (prophylactic, preventive) application of B-OT and / or OT according to the invention for the purpose of avoiding a plasmodia infection and / or malaria disease, in particular one or more of the following effects are induced in the potential patient, preferably a human: - Protection against infections with plasmodia; - Inhibition of extracellular forms of plasmodia; - cellular immune response against plasmodia; - Activation of the innate immune system, particularly macrophages (phagocytic cells) to eliminate plasmodia by phagocytosis; - humoral immune response (B cell response) against plasmodia antigens; - protective cellular immunity against infection by Plasmodium or against Plasmodium-induced pathology; - Reduction or prevention of the symptoms of a plasmodia infection and / or malaria disease.

[0021] The present invention is based on the inventor's new and surprising discovery and finding that plasmodia have developed a similar strategy to cancer cells to grow and multiply in the human body.

[0022] Plasmodia and cancer cells both thrive on the organism by multiplying, often causing such severe damage that the organism / host dies. Both utilize the blood and its nutrients to grow at the expense of the human host. Over the course of evolution, plasmodia and cancer cells have developed a metabolic dualism. This metabolic dualism of plasmodia exhibits striking similarities to the metabolic dualism of tumor cells. In plasmodia, metabolism changes depending on the plasmodial stage. In tumor cells, the metabolic change leads to a transition from benign tumor cells to malignant tumor cells (cancer cells).

[0023] Traits that lead to evolutionary advantages for survival provide a selective advantage. In evolution, these changes, which provide positive advantages, are often achieved through different pathways. An example of an evolutionary advantage that has evolved independently through three different pathways is the locomotion of living organisms by means of flight. Flight was first discovered by insects, then by birds, and finally again by mammals (bats). If a trait is advantageous, then, as with the evolution of flight, convergent developments can occur that lead to the same goal—namely, a selective advantage—in different ways.

[0024] In their evolution, Plasmodia have developed a metabolic pathway independently of mammals that gives them enormous advantages in reproducing within the host. This evolution was also characterized by coevolution with the host, which has led to the metabolism of Plasmodium in humans being significantly different from that of Plasmodium in rodents. This difference was and is largely due to the different diets of humans (mixed diets) and rodents (high fiber content).

[0025] Plasmodium can multiply very rapidly in humans. This is especially true in the intraerythrocytic stage. Rapid multiplication requires an anabolic metabolism capable of rapidly generating large quantities of building blocks for new cell formation.

[0026] Cancer cells also utilize large amounts of glucose from the blood to proliferate. They use it for fermentative metabolism, which, in addition to lactic acid, also generates ribose and acetyl-CoA.

[0027] Intraerythrocytic plasmodia also perform a metabolic process that leads to the uptake of large amounts of glucose from the blood and is used for fermentative metabolism, generating lactic acid, as well as ribose and acetyl-CoA. Glucose uptake by erythrocytes harboring intracellular plasmodia is 100-fold higher than in non-infected erythrocytes.

[0028] In terms of both the starting product and the end products of metabolism, cancer cells and plasmodia-containing erythrocytes behave very similarly. This is a reflection of anabolic metabolism, as this metabolism enables very rapid growth because glucose, the basis for this metabolism, is present in large quantities in the blood, and glucose consumption is made possible by the body's continued supply of glucose.

[0029] In mammals, this glucose-based anabolic metabolism was made possible by the first duplication of the transketolase gene (TKT) during vertebrate evolution and then, through multiple mutations, altering it into the so-called transketolase-like 1 (TKTL1) gene. The protein encoded by this gene, TKTL1, which occurs only in mammals, is largely responsible for the fact that, in this extremely effective anabolic metabolism, not only a transketolase enzyme reaction takes place, which massively increases the formation of ribose, but also the direct formation of acetyl-CoA. Furthermore, it facilitates the formation of lactic acid. The TKTL1 protein controls the cell cycle and forms a heterodimer with the TKT transketolase.This TKTL1 / TKT heterodimer is responsible for the formation of large amounts of ribose via this anabolic pathway even before cell division (100% increase of ribose in the cells), so that ribose is available in sufficient quantities as a building block for DNA replication.

[0030] Until the study by Li et al., published in 2019, experts thought that TKT transketolase was responsible for ribose formation. However, for a "housekeeping" gene / protein such as TKT transketolase, it is neither necessary nor useful to produce large amounts of ribose if DNA duplication is not required. A massive increase in ribose production only makes sense if DNA duplication is to be achieved. The control of ribose production by TKTL1 allows for a very efficient adaptation of ribose production to the current needs of the cells. In parallel, TKTL1 controls overall metabolism in such a way that the glucose flux is redirected from the Embden-Meyerhof pathway to pentose phosphate metabolism and thus to TKTL1 / TKT.

[0031] In addition to ribose, acetyl-CoA is also required as another crucial building block for cell division and cell duplication. The TKTL1 protein also plays a key role in the formation of acetyl-CoA as a building block for new cells: When acetyl-CoA is needed for anabolic purposes such as cell division or cell duplication, TKTL1 is activated and the acetyl-CoA-forming enzyme pyruvate dehydrogenase is simultaneously inhibited. The TKTL1-triggered redirection of glucose flow away from the Embden-Meyerhof pathway and the associated pyruvate dehydrogenase to the pentose phosphate pathway, with TKTL1 as the key enzyme, enables the formation of ribose and acetyl-CoA, as well as other important metabolites for the formation of new cells, in the same metabolic pathway.

[0032] TKTL1 represents the result of convergent evolution, as the so-called phosphoketolase protein also evolved during heterofermentative lactic acid fermentation in lactic acid bacteria. This protein directly forms acetyl-CoA and pyruvate from a C5 sugar, converting pyruvate into lactic acid. With the help of thiamine as a cofactor, both phosphoketolase and TKTL1 transketolase are capable of forming acetyl-CoA from a pentasaccharide without decarboxylation and the associated loss of carbon atoms. In contrast, pyruvate dehydrogenase, with the help of the cofactor thiamine, forms acetyl-CoA through decarboxylation, so that every third carbon atom is lost. For anabolic purposes, acetyl-CoA formation by phosphoketolase enzyme and acetyl-CoA formation by TKTL1 transketolase are therefore superior to acetyl-CoA formation by pyruvate dehydrogenase.

[0033] In addition to acetyl-CoA formation, lactic acid formation via TKTL1 is a key development in the course of mammalian evolution, as this TKTL1-mediated lactic acid formation also occurs when sufficient oxygen is available. Macrophages, for example, utilize this for lactic acid-mediated tissue remodeling / matrix degradation and the resulting suppression of the immune system. TKTL1-mediated lactic acid formation is independent of the lactic acid formation known in mammals via the Embden-Meyerhof pathway, and in contrast, it is not suppressed by oxygen. TKTL1 thus represents the enzymatic basis of the Warburg effect and significantly alters its significance, since not only lactic acid but also acetyl-CoA is a key product of this metabolic pathway.

[0034] In cancer cells, TKTL1 plays a crucial role in suppressing the patient's immune system due to the production of lactic acid. The resulting lactic acid prevents the immune system from attacking the cells and also triggers immunosuppression. This is achieved by arresting certain immune cells (e.g., killer cells) and by activating PD-L1 ("programmed death-ligand 1") in the cancer cell membrane, which triggers immunosuppression.

[0035] In a very similar way, the metabolism of intracellularly growing Plasmodium has evolved to absorb large amounts of glucose and excrete large amounts of lactic acid. This is achieved by not transferring glucose via the Embden-Meyerhof pathway and pyruvate dehydrogenase (which then generates acetyl-CoA, which is utilized in the citric acid cycle), but rather by a thiamine-dependent enzyme that normally degrades branched-chain amino acids, the so-called branched-chain ketodehydrogenase (BCKDH), which converts glucose to form acetyl-CoA.

[0036] From an evolutionary perspective, the metabolic pathways in intraerythrocytic growing Plasmodium and the TKTL1 metabolism in humans, and especially in invasively growing cancer cells, represent the result of a convergent metabolic development based on different enzymes, but having one thing in common: the use of thiamine as a cofactor of these enzymes.

[0037] Thiamine-dependent enzymes allow the cleavage of carbon-carbon bonds. During the evolution of life on Earth, two subfamilies have evolved: thiamine-dependent enzymes, which perform a single-substrate mechanism, and thiamine-dependent enzymes, which perform a two-substrate mechanism.

[0038] In the two-substrate mechanism, a C2 unit is cleaved from a first substrate (S1) during a nucleophilic attack with the aid of thiamine, which initially remains bound to the thiamine. The first substrate then leaves the enzyme and a second substrate (S2) is bound, to which the C2 unit is transferred.

[0039] Transketolases are thiamine-dependent enzymes that operate according to the two-substrate principle, allowing them to convert sugars into other sugars. The formation of the energy-rich compound acetyl-CoA is not involved.

[0040] This is quite different with thiamine-dependent enzymes, which operate using a single-substrate mechanism. Here, in interaction with other enzyme components, acetyl-CoA is formed and decarboxylated. Alternatively, as in the case of phosphoketolase, the single-substrate reaction leads to the formation of acetyl-CoA without decarboxylation. An example of a single-substrate reaction with decarboxylation is pyruvate dehydrogenase (PDH), which catalyzes the decarboxylation of pyruvate to acetyl-CoA and carbon dioxide. The carbon dioxide is lost as gas, and if the cell is pursuing an anabolic program, this represents a loss of valuable carbon atoms.

[0041] If a cell wants to grow on the basis of glucose, i.e. if it wants to convert the carbon atoms from the glucose into new fats or membrane building blocks or other metabolites such as amino acids as effectively as possible, glucose breakdown by means of PDH is an extremely unsuitable method because every third C atom of the glucose, i.e. one third of the total glucose, is lost.

[0042] The TKTL1 gene and the resulting TKTL1 protein enable mammalian cells to perform a phosphoketolase-like enzyme reaction that first emerged early in evolution in heterofermentative lactic acid bacteria. This reaction involves the degradation of a C5 sugar directly into acetyl-CoA and pyruvate. The pyruvate is then converted into lactic acid or reconverted to a C5 sugar. The cell can thus decide how much lactic acid and how much acetyl-CoA is produced. If lactic acid is not needed, 100% of the sugar can be converted into acetyl-CoA without any loss of carbon atoms.

[0043] The advantage of the TKTL1 / phosphoketolase enzyme reaction is of immense importance in an anabolic metabolic situation: 100% of the available glucose can be converted into acetyl-CoA, whereas only two-thirds of the glucose is converted into acetyl-CoA in the PDH reaction. The 33% increase in cell mass possible with the TKTL1 enzyme reaction provided a decisive evolutionary selective advantage for mammals. Only recently, it was shown that TKTL1-mediated acetyl-CoA formation is the basis for the increased neuron formation in the neocortex and the stronger folding of the neocortex cortex in Homo sapiens compared to Neanderthals, and that the TKTL1 enzyme was very likely crucial for the changes in cognitive-intellectual abilities of modern humans.

[0044] The TKTL1 protein thus represents an enzyme that, as a heterodimer with TKT, performs both the classic two-substrate reaction, thus massively increasing ribose formation, and forms acetyl-CoA via a single-substrate reaction. This enables the extremely effective conversion of glucose into the building blocks ribose and acetyl-CoA, thus creating ideal conditions for rapid and efficient growth. At the same time, the formation of lactic acid opens up the possibility of fending off attacks by immune cells and also triggering immunosuppression via PD-L1.

[0045] In the evolution of Plasmodium, a convergent metabolic development has occurred: In the metabolic situation in which rapid and effective synthesis of cell material and proliferation of the Plasmodium is necessary, i.e., in their intraerythrocytic life phase, glucose breakdown is not carried out by the PDH enzyme reaction, but rather by fermentative glucose metabolism, which produces acetyl-CoA and lactic acid. Just as in the TKTL1 metabolism in mammals, a mutation in a thiamine-dependent enzyme in Plasmodium has altered its enzymatic properties such that fermentative glucose metabolism, without the use of pyruvate dehydrogenase, produces acetyl-CoA and lactic acid. The lactic acid is secreted by the erythrocytes, and just as in the TKTL1 metabolism in mammalian cancer cells, this leads to defense against attack by immune cells and systematic immunosuppression.

[0046] Previous research has shown that plasmodia are capable of synthesizing the vitamins they need for growth, with the exception of vitamin B5 (pantothenate). For all other vitamins, plasmodia are not dependent on external uptake, i.e., from host cells or the host organism.

[0047] With regard to vitamin B1, thiamine, all genes encoding enzymes for thiamine biosynthesis are present in the genome of Plasmodium, and the enzymes they encode are capable of producing thiamine (vitamin B1). Nevertheless, Plasmodium utilizes thiamine from the host blood. This saves them the effort of synthesizing their own thiamine and allows them to use the saved resources for other processes necessary for their growth and reproduction. Apparently, the evolution of Plasmodium has led to the establishment of uptake systems for absorbing vitamin B1 from the host, enabling them to grow faster. Due to the selective advantage that the uptake of thiamine from the host's blood provides to Plasmodium, Plasmodium in human erythrocytes predominantly utilize thiamine from human blood for their reproductive metabolism.

[0048] A similar strategy has been developed by pathogenic bacteria such as Pseudomonas aeruginosa, which can produce thiamine themselves but utilize the thiamine from infected humans to grow faster and more effectively. Thiamine uptake from the infected organism thus represents another example of convergent evolution that has led to a selective survival advantage in both bacteria and Plasmodium.

[0049] While most bacteria, fungi, and plants can produce thiamine (vitamin B1) de novo, mammals, including humans, depend exclusively on the intake of thiamine / vitamin B1 through their diet. Since thiamine (vitamin B1) in its active form, thiamine diphosphate (ThDP), is an essential cofactor for the human organism, thiamine is an essential component of human blood and the rest of the body.

[0050] Many patients with Plasmodium infection exhibit thiamine deficiency, which can be explained by the Plasmodium extracting thiamine from the host's blood. Plasmodium, which generally act as parasites, have also developed a parasitic behavior with regard to thiamine: They extract thiamine from the host's blood, thus saving themselves the effort of synthesizing thiamine themselves. This has the significant advantage for the Plasmodium that they save energy and effort for growth and can therefore grow faster.

[0051] The parasitic behavior of plasmodia with regard to the uptake of thiamine from the host's blood opens up a therapeutic option for the control of plasmodia in the blood of the human host organism.

[0052] Humans are omnivores who generally consume very little thiamine. A diet consisting primarily of rice and / or raw fish can lead to a severe thiamine deficiency because hulled rice is one of the few foods that is thiamine-free, and because raw fish contains the enzyme thiaminase, which breaks down thiamine. A severe thiamine deficiency can manifest itself in the form of beri beri, neurodegenerative diseases such as Wernicke-Korsakoff syndrome, or other thiamine deficiency diseases.

[0053] Over the course of their evolution, humans have evolved into omnivores who prefer high-calorie foods with a relatively high protein content (meat and / or fish) and relatively low in indigestible components (fiber). In contrast, rodents such as mice and rats consume foods with a high fiber content.

[0054] Fiber cannot be digested directly. Only with the help of bacteria and single-celled organisms in the cecum do they convert some of the fiber into fermentation and other metabolic products. These include thiamine (vitamin B1), which is produced by bacteria and single-celled organisms.

[0055] The cecum of rodents is very large compared to humans. Rodents such as mice and rats therefore have no problem absorbing sufficient thiamine through their digestive tract, as the thiamine concentration is high due to the thiamine produced by bacteria and single-celled organisms.

[0056] In omnivores with a relatively small cecum and a diet containing little fermentable fiber, such as humans or dogs, the situation with regard to thiamine is completely different. They are fundamentally dependent on very effective intestinal absorption of the thiamine present in their primary diet, as no significant new production of thiamine by bacteria and single-celled organisms increases the amount of thiamine. Due to the low amounts of thiamine in the human diet, absorption systems have developed in the human intestine over the course of evolution that make it possible to absorb thiamine very effectively from food. In contrast, the amounts of thiamine in the intestines of rodents are so high that there was no evolutionary need to develop such effective absorption systems for thiamine.

[0057] These large differences between humans and rodents in the amount of thiamine in the intestine and the different efficiency of thiamine absorption have had serious and very negative consequences for the research and treatment of thiamine-related diseases: Mice and rats are typically used as animal models for in vivo testing and preclinical drug development. The NOAEL (no-observed-adverse-effect level) plays a crucial role here. The NOAEL (no-observed-adverse-effect level) is the experimentally or observationally determined exposure level of an active substance in an organism at which no biologically or statistically significant increase in the frequency or severity of adverse effects is observed. In drug development, the NOAEL of a new drug is determined in laboratory animals, particularly mice and rats, before human trials begin in order to establish a safe starting clinical dose for humans.

[0058] However, the NOAEL values ​​obtained from mice or rats have had a lasting, extremely negative impact on research into thiamine-associated diseases for decades, even over a century. Because the data obtained from mice and rats on thiamine or thiamine derivatives such as oxythiamine are not transferable to humans due to the differences in thiamine intake described above. However, the transfer that has occurred has led to false-negative results, which have led to incorrect conclusions. Ultimately, this has prevented the development and establishment of medications associated with thiamine or those that can be addressed with thiamine derivatives.

[0059] Studies conducted by various research groups have repeatedly shown that mice and rats tolerate high oral doses of oxythiamine over a relatively long period of time. Rais et al. (1999) administered high doses of 500 mg per kg of body weight per day for 4 days and lower doses of 300 mg per kg of body weight per day for 14 days without observing any toxicity. In a subsequent study by another research group (Yang et al. 2010), similar doses of oxythiamine were used as in the study by Rais et al., but the drug was administered orally for a period of up to 5 weeks. No toxicity was observed in this study either. The inventor's own experiments have confirmed this high tolerance of mice and rats to the oral administration of oxythiamine or benfo-oxythiamine (B-OT).

[0060] The active ingredient B-OT (developed by the inventor) is a prodrug that releases oxythiamine in the body. A Phase 1 clinical study and the associated pharmacokinetics showed that B-OT, only oxythiamine, does not appear in the blood. Oxythiamine is released immediately after oral administration, and maximum levels of released oxythiamine can be detected in the blood after 1 to 2 hours. B-OT is the world's first and only inhibitory thiamine derivative to have been successfully evaluated in a Phase 1 clinical trial. Since B-OT is a prodrug that releases oxythiamine (OT), a direct link between OT data and B-OT is possible.

[0061] The inventor's experiments have shown that rats tolerate an oral dose of 1,000 mg of B-OT per kg of body weight for 7 days without toxicity. This confirms the studies described above on the tolerability of high doses of oxythiamine in mice and rats. If these data were extrapolated to humans, this would mean that a human weighing 80 kg could consume 80 grams of B-OT or 77 grams of OT every day for a week without experiencing adverse effects. However, preclinical experiments conducted by the inventor have shown that the high orally administered doses of B-OT, and thus also OT, obtained in mouse and rat experiments are not tolerated by dogs.Due to the above-described major differences in the digestive systems of mixed feeders (human / dog) and rodents and the associated extremely different amounts of naturally occurring thiamine and the absorption systems designed for it, the sensitivity of dogs with regard to B-OT / OT is 1,000 times higher.

[0062] The data on the tolerability of OT in mice and rats therefore do not reflect the situation in dogs. The inventor was able to demonstrate through a Phase I clinical study with healthy volunteers that no serious adverse effects occur when B-OT / OT is administered at a dosage based on the NOAEL values ​​determined in dogs and a calculated adaptation to humans.Increasing the daily oral dose of B-OT to 5 mg (per approximately 80 kg body weight) administered over seven days also did not cause any serious side effects: In both the first part of clinical phase I, in which 0.5 mg to 5 mg of B-OT was administered orally as a single dose on one day (at approximately 80 kg body weight), and the second part of clinical phase I, in which 1 mg of B-OT was administered orally on seven consecutive days, up to a maximum of 5 mg of B-OT (at approximately 80 kg body weight each), no serious side effects were observed. This demonstrates for the first time that B-OT is a dosage form of OT that can be used clinically. Self-experiments by the inventor as well as the use of B-OT in terminal cancer patients and hospitalized coronavirus patients have also provided promising indications of the efficacy of B-OT.

[0063] The therapeutic approach of inhibiting the proliferation of plasmodia in erythrocytes using B-OT and the OT released from it represents a completely new approach in several respects: Oxythiamine is an inhibitory thiamine derivative that, unlike many other thiamine derivatives, differs only slightly from thiamine and is therefore indistinguishable by enzymes that bind thiamine or by transport systems that transport thiamine, meaning it is bound and transported with similar affinity. It is precisely this pronounced similarity between thiamine and oxythiamine that enables the transport systems in the plasmodia membranes to capture oxythiamine (instead of thiamine) from the erythrocytes and transport it into the plasmodium, resulting in thiamine transport from the blood into the erythrocytes and then into the plasmodia. However, even this is not sufficient to inhibit thiamine-dependent enzymes inside the plasmodia, because, just like thiamine, oxythiamine must first be converted into the pyrophosphate form by an enzymatic step.The enzymatic step that converts thiamine to thiamine pyrophosphate (TPP) is carried out by the enzyme thiamine pyrophosphokinase. The high similarity between thiamine and oxythiamine allows thiamine pyrophosphokinase to accept oxythiamine as a substrate and produce oxythiamine pyrophosphate (OTPP). OTPP then competes directly with TPP in the Plasmodium for access to the binding sites of the Plasmodium's thiamine-dependent enzymes, particularly oxoglutarate dehydrogenase, pyruvate dehydrogenase, branched-chain keto acid dehydrogenase (BCKDH), and transketolase.

[0064] The simultaneous inhibition of various enzymes, which in turn are essential in different metabolic pathways, is of enormous importance for the effectiveness of a drug to inhibit Plasmodium. Enzymatic bypass pathways often exist in the metabolism when a specific enzyme is blocked.

[0065] In the case of B-OT / OT, the four thiamine-dependent enzymes oxoglutarate dehydrogenase, pyruvate dehydrogenase, branched-chain keto acid dehydrogenase (BCKDH), and transketolase are simultaneously inhibited. By blocking pyruvate dehydrogenase (in the apicoblast) and oxoglutarate dehydrogenase in the citric acid cycle (in the mitochondria), two metabolic pathways (in two different organelles) are inhibited. Their significance for intraerythrocytic plasmodia growth is relatively minor, as both pathways are rarely utilized. The key effect is the inhibition of transketolase in the pentose phosphate cycle, which inhibits the formation of ribose, so that no more ribose is formed and thus no building blocks are available for the formation of DNA and RNA.By inhibiting BCKDH in the mitochondria, this enzyme, which is crucial for acetyl-CoA production, is inhibited, so that lipid synthesis, but also amino acid metabolism, is significantly inhibited.

[0066] Comparing the convergent metabolic situation in mammalian cells and plasmodia, TKTL1, or the heterodimer with TKT, is the key enzyme in mammalian cells, inhibiting ribose and acetyl-CoA production through its blockade by B-OT / OT. In intraerythrocytic plasmodia, the B-OT / OT-mediated blockade of the two independently acting enzymes BCKDH and transketolase inhibits ribose and acetyl-CoA production. In both cases, however, this prevents the synthesis of two essential building blocks for the formation of new cells. The growth of cancer cells in mammals and the growth of intraerythrocytic plasmodia thus represent two sides of the same coin: Both metabolic pathways are based on mutations in thiamine-dependent enzymes that enable acetyl-CoA formation without decarboxylation and the associated loss of carbon atoms.

[0067] The simultaneous inhibition of the formation of ribose and acetyl-CoA by B-OT / OT thus very effectively blocks the proliferation of plasmodia in erythrocytes.

[0068] Erythrocytes are cells that no longer contain a nucleus and, in this respect, differ dramatically from other cells. Therefore, erythrocytes lack the normal ability to transcribe genes and translate mRNA into protein as needed. In the case of human transketolase in erythrocytes, during erythrocyte formation (during erythropoiesis in the bone marrow), thiamine binds to the newly synthesized transketolase protein via a covalent bond. This creates the functional enzyme consisting of a protein moiety and a cofactor.

[0069] The addition of OT to erythrocytes does not inhibit the transketolase enzyme reaction, as OT is unable to displace the covalently bound thiamine. Therefore, there is no competitive displacement; rather, the timing of transketolase protein synthesis and the presence of the cofactor determine permanent binding. If the transketolase protein is formed and OT instead of thiamine reaches the cofactor binding site of the transketolase protein at this time, the OT is bound. The transketolase proteins formed previously and in the presence of thiamine contain covalently bound thiamine, which can no longer be displaced by the now present OT.

[0070] Therapeutically, this means that the status quo of the host cells' thiamine-dependent enzymes remains protected, allowing the cells to continue functioning, while newly formed cells are subject to strong inhibition by OT. This is precisely a decisive advantage in the treatment of people with Plasmodium infection and Plasmodium proliferation in erythrocytes. Normal (healthy) erythrocytes without Plasmodium infection are protected from the inhibitory effect of OT via the covalent binding of thiamine to the transketolase protein. In Plasmodium-infected erythrocytes, the same applies to the thiamine-dependent erythrocyte enzymes. The thiamine-dependent enzymes of the Plasmodium, however, are inevitably newly formed as the Plasmodium proliferates, and this is where the inhibitory effect of the applied OT takes effect.Although OT does not selectively inhibit Plasmodium transketolase, the covalent binding of thiamine to erythrocyte transketolase results in a de facto selectivity of OT toward inhibition of Plasmodium transketolase. Because OT is not toxic but merely inhibits proliferation, this de facto selectivity applies to almost all cells of the host organism, as most cells and cell types do not proliferate continuously. Many cell types that normally proliferate continuously, such as hair root cells, intestinal epithelial cells, etc., do not need to proliferate continuously. Although their proliferation is inhibited by OT, they can tolerate a temporary pause in proliferation very well. The faster and more efficiently a Plasmodium replicates in erythrocytes, the greater the damaging effect when Benfo-Oxythiamine is applied, and oxythiamine inhibits the Plasmodium enzymes. Benfo-Oxythiamine is therefore also suitable for saving patients who have already reached advanced stages of the disease.

[0071] The following advantages are associated with the inventive use of B-OT / and / or OT: It enables a new malaria therapy based on a novel mode of action and with extremely high protection against resistance development. The tolerability, safety, and pharmacokinetics of B-OT / OT administration have already been successfully evaluated in a Phase I clinical trial with healthy volunteers. It opens up the possibility of influencing the individual stages of plasmodia development in such a way that their spread via mosquitoes is significantly reduced. It opens up the possibility of altering the metabolism of the plasmodia in such a way that their proliferation in the host is inhibited, their immunosuppressive effect is reduced, and the patient's immune system can better recognize and eliminate the plasmodia. This also promotes the development of immunity in the patient against subsequent plasmodia infections.

[0072] For other pathogenic sporozoa that, like Plasmodia, reproduce obligately as intracellular parasites in certain cells in the blood of the host organism and have a similar development cycle to Plasmodia, for example Leishmania (flagellated protozoa, with a host switch between insects and vertebrates and with macrophages as host cells in the human blood), the treatment with B-OT / OT described above also appears to be a suitable therapeutic approach.

[0073] In view of the information on B-OT / OT tolerability and B-OT / OT efficacy known in the prior art, it is a routine task for the person skilled in the art to conduct appropriate clinical studies in order to determine suitable dosage and administration regimens with which the aforementioned effects can be achieved.

[0074] The following exemplary embodiments with figures illustrate the invention.

[0075] The figures show: Fig. Figure 1: Change in OT plasma concentrations over time (over 24 hours and 168 hours) in male volunteers. B-OT was administered orally once daily for seven days at a dose of 3.0 mg per volunteer (mean body weight 80 kg). The values ​​shown represent mean values ​​(with standard deviation of the geometric mean) of a cohort of six individuals. On the x-axis the time is given in hours (h = hours) The y-axis shows the plasma concentration of OT in ng / ml. (A) = Change in OT plasma concentration during day 1 after B-OT administration. (B) = Change in OT plasma concentration during day 7 after B-OT administration. Compared to day 1 ( Fig. 1 A) a doubling of the amount of OT in the serum can be observed after twelve hours (12 h). (C) = Change in OT plasma concentration over the course of day 7 and the subsequent period up to day 14 (168 h). After 24 h, the OT value has decreased to 0.5 ng / ml, and after 96 h, 0.1 ng / ml of OT is still detectable. Fig. Figure 2: Changes in OT plasma concentrations over time (over 24 hours and 168 hours) in male volunteers. B-OT was administered orally once daily for seven days at a dose of 5.0 mg per volunteer (mean body weight: 80 kg). The values ​​shown represent mean values ​​(with standard deviation of the geometric mean) of a cohort of six individuals. On the x-axis the time is given in hours (h = hours). The y-axis shows the plasma concentration of OT in ng / ml. (A) = Change in OT plasma concentration during day 1 after B-OT administration. (B) = Change in OT plasma concentration during day 7 after B-OT administration. Compared to day 1 ( Fig. 1 A) after twelve hours (12 h) the OT value increased from 1.1 ng / ml to 1.9 ng / ml. (C) = Change in OT plasma concentration over the course of day 7 and the subsequent period up to day 14 (168 h). After 24 h, the OT value has decreased to 0.8 ng / ml, and after 96 h, 0.2 ng / ml of OT is still detectable, i.e., twice as much as when 3 mg B-OT was administered at the same time point (96 h). Example 1: Study on healthy male volunteers on the oral administration of Benfo-Oxythiamine “B-OT” and the detection of released Oxythiamine “OT” in the organism (serum)

[0076] Male volunteers were administered B-OT (benfo-oxythiamine) orally once daily for periods of one to seven days at doses of 1 mg / person / day, 2 mg / person / day, 3 mg / person / day, and 5 mg / person / day.

[0077] The toxicokinetics of the active metabolite OT (oxythiamine) were determined in plasma samples collected on the first day (“Day 1”), on the seventh day (“Day 7”), and from “Day 7” to “Day 14” after the start of administration, each at different time points (on the respective day). The measured results for a dose of 3 mg / person (subject) / day are shown in Fig. 1 (A) to (C) are shown graphically, the measured results for the dose of 5 mg / person / day are shown in Fig.2 (A) to (C) are shown graphically. The values ​​shown represent the mean values ​​of a cohort of six individuals (test subjects).

[0078] Fig. Figure 1 (A) shows the change in oxythiamine (OT) plasma concentration on day 1 after oral administration of a single dose of B-OT at 3 mg per subject.

[0079] Fig. Figure 1 (B) shows the change in OT plasma concentration on day 7 after oral administration of a single dose of B-OT in the amount of 3 mg per subject.

[0080] On day 7, a doubling of the OT amount in serum can be observed after twelve hours compared to day 1.

[0081] Fig. Figure 1 (C) shows the change in OT plasma concentration on day 7 and in the subsequent period up to day 14 (168 h) after oral administration of a single dose of B-OT in the amount of 3 mg per subject.

[0082] After 24 hours, the OT value has dropped to 0.5 ng / ml and after 96 hours, 0.1 ng / ml OT is still detectable in the serum.

[0083] Fig. Figure 2 (A) shows the change in OT plasma concentration on day 1 after oral administration of a single dose of B-OT at 5 mg per subject.

[0084] Fig. Figure 2 (B) shows the change in OT plasma concentration on day 7 after oral administration of a single dose of B-OT in the amount of 5 mg per subject.

[0085] On day 7, after twelve hours, the OT value increased from 1.1 ng / ml to 1.9 ng / ml compared to day 1.

[0086] Fig. Figure 2 (C) shows the change in OT plasma concentration on day 7 and in the subsequent period up to day 14 (168 h) after oral administration of a single dose of B-OT in the amount of 5 mg per subject.

[0087] After 24 hours (h), the OT value has dropped to 0.8 ng / ml and after 96 hours (h), 0.2 ng / ml OT is still detectable, which is twice as much as when 3 mg B-OT was administered at the same time point (96 h).

[0088] Both single and repeated doses of B-OT were very well tolerated by the subjects. This was confirmed by physical examinations of the subjects, their vital signs, their laboratory values, and electrocardiographic studies. Analysis of side effects showed that B-OT could be used safely and was well tolerated. The pharmacokinetics of B-OT were measured and documented in detail. The observed pharmacokinetics demonstrate that B-OT is well-suited for use in humans. Certain side effects such as hematuria, tachycardia, chills, and fever occurred in a few moderate cases. The evaluation of B-OT with healthy volunteers (males) in the Phase I clinical trial confirmed that B-OT is a prodrug for humans, releasing OT into the blood. B-OT, only OT, could not be detected in humans.The humans were therefore exposed to the active metabolite OT, but not to the precursor (prodrug) B-OT. Essentially the same results have already been described in the prior art for rats and dogs. In these species, B-OT also acts as a prodrug, releasing OT into the blood, where it is undetectable. Example 2: Dosage and administration regimens

[0089] Based on the tolerability and efficacy established so far for B-OT / OT, the following dosage and administration regimens are suitable and intended for treatment with B-OT / OT according to the invention. They can be clinically tested and optimized without any special effort. Such testing and optimization procedures are routine work for the person skilled in the art. (I) Dosage and administration regimen for infected individuals with symptoms: On day 1: 0.125 mg B-OT per kilogram of body weight per day On day 2: 0.094 mg B-OT per kilogram of body weight per day On day 3: 0.0625 mg B-OT per kilogram of body weight per day On day 4: 0.0625 mg B-OT per kilogram of body weight per day On day 5: 0.0625 mg B-OT per kilogram of body weight per day On day 6: 0.0625 mg B-OT per kilogram of body weight per day On day 7: 0.0625 mg B-OT per kilogram of body weight per day (II) Dosage and administration regimen in case of suspected Plasmodium infection (patient still without symptoms) On day 1: 0.0625 mg B-OT per kilogram of body weight per day On day 2: 0.03 mg B-OT per kilogram of body weight per day On day 3: 0.03 mg B-OT per kilogram of body weight per day On day 4: 0.03 mg B-OT per kilogram of body weight per day On day 5: 0.03 mg B-OT per kilogram of body weight per day On day 6: 0.03 mg B-OT per kilogram of body weight per day On day 7: 0.03 mg B-OT per kilogram of body weight per day (III) Dosage and administration regimen for asymptomatic people at increased risk of Plasmodium infection: On day 1: 0.02 mg B-OT per kilogram of body weight per day On day 2: 0.02 mg B-OT per kilogram of body weight per day On day 3: 0.02 mg B-OT per kilogram of body weight per day On day 4: 0.02 mg B-OT per kilogram of body weight per day On day 5: 0.02 mg B-OT per kilogram of body weight per day On day 6: 0.02 mg B-OT per kilogram of body weight per day On day 7: 0.02 mg B-OT per kilogram of body weight per day (IV) Dosage and administration regimen for asymptomatic individuals with a moderately increased risk of Plasmodium infection: On day 1: 0.01 mg B-OT per kilogram of body weight per day On day 2: Do not take B-OT On day 3: 0.01 mg B-OT per kilogram of body weight per day On day 4: Do not take B-OT On day 5: 0.01 mg B-OT per kilogram of body weight per day On day 6: Do not take B-OT On day 7: 0.01 mg B-OT per kilogram of body weight per day (V) Dosage and administration regimen for asymptomatic individuals with a relatively low risk of Plasmodium infection: On day 1: 0.01 mg B-OT per kilogram of body weight per day On day 2: Do not take B-OT On day 3: Do not take B-OT On day 4: 0.01 mg B-OT per kilogram of body weight per day On day 5: Do not take B-OT On day 6: Do not take B-OT On day 7: 0.01 mg B-OT per kilogram of body weight per day

[0090] All dosage amounts given above under (I) to (V) for B-OT can be increased by up to 50% or even up to 100% or reduced by up to 75% for the specific application in or against plasmodia infections and malaria diseases. Cited non-patent literature: Boateng R.A., Tastan Bishop Ö., Musyoka T.M.: Characterisation of plasmodial transketolases and identification of potential inhibitors: an in silico study. Malar J. 2020 Nov 30; 19(1):442. doi: 10.1186 / s12936-020-03512-1. PMID: 33256744; PMCID: PMC7756947. Chan X.W., Wrenger C., Stahl K., Bergmann B., Winterberg M., Müller I.B., Saliba K.J.: Chemical and genetic validation of thiamine utilization as an antimalarial drug target. Nat Commun. 2013; 4:2060. doi: 10.1038 / ncomms3060. PMID: 23804074. Fadare O.A., Omisore N.O., Adegbite O.B., Awofisayo O.A., Ogundolie F.A., Adesanwo J.K., Obafemi C.A.: Structure based design, stability study and synthesis of the dinitrophenylhydrazone derivative of the oxidation product of lanosterol as a potential P. falciparum transketolase inhibitor and in-vivo antimalarial study. In Silico Pharmacol. 2021 Jun 18; 9(1):38. doi: 10.1007 / s40203-021-00097-8. PMID: 34168948; PMCID: PMC8213873. Hasan M.A., Mazumder M.H.H., Chowdhury A.S., Datta A., Khan M.A.: Molecular-docking study of malaria drug target enzyme transketolase in Plasmodium falciparum 3D7 portends the novel approach to its treatment. Source Code Biol Med 10, 7 (2015). https: / / doi.org / 10.1186 / s13029-015-0037-3 Joshi S., Singh A.R., Kumar A., Misra P.C., Siddigi M.I., Saxena J.K.: „Molecular cloning and characterization of Plasmodium falciparum transketolase“; Mol. Biochem. Parasitol. 2008; 160(1):32-41; DOI:10.1016 / j.molbiopara.2008.03.005 Kaushik M., Hoti S.L., Saxena J.K., Hingamire T., Shanmugam D., Joshi R.K., Metgud S.C., Ungar B., Singh I., Hegde H.V.: Antimalarial Activity of Anacardium occidentale Leaf Extracts Against Plasmodium falciparum Transketolase (PfTK). Acta Parasitol. 2023 Dec; 68(4):832-841. doi: 10.1007 / s11686-023-00718-6. Epub 2023 Oct 13. PMID: 37831282. Li Y., Yao C.F, Xu F.J., Qu Y.Y., Li J.T., Lin Y., Cao Z.L., Lin P.C., Xu W., Zhao S.M., Zhao J.Y.: APC / C CDHI synchronizes ribose-5-phosphate levels and DNA synthesis to cell cycle progression. Nat Commun. 2019 Jun 7; 10(1):2502. doi: 10.1038 / s41467-019-10375-x. PMID: 31175280; PMCID: PMC6555833. Rais, B. et al. Oxythiamine and dehydroepiandrosterone induce a G1 phase cycle arrest in Ehrlich's tumor cells through inhibition of the pentose cycle. FEBS Lett. 456, 113-118 (1999). Yang, C. M., Liu, Y. Z., Liao, J. W. & Hu, M. L. The in vitro and in vivo anti-metastatic efficacy of oxythiamine and the possible mechanisms of action. Clin. Exp. Metastasis 27, 341-349 (2010). ZITATE ENTHALTEN IN DER BESCHREIBUNG

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] Hasan et al. 2015, Boateng et al. 2020

[0009] Li et al., who in 2019

[0030] Fadare OA, Omisore NO, Adegbite OB, Awofisayo OA, Ogundolie FA, Adesanwo JK, Obafemi CA: Structure based design, stability study and synthesis of the dinitrophenylhydrazone derivative of the oxidation product of lanosterol as a potential P. falciparum transketolase inhibitor and in-vivo antimalarial study. In Silico Pharmacol. 2021 Jun 18; 9(1):38. doi: 10.1007 / s40203-021-00097-8. PMID: 34168948; PMCID: PMC8213873

[0090] Hasan M.A., Mazumder M.H.H., Chowdhury A.S., Datta A., Khan M.A.: Molecular-docking study of malaria drug target enzyme transketolase in Plasmodium falciparum 3D7 portends the novel approach to its treatment. Source Code Biol Med 10, 7 (2015). https: / / doi.org / 10.1186 / s13029-015-0037-3

[0090] Joshi S., Singh A.R., Kumar A., Misra P.C., Siddigi M.I., Saxena J.K.: „Molecular cloning and characterization of Plasmodium falciparum transketolase“; Mol. Biochem. Parasitol. 2008; 160(1):32-41; DOI:10.1016 / j.molbiopara.2008.03.005

[0090] Kaushik M., Hoti S.L., Saxena J.K., Hingamire T., Shanmugam D., Joshi R.K., Metgud S.C., Ungar B., Singh I., Hegde H.V.: Antimalarial Activity of Anacardium occidentale Leaf Extracts Against Plasmodium falciparum Transketolase (PfTK). Acta Parasitol. 2023 Dec; 68(4):832-841. doi: 10.1007 / s11686-023-00718-6. Epub 2023 Oct 13. PMID: 37831282

[0090] Li Y., Yao C.F, Xu F.J., Qu Y.Y., Li J.T., Lin Y., Cao Z.L., Lin P.C., Xu W., Zhao S.M., Zhao J.Y.: APC / C CDHI synchronizes ribose-5-phosphate levels and DNA synthesis to cell cycle progression. Nat Commun. 2019 Jun 7; 10(1):2502. doi: 10.1038 / s41467-019-10375-x. PMID: 31175280; PMCID: PMC6555833

[0090] Rais, B. et al. Oxythiamine and dehydroepiandrosterone induce a G1 phase cycle arrest in Ehrlich's tumor cells through inhibition of the pentose cycle. FEBS Lett. 456, 113-118 (1999

[0090] Yang, C. M., Liu, Y. Z., Liao, J. W. & Hu, M. L. The in vitro and in vivo anti-metastatic efficacy of oxythiamine and the possible mechanisms of action. Clin. Exp. Metastasis 27, 341-349 (2010

[0090]

Claims

[1] Benfo-oxythiamine and / or oxythiamine for use as an active ingredient of a medicinal product for the therapeutic treatment of infections with sporozoa of the genus Plasmodium and resulting malaria disease in a patient or potential patient. [2] Use according to claim 1, wherein the medicament is a human medicament. [3] Application according to claim 1 or 2, characterized bythat the therapeutic treatment is a treatment which alleviates symptoms and / or cures them, whereby benfo-oxythiamine and / or oxythiamine inhibit the development of the plasmodia in the patient's erythrocytes, so that the plasmodia remain in their erythrocytes, thereby significantly reducing or preventing their spread to other potential patients, and thereby reducing or preventing the suppression of the patient's immune system caused by the plasmodia and / or the erythrocytes infected by them, so that the immune system is activated to develop an effective immunological defense reaction by means of which the plasmodia and / or the erythrocytes infected by them can be eliminated, and also to develop an immune response which counteracts the proliferation of plasmodia in the patient in the event of subsequent reinfections with plasmodia. [4] Use according to claim 3, wherein benfo-oxythiamine and / or oxythiamine causes one or more of the following effects in the potential patient, preferably a human: - Inhibiting or preventing the formation of extracellular forms of plasmodia; - cellular immune response against plasmodia; - Activation of the innate immune system, particularly macrophages (phagocytic cells) to eliminate plasmodia by phagocytosis; - humoral immune response (B cell response) against plasmodia antigens; - protective cellular immunity against infection by Plasmodium or against Plasmodium-induced pathology; - Reduction of the severity of symptoms of plasmodia infection and / or malaria; - Increase survival time. [5] Application according to claim 1 or 2, characterized bythat the therapeutic treatment is a preventative treatment of potential patients, in particular mammals, in particular humans, wherein the preventively administered benfo-oxythiamine and / or oxythiamine, in the case of a plasmodia infection, inhibits the development of the plasmodia in the host cells, in particular the erythrocytes of the patient, so that the proliferation of the plasmodia is inhibited and the plasmodia remain in their host cells, whereby their spread to other potential patients is significantly reduced or prevented, and whereby the plasmodia and / or the erythrocytes infected by them are recognizable to the immune system, so that an immune response is elicited by means of which the plasmodia and / or the erythrocytes infected by them can be eliminated, and whereby the manifestation of symptoms of a plasmodia infection and / or a malaria disease is reduced or prevented. [6] Application of claim 5, characterized by that the immune response provides lasting immunity against the plasmodia acting as a live vaccine. [7] Use according to claim 6, wherein benfo-oxythiamine and / or oxythiamine causes one or more of the following effects in the potential patient, preferably a human: - Protection against infections with plasmodia; - Inhibition of extracellular forms of plasmodia; - cellular immune response against plasmodia; - Activation of the innate immune system, particularly macrophages (phagocytic cells) to eliminate plasmodia by phagocytosis; - humoral immune response (B cell response) against plasmodia antigens; - protective cellular immunity against infection by Plasmodium or against Plasmodium-induced pathology; - Reduction or prevention of the symptoms of a plasmodia infection and / or malaria disease.

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