ABSTRACT
Orally delivered drugs offer significant benefits in the fight against viral infections, and cost-effective production is critical to their impact on pandemic response in low- and middle-income countries. One example, molnupiravir, a COVID-19 therapy developed by Emory, Ridgeback, and Merck & Co., had potential to benefit from significant cost of goods (COGs) reductions for its active pharmaceutical ingredient (API), including starting materials. A holistic approach to identifying, developing, and evaluating optimized synthetic routes, which includes detailed COGs modeling, provides a rapid means to increase the availability, uptake and application of molnupiravir and other antivirals in global markets. Identification and development of alternate processes for the synthesis of molnupiravir has been conducted by the Medicines for All Institute at Virginia Commonwealth University (M4ALL) and the Green and Turner Labs at the University of Manchester. Both groups developed innovative processes based on synthetic route design and biocatalysis aimed at lowering costs and improving global access. The authors then performed COGs modeling to assess cost saving opportunities. This included a focus on manufacturing environments and facilities amenable to global public health and the identification of key parameters using sensitivity analyses. While all of the evaluated routes provide efficiency benefits, the best options yielded 3-6 fold API COGs reductions leading to treatment COGs as low as <$3/regimen. Additionally, key starting materials and cost drivers were quantified to evaluate the robustness of the savings. Finally, COGs models can continue to inform the focus of future development efforts on the most promising routes for additional cost savings. While the full price of a treatment course includes other factors, these alternative API synthetic approaches have significant potential to help facilitate broader access in low- and middle-income countries. As other promising therapeutics are developed, a similar process could enable rapid cost reductions while enhancing global access.
ABSTRACT
Malaria is one of the most significant causes of childhood mortality, but disease control efforts are threatened by resistance of the Plasmodium parasite to current therapies. Continued progress in combating malaria requires development of new, easy to administer drug combinations with broad-ranging activity against all manifestations of the disease. DSM265, a triazolopyrimidine-based inhibitor of the pyrimidine biosynthetic enzyme dihydroorotate dehydrogenase (DHODH), is the first DHODH inhibitor to reach clinical development for treatment of malaria. We describe studies profiling the biological activity, pharmacological and pharmacokinetic properties, and safety of DSM265, which supported its advancement to human trials. DSM265 is highly selective toward DHODH of the malaria parasite Plasmodium, efficacious against both blood and liver stages of P. falciparum, and active against drug-resistant parasite isolates. Favorable pharmacokinetic properties of DSM265 are predicted to provide therapeutic concentrations for more than 8 days after a single oral dose in the range of 200 to 400 mg. DSM265 was well tolerated in repeat-dose and cardiovascular safety studies in mice and dogs, was not mutagenic, and was inactive against panels of human enzymes/receptors. The excellent safety profile, blood- and liver-stage activity, and predicted long half-life in humans position DSM265 as a new potential drug combination partner for either single-dose treatment or once-weekly chemoprevention. DSM265 has advantages over current treatment options that are dosed daily or are inactive against the parasite liver stage.
