Molnupiravir

Molnupiravir

File:MK-4482.svg
Systematic (IUPAC) name
((2R,3S,4R,5R)-3,4-dihydroxy-5-(4-(hydroxyimino)-2-oxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-2-yl)methyl isobutyrate
Clinical data
Legal status	US: Investigational drug
Identifiers
CAS Number	2349386-89-4
PubChem	CID: 145996610
UNII	YA84KI1VEW
KEGG	D11943
Synonyms	MK-4482, EIDD-2801
Chemical data
Formula	C13H19N3O7
Molecular mass	329.31
SMILES CC(C)C(=O)OC[C@@H]1[C@H]([C@H]([C@@H](O1)N2C=CC(=NC2=O)NO)O)O
InChI InChI=1S/C13H19N3O7/c1-6(2)12(19)22-5-7-9(17)10(18)11(23-7)16-4-3-8(15-21)14-13(16)20/h3-4,6-7,9-11,17-18,21H,5H2,1-2H3,(H,14,15,20)/t7-,9-,10-,11-/m1/s1 Key:HTNPEHXGEKVIHG-QCNRFFRDSA-N

Molnupiravir (development codes MK-4482 and EIDD-2801) is an experimental antiviral drug which is orally active and was developed for the treatment of influenza. It is a prodrug of the synthetic nucleoside derivative N4-hydroxycytidine, and exerts its antiviral action through introduction of copying errors during viral RNA replication.

The drug was developed at Emory University by the university's drug innovation company, Drug Innovation Ventures at Emory (DRIVE). It was then acquired by Miami-based company Ridgeback Biotherapeutics, who later partnered with Merck & Co. to develop the drug further.

Safety controversy

In April 2020, a whistleblower complaint by former Head of US Biomedical Advanced Research and Development Authority (BARDA) Rick Bright revealed concerns over providing funding for the further development of molnupiravir due to similar drugs having mutagenic (DNA damaging) properties. A previous company, Pharmasset, that had investigated the drug's active ingredient had abandoned it. These claims were denied by George Painter, CEO of DRIVE, noting that toxicity studies on molnupiravir had been carried out and data provided to regulators in the US and UK, who permitted safety studies in humans to move forward in the spring of 2020. Also at this time, DRIVE and Ridgeback Biotherapeutics stated they planned future safety studies in animals.

COVID-19

In late July 2020 Merck, which had been partnering with Ridgeback Biotherapeutics on developing the drug, announced its intention to move molnupiravir to late stage trials beginning in September 2020. On October 19 2020, Merck began a one year Stage 2/3 trial focused on hospitalized patients. In June 2021, the US Department of Health and Human Services committed to buy $1.2 billion worth of molnupiravir from Merck if it receives FDA approval.