Simnotrelvir/ritonavir

Simnotrelvir/ritonavir (trade name Xiannuoxin) is a pharmaceutical drug used for the treatment of COVID-19.^[2] Simnotrelvir/ritonavir is a combination drug of simnotrelvir, an inhibitor of SARS-CoV-2 3CL^pro, and ritonavir,^[3] a CYP3A inhibitor.

Simnotrelvir/ritonavir

Chemical structures of simnotrelvir (top) and ritonavir (bottom)
Combination of
Simnotrelvir	SARS-CoV-2 3CLpro inhibitor
Ritonavir	Protease inhibitor
Clinical data
Trade names	先诺欣 (Xiannuoxin)
Pregnancy category	Contraindicated (CN)
Routes of administration	Oral
Legal status
Legal status	Rx in China

Simnotrelvir

Clinical data
Other names	SIM0417, SSD8432
Routes of administration	Oral
Drug class	SARS-CoV-2 3CLpro inhibitor
Legal status
Legal status	Not approved on its own
Pharmacokinetic data
Protein binding	72.5%[1]
Metabolism	hepatic (CYP3A)[1]
Elimination half-life	3.1 h; 4.1 h with ritonavir[1]
Excretion	urine (55.4%), feces (36.7%)[1]
Identifiers
IUPAC name (8S)-N-[(1S)-1-cyano-2-[(3S)-2-oxopyrrolidin-3-yl]ethyl]-7-[(2S)-3,3-dimethyl-2-[(2,2,2-trifluoroacetyl)amino]butanoyl]-1,4-dithia-7-azaspiro[4.4]nonane-8-carboxamide
PubChem CID	168476146
Chemical and physical data
Formula	C22H30F3N5O4S2
Molar mass	549.63 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC(C)(C)[C@@H](C(=O)N1CC2(C[C@H]1C(=O)N[C@@H](C[C@@H]3CCNC3=O)C#N)SCCS2)NC(=O)C(F)(F)F
InChI InChI=InChI=1S/C22H30F3N5O4S2/c1-20(2,3)15(29-19(34)22(23,24)25)18(33)30-11-21(35-6-7-36-21)9-14(30)17(32)28-13(10-26)8-12-4-5-27-16(12)31/h12-15H,4-9,11H2,1-3H3,(H,27,31)(H,28,32)(H,29,34)/t12-,13-,14-,15+/m0/s1 Key:LQBRGTAIBBFUJJ-ZQDZILKHSA-N

It was developed by Simcere Pharmaceutical and conditionally approved in China by the National Medical Products Administration (NMPA) in January 2023.^[4] Results for the phase Ib trial are available.^[5] In a phase II/III trial, it reduced the duration of symptoms by a median of 36 hours compared to placebo.^[6]

See also

• Nirmatrelvir/ritonavir