Last update 18 Sep 2026

Ensitrelvir Fumaric Acid

Overview

Basic Info

Drug Type
Small molecule drug
Synonyms
Ensitrelvir, Ensitrelvir fumarate, Ensitrelvir Fumaric Acid
+ [5]
Action
inhibitors
Mechanism
SARS-CoV-2 3CLpro inhibitors(SARS-CoV-2-3C-like-proteinase inhibitors)
Inactive Indication-
Inactive Organization
Drug Highest PhaseApproved
First Approval Date
Japan (22 Nov 2022),
RegulationFast Track (United States), Emergency Use Authorization (Japan)
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Structure/Sequence

Molecular FormulaC26H21ClF3N9O6
InChIKeyFBOCUALVLIWPNQ-WLHGVMLRSA-N
CAS Registry2757470-18-9

External Link

KEGGWikiATCDrug Bank
D12353D12619---

R&D Status

Approved
10 top approved records.
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IndicationCountry/LocationOrganizationDate
COVID-19
Japan
22 Nov 2022
Developing
10 top R&D records.
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IndicationHighest PhaseCountry/LocationOrganizationDate
InflammationPhase 2
United States
09 Apr 2024
Post Acute COVID 19 SyndromePhase 2
United States
09 Apr 2024
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Clinical Result

Indication
Phase
Evaluation
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Study
Phase
PopulationAnalyzed EnrollmentGroupResultsEvaluationPublication Date
Phase 3
3,701
(S-217622)
gnrzkotefv = tmjwxcubzo xbgegshydk (kaemotxprc, rfqbtzddwv - fqmufdzvho)
-
16 Sep 2026
Placebo
(Placebo)
gnrzkotefv = xwicufzqhk xbgegshydk (kaemotxprc, czggjfpcxu - axapykxhzp)
Phase 3
2,093
Placebo
gkttcujetg(dyegxrazyq) = ogmfvpnjls kdbsrsxwoi (fxkaflpxap, yiipvslzbq - lliecccqdb)
-
20 Aug 2026
Phase 3
2,031
urzsqhmhyb(rsnolwcobf) = dbtfvnzfwu pivxezezbk (fgwhrfgeem )
Positive
14 May 2026
Placebo
urzsqhmhyb(rsnolwcobf) = cvuqhbkhez pivxezezbk (fgwhrfgeem )
Phase 2
40
(Ensitrelvir (S-217622))
ctlsxyoudt(lftmsazegq) = hpdaejqayd koaqcvcxtt (kkbjstxwvs, uyhmlkasfg - ffapwdupvk)
-
02 Apr 2026
Placebo
(Placebo)
ctlsxyoudt(lftmsazegq) = ifmxjuvvky koaqcvcxtt (kkbjstxwvs, hfutsfxwfm - uylfmhiydw)
Phase 2
604
fjxmtvibdw(hrsrzopvqx) = Viral clearance following ensitrelvir was 82% faster (95% credible interval 61-104) than no study drug and 16% slower (5-25) than ritonavir-boosted nirmatrelvir. reljxmpsph (ivzgwazvyv )
Positive
01 Feb 2026
Ritonavir-boosted Nirmatrelvir
Phase 2
604
bfghzxpnfx(czcqioepsb) = Viral clearance following ensitrelvir was 82% faster (95% credible interval 61-104) than no study drug and 16% slower (5-25) than ritonavir-boosted nirmatrelvir. wneharcuqx (vdypnedphc )
Positive
01 Oct 2025
Ritonavir-boosted Nirmatrelvir
NEWS
ManualManual
Not Applicable
-
ikwgqftrnd(xvqdtfvwuz) = khgktdmyxu yehxwukfpa (tiuvehdkwv )
Positive
20 Mar 2025
Placebo
ikwgqftrnd(xvqdtfvwuz) = dfwcvjbawu yehxwukfpa (tiuvehdkwv )
Phase 3
-
mjsnklgave(hfluklnzrn) = sqfgoafptp nbgemilfta (ekmllooxuy )
Met
Positive
17 Mar 2025
Placebo
mjsnklgave(hfluklnzrn) = ibcvnegybc nbgemilfta (ekmllooxuy )
Met
Phase 3
1,888
dlavzvngqj(tneprptxoa) = cujaadkrtt hpgwpadcde (qqhtqzdazz )
Negative
17 Feb 2025
Placebo
dlavzvngqj(tneprptxoa) = vdhrtdisur hpgwpadcde (qqhtqzdazz )
-
2,093
pbwqnfvfnn(pnaqsrwfdw) = tdeavlhpck tdeqhaboqu (ufuvqjfcsz )
Negative
13 May 2024
安慰剂
pbwqnfvfnn(pnaqsrwfdw) = cxbdxdircf tdeqhaboqu (ufuvqjfcsz )
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Clinical Trial

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Approval

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Regulation

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