ANTI-HERPESVIRUS THERAPIES: BASIC STRATEGIES AND APPLICATIONS
Erik DE CLERCQ Rega Institute for Medical Research, K.U.Leuven B-3000 Leuven, Belgium Herpesviridae Human herpesviruses (HHV)
HHV-1: Herpes simplex virus type 1 (HSV-1) HHV-2: Herpes simplex virus type 2 (HSV-2) HHV-3: Varicella-zoster virus (VZV) HHV-4: Epstein-Barr virus (EBV) HHV-5: Human cytomegalovirus (HCMV) HHV-6: Human herpes simplex virus type 6 (HSV-6) HHV-7: Human herpes simplex virus type 7 (HSV-7) HHV-8: Kaposi’s sarcoma herpesvirus (KSHV) O
N HN
N H2N N
HO O
Acyclovir, Aciclovir (ACV), Acycloguanosine 9-[(2-Hydroxyethoxy)methyl]guanine Zovirax® O O
N N HN HN
N N H2N N H2N N
H2N CH CO O HO O O CH H3CCH3 Acyclovir Acyclovir valyl ester Valaciclovir
O O N N HN HN N N H2N N H2N N
H2N CH CO O H2N CH2 CO O O O CH3
Acyclovir glycyl ester Acyclovir alanyl ester O
N HN
N H2N N O H H2N C C O O CH H3CCH3
Valaciclovir Valine ester of acyclovir Valtrex®, Zelitrex® Antiviral activity spectrum of valaciclovir (acyclovir)
Herpesviridae ! Herpes simplex virus type 1 (HSV-1) ! Herpes simplex virus type 2 (HSV-2) ! Varicella-zoster virus (VZV) ! Epstein-Barr virus (EBV) " Human cytomegalovirus (HCMV) " Human herpesvirus type 6 (HHV-6) " Human herpesvirus type 7 (HHV-7) " Human herpesvirus type 8 (HHV-8) " Thymidine kinase-deficient HSV (TK- HSV) " Thymidine kinase-deficient VZV (TK- VZV) Major clinical indications of valaciclovir
Systemic (oral) treatment of HSV and VZV infections: • primary and recurrent genital herpes, mucocutaneous HSV-1 and HSV-2 infections in immuno-compromised and –competent patients • varicella-zoster in immuno-compromised and –competent patients O
N N N HN
N N H2N N H2N N O
H3C O HO
H3CO OH
O
Famciclovir Penciclovir Famvir® N N N N N N
N N N H2N N H2N N H2N N O O
H3C O Esterase H3C O Esterase HO
H3C O OH OH
O
Xanthine Xanthine Xanthine oxidase oxidase oxidase
O O O
N N N HN HN HN
N N N H2N N H2N N H2N N O O Esterase Esterase H3C O H3C O HO
H3C O OH OH
O Intravenous penciclovir versus acyclovir in the treatment of HSV infections in immunocompromised patients
Kaplan-Meier plot of time to healing of lesions for penciclovir at 5 mg/kg q12 h (long-dashed line), penciclovir at 5 mg/kg q8h (short-dashed line), and acyclovir at 5 mg/kg q8h (solid line) Lazarus et al., Antimicrob. Agents Chemother. 43: 1192-1197 (1999) O
N HN
N H2N N
HO O
OH Ganciclovir (GCV) 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG) Cymevene®, Cytovene® O
N HN
N H2 N N
O H H2N C C O O CH H3CCH3 OH
Valganciclovir Valcyte® Nucleoside kinase O O + -O P C 3 Na O- O-
Foscarnet Phosphonoformate (trisodium salt) PFA Foscavir® O
N NH
N N NH2
HO HO HO O O
OH OH Acyclovir Ganciclovir H2G HO HO HO O
OH OH OH Penciclovir Lobucavir Anhydrohexitol guanine
HO HO HO
HO OH Synguanol A-5021 D/L-Cyclohexenyl guanine O
N HN
N H2N N
HO
OH
Lobucavir O
HN N N H2N N
HO
OH
(-) 2HM-HBG H2G (-)-9-[4-hydroxy-2-(hydroxymethyl)butyl]guanine NH2 O
N N N NH
HO N HO N N N NH2
Synadenol Syngenol
Methylene cyclopropane nucleoside analogues O
N NH
N N NH2 HO
OH
D/L-Cyclohexenyl guanine O
N NH
N N NH2 HO
HO
A-5021 O
N N N NH
N N N NH2 N NH2
HO HO
OH OH
AV-038 A-5021 Comparative potency of different antiherpetic compounds against different herpesviruses
Compound 50% Effective concentration EC50 (µM) HSV-1 HSV-2 VZV HCMV Acyclovir +++ +++ ++ + Penciclovir +++ ++ ++ (+) Ganciclovir +++++ +++++ ++ ++ Lobucavir ++++ ++++ +++ ++ H2G ++++ ++++ ++++ (+) A-5021 ++++ +++ +++ + Synguanol + - + ++ Anhydrohexitol G ++(+) +++(+) ++ ++ D-Cyclohexenyl G ++++ +++ ++ ++ L-Cyclohexenyl G +++(+) +++ ++ ++
EC50 (µM)= 10-100 (+), 1-10 (++), 0.1-1 (+++), 0.01-0.1 (++++), 0.001-0.01 (+++++) H2N N N
N N
HO O
OH
S2242 2-Amino-7-[(1,3-dihydroxy-2-propoxy)methyl]purine O OH CH3 OH C O O OCH3
CH3
Mycophenolic acid O OH CH3 O C N O O O OCH3
CH3
Mycophenylate mofetil (Cellcept®) 2-Morpholinoethyl ester of mycophenolic acid MPA-IMPDH interactions
Sintchak et al., Cell 85: 921-930 (1996) Phosphoribosylamine (PRA)
+ Mycophenolic acid H2O + NAD IMP
IMP dehydrogenase
+ NADH + H XMP Deoxyguanosine Guanosine analogues
GMP dGMP dGMP analogues
GDP dGDP dGDP analogues
GTP dGTP dGTP analogues
RNA DNA synthesis synthesis Inhibitory effects of mycophenolate mofetil (MMF) and lobucavir (LBV) on cytopathicity of HCMV in human embryonic lung (HEL) cells
Virus Control 2.5 µg/ml MMF
1 µg/ml LBV 1 µg/ml LBV + 2.5 µg/ml MMF Inhibitory effects of topical mycophenolate mofetil (MMF) 5% and topical acyclovir (ACV) 0.1% on HSV-1-induced lesions in hairless mice Virus Control MMF
ACV MMF + ACV O I HN
O N HO O
OH
Idoxuridine 5-iodo-2’-deoxyuridine (IDU) Stoxil® O
CF3 HN
O N HO O
OH
Trifluridine, Trifluorothymidine (TFT) 5-Trifluoromethyl-2’-deoxyuridine Viroptic®, TFT-Ophthiol® O Br HN
O N
HO O
HO
Brivudin, Bromovinyldeoxyuridine (E)-5-(2-bromovinyl)-2’-deoxyuridine (BVDU) Zostex®, Zonavir® Antiviral activity spectrum of BVDU
De Clercq, Recent Advances in Nucleosides: Chemistry and Chemotherapy, pp 433-454 (2002) O O O Br Br Br HN HN HN
O N O N O N
HO HO HO O O HO
HO HO OH HO
BVaraU BVriboU C-BVDU
De Clercq, Recent Advances in Nucleosides: Chemistry and Chemotherapy, pp 433-454 (2002) O NH2 O Br Br Br HN N HN
O N O N O N
HO HO S O HO OH O HO HO
S-BVDU BVDC L-BVDU
De Clercq, Recent Advances in Nucleosides: Chemistry and Chemotherapy, pp 433-454 (2002) N
O N N Br O HN Br N Br HN O N O N O N HO S HO O HO O
HO O HO
S-BVMU Triazolyl BVDC L-BVODDU derivative
De Clercq, Recent Advances in Nucleosides: Chemistry and Chemotherapy, pp 433-454 (2002) O O O Br Br Br HN HN HN
O N O N O N
HO O HO O H3C HO
HO OH OH
BMS-181165 4’-methyl BVDU AV-100
De Clercq, Recent Advances in Nucleosides: Chemistry and Chemotherapy, pp 433-454 (2002) Mechanism of action of BVDU HSV-1 dThd kinase DNA polymerase
BVDU BVDUMP BVDUDP BVDUTP DNA
BVDU BVDUMP
HSV-2 dThd kinase O O H Br H Br C C C C HN H HN H
O N O N H
HO HO O O O P + Pi BVU + Thymidine phosphorylase HO HO BVDU BVU O O F F HN HN Dihydrothymine O N O N H H dehydrogenase
5-Fluorouracil 5-Fluorodihydrouracil Major clinical indications of BVDU (Brivudin)
Topical: - herpetic keratitis (BVDU eyedrops) - herpes labialis (BVDU cream)
Systemic: - mucocutaneous HSV-1 and VZV infections (oral) - immunocompromised patients - immunocompetent patients Oral brivudin versus intravenous acyclovir in the treatment of severe herpes zoster in cancer patients
BRIVUDIN: BVDU: (E)-5-(2-bromovinyl)-2’-deoxyuridine orally 125 mg x 4 per day for 5 days
ACYCLOVIR: ACV: 9-(2-hydroxyethoxymethyl)guanine intravenously 10 mg/kg x 3 per day for 5 days
Multicentered, double-blind, randomized BVDU group (24 patients) also received placebo i.v. ACV group (23 patients) also received placebo p.o.
Wutzler et al., J. Med. Virol. 46: 252-257 (1995) Double-blind study BVDU versus ACV
100 ---- ACV (n = 23) — BVDU (n = 24) 80
60
40
% Patients with new vesicles new with Patients % 20
0 1 2 3 4 5 6 7
Number of days following start of therapy Current antiviral therapy for zoster
Valaciclovir oral 1000 mg 3 x daily 7 days
Acyclovir oral 800 mg 5 x daily 7 days
Acyclovir intravenous 5-10 mg/kg 3 x daily 7-10 days
Famciclovir oral 250 mg 3 x daily 7 days
Brivudin oral 125 mg 1 x daily 7 days
Gross et al., J. Clin. Virol., in press (2003) Brivudin compared to acyclovir Incidence of postherpetic pain
A randomized, double-blind post-study survey on the effect of brivudin in the prevention of postherpetic pain in comparison with acyclovir
Survey patients (n = 608)
Brivudin Acyclovir (n = 309) (n = 299) Patients with postherpetic pain n(%) 101 (32.7) 130 (43.5)
Odds ratio (95% Cl) 1.61 (1.15 – 2.25) p value for difference 0.006
Prof. Dr. S.W. Wassilew Brivudin compared to famciclovir
Brivudin compared to famciclovir in the prevention of postherpetic neuralgia: a prospective randomized, double-blind multicenter trial
Prevalence of postherpetic pain ITT (n = 1954)
Brivudin Famciclovir (n = 980) (n = 974) Patients with postherpetic pain n(%) 109 (11.1) 90 (9.2)
Odds ratio (95% Cl) 1.23 (0.92 – 1.65) p value for non-inferiority 0.0102
Prof. Dr. S.W. Wassilew Brivudin compared to famciclovir
Brivudin compared to famciclovir in the prevention of postherpetic neuralgia: a prospective randomized, double-blind multicenter trial
Duration of postherpetic pain ITT (n = 199)
Brivudin Famciclovir (n = 109) (n = 90) Duration of postherpetic pain Mean ± SD 69.3 ± 62.8 72.9 ± 63.7 Median 47.0 54.0 Risk ratio (95% Cl) 1.05 (0.76 – 1.45) p value for non-inferiority 0.049
Prof. Dr. S.W. Wassilew Brivudin compared to famciclovir Duration of ZAP (Zoster-Associated Pain), n = 1712
1 Brivud in 0,9 Fam ciclovir 0,8
0,7
0,6
0,5 Probability 0,4
0,3 0,2
0,1
0 0 30 60 90 120 150 180 210 240 270 Duration of ZA P [days, after start of tre a tment]
Prof. Dr. S.W. Wassilew Nucleoside Analogues Non-nucleoside Analogues 4-Hydroxyquinoline-3-carboxamides (4-HQC)
OH O
HO N H N Cl
PNU-181465 inhibit replication of HSV-1, VZV and HCMV, through inhibitory effect on HSV-1, VZV and HCMV DNA polymerase
Oien et al., Antimicrob. Agents Chemother. 46: 724-730 (2002) O H N N
N O N H3C NH2 S
BILS 179 BS inhibits replication of HSV (and other herpesviruses ?) through inhibitory effect on helicase/primase (UL5, UL8 and UL52 gene products)
Crutz et al., Nature Medicine 8: 386-391 (2002) CH3 O NON SNH2 N S O
CH3
BAY 57-1293
N-[5-(aminosulfonyl)-4-methyl-1,3-thiazol-2-yl]-N-methyl-2-[4-(2-pyridinyl)- phenyl]acetamide inhibits replication of HSV (and other herpesviruses ?) through inhibitory effect on helicase /primase (UL5, UL8 and UL52 gene products)
Kleymann et al., Nature Medicine 8: 392-398 (2002) BAY 57-1293 in the rat lethal challenge model
_#_ Placebo _≤_ Valaciclovir 45 mg/kg _X_ Valaciclovir 135 mg/kg _π_ BAY 57-1293 0.5 mg/kg _′′′_ BAY 57-1293 2 mg/kg
Lewis rats were inoculated with HSV-1walki intranasally and were treated via oral gavage t.i.d. from day 0 to day 4 post infection. Five animals for each group were used.
Betz et al., Antimicrob. Agents Chemother. 46: 1766-1772 (2002) BAY 57-1293 in the murine lethal challenge model
12
Mice were infected intranasally with HSV-2 MS and were treated via oral gavage once-daily from day 0 to day 4 post infection. Ten animals for each group were used.
Betz et al., Antimicrob. Agents Chemother. 46: 1766-1772 (2002) 1,4-Dihydroxynaphthalene 1,4-Naphthoquinone
OH O
OH O
inhibit HSV-1 and HCMV proteases, could be considered as scaffold for development of non-peptidic anti-herpesvirus agents
Matsumoto et al., Biol. Pharm. Bull. 24: 236-241 (2001) CMV423
O NH2
Cl N
N
2-Chloro-3-pyridin-3-yl-5,6,7,8-tetrahydroindolizine-1- carboxamide inhibits HCMV replication, acts at an early stage (coinciding with IE antigen synthesis) of the HCMV replication cycle
Snoeck et al., Antiviral Res. 55: 413-424 (2002) Pyrrolopyrimidines
S S NH NH NH NH NH 2 2 2 2 2 CN
N N N NH2 N N N N N N
H3CO O
H3CO H3C 828 951 1028 inhibit HCMV replication, target a viral protein that is expressed early in the HCMV replication cycle
Jacobson et al., Antimicrob. Agents Chemother. 43: 1888-1894 (1999) Naphthyridine and dihydroisoquinoline derivatives
N H N
O N H
7,8-Dihydroisoquinoline-6-carboxyl-[2-(1-indol-3-yl) ethyl]amide inhibits HCMV (and HSV) replication, affects early (post-adsorption) event(s) of HCMV replication cycle
Bedard et al., Antimicrob. Agents Chemother. 44, 929-937 (2000) BAY 38-4766
H3CCH3 N
CH3 H N OH
O CH3 S O O N H
3-Hydroxy-2,2-dimethyl-N-[4({[5-dimethylamino)-1-naphthyl] sulfonyl}amino)-phenyl]propanamide inhibits HCMV replication, targets HCMV DNA maturation via UL89 and UL56 gene products, inhibits cleavage of high-molecular-weight DNA concatemers and packaging of monomeric genomes into procapsids
Buerger et al., J. Virol. 75: 9077-9086 (2001) BDCRB
Cl N Br Cl N
HO O
HO OH 1-(β-D-Ribofuranosyl)-2-bromo-5,6-dichlorobenzimidazole inhibits HCMV replication, targets HCMV DNA maturation via UL89 and UL59 gene products which are responsible for cleavage of high-molecular-weight DNA concatemers and packaging of monomeric genomes into procapsids
Biron et al., Antimicrob. Agents Chemother. 46: 2365-2372 (2002) 1263W94 Maribavir
Cl N CH3 N H CH3 Cl N
OH O
HO OH
1-(β-L-Ribofuranosyl)-2-isopropylamino-5,6-dichlorobenzimidazole
inhibits HCMV replication, through interaction with the UL97 gene product (which is required for egress of viral nucleocapsids from the nucleus)
Biron et al., Antimicrob. Agents Chemother. 46: 2365-2372 (2002) [Krosky et al., J. Virol. 77: 905-914 (2003)] Indolocarbazoles
H O N
N N
CH3
CN Gö 6976 inhibit HCMV replication, target UL97 gene product (which is required for egress of viral nucleocapsids from the nucleus) Zimmermann et al., Antiviral Res. 48: 49-60 (2000) [Krosky et al., J. Virol. 77: 905-914 (2003)] CONCLUSION
Marketed antiviral drugs for treatment of HSV, VZV and CMV infections:
HSV VZV CMV
Acyclovir Ganciclovir Valaciclovir Valganciclovir Famciclovir Foscarnet Brivudin Cidofovir Fomivirsen