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 0,9 Brivud in 0,8 Fam ciclovir 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.