Cell experiment:

In order to evaluate drug toxicity, 96-well microtitre plates are prepared with 100 μL of EMEM/10 per well. After addition of 2 μL of 50 mM Tomeglovir stock solutions in duplicate into 198 μL in row 2, serial two-fold dilutions are made with 100 μL up to row 12 and 100 μL of a HELF, NHDF or 3T3 cell suspension (5 × 103 cells/mL) are added per well. Row 1 serves as an untreated cell control. After incubation for 6 days at 37℃ and 5% CO2, the cells are washed once with phosphate-buffered saline (PBS), and 200 μL of a 10 μg/mL fluorescent dye solution in PBS, pH 7.2 (fluorescein diacetate) are dispensed per well. After 45 min, the fluorescence signal is measured with a Fluorskan Ascent fluorimeter (excitation filter 485 ± 11 nm, emission filter 530 ± 15 nm). The relative fluorescence units (RFUs) of treated cells are expressed as percentages of untreated cell controls and CC50 values are determined graphically[2].

Animal experiment:

Mice[1]NOD/LtSz-scid/j mice, 20-30 g body weight, are anesthesized with 0.015-0.017 mL/g body weight Avertin 2.5% (Avertin 100% consists of 10 g tribromoethyl alcohol in 10 mL tertiary amyl alcohol). After shaving and cleaning the belly aseptically, the abdomens are opened and the fibers inserted intra-abdominally. The abdomens are closed with two suture layers. Only asymptomatic animals are included in the study. Starting 1 day after transplantation, the mice are treated with the Tomeglovir at indicated dosages twice daily for four consecutive days per os. In preliminary experiments, viral peak titers are observed on day 5 under these conditions[1].

Tomeglovir is a potent anti-CMV agent, inhibiting processing of viral DNA-concatemers, with IC50s of 0.34 μM and 0.039 μM for HCMV and MCMV.

Tomeglovir (BAY 38-4766) is a potent anti-CMV agent, with IC50s of 0.34 μM and 0.039 μM for HCMV and MCMV. Tomeglovir also suppresses HELF and NIH 3T3 cells, with CC50s of 85 μM and 62.5 μM, respectively[1]. Tomeglovir (BAY 38-4766) inhibits HCMV Davis and various monkey CMV strains with EC50s of 1.03 ± 0.57 μM and< 1 μM[2].

Tomeglovir (BAY 38-4766; 3, 10, 30, 100 mg/kg, p.o.) dose-dependently reduces MCMV-DNA in salivary glands, livers and kidneys of MCMV-infected NOD-SCID mice, and prolongs the survival of the mice. Tomeglovir (10, 25 and 50 mg/kg) shows antiviral activity in the hollow fiber mouse model[1]. Tomeglovir (BAY 38-4766) shows antiviral activity in SCID mice with MCMV, and the LD50 is >2000 mg/kg in mice and rats[2].

[1]. Weber O, et al. Inhibition of murine cytomegalovirus and human cytomegalovirus by a novel non-nucleosidic compound in vivo. Antiviral Res. 2001 Mar;49(3):179-89. [2]. Reefschlaeger J, et al. Novel non-nucleoside inhibitors of cytomegaloviruses (BAY 38-4766): in vitro and in vivo antiviral activity and mechanism of action. J Antimicrob Chemother. 2001 Dec;48(6):757-67.