In clinical trial SGI-1776 was administered orally at escalating dose levels ranging from 350 to 1600 mg/day. Clinical trial was prematurely terminated due to unacceptable toxicity of SGI-1776.

CLL cells were treated with DMSO alone or with 0.3, 1, 3, or 10 μmol/L SGI-1776 for 24 hours. Cells (10^6) were washed, resuspended in 100 μL of annexin binding buffer, and mixed with 5 μL of annexin–fluorescein isothiocyanate (FITC) solution and 5 μL of propidium iodide solution with 2.5 μg/mL DNase-free RNase A (Roche). At least 10 000 cells were measured per sample by the use of a Becton Dickinson FACSCalibur flow cytometer. Caspase inhibitor N-benzyloxycarbonyl-valyl-alanyl-aspartyl-fluoromethylketone (ZVAD) was obtained from Alexis Biochemicals, and cells were treated with DMSO alone or 25 μmol/L ZVAD with or without 10 μmol/L SGI-1776 treatment for 24, 48, and 72 hours and then analyzed by flow cytometry. In vitro incubation of primary CLL cells (n = 7), with 1, 3, and 10 μmol/L SGI-1776 for 24 hours resulted in an average increase in apoptosis of 10%, 22%, and 38%, respectively, compared with untreated cells.