Sequential dose-escalating cohorts of three to six patients with
hematological malignancies received
belinostat administered as a 30-min i.v. infusion on days 1-5 of a 21-d cycle. Experience from a parallel dose-finding study in patients with solid
tumors influenced the selection of the final dose.
RESULTS: Sixteen patients received
belinostat at one of three dose levels: 600 mg/m(2)/d (three patients), 900 mg/m(2)/d (three patients) and 1000 mg/m(2)/d (10 patients), the dose determined to be the MTD in a phase I solid
tumor study [Steele et al. (2008) Clin
Cancer Res, 14, 804-10]. The most common treatment-related adverse events (all grades) were
nausea (50%),
vomiting (31%),
fatigue (31%) and
flushing (31%). No grade 3 or 4 hematological toxicity compared with baseline occurred except one case of grade 3
lymphopenia. There were two related grade 4 adverse events of
renal failure observed. Both events occurred in patients with
multiple myeloma and had similar characteristics, i.e. an acute episode of decrease in renal function (pre-existing nephropathy in one patient), with a metabolic profile and decrease in
tumor burden consistent with
tumor lysis syndrome. No other related grade 4 events were noted. The only related grade 3 events noticed in more than one patient were
fatigue and neurological symptoms (one patient had
status epilepticus in association with
uremia and one patient had
paresthesia), all other related grade 3 events occurred in single patients. No
cardiac events were noted. No complete or partial remissions were noted in these heavily pre-treated (median of four prior regimens) patients. However, five patients, including two patients with
diffuse large-cell lymphoma [including one patient with transformed chronic myelocytic leukaemia (CLL)], two patients with CLL and one patient with
multiple myeloma, achieved disease stabilization in of two to nine treatment cycles.
CONCLUSIONS: Intravenous
belinostat at 600, 900 and 1000 mg/m(2)/d is well tolerated by patients with
hematological malignancies. The study was carried out in parallel to a similar dose-finding study in patients with solid
tumors, in which the MTD was determined to be 1000 mg/m(2)/d days 1-5 in a 21-d cycle. This dose can also be recommended for phase II studies in patients with
hematological neoplasms.