Hematological Toxicity. Table 3 summarizes the drugrelated
hematological toxicities observed during the study.
Grade 3 neutropenia occurred in 1 patient at dose levels 3 and 4,
respectively. Grade 4 neutropenia was observed at dose level 5
in a patient who had refractory small cell lung cancer and had
been previously heavily pretreated with etoposide, cisplatin,
topotecan, gemcitabine, and carboplatin. However, no patient
with grade 3 or 4 neutropenia experienced any related complications
such as fever. Because the neutrophil count recovered by
day 21, treatment delay or growth factor support due to neutropenia
was never required.