4. Subjects fulfilling one of the following criteria are eligible to participate in the study: Subjects with measurable disease as per RECIST criteria. This is defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded) as over 20 mm with conventional technique or as over 10 mm with spiral CT scan or MRI. Subjects with bone lesions, lytic or mixed (lytic + sclerotic), in the absence of measurable disease as defined by RECIST criteria. The lytic component of at least one bone lesion should measure 20 mm with conventional techniques or 10 mm with spiral CT scan or MRI. At least one bone lesion satisfying these criteria must be outside any previously irradiated area.