- At least one measurable lesion defined as lesion(s) that can be accurately measured in at least two dimensions and is ≥ 10 mm in each dimension by Gadolinium (Gd)-MRI, irrespective of slice thickness/reconstruction interval, for CNS lesions and CT or MRI (with or without contrast) for non-CNS lesions. All patients with CNS lesions must have a brain MRI with and without gadolinium and a spine MRI with gadolinium within 2 weeks prior to first dose of study treatment.