If none of the first three patients experiences a dose-limiting toxicity (DLT) during the first cycle (3 weeks), the next 3 patients will receive the next dose level. If there is a DLT in one of the first three patients, this dose level will be expanded to 6 patients. If 1 patient out of 6 experiences DLT, the next patients will receive the next dose level. If ≥ 2 patients experience DLT at any dose level, this dose level will be declared the Maximally Administered Dose. The Maximally Tolerated Dose (MTD) and RPTD will be the highest dose level below the Maximally Administered Dose with 0 out of 3 patients or one out of 6 patients with DLT. Dosing will be reduced to the immediate lower dose for any patient who experiences a DLT at any time.