- Once the MTD has been determined, the study then will proceed to the phase II portion using a phase II optimal design where initially 21 evaluable patients will be enrolled in each of 2 cohorts. If 0 or 1 of the 21 patients experiences a clinical response, then no further patients will be enrolled but if 2 or more of the first 21 evaluable patients enrolled have a clinical response, then accrual will continue until a total of 41 evaluable patients have been enrolled.