<qa>  How many patients will be enrolled at the defined dose?To evaluate the activity of Erwinaze to reduce the serum glutamine to the desired level, the dose will be adjusted according to a pre-defined algorithm based on 48-hour trough serum glutamine level biochemical response prior to dose 6 of each patient. If the safety profile is acceptable, we will enroll up to a total of 15 patients at that dose level to better study and analyze the glutamine-reducing effect of Erwinaze at the defined dose. 