Evaluate the Safety and Efficacy for Oral Mucositis Prevention of MIT-001 in Auto HSCT

In Part 1, it was to determine Recommended Part 2 Dose(RP2D) the prevention effect of MIT-001 in combination with conditioning regimen in autologous hematopoietic stem cell transplantation(auto-HSCT) and to evaluate the pharmacokinetic characteristics of MIT-001.

In Part 2, it's to determine the optimal dose of MIT-001 in combination with conditioning regimen in auto-HSCT.

This clinical trial consists of a 28-days of screening period, 4 to 9 days of conditioning chemotherapy with MIT-001 treatment, auto-HSCT and a 14-days of follow-up and recovery period.

MIT-001 group consists of 5 mg (group 1), 10 mg (group 2), and 20mg (group 3), and the subject will be assigned to from 5 mg of MIT-001 sequentially.

After completion of MIT-001 administration from all 3 MIT-001 groups, Steering Committee (SC) was convened and reviewed the safety and efficacy to determine one of the followings.

* Determine whether the next dose (Group 4: 30 mg) in Part 1: It was not proceeded. * Determine the RP2D to enter Part 2 phase: 5mg as low dose, 20mg as high dose for Part 2 The investigators will continuously monitor the safety of MIT-001, and can request the steering committee call at any time, and can be carefully reviewed the data such as safety and efficacy.

In Part 2, the subjects are randomly assigned to either one of MIT-001 treatment groups (high-dose, low-dose among RP2D) and placebo at a ratio of 1: 1: 1. If two or more conditioning regimen are determined, conditioning regimen can be considered the stratification factor. Subject will be randomly assigned to either group in blinded method.