A Phase I Study of Seclidemstat (SP-2577) with and without Topotecan and Cyclophosphamide in Patients with Recurrent or Persistent Ewing Sarcoma and Other Select Sarcomas


Full Title

Phase 1 Trial of the LSD1 Inhibitor Seclidemstat (SP-2577) with and without Topotecan and Cyclophosphamide in Patients with Relapsed or Refractory Ewing Sarcoma and Select Sarcomas


The purpose of this study is to evaluate the safety and tolerability of SP-2577 (seclidemstat) alone and with topotecan and cyclophosphamide (TC) in patients with recurrent or persistent Ewing sarcoma and other select sarcomas. SP-2577 is designed to block the activity of a protein called LSD1. This protein plays a role in selecting which genes are turned on to make other proteins.

Blocking LSD1 may prevent a protein responsible for Ewing sarcoma from binding to DNA and changing the function of other genes, allowing genes to make cells function like normal cells rather than cancer cells. SP-2577 is taken orally (by mouth).


To be eligible for this study, patients must meet several criteria, including but not limited to the following:

  • Patients must have Ewing sarcoma or other select types of sarcoma, such as myxoid liposarcoma, desmoplastic small round cell tumor, or other sarcomas that have genetic features similar to those in Ewing sarcoma. The study treatment that patients receive (SP-2577 alone or with TC) will depend on their tumor type and prior therapies.
  • Patients must recover from the serious side effects of prior therapies before entering the study.
  • This study is for patients age 12 and older.

For more information about this study and to inquire about eligibility, please contact 1-833-MSK-KIDS.





Disease Status

Relapsed or Refractory