EWSR1 Immunotherapy in Ewing Sarcoma and DSRCT

Trial statusNot yet recruiting
Trial phasePhase 1
Trial typeInterventional
Biological sexAll
Age2+
SponsorRabi Hanna

About this trial

This study is for people who have high-risk Ewing sarcoma (ES), or a related Ewing's family tumor, desmoplastic small round cell tumor (DSRCT). The purpose of this study is to see if a new EWSR1 immunotherapy (a lipid nanoparticle coated with EWSR1 mRNA) which is given as a shot is safe and whether it can help the body's immune system better recognize and fight cancer.

This EWSR1 immunotherapy is designed to target a specific genetic change (EWSR1 fusion gene) that is found in cancer cells but not in normal, healthy cells. Because the EWSR1 gene is broken in cancer cells and the small protein it makes are only in the ES or DSRCT cancer cells, the goal of EWSR1 immunotherapy is to help the immune system identify and attack the cancer without harming normal cells. It is not yet approved by the Food and Drug Administration (FDA).

EWSR1 immunotherapy will be given as a shot into the muscle of the arm, leg, or buttock. If participants also receive botensilimab (4 doses after each EWSR1 immunotherapy shot) and balstilimab (an infusion every 2 weeks), these are given intravenously (IV) by a needle in the arm over 30 minutes. Participants in this study will receive treatment for about 6 months or until their cancer gets worse. Participants will remain in the study for follow-up for an additional year, for a total time of about 1.5 years in the study.

Eligibility criteria

Qualifiers

Participants must have histologically confirmed Ewing sarcoma (ES) or desmoplastic small round cell tumor (DSRCT) and confirmation of fusion gene rearrangement and breakpoint EWSR1-FLI1, EWSR1-ERG, EWSR1-WT1, who have completed standard of care vincristine + doxorubicin + cyclophosphamide alternating with ifosfamide + etoposide (VDC/IE) and have relapsed or had metastatic disease or are very high-risk disease (Bosma groups C, D, E, and/or very poor necrosis after VDC/IE) are eligible. All EWSR1 immunotherapy monotherapy participants are expected to have completed standard of care VDC/IE chemotherapy with local control and have had end of therapy follow-up for > 3 months.

Participants must have demonstrated HLA (human leukocyte antigens) fit with an EWSR1 gene fusion peptide contained in the EWSR1 immunotherapy, as determined by HLA-binding analysis of peptides that span the EWSR1 fusion gene breakpoint and analysis of HLA fit to one of the constructs included in EWSR1 immunotherapy.

Participants may have no evidence of active disease, detectable disease (e.g., lung metastases < 1 cm or bone metastases), or measurable disease by iRECIST (Immune Response Evaluation Criteria in Solid Tumors) criteria. The presence of RECIST measurable disease is not required for study entry.

At least 1 line of prior therapy (VDC/IE) is needed.

Disqualifiers

Participants on concurrent chemotherapy or other immunotherapy.

Participants who have not recovered from adverse events due to prior anti-cancer therapy (i.e., have residual toxicities ≥ Grade 2) with the exception of alopecia and lymphopenia, post-nadir neutropenia and thrombocytopenia, and decreased function that has achieved a "new and stable baseline" from cancer, surgery, or radiation.

Participants who are receiving any other investigational agents.

Participants on total parenteral nutrition.

Trial design

Treatments tested in this trial

  • EWSR1 immunotherapy
  • Botensilimab
  • Balstilimab

Treatment groups

24 Participants
are divided into 2 treatment groups

Sponsors and collaborators

Rabi Hanna

Lead sponsor

Case Comprehensive Cancer Center

Sponsor institution

The Little Warriors Foundation

Collaborator