The cancer that knocked Philadelphia Flyers phenom Oskar Lindblom out of the remaining hockey season may soon face a new targeted therapy drug. The U.S. Food and Drug Administration recently announced that a drug called SP-2577 (seclidemstat) for relapsed or recurrent Ewing sarcoma has gained “fast track” designation in ongoing clinical trials led by a Moffitt Cancer Center physician scientist.

Ewing sarcoma is a type of tumor that forms in bone or soft tissue. Though rare, this cancer most often occurs in adolescents or young adults. It’s frequently diagnosed through unexplained fever, limb or chest pain, or bone breaks for no apparent reason. Chemotherapy, tumor resection surgery and radiation therapy are currently the only treatment options available. If the cancer should recur after treatment, survival statistics are grim: a 70 – 90% five-year mortality rate for recurrent Ewing sarcoma patients.

“There are no approved targeted therapies for Ewing sarcoma,” noted Dr. Damon Reed, director of Moffitt’s Adolescent and Young Adult Program and principle investigator for the seclidemstat clinical trial. “This drug has demonstrated a potential to address this considerable unmet need, and we look forward to rapidly advancing its development so that it soon may be available to those patients most in need.”

The phase 1/2 clinical trial sponsored by the drug’s developer, Salarius Pharmaceuticals, has been enrolling patients since 2018. Salarius is expected to release data on the first group of participants early in 2020. Patients are still being recruited for the phase 2 portion of the trial. The open label, non-randomized, single-arm study will use an accelerated dose escalation, followed by a conventional 3+3 dose escalation to achieve maximum tolerated dose. Current study participants take the drug by mouth twice daily.

More than 85% of Ewing sarcoma is caused by translocation errors in the EWS gene, which produces a protein called EW. It’s thought that the cancer occurs when the EW protein interacts with a substance called lysine-specific histone demethylase 1 (LSD1). Seclidemstat is a potent reversible LSD1 inhibitor and has resulted in cures in animal models. Because it is reversible, seclidemstat could potentially offer more efficacy, more flexible dosing and less toxicity.

Drug development of seclidemstat was made possible with ongoing support from the National Pediatric Cancer Foundation (NPCF). “The Foundation is proud to provide financial support to advance the Ewing sarcoma clinical program through our Sunshine Project research initiative,” stated David Frazer, CEO of NPCF.   The Sunshine Project is a national collaborative consortium involving 24 leading hospital to research less toxic, more therapeutic therapies for pediatric cancer.  And in this case, the efforts have the potential to help young adults diagnosed with Ewing sarcoma as well.