Investigator-Initiated Phase 1/2 Clinical Trial Using Salarius Pharmaceuticals' Seclidemstat In Combination With Azacitidine To Treat Hematologic Cancers Resumes Patient Enrollment

Author: Benzinga Newsdesk | January 03, 2024 09:44am

Salarius Pharmaceuticals, Inc. (NASDAQ:SLRX) announces that the hematologic cancer Phase 1/2 clinical trial being conducted at the University of Texas MD Anderson Cancer Center (MDACC or MD Anderson) is now listed as active and recruiting on clinical trials.gov – trial NCT04734990. Salarius also announces that an additional Ewing sarcoma patient treated with seclidemstat, topotecan and cyclophosphamide (TC) has achieved a partial response as demonstrated by at least a 30% decrease in the sum of diameters of the patient's target lesions, bringing the objective response rate (ORR) in Ewing sarcoma first-relapse patients to 60%, with a 60% disease control rate (DCR).

 

As reported on August 8, 2023, Salarius retained Canaccord Genuity, LLC to lead a comprehensive review of strategic alternatives focusing on maximizing shareholder value. While these efforts are ongoing, the Company continues to support the continuation of its clinical programs, as appropriate.

In October 2022, the FDA placed the MDACC investigator-initiated trial under a partial clinical hold following a suspected unexpected serious adverse reaction (SUSAR) in the FET-rearranged arm of Salarius' Phase 1/2 trial with seclidemstat in sarcomas. The SUSAR observed in the FET-rearranged patients has not been observed in patients in the MDACC investigator-initiated trial.

"We are pleased that the FDA has removed the partial clinical hold on the MD Anderson trial with seclidemstat in blood cancers, and we are excited about the prospect of MD Anderson enrolling additional patients and building a broader database of patient data," said David Arthur, president and chief executive officer of Salarius Pharmaceuticals. "MDACC researchers previously reported what we believe are encouraging interim results, and we look forward to learning what potential benefits patients will experience at higher doses of seclidemstat."

"We are also pleased to see that patients continuing treatment with seclidemstat and TC continue to improve. With our Food and Drug Administration Type B meeting process completed, we plan to file an amended Ewing protocol focusing on first relapse patients, who we believe will benefit from Seclidemstat and TC combination therapy," concluded Mr. Arthur.

Seclidemstat is a novel oral reversible inhibitor of the LSD1 enzyme and has received fast track, orphan drug and rare pediatric disease designations for Ewing sarcoma from the FDA. In addition to the MDACC investigator-initiated clinical trial, seclidemstat has been studied in a company-sponsored Phase 1/2 clinical trial evaluating its use in combination with TC for the treatment of relapsed/refractory Ewing sarcoma.

Researchers at MDACC previously reported interim clinical trial results evaluating seclidemstat in combination with azacitidine for the treatment of myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML) patients who relapsed or progressed after hypomethylating agent therapy. Of eight evaluable patients, four (50%) had an objective response. These researchers reported a 90% probability of survival for 11 months in patients receiving seclidemstat plus azacitidine. Typically, overall survival is four to six months after failing therapy with hypomethylating agents.

The Company-sponsored Ewing sarcoma clinical trial focuses on seclidemstat in combination with TC as a treatment for relapsed and refractory Ewing sarcoma. As of December 2023, a total of 13 relapsed Ewing sarcoma patients, including five patients with first relapse and eight patients with second relapse, were enrolled at seclidemstat doses of 600 mg or 900 mg twice daily in combination with TC chemotherapy.

• The five first-relapse patients demonstrated a 60% ORR and a 60% DCR including a complete response and two partial responses. Among the three patients achieving ORR, the median progression-free survival (mPFS) has not been reached with these patients still having disease control and objectives responses at 17.4, 25.7 and 27.2 months, and increasing, after starting seclidemstat + TC combination treatment.
• The eight second-relapse patients demonstrated a 13% ORR, a 25% DCR and a mPFS of 1.6 months (range: 0.0 months to 10.7 months).
  • Together the 13 first- and second-relapse patients demonstrated a mPFS of 8.1 months (range: 2.0 months to 27.2 months). Five patients, or 38%, achieved confirmed disease control and progression has not been observed in any of these patients while on study.
     

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