Electra Therapeutics presents first clinical data from ongoing Phase 1b study of ELA026 for treatment of secondary hemophagocytic lymphohistiocytosis (sHLH)

Electra Therapeutics, Inc., a clinical stage biotechnology company developing antibody therapies against novel targets for immunological diseases and cancer, announced the presentation of the first clinical data for ELA026, the company's lead candidate in development for the treatment of secondary hemophagocytic lymphohistiocytosis (sHLH), a life-threatening inflammatory disease. The results were presented at the American Society of Hematology (ASH) annual meeting being held in San Diego, California, December 9-12, 2023.

Data from ten sHLH patients in the ongoing Phase 1b clinical study showed favorable safety results and overall response rate (ORR) of 70% in all patients dosed with ELA026. An ORR of 88% was observed in the eight patients with evaluable data. The majority of enrolled patients were difficult-to-treat, malignancy-associated HLH and displayed poor prognostic clinical and biomarker features at baseline.

ELA026 is a monoclonal antibody that targets signal regulatory protein (SIRP)-?/?1/? on the cell surface of myeloid and T cells, the pathological immune cells that induce the hyperinflammatory response in sHLH. The Phase 1b study is an ongoing open-label, multi-dose, single-arm, multicenter study designed to evaluate the safety and efficacy of ELA026, assess biomarkers and identify a dose for Phase 2/3 testing (ClinicalTrials.gov identifier: NCT05416307).

"sHLH is a life threatening and challenging disease that is devastating for patients and has no approved treatment options," said Swaminathan P. Iyer, MD, Professor in the Department of Lymphoma/Myeloma at The University of Texas MD Anderson Cancer Center. "The patients enrolled in the study thus far are among the sHLH patient subtypes with the worst prognosis, and we are encouraged by this data showing that ELA026 is well tolerated and leads to promising responses."

Study Results Presented at ASH Annual Meeting

The poster presentation at ASH, titled "A Phase 1b Study of ELA026, a Monoclonal Antibody Targeting Signal Regulatory Protein-?/?1/?, in Patients with Newly Diagnosed and Previously Treated Secondary Hemophagocytic Lymphohistiocytosis," was presented by the lead author, Abhishek Maiti, MD, Assistant Professor in the Department of Leukemia at The University of Texas MD Anderson Cancer Center. The data describe an analysis of ten patients in the first two cohorts of the ongoing clinical study, including the following highlights:

• Of the ten enrolled patients, eight were associated with a malignancy trigger and two had an unknown trigger. Five patients had relapsed/refractory sHLH.
• Overall, ELA026 was well tolerated with a favorable safety profile in the study.
• ELA026 achieved ORR of 70% in ten patients dosed and ORR of 88% in eight patients with evaluable data, despite poor baseline prognostic and clinical indicators related to sHLH.
• Three patients with ? 90% reduction of ferritin and sCD25 from baseline or peak values also had tumor complete responses, including a patient with peripheral T-cell lymphoma refractory to chemotherapy.
• ELA026 reduced peripheral monocyte and lymphocyte counts and resulted in early and rapid decrease in c-reactive protein (CRP) and sHLH-associated cytokines and biomarkers.

"We are pleased to present these promising first clinical results for ELA026 in the treatment of sHLH patients," said Kim-Hien Dao, DO, PhD, Vice President, Head of Clinical Development at Electra. "We are extremely encouraged by the data from the first two cohorts, and we look forward to continuing enrollment for this study as we advance the ELA026 clinical program."

About Secondary Hemophagocytic Lymphohistiocytosis (sHLH)

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening hyperinflammatory condition for which there is no approved treatment. It can be triggered by cancer (malignancy-associated HLH, or mHLH), infections, or autoimmune disease. sHLH is associated with a systemic inflammatory response for which patients require immediate and aggressive treatment with intensive care. Without treatment, patients may experience multiple organ failure and death. sHLH has a high mortality rate during the first months of diagnosis, with mHLH patients having the poorest outcomes.

About Electra Therapeutics

Electra Therapeutics is a clinical stage biotechnology company developing therapies against novel targets for the treatment of immunological diseases and cancer. Electra currently has one program in clinical development and additional preclinical programs. The company's lead product candidate, ELA026, is a monoclonal antibody that targets SIRP on the cell surface of myeloid and T cells, and precisely depletes pathological immune cells. ELA026 is in clinical development for secondary hemophagocytic lymphohistiocytosis (sHLH), a life-threatening hyperinflammatory condition for which there is no approved treatment. For more information, please visit www.electra-therapeutics.com and follow us on LinkedIn.