Electra Therapeutics highlights ELA026 Phase 1b study in sHLH and presents preclinical data at ASH Annual Meeting

• Ongoing Phase 1b study progressing in US and EU for ELA026 in sHLH, a life-threatening inflammatory disease
• Preclinical data demonstrate ELA026 proof-of-mechanism of SIRP targeting and depletion of pathological immune cells that drive sHLH
• Company also presents results of sHLH natural history study

SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)--Electra Therapeutics, Inc., a clinical stage biotechnology company developing novel antibody therapies that target signal regulatory proteins (SIRP), today announced presentations and clinical progress for ELA026, the company’s first-in-class antibody in development for the treatment of secondary hemophagocytic lymphohistiocytosis (sHLH), a life-threatening inflammatory disease. Three poster presentations supporting the company’s clinical development of ELA026 in sHLH are highlighted at the 64^th American Society of Hematology (ASH) Annual Meeting being held in New Orleans from December 10-13, 2022.

Electra also announced today that a Phase 1b global study of ELA026 in sHLH patients has been initiated and is ongoing (ClinicalTrials.gov identifier: NCT05416307). The Phase 1b study is highlighted as a clinical trial in progress poster at ASH, titled “A Phase 1b study of ELA026 in patients with secondary hemophagocytic lymphohistiocytosis.” The Phase 1b study is an open-label, single-arm, multicenter study which will evaluate the safety and efficacy of ELA026, assess biomarkers and identify a dose for Phase 2/3 testing.

“We are excited to advance ELA026 in the clinic as a novel approach targeting SIRP to address the aberrant myeloid and T cell activity that drives the sHLH disease process,” said Gary Patou, MD, Chief Medical Officer of Electra. “We have created a robust design for this Phase 1b study with the aim of progressing rapidly toward a Phase 2/3 study so we can accelerate ELA026 as a potential treatment option for sHLH patients in need.”

Study Results Presented at ASH Annual Meeting

Preclinical studies demonstrated ELA026’s proof-of-mechanism of SIRP targeting and depletion of pathological immune cells that drive sHLH. The poster presentation at ASH, titled “Characterization of ELA026, a clinical-stage monoclonal antibody that rapidly and potently depletes myeloid cells and T lymphocytes,” describes the pharmacology of ELA026 which binds to and depletes SIRP-expressing cells, and its pharmacokinetic (PK) profile and pharmacodynamic (PD) effects in non-human primates. The preclinical data includes the following highlights:

• In in vitro studies, ELA026 was shown to bind to SIRP proteins on the surface of primary human and cynomolgus monkey monocytes and T cells, inducing potent antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP).

• In vivo administration of ELA026 in cynomolgus monkeys showed a rapid and potent depletion of SIRP-expressing monocytes and lymphocytes, with a well-defined PK/PD relationship. Reversibility of the PD effect was achieved following washout suggesting that ELA026 treatment is not associated with long-term immunosuppression.

Electra also presented results of a sHLH natural history study at the ASH Annual Meeting in a poster, titled “Identification and characterization of a retrospective cohort of secondary hemophagocytic lymphohistiocytosis (sHLH) patients in the US,” showing that sHLH is a complex disease to diagnose and treat. The study has thus far reviewed approximately 1,500 unique patient medical records from a large medical system in the US and supports the need to improve our ability to identify sHLH patients and better understand the potential underestimation of the incidence of sHLH.

“We appreciate the dedication of the Electra team in supporting patients and families impacted by histiocytosis. sHLH is a life-threatening inflammatory disease with no approved treatments and, as a result, many patients suffer the debilitating effects of this condition,” said Deanna Fournier, Executive Director, Histiocytosis Association. “We welcome the promising new approach that ELA026 offers, and we join the patient community in supporting the advancement of new treatments for sHLH. Opportunities like these are what continue to give us hope!”

The three posters are available on Electra’s website.

About Secondary Hemophagocytic Lymphohistiocytosis (sHLH)
Secondary hemophagocytic lymphohistiocytosis (sHLH) is a life-threatening hyperinflammatory condition for which there is no approved treatment. sHLH can be triggered by cancer, immunotherapy, infection, or an autoimmune disease. Once triggered, sHLH requires immediate intervention. Without treatment, it can rapidly progress from symptoms such as persistent fever, hepatomegaly and/or splenomegaly, and cytopenias, to multi-organ failure and death.

About Electra Therapeutics
Electra Therapeutics is a clinical stage biotechnology company developing therapies that target signal regulatory proteins (SIRP) 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 Electra Therapeutics and follow us on Twitter @ELECTRA_Biotech and LinkedIn.