ELA026 Shows Promise for Secondary HLH in Phase 1b Study

Swaminathan P. Iyer, MD

Credit: The University of Texas

ELA026 displayed a high overall response rate (ORR) and a favorable safety profile across a range of patients with secondary hemophagocytic lymphohistiocytosis (sHLH), according to late-breaking data presented at the European Hematology Association (EHA) Congress.¹

Announced by Electra Therapeutics on June 16, 2024, these results showed treatment-naive patients with malignancy-associated HLH (mHLH), the deadliest sHLH subtype, demonstrated a 100% overall response rate at week 4, with improved survival at two months, compared with natural history studies.

“These data show very promising results for ELA026 as a potential treatment for sHLH, which is a challenging disease that is devastating for patients and has no approved treatment options,” said Swaminathan P. Iyer, MD, a professor in the department of lymphoma/myeloma at The University of Texas MD Anderson Cancer Center.¹ “Notably, the analysis reveals improved survival was achieved with ELA026 in treatment-naïve mHLH patients, suggesting benefit from early treatment intervention for patients with this rapidly progressing disease.”

A rare, life-threatening inflammatory disease, sHLH has no current approved treatment.² The disease can be prompted by cancer, infection, autoimmune disease, or immunotherapy. It is linked to a systemic inflammatory response which can require immediate intervention.

Without receiving treatment, patients can experience multiple organ failure or death. sHLH has demonstrated an increased mortality rate during the first few months after diagnosis, and patients with the mHLH subtype typically exhibit worse outcomes.²

ELA026 is a first-in-class monoclonal antibody targeting signal regulatory protein α/β1/γ on the cell surface of myeloid cells and T lymphocytes, which induce hyperinflammation in sHLH.³ This Phase 1b study is an ongoing, open-label, multi-dose, single-arm, multi-center study designed to assess the safety and efficacy of ELA026 and evaluate biomarkers.¹ It also set out to identify a dose for further Phase 2/3 testing.

Most patients in the trial had mHLH which has the poorest outcomes, with a mortality of nearly 50% at two months. The analysis demonstrated a favorable safety profile of ELA026 in patients with mHLH, with reasonable adverse events.

Across the completely enrolled Cohorts 1 and 2 (n = 12), ELA026 reached an ORR of 75% by Week 4. Cohort 3 enrollment is ongoing, with 5 patients enrolled as of April 2024.

Among those enrolled, 8 patients had treatment-naive mHLH. For this cohort, ELA026 demonstrated an ORR of 100% by Week 4 and survival of 88% at two months. Pharmacodynamic and biomarker responses were shown to correlate with clinical response.

The Phase 1b study plans to expand to include up to 20 patients in Cohort 3 and continue to evaluate ELA-26 in frontline treatment settings across multiple subtypes of sHLH. Electra indicated the clinical development program will continue to prioritize the safety and efficacy of ELA026 for SLH, which has no current approved therapies.

“This interim data is extremely encouraging, particularly with the high response rates and improved survival at two months achieved in treatment-naïve mHLH patients, and suggests ELA026’s promise as a first-line treatment,” said Kim‑Hien Dao, DO, PhD, Chief Medical Officer at Electra.¹ “Survival at two months is a clinically meaningful benefit for this patient population and demonstrates the ability of ELA026 to rapidly extinguish the hyperinflammation in sHLH, enabling mHLH patients to pursue curative therapies for their underlying cancer.”

References

1. _{Electra Therapeutics presents late-breaking clinical data at EHA2024 from ongoing phase 1b study of ELA026 in secondary hemophagocytic lymphohistiocytosis (sHLH). ELECTRA Therapeutics. June 16, 2024. Accessed June 18, 2024. https://electra-therapeutics.com/electra-therapeutics-presents-late-breaking-clinical-data-at-eha2024-from-ongoing-phase-1b-study-of-ela026-in-secondary-hemophagocytic-lymphohistiocytosis-shlh/.}
2. _{Hines M, Bhatt N, Talano JAM. Diagnosis, Treatment, and Management of Hemophagocytic Lymphohistiocytosis in the Critical Care Unit. Critical Care of the Pediatric Immunocompromised Hematology/Oncology Patient. 2018;159-182. Published 2018 Oct 10. doi:10.1007/978-3-030-01322-6_9}
3. _{ELA026. ELECTRA Therapeutics. Accessed June 19, 2024. https://electra-therapeutics.com/ela026/.}