Release Details

Phase 1 study builds on early signals of anti-tumor activity in patients with refractory T and B cell lymphomas

Ipsoprubart, a first-in-class SIRP-targeting therapy, expands into T cell malignancies alongside ongoing pivotal study in secondary hemophagocytic lymphohistiocytosis (sHLH)

SOUTH SAN FRANCISCO, CA, May 5, 2026 – Electra Therapeutics, a clinical stage biotechnology company pioneering therapies against novel targets for diseases in immunology and cancer, today announced dosing of the first patient in a Phase 1 study of ipsoprubart (ELA026) in patients with T cell malignancies. Ipsoprubart, a first-in-class monoclonal antibody targeting signal regulatory proteins (SIRP) on immune cells, is designed to selectively deplete pathological T cells and myeloid cells, with the potential to inhibit tumor growth and survival through both direct tumor cell elimination and tumor microenvironment modulation.

Initial evidence of anti-tumor activity in lymphoma, including T cell malignancies, was observed in a Phase 1b study of ipsoprubart in secondary hemophagocytic lymphohistiocytosis (sHLH), in patients whose disease was triggered by the underlying lymphoma. These findings supported advancement into a dedicated study in T cell malignancies, extending the clinical program for ipsoprubart beyond the ongoing pivotal study in sHLH. The Phase 1 study in T cell malignancies will evaluate safety and efficacy in patients treated with ipsoprubart monotherapy. T cell malignancies are a group of rare, aggressive lymphomas and leukemias arising from mature or immature T lymphocytes. More than 13,000 patients in the US are diagnosed annually with T cell malignancies and have limited effective treatment options that provide durable disease control.

“Our team has pioneered SIRP targeting as a therapeutic approach to selectively deplete pathological immune cells,” said Kathy Dong, PharmD, MBA, President and CEO of Electra Therapeutics. “We are excited to follow the science and expand into T cell malignancies, where new treatment approaches are needed for patients and ipsoprubart has shown promising potential.”

The open-label Phase 1 study will enroll adults with relapsed or ​refractory T cell malignancies. Patients may receive up to six cycles (24 weeks) of treatment with ipsoprubart. The study consists of two parts: Part 1 will enroll up to 24 patients to identify up to two dosing regimens with acceptable safety profiles; Part 2 will further evaluate these regimens in expansion cohorts. The primary endpoint is safety, including drug-related toxicities and treatment-emergent adverse events. Secondary endpoints include overall response rate, duration of response, and disease control rate. Additional details are available on clinicaltrials.gov (NCT07465835).

“The initiation of this study reflects strong interest from clinical investigators who were highly encouraged by the anti-tumor effect observed within weeks of treatment with ipsoprubart in the Phase 1b study in sHLH,” said Kim‑Hien Dao, DO, PhD, Chief Medical Officer of Electra Therapeutics. “Patients with relapsed or refractory T cell malignancies have limited treatment options and poor outcomes. The promising activity observed in heavily treated patients, including responses to ipsoprubart monotherapy, supports our further evaluation in this setting.”