SystImmune has dosed the first patient in the global Phase III BrenDeLL‑Lung01 trial testing BL‑M14D1 plus atezolizumab in previously untreated ES‑SCLC. The randomised, multi‑centre study aims to enrol about 580 patients and will use progression‑free survival by blinded independent central review as the primary endpoint. BL‑M14D1 is a DLL3‑targeting ADC based on the brengitecan platform that delivers a topoisomerase I inhibitor; its move to Phase III follows promising Phase I data presented at ASCO 2026.
SystImmune Doses First Patient in Global Phase III BrenDeLL‑Lung01 Trial of DLL3‑Targeting ADC BL‑M14D1 for ES‑SCLC
BL-M14D1 targets DLL3
SystImmune has dosed the first patient in its global Phase III study, BrenDeLL‑Lung01, which will evaluate the investigational antibody‑drug conjugate (ADC) BL‑M14D1 in combination with the PD‑L1 inhibitor atezolizumab for adults with previously untreated extensive‑stage small cell lung cancer (ES‑SCLC).
The randomised, multi‑centre trial is planned to recruit approximately 580 participants and will compare BL‑M14D1 plus atezolizumab against the current standard of care. The study's primary endpoint is progression‑free survival (PFS) as assessed by a blinded independent central review (BICR).
About BL‑M14D1
BL‑M14D1 is an investigational ADC that recognises delta‑like protein 3 (DLL3), a surface protein expressed at high levels on small cell lung cancer and other neuroendocrine tumour cells. Built on SystImmune's brengitecan platform, the ADC is engineered to selectively deliver a topoisomerase I inhibitor payload to DLL3‑positive tumour cells to maximise tumour cell killing while limiting off‑target effects.
Clinical Background
The launch of this Phase III programme follows encouraging first‑in‑human data from the Phase I trial BL‑M14D1‑101, which SystImmune presented at the 2026 ASCO Annual Meeting. In that study, BL‑M14D1 showed anti‑tumour activity and a manageable safety profile in patients who had received multiple prior lines of therapy for SCLC and other neuroendocrine carcinomas.
"The initiation of our global Phase III programme marks an important milestone for BL‑M14D1 and reflects our commitment to bringing innovative treatment options to patients with small cell lung cancer," said Jonathan Cheng, SystImmune's chief medical officer. "Despite recent advances, outcomes for patients with extensive‑stage disease remain poor, and we are encouraged to evaluate BL‑M14D1 in a registrational setting."
Beyond BL‑M14D1, SystImmune's development pipeline includes programmes targeting both solid tumours and hematologic malignancies, with multiple assets at various preclinical and clinical stages.
Originally reported by Clinical Trials Arena (a GlobalData brand).
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