Evaluating tocilizumab in ischemic stroke: Findings from the SPAN multicenter trial

Area of Science:

• Neuroscience
• Immunology
• Pharmacology

Background:

• Interleukin-6 (IL-6) signaling is a key factor in stroke pathophysiology, with high levels linked to poor patient outcomes.
• Targeting IL-6 signaling presents a potential therapeutic strategy to reduce stroke-induced damage and enhance recovery.

Purpose of the Study:

• To evaluate the efficacy of tocilizumab (TCZ), an IL-6 receptor inhibitor, in preclinical stroke models.
• To assess TCZ's impact on sensorimotor recovery and brain tissue loss following middle cerebral artery occlusion (MCAO).

Main Methods:

• Analysis of behavioral and MRI data from 701 rodents (mice and spontaneously hypertensive rats) subjected to MCAO.
• Treatment with saline (placebo) or TCZ at varying doses based on species.
• Assessment of long-term sensorimotor function and brain lesion volume via MRI morphometry.

Main Results:

• TCZ did not significantly improve overall sensorimotor recovery or reduce brain tissue loss in the general mouse cohort.
• Modest motor function improvements were observed in aging mice treated with TCZ.
• TCZ enhanced sensory-motor function in spontaneously hypertensive rats, particularly males, and provided early cerebroprotection, but did not prevent later tissue atrophy.

Conclusions:

• IL-6 receptor blockade with TCZ demonstrated functional benefits in specific rodent models (aging mice, male hypertensive rats) but lacked durable effects on brain tissue loss.
• These findings support IL-6 signaling as a therapeutic target for stroke recovery.
• Further investigation of IL-6 receptor inhibition is recommended for stroke treatment strategies.