Key Takeaways
AC Immune SA’s experimental diagnostic tool for the first time showed signs of detecting the pathological protein TDP-43 in key brain regions of living ALS patients, a crucial step in developing targeted treatments for the fatal neurodegenerative disease.
The Swiss biopharmaceutical company’s ACI-19626 PET tracer showed significantly higher uptake in the brain stem and precentral gyrus of patients with amyotrophic lateral sclerosis, according to preliminary Phase 1 data presented Friday. The results, shared at the 2026 TDP43 Summit in Wisconsin, could advance a precision-medicine approach to diagnosing a range of neurological conditions.
"These data in ALS patients provide further evidence of ACI-19626’s potential to detect pathological TDP-43 in the brains of patients with TDP-43 proteinopathies," Andrea Pfeifer, CEO of AC Immune, said in a statement. "Early diagnosis is essential for early intervention."
The findings are significant because the TDP-43 protein is a primary component of toxic brain inclusions in patients with ALS, frontotemporal dementia (FTD), and other neurological disorders. While its presence is a known hallmark of disease, it has historically been confirmed only through post-mortem studies. An effective PET (positron emission tomography) tracer that can visualize these protein clumps in living patients would be a major advance for the field.
The new data from the ongoing trial (NCT06891716) complements previously reported results where the tracer also showed higher uptake in patients with a genetic form of FTD. AC Immune confirmed the tracer continues to show a good safety profile and has properties suitable for human brain imaging.
The Phase 1 study is divided into two parts. The first, which is now complete, evaluated the tracer in healthy volunteers and patients with genetic FTD. The second part has started and will expand to include up to 30 patients with FTD, ALS, or a related condition known as LATE.
For investors, the clinical progress is set against a backdrop of strategic shifts and a volatile stock performance. Shares of AC Immune have returned 68% over the past year, but fell 1.38% to $2.85 in Friday trading following the announcement. The company, which has a market capitalization of approximately $285 million, is well-financed, reporting a cash runway extending into the fourth quarter of 2027 after a restructuring in 2025.
The results come as the company prepares for a leadership transition, with long-serving CEO Andrea Pfeifer set to retire in June. The firm has active development partnerships with major pharmaceutical companies including Janssen, Takeda, and Eli Lilly. Analyst price targets on the stock range from $7 to $12 per share, suggesting Wall Street sees significant potential value in the company's pipeline beyond its current valuation.
This article is for informational purposes only and does not constitute investment advice.
