A new monoclonal antibody treatment, trontinemab, has shown remarkable promise for Alzheimer’s disease, prompting hopes that it may become the first drug capable of halting progression, rather than merely slowing decline.
Game‑Changing Early Results from Trontinemab Trials
At the Alzheimer’s Association International Conference in Toronto, early‑phase studies revealed that up to 91 percent of patients receiving the highest doses became amyloid‑negative within 28 weeks. That level of plaque clearance vastly exceeds the speed reported for lecanemab and donanemab, which typically require many months or longer to achieve similar effects.
Phase II trials involving roughly 1,600 patients are underway, including cohorts in the UK, with the intention to assess clinical efficacy, safety, and cost‑effectiveness for potential NHS adoption. Remarkably, side effects have been minimal: only around three percent of participants in one subgroup showed temporary brain swelling or lesions, and a single fatal brain haemorrhage occurred during an earlier phase I trial.
Professor Sir John Hardy of University College London has described the results as “game‑changing,” noting that trontinemab “sucks the plaque out of the brain” far more quickly than existing antibody treatments.
Clinical and Scientific Significance
Trontinemab represents a new generation of amyloid‑targeting therapies. The ability to remove amyloid plaques rapidly may offer a critical window for intervention in the earliest stages of Alzheimer’s disease, possibly even before symptoms arise. Such preventive use is under consideration in further trials currently underway.
Compared to existing monoclonal treatments like lecanemab (marketed as Leqembi) and donanemab (Kisunla), trontinemab has demonstrated not only a faster reduction in amyloid burden but also a markedly lower incidence of amyloid‑related imaging abnormalities (ARIA) a major safety concern with previous drugs. Lecanemab and donanemab are associated with higher rates of cerebral edema and small haemorrhages, occasionally with serious consequences.
Regulatory and Access Landscape
As of July 2025, lecanemab and donanemab have been approved by the U.S. Food and Drug Administration for use in individuals with mild cognitive impairment or mild dementia due to Alzheimer’s disease. In the UK, UK regulators have granted marketing authorisation for both drugs, though neither is currently recommended for coverage by the NHS, owing to cost‑effectiveness concerns. NICE has estimated annual treatment costs of £20,000–£25,000 per patient, excluding the added costs of imaging and infusion sessions, leading to private charges of £60,000–£80,000 per year.
Donanemab was rejected by European regulators in early 2025 due to safety concerns, and its marketing authorisation remains under re‑examination. By contrast, lecanemab has since received conditional approval in the EU for early Alzheimer’s in patients without two copies of the ApoE4 gene, who are less prone to ARIA
What Comes Next
If trontinemab continues to perform well in larger Phase III trials, it may offer the most powerful and safest antibody‑based therapy yet for early Alzheimer’s. Ongoing studies will determine whether plaque clearance translates into meaningful preservation of cognitive and functional abilities, as well as whether the treatment is affordable and deliverable at scale, including potential NHS access in the UK.
For clinicians and researchers, trontinemab represents an important proof of principle: antibodies tailored for rapid amyloid removal with an improved safety profile could shift Alzheimer’s treatment toward true disease modification or even prevention.
Sources: The Telegraph, The Times, LBC, Mayo Clinic, AP News, Alzheimer’s Association, Wikipedia
