FDA Approves First Alzheimer's Blood Test, Potentially Boosting Uptake of New Therapies

The U.S. Food and Drug Administration (FDA) has approved the first blood-based diagnostic device for the early detection of Alzheimer's disease, potentially transforming the landscape for both patients and drug developers. The Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio test, manufactured by Tokyo-based Fujirebio Diagnostics, offers a less invasive and more accessible alternative to current diagnostic methods.

A Game-Changing Diagnostic Tool

The Lumipulse test works by measuring the levels of two proteins in the blood: pTau217 and ß-Amyloid 1-42. The ratio of these molecules can reliably predict the presence or absence of amyloid pathology associated with Alzheimer's disease. This new diagnostic approach significantly reduces the need for PET scans, which are currently the standard method for detecting amyloid plaques but can be costly and time-consuming.

In a clinical trial involving 499 patients with cognitive impairment, the Lumipulse test demonstrated high accuracy. 91.7% of patients who tested positive on the Lumipulse showed amyloid plaques when assessed by PET scan or cerebrospinal fluid (CSF) tests. Conversely, 97.3% of patients with negative Lumipulse results also had negative PET or CSF test results.

Howard Fillit, chief scientific officer at the Alzheimer's Drug Discovery Foundation, hailed the approval as a "major milestone for patients and clinicians," particularly as the number of people developing Alzheimer's continues to increase exponentially. Fillit emphasized that a simple and convenient blood test would allow "more patients to receive treatment options that have the potential to significantly slow or even prevent the disease."

Implications for Alzheimer's Therapies

The approval of the Lumipulse test could have significant implications for the uptake of new Alzheimer's therapies. Analysts at BMO Capital Markets suggest that this non-invasive blood test might serve as a "tailwind" for two commercial anti-amyloid Alzheimer's therapies that have struggled to gain traction in the market: Biogen and Eisai's Leqembi, and Eli Lilly's Kisunla.

Both Leqembi and Kisunla have faced challenges in securing a stable foothold in the market. Eisai, which co-owns Leqembi with Biogen, recently lowered its sales forecast for the drug due to "delayed uptake in the US market." For its fiscal year 2027, ending in March 2028, Eisai now expects Leqembi to generate ¥250 billion to ¥280 billion ($1.7 billion to $1.9 billion USD), a significant drop from its previous forecast of around ¥500 billion ($3.45 billion USD).

Eli Lilly's Kisunla has also struggled to gain momentum. According to a recent report from Jefferies, the drug sold $10.1 million in April, representing a 22% month-on-month growth from its $8.3 million earnings in March.

While the approval of the Lumipulse test is seen as a positive development for these therapies, analysts at Mizuho Securities caution that further details on reimbursement and physician usage are needed, given the noted risk of false positives and negatives associated with the test. The FDA has identified these risks as the main concerns associated with the Lumipulse, which could lead to improper medical management if not carefully considered.

As the pharmaceutical industry continues to grapple with the challenges of Alzheimer's disease treatment and diagnosis, the approval of the Lumipulse test marks a significant step forward. Its potential to streamline the diagnostic process and facilitate earlier intervention could have far-reaching implications for both patients and drug developers in the years to come.