In the current Alzheimer’s disease (AD) therapeutic space, the two approved disease-modifying therapies (DMTs) employ different treatment strategies, although both are anti-amyloid-beta (Aβ) monoclonal antibodies (mAbs). Eisai/Biogen’s Leqembi (lecanemab) is approved for continuous treatment until progression to moderate AD, whereas Eli Lilly’s Kisunla (donanemab) is being positioned as a finite treatment option that can be discontinued once significant amyloid clearance has been achieved. Real-world data for long-term Kisunla and Leqembi treatment strategies beyond just a couple of years will be crucial to evaluate these differing strategies, says GlobalData, a leading intelligence and productivity platform.
Both companies used the recent AD/PD 2026 International Conference on Alzheimer’s and Parkinson’s Diseases and Related Neurological Disorders to present long-term data from clinical trials in support of their drugs’ treatment strategies.
At four years, continued Leqembi treatment resulted in slowed disease progression compared with untreated controls, equivalent to a 9.8-month delay in progression with more patients remaining at an earlier disease stage. An additional post-hoc analysis in patients with early AD and low tau showed that 73% had no decline in Clinical Dementia Rating – Sum of Boxes (CDR-SB) score at four years.
Philippa Salter, Managing Neurology Analyst at GlobalData, comments: “While the data presented at AD/PD 2026 is important for showing clinicians, patients, and insurers that the continued use of Leqembi can provide ongoing benefit to patients without increasing safety concerns, it is not enough to conclude that Leqembi’s treatment strategy is superior to Kisunla’s. Questions remain over longer-term continued use of Leqembi in patients whose disease continues to remain stable rather than progressing, as well as the benefit versus the cost of continued treatment.”
Eisai and Biogen have recently received approval of Leqembi Iqlik, a subcutaneous (SC) formulation of lecanemab, for maintenance treatment. They have also submitted a supplemental application for Leqembi Iqlik for the initiation phase of the treatment.
Salter adds: “If approved, this would allow SC dosing for the whole treatment period, thereby reducing patient burden and increasing patient compliance to the drug, as patients would be able to administer Leqembi Iqllik at home, rather than visiting an infusion center every two weeks.”
Lilly also presented data at AD/PD 2026 showing that, among patients who achieve early amyloid clearance, within one year of initiating Kisunla, stopping treatment does not result in rapid amyloid accumulation. The data also showed that patients who do not achieve early amyloid clearance, continuing to take Kisunla can still result in amyloid clearance.
Salter continues: “Lilly is looking to further increase confidence in its finite treatment strategy with TRAILBLAZER-ALZ 2 Addendum 11, an ongoing study designed to characterize amyloid re-accumulation for an additional three years. However, further research into whether Kisunla should be reinitiated once amyloid levels rise above a threshold level, what that would look like in practice in terms of frequency of amyloid monitoring, and how this correlates to disease progression, is needed to provide a truly long-term picture of what AD treatment and management could look like with Kisunla.”
As uptake of Kisunla increases globally, real-world use of the drug outside of clinical trials will also help consolidate its treatment strategy and how it correlates to clinical impact, not just the pathological clearance and slow re-accumulation of amyloid.
Salter concludes: “Ultimately, as the use of Leqembi and Kisunla increases globally, longer-term real-world data will provide a deeper understanding of the advantages and disadvantages of the mechanisms and treatment strategies of these drugs, as well as patient and provider preferences for each option.”
