On Tuesday, the FDA approved Eli Lilly and Co's (NYSE: LLY) Kisunla (donanemab) once-monthly injection for IV infusion) for adults with early symptomatic Alzheimer's disease.
Once-monthly, Kisunla is the first and only amyloid plaque-targeting therapy with evidence to support stopping therapy when amyloid plaques are removed, which can result in lower treatment costs and fewer infusions.
Amyloid is a protein produced naturally in the body that can clump together to create amyloid plaques. The excessive buildup of amyloid plaques in the brain may lead to memory and thinking issues associated with Alzheimer's disease.
In the TRAILBLAZER-ALZ 2 Phase 3 study, individuals treated with Kisunla who were less advanced in their disease showed a 35% reduction in decline compared with placebo on the integrated Alzheimer's Disease Rating Scale (iADRS), which measures memory, thinking, and daily functioning.
The overall population's response to treatment was also statistically significant using the iADRS at 22%.
Among the two groups analyzed, participants treated with Kisunla had up to a 39% lower risk of progressing to the next clinical stage of disease than those taking a placebo.
Among the overall population of participants, Kisunla reduced amyloid plaques on average by 61% at six months, 80% at 12 months, and 84% at 18 months compared to the start of the study.
Kisunla approval follows that of Biogen Inc's (NASDAQ: BIIB) / Eisai Ltd's (OTC: ESALF) Leqembi as the second approved anti-beta-amyloid monoclonal antibody for Alzheimer's in as many years.
Kisunla will be the more expensive per-year option, with a list price of $32,000, compared to Leqembi, which is priced at $26,500 annually.
However, it comes with the option of stopping dosing early if minimal levels of amyloid plaque are identified via PET scan, which could offset longer-term costs (47% of donanemab-treated subjects in TRAILBLAZER-2 stopped therapy after 12 months).
William Blair states that Kisunla's broad label reflects AdCom sentiment and regulatory confidence in anti-amyloid antibodies for Alzheimer's treatment.
The analyst writes this was an expected outcome and should have only a marginal impact on Biogen's shares.
While Kisunla is a strong competitor to Leqembi, there is ample market space for both, given the over 6 million Alzheimer's patients in the U.S.
A second approval will bolster confidence in anti-amyloid antibody efficacy following the Aduhelm setback.
Eisai forecasts $350 million in Leqembi sales from March 2024 to March 2025, and the analyst will monitor the uptake, noting Kisunla's initial potential advantages.
Overall, William Blair maintains an Outperform rating for Biogen, seeing Leqembi as a crucial growth driver despite a slower start.
Goldman Sachs writes the approval label as in line with expectations, with similar warnings and monitoring requirements outlined for Leqembi and no requirement for tau-based screening.
Goldman Sachs updates the model to reflect the increased probability of success on the program to 100% in the U.S., with Eli Lilly's price target of $793 (vs. $785 prior).
Biogen focuses on the launch's progress regarding infrastructural/logistical bottlenecks. A Goldman Sachs analyst writes that Kisunla's entry is a positive development in building/expanding the market overall for this generation of Alzheimer's disease therapeutics.
Price Action: LLY shares are down 2.21% at $886.90, and BIIB stock is down 2.43% at $223.27 at the last check on Wednesday.