Injected version of Eisai/Biogen Alzheimer's drug effective, side effects higher

BioArctic AB

25/10/2023 22:25

By Julie Steenhuysen and Deena Beasley
       BOSTON, Oct 25 (Reuters) - An injected version of Eisai
 4523.T  and Biogen's  BIIB.O  Alzheimer's drug Leqembi works as
well as the current intravenous administration at removing toxic
brain plaques, but rates of serious side effects were higher,
according to an analysis presented by Eisai on Wednesday.
    The Japanese drugmaker's review compared data for 72
patients with early Alzheimer's given Leqembi by subcutaneous
injection to prior pivotal trial results from 898 patients who
received the drug by infusion.
    The intravenous (IV) form of Leqembi won U.S. approval based
on that larger 18-month study showing the drug, which works by
removing sticky clumps of beta amyloid from the brain, slowed
cognitive decline by 27% for people with early Alzheimer's
disease.
    A weekly shot form of Leqembi, given as two consecutive
injections, could simplify use of the groundbreaking Alzheimer's
treatment, potentially allowing patients to receive the drug at
home instead of traveling to an infusion center twice a month.
    The latest data, presented at the Clinical Trials on
Alzheimer's Disease meeting in Boston, showed that after six
months of treatment, the shot form of Leqembi removed 14% more
amyloid than the approved IV formulation. 
    Blood concentration levels of the drug were 11% higher with
subcutaneous Leqembi than the IV version.  
    Rates of infusion- or injection-related side effects were
lower for the subcutaneous formulation, but rates of serious
side effects were higher.
    The incidence of brain swelling known as ARIA-E was 16.7%
for the subcutaneous group and 12.6% for intravenous patients.
    ARIA-H, or brain bleeding, occurred in 22.2% of the
subcutaneous patients versus 17.3% of the IV group. 
    "We believe that the safety is actually consistent," Priya
Singhal, Biogen's head of development, said in an interview.
    "Because it's a very small cohort," she said of the
72-patient group, "one or two cases can actually swing the
numbers pretty significantly." 
    Eisai and U.S. partner Biogen said they plan to apply for
U.S. approval of subcutaneous Leqembi by the end of March based
on data from 394 patients.
    
    LOW TAU DATA
    Separately, Eisai presented an analysis of a small subgroup
of patients from its pivotal trial who had early Alzheimer's and
low levels of tau, a second protein linked with disease
progression and brain cell death.
    It found that in the low-tau population, 60% of patients had
improvement in cognitive function, compared with 28% of the
placebo group. 
    Michael Irizarry, head of clinical research at Eisai's
neurology division, acknowledged in an interview that
Alzheimer's does not typically progress much for people in the
earliest stages of the disease, but said the data "supports
treating as early as possible." 
    The U.S. government and Eisai are testing Leqembi to see if
giving the drug early can prevent dementia symptoms in people
who are still cognitively normal but have amyloid in their
brain. 

 (Reporting by Julie Steenhuysen in Boston and Deena Beasley in
Los Angeles; Editing by Bill Berkrot)
 ((julie.steenhuysen@thomsonreuters.com; 312-408-8131; Reuters
Messaging: Julie.steenhuysen.reuters.com@reuters.net))