As of the last check Thursday, Biogen Inc. (BIIB) had fallen -7.50% at $34.00. Last trading session, Biogen stock lost -0.67% as it closed at $371.90. BIIB stock traded between $364.30 and $376.01 during the day. BIIB traded 1.78 million shares, which was in line with its average daily volume of 1.61 million shares over the past 100 days.

In the last five days, BIIB’s shares declined by -4.96%, while they increased by 33.36% last month. In the current market, BIIB has a price-to-earnings ratio of 19.51, and a price-to-book ratio of 5.29. BIIB stock is falling even after getting a positive status from the US Food and Drug Administration (FDA).

Why is the BIIB stock falling?

Biogen is a pioneer in neuroscience that develops, produces, and delivers innovative therapies worldwide for people living with neurological diseases and neurodegenerative disorders, as well as for people suffering from other conditions.

A pioneer in global biotechnology, BIIB was founded in 1978 by Charles Weissmann, Heinz Schaller, Kenneth Murray, Walter Gilbert, and Phillip Sharp, who won Nobel Prizes in chemistry. With the introduction of the first approved treatment for spinal muscular atrophy, the BIIB has the leading portfolio of medicines to treat multiple sclerosis. It also commercializes biosimilars of advanced biologics.

Biogen and Eisai Co. Ltd. have announced that the FDA has approved lecanemab (BAN2401).

• Lecanemab is an investigational anti-amyloid beta (Aβ) protofibril antibody for the treatment of Alzheimer’s disease (AD).
• Together, Eisai and BIIB develop and commercialize treatments for AD.
• As principle developer of lecanemab, Eisai leads the development process.
• Based on the results of a recently published Phase 2b clinical trial (Study 201), the FDA recently designated lecanemab as a Breakthrough Therapy for Alzheimer’s disease (AD) and mild AD with pathology confirmed by amyloid testing.
• Lecanemab treatment reduced brain amyloid beta (Aβ) and clinical decline in Proof-of-Concept Study 201.
• At the highest doses, at least three clinical endpoints and several biomarker measurements showed consistent reductions in clinical decline.

How BIIB went through this?

Approximately 1,795 patients with early Alzheimer’s disease have been enrolled in the Clarity AD study, conducted by Eisai and Biogen (BIIB). By the end of September 2022, the study’s primary endpoint should be complete.

As a Breakthrough Therapy, Biogen (BIIB) will receive more intensive guidance on an efficient development program of Lecanemab, and will be eligible for rolling review and priority review.