BIIB vs MKL Comparison

Biogen is an established biopharmaceutical company focused on treatments for neurological diseases and rare diseases. Its declining multiple sclerosis franchise is its largest revenue generator and contributed 45% of total revenue in 2024. Biogen also generates significant revenue from its CD20 collaboration agreements with Roche (18% of total in 2024), which includes oncology drugs Rituxan and Gazyva and multiple sclerosis drug Ocrevus. Biogen's newer franchises include Spinraza (spinal muscular atrophy, with partner Ionis), Leqembi (Alzheimer's disease, collabroation revenue from its partner Eisai), Skyclarys (Friedreich's ataxia, Reata), Zurzuvae (postpartum depression, Sage), and Qalsody (amyotrophic lateral sclerosis, Ionis).

Markel's primary business is property and casualty insurance. The company focuses primarily on specialty lines, ranging from areas such as executive liability to commercial equine insurance. The acquisition of Alterra in 2013 added substantial reinsurance operations, which now account for a little over 10% of premiums. The company uses capital generated by its insurance operations to buy noninsurance operations in diverse areas, such as bakery equipment manufacturing and residential homebuilding.