BIIB vs DGX Comparison

Biogen is an established biopharmaceutical company focused on treatments for neurodegenerative and rare diseases. Its declining multiple sclerosis franchise is its largest revenue generator and contributed 40% of total revenue in 2025. Biogen also generates significant revenue from its CD20 collaboration agreements with Roche (19% of total in 2025), 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).

Quest Diagnostics is a leading independent provider of diagnostic testing, information, and services in the US. The company generates over 97% of its revenue through clinical testing, anatomic pathology, esoteric testing, and substance abuse testing with specimens collected at its national network of roughly 2,400 patient service centers, as well as multiple doctors offices and hospitals. The firm also runs a much smaller diagnostic solutions segment that provides clinical trials testing, risk-assessment services, and information technology solutions.