CSL Limited

CSL Limited at $115 billion market cap operates the world's largest plasma collection network—a biological infrastructure extracting immunoglobulins, albumin, and clotting factors from 50 million donor sessions annually across 300+ centers. This positions CSL as apex predator in the rare disease therapy ecosystem, where plasma scarcity creates absolute supply constraints. Unlike pharmaceutical synthesis, immunoglobulin production requires human donors—a biological bottleneck that grants incumbents with collection infrastructure durable competitive moats.

The company's three divisions demonstrate adaptive radiation from common plasma substrate. CSL Behring ($8.2B revenue FY24) focuses on immunology and hematology with products treating primary immunodeficiency, hemophilia, and hereditary angioedema. Seqirus ($2.1B) produces influenza vaccines using egg-based and cell-based manufacturing. The 2022 Vifor Pharma acquisition ($11.7B) added iron deficiency and nephrology treatments, diversifying beyond plasma dependence. This mimics Darwin's finches: ancestral plasma expertise radiated into distinct therapeutic niches through specialized product development.

CSL's plasma collection model functions as ecosystem engineering: the company maintains donor pools through compensation ($50-$100 per donation in US markets) and convenience optimization. Twice-weekly donation frequency from regular donors creates renewable resource extraction—sustainable harvesting that preserves donor health while maximizing yield. Centers cluster in regions with economic need, where plasma donation provides supplemental income. This symbiotic exchange mirrors cleaner fish relationships: donors provide resource, CSL provides compensation and health screening.

The Vifor acquisition shows resource reallocation toward non-plasma growth. With plasma supply constrained by donor availability and regulatory hurdles for new centers, CSL faces metabolic ceilings. Vifor's iron deficiency franchise operates in faster-growing markets (chronic kidney disease, heart failure) without collection network requirements. Yet integration challenges persist: merging Swiss pharma culture with Australian biotech proved harder than modeled, resulting in $400M goodwill impairment charges.

CSL's FY24 revenue of $15.8 billion (up 11% constant currency) and $2.9B net profit demonstrates rare disease pricing power: when your product prevents death for primary immunodeficiency patients, demand curves approach vertical. This monopolistic competition mimics keystone mutualists: patients and healthcare systems have no substitute for immunoglobulin therapy, granting CSL pricing leverage constrained only by willingness-to-pay thresholds and regulatory intervention.