GlaxoSmithKline plc / Genmab A/S (ofatumumab/HuMax-CD20)

Chronic Lymphocytic Leukemia (CD20-positive B-cell)

23K US cases/yr

Disease Overview

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in Western countries, typically diagnosed around age 71. It is an indolent B-cell malignancy where many patients live years with disease but eventually require treatment for cytopenias, bulky disease, or refractory progression — fludarabine-refractory CLL was the high unmet-need niche at the time of this deal.

Competitive Landscape

In late 2006, the CD20-targeted B-cell therapy market was dominated by Roche/Genentech/Biogen Idec's Rituxan (rituximab), a chimeric anti-CD20 mAb approved for non-Hodgkin lymphoma since 1997 and widely used off-label in CLL, with peak global sales heading toward ~$5B. Standard CLL chemo backbones included fludarabine (Berlex/Bayer), cyclophosphamide, and chlorambucil; combination regimens like FCR were emerging as front-line. Genmab's HuMax-CD20 (ofatumumab) was a fully human IgG1 anti-CD20 mAb engineered to bind a distinct small-loop epitope with stronger CDC than rituximab, positioned for fludarabine-refractory CLL plus follicular NHL (Phase 3) and rheumatoid arthritis (Phase 2). For GSK, the deal added an oncology mAb to a portfolio historically light on biologics. Total potential ~$2.1B included a ~$102M license fee, a ~$357M equity investment in Genmab, plus up to ~$1.6B in milestones — a record biotech license at the time. Ofatumumab (Arzerra) ultimately won FDA approval October 2009 for fludarabine/alemtuzumab-refractory CLL, but commercial uptake disappointed against rituximab; rights transferred from GSK to Novartis in 2014.