Pharmacokinetics and pharmacokinetic/pharmacodynamic associations of ofatumumab, a human monoclonal CD20 antibody, in patients with relapsed or refractory chronic lymphocytic leukaemia: a phase 1-2 study.

Author(s): Coiffier B, Losic N, Ronn BB, Lepretre S, Pedersen LM, Gadeberg O, Frederiksen H, van Oers MH, Wooldridge J, Kloczko J, Holowiecki J, Hellmann A, Walewski J, Robak T, Petersen J

Affiliation(s): Departement d'Hematologie, Centre Hospitalier Lyon Sud, Pierre-Benite Cedex, France. bertrand coiffier@chu-lyon.fr

Publication date & source: 2010-07, Br J Haematol., 150(1):58-71. Epub 2010 Apr 16.

Publication type: Clinical Trial, Phase I; Clinical Trial, Phase II

The purpose of this phase 1-2 study was to investigate the association between the pharmacokinetic properties of ofatumumab, a human monoclonal CD20 antibody, and outcomes in 33 patients with relapsed/refractory chronic lymphocytic leukaemia receiving 4 weekly infusions of ofatumumab. The ofatumumab concentration profiles were fitted well by a two-compartment model with different elimination rate constant at first infusion compared to the remaining infusions in line with the observed rapid and sustained B-cell depletion. Exposure to ofatumumab was linked to clinical outcomes: high exposure was associated with higher probability of overall clinical response and longer progression-free survival. This association still remained statistically significant even when adjusting for relevant baseline covariates including tumour burden.