Systems and methods providing a clotting factor VIII dosing regimen are disclosed. The systems and methods include determining an estimated pharmacokinetic profile of a patient using a Bayesian model of pharmacokinetic profiles of sampled patients. The systems and methods can determine a first dosing regimen for a first dosing interval including (i) a first dosage and (ii) a first therapeutic plasma protein level in the patient varying over time based at least upon the estimated pharmacokinetic profile. The systems and methods can determine a second dosing regimen for a second dosing interval including (i) a second dosage and (ii) a second therapeutic plasma protein level in the patient varying over time. The estimated pharmacokinetic profile can be adjusted based on previous patient treatments. Further, a user can select which days a dosage is to be applied such that the protein level does not fall below a target trough.