Comparative Pharmacology
Head-to-head clinical analysis: ARZERRA versus XTANDI.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ARZERRA versus XTANDI.
ARZERRA vs XTANDI
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Ofatumumab is a fully human monoclonal antibody that binds specifically to the CD20 molecule on B lymphocytes, resulting in complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) of CD20+ cells.
Androgen receptor inhibitor; binds to the androgen receptor, inhibits nuclear translocation, DNA binding, and transcription of androgen-responsive genes.
ARZERRA (ofatumumab) for chronic lymphocytic leukemia (CLL): Initial dose 300 mg IV, then 1 week later 2000 mg IV weekly for 6 doses, then 2000 mg IV every 4 weeks for up to 4 additional doses. For relapsed CLL: 300 mg IV followed by 1000 mg IV on day 8, then 1000 mg IV on day 15 and day 22 of cycle 1, then 1000 mg IV on day 1 of cycles 2-6 (28-day cycles). Premedicate with acetaminophen, antihistamine, and corticosteroid.
160 mg orally once daily.
None Documented
None Documented
Mean terminal elimination half-life after first dose is approximately 14 days (range 7–21 days) and increases with repeated dosing due to target-mediated clearance saturation; at steady state, half-life is ~24 days.
Enzalutamide: 5.8 days; active metabolite N-desmethyl enzalutamide: 7.8-8.6 days. Steady state achieved after ~28 days.
Arzerra (ofatumumab) is eliminated primarily via the reticuloendothelial system and catabolism; renal excretion is minimal (<1% of dose as intact antibody). Biliary/fecal excretion has not been characterized, but as a monoclonal antibody, it is not significantly excreted in urine or feces.
Primarily hepatic metabolism; 77% of dose recovered in feces (as metabolites), 15% in urine (as metabolites); less than 1% excreted unchanged.
Category C
Category C
Antineoplastic, Monoclonal Antibody
Antineoplastic