Comparative Pharmacology
Head-to-head clinical analysis: ARZERRA versus TRISENOX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ARZERRA versus TRISENOX.
ARZERRA vs TRISENOX
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.
Arsenic trioxide induces apoptosis in acute promyelocytic leukemia (APL) cells by targeting the PML-RARα fusion protein, leading to its degradation and subsequent differentiation and apoptosis. It also generates reactive oxygen species, disrupts mitochondrial function, and activates caspases.
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.
0.15 mg/kg IV daily until bone marrow remission, then 0.15 mg/kg IV 5 days/week for 2 weeks with 2 weeks off for up to 6 cycles.
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.
Terminal elimination half-life for inorganic arsenic is approximately 10-14 hours, with a mean of 12 hours. The methylated metabolites have longer half-lives, contributing to accumulation with repeated dosing. Clinical context: Supports daily dosing schedule with monitoring for toxicity.
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 renal excretion of unchanged arsenic (approximately 15-30% of the dose within 24 hours) with the remainder undergoing hepatic methylation to monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), which are excreted renally. Biliary and fecal elimination are minor (<5%).
Category C
Category C
Antineoplastic, Monoclonal Antibody
Antineoplastic, Arsenic Trioxide