Brentuximab vedotin is used in relapsed classical Hodgkin lymphoma. Its cytotoxic payload reaches tumor cells because:

• A The antibody blocks CD20 and the payload diffuses freely into neighbouring cells
• B The antibody binds CD19 and delivers calicheamicin directly into the nucleus
• C The antibody inhibits topoisomerase II after binding CD25
• D The antibody binds CD30 and the payload MMAE is released after lysosomal cathepsin cleavage of the linker ✓

Explanation

Brentuximab vedotin is an antibody-drug conjugate: the anti-CD30 IgG1 carries monomethyl auristatin E (MMAE), a microtubule-disrupting agent, attached via a valine-citrulline linker cleaved by cathepsin B in lysosomes after internalization. Reed-Sternberg cells strongly express CD30, giving selectivity. Option B describes gemtuzumab ozogamicin (CD33 with calicheamicin), a different conjugate, making it the tempting distractor for students who mix up ADC pairs.

Reference: Katzung Basic and Clinical Pharmacology, 16th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.