A pathophysiology diagram illustrating the mechanism of action (MOA) for Brentuximab vedotin, an antibody-drug conjugate (ADC), within a tumor cell. The process is depicted in five sequential stages: (1) Receptor-mediated endocytosis where the purple Y-shaped anti-CD30 monoclonal antibody, conjugated with yellow MMAE (monomethyl auristatin E) molecules, binds to the CD30 surface antigen. (2) Formation of an intracellular endosome containing the ADC complex. (3) Fusion of the endosome with a lysosome to form an endolysosome, where lysosomal proteases cleave the linker, releasing free MMAE into the cytosol. (4) Released MMAE binds to and disrupts microtubule polymerization, leading to cell cycle arrest. (5) Final induction of tumor cell apoptosis, represented by a skull and crossbones icon. The diagram uses standard biological iconography to explain targeted chemotherapy delivery in oncology, specifically for CD30-positive malignancies like Hodgkin lymphoma.

This three-panel pathophysiology diagram illustrates the mechanism of action of recombinant human hyaluronidase PH20 (rHuPH20) in facilitating subcutaneous drug delivery. Panel A depicts the baseline state of the subcutaneous extracellular matrix, where a dense, interconnected network of hyaluronan (represented as thick, brownish fibrous strands) creates a physical barrier that resists bulk fluid flow. Panel B shows the introduction of rHuPH20 (magenta globular molecules), which acts to depolymerize and fragment the hyaluronan strands, reducing the matrix viscosity. Panel C demonstrates the final stage where the hyaluronan is significantly degraded and sparse, allowing for the widespread dispersion and absorption of a co-administered therapeutic product (green clusters) into the interstitial space and surrounding vasculature. The diagram effectively teaches how enzymatic degradation of the interstitial barrier increases the permeability of the subcutaneous tissue, enabling the delivery of larger volumes of therapeutic agents.

This medical schematic diagram illustrates the mechanism of action of a dual-target protein drug (PMIBcr/Abl-R6) in Philadelphia chromosome-positive (Ph+) leukemia cells. The top panel depicts the pathological pathway: Bcr/Abl expression leads to oligomerization via the OLI domain, followed by Abl kinase autophosphorylation and signal overactivation, resulting in leukemia cell proliferation. The middle panel shows the drug design, combining the Bcr/Abl oligomerization domain (α2 and α1 helices) with an MDM2-targeting peptide. The bottom panel demonstrates the therapeutic mechanism: the dual-target drug inhibits p53/MDM2 interaction to release and activate p53, while simultaneously disrupting Bcr/Abl oligomerization. Furthermore, by recruiting MDM2 (an E3 ligase) to Bcr/Abl, the drug facilitates Bcr/Abl protein degradation. The synergistic effect of Bcr/Abl inhibition/degradation and p53 activation promotes apoptosis in Ph+ leukemia cells. This diagram is intended for hematology-oncology education, focusing on molecular targeted therapy and PROTAC mechanisms.