Prodrugs in cancer chemotherapy

Area of Science:

• Oncology
• Pharmacology
• Biotechnology

Background:

• Conventional chemotherapy has limited efficacy against metastatic solid tumors.
• Higher doses of anticancer agents could be curative but are not clinically attainable.
• Enzyme-activated prodrugs can achieve high local doses, but tumor-specific enzyme expression is rare.

Purpose of the Study:

• To explore novel prodrug delivery strategies for enhanced cancer chemotherapy.
• To overcome limitations of traditional prodrug therapy in solid tumors.
• To evaluate the potential of antibody-directed enzyme prodrug therapy (ADEPT) and gene-directed enzyme prodrug therapy (GDEPT).

Main Methods:

• ADEPT involves conjugating prodrug-activating enzymes to tumor-associated antibodies for targeted delivery.
• Following conjugate clearance, an inert prodrug is administered and activated by the localized enzyme.
• GDEPT utilizes genes encoding prodrug-activating enzymes delivered to tumors, often via viruses.

Main Results:

• ADEPT demonstrated significant sensitivity in various human tumor xenografts resistant to conventional chemotherapy.
• Early clinical trials for ADEPT are promising for solid cancer treatment.
• GDEPT has shown positive results in preclinical laboratory systems.

Conclusions:

• ADEPT and GDEPT represent promising advancements in cancer chemotherapy, potentially realizing the full potential of prodrugs.
• These targeted enzyme-prodrug strategies may offer effective treatments for solid cancers with known tumor-associated antibodies.
• Further clinical development of ADEPT and GDEPT is warranted for broad application in oncology.