From 'Targeted Therapy' to Targeted Therapy

Area of Science:

• Oncology
• Pharmacology
• Cancer Therapeutics

Background:

• The term 'targeted therapy' gained prominence in the early 2000s, often equated with tyrosine kinase inhibitors (TKIs).
• However, the concept of targeted therapy predates TKIs, encompassing strategies like targeting tumor metabolism (e.g., methotrexate, 5-fluorouracil) and hormone therapy.
• Imatinib's success against BCR-ABL in chronic myeloid leukemia marked a significant advancement in TKI development.

Purpose of the Study:

• To review the historical development and evolution of targeted anticancer agents.
• To differentiate between broadly acting TKIs and more specific, truly targeted therapies.
• To highlight advancements in targeted therapies, including newer TKIs.

Main Methods:

• Review of historical literature and clinical applications of targeted therapies.
• Analysis of the specificity and targets of various tyrosine kinase inhibitors.
• Discussion of key examples like imatinib, ALK-EML4 inhibitors, and osimertinib.

Main Results:

• Targeted therapy encompasses a broader range of treatments than initially recognized in the early 2000s.
• Many early TKIs were not truly targeted due to multiple off-target effects.
• Recent advancements have led to the development of highly specific TKIs targeting specific mutations (e.g., ALK-EML4, EGFR T790M).

Conclusions:

• The definition and application of targeted therapy have evolved significantly over time.
• Increasing specificity in drug development, particularly with TKIs, represents a major step forward in cancer treatment.
• Future directions in targeted therapy focus on precision medicine approaches for improved patient outcomes.