Background: As a new tumor therapy, targeted therapy is becoming a hot topic due to its high efficiency
and low toxicity. Drug effects of targeted tumor drugs are closely related to pharmacokinetics, so it is important
to understand their distribution and metabolism in vivo.
Methods: A systematic review of the literature on the metabolism and distribution of targeted drugs over the
past 20 years was conducted, and the pharmacokinetic parameters of approved targeted drugs were summarized
in combination with the FDA's drug instructions. Targeting drugs are divided into two categories: small
molecule inhibitors and monoclonal antibodies. Novel targeting drugs and their mechanisms of action, which
have been developed in recent years, are summarized. The distribution and metabolic processes of each drug in
the human body are reviewed.
Results: In this review, we found that the distribution and metabolism of small molecule kinase inhibitors (TKI)
and monoclonal antibodies (mAb) showed different characteristics based on the differences of action mechanism
and molecular characteristics. TKI absorbed rapidly (Tmax ≈ 1-4 h) and distributed in large amounts (Vd >
100 L). It was mainly oxidized and reduced by cytochrome P450 CYP3A4. However, due to the large molecular
diameter, mAb was distributed to tissues slowly, and the volume of distribution was usually very low (Vd <
10 L). It was mainly hydrolyzed and metabolized into peptides and amino acids by protease hydrolysis. In addition,
some of the latest drugs are still in clinical trials, and the in vivo process still needs further study.
Conclusion: According to the summary of the research progress of the existing targeting drugs, it is found that
they have high specificity, but there are still deficiencies in drug resistance and safety. Therefore, the development
of safer and more effective targeted drugs is the future research direction. Meanwhile, this study also provides
a theoretical basis for clinical accurate drug delivery.