Table 3.

Investigational agents under development and its mechanism of action

Investigational agent	Brand name	Class	Mechanism of action
Gemtuzumab Ozogamycin	Mylotarg	Monoclonal antibody	Recombinant humanized monoclonal antibody conjugated with calicheamicin directed against the surface glycoprotein CD33
Tipifarnib	Zarnestra	Farnesyl transferase inhibitor	Competitively and irreversibly inhibit Farnesyl transferase enzyme, a key enzyme that regulates cancer cell signaling, proliferation, and differentiation
Clofarabine	Clolar	Second generation purine analog	Inhibit DNA synthesis and repair via  inhibition of ribonucleotide reductase  (RnR) and DNA polymerases
5-azacytidine	Vidaza	DNA Methylation Inhibitor	Cause hypomethylation of DNA that leads to direct cytotoxicity on abnormal hematopoietic cells in the bone marrow
Decitabine	Dacogen	DNA Methylation Inhibitor	Cause hypomethylation of DNA that leads to direct cytotoxicity on abnormal hematopoietic cells in the bone marrow
Sapacitabine	Cyclacel	Nucleoside analogue	Interferes with DNA synthesis by causing single strand breaks which are subsequently converted to double strand breaks resulting in cell death. It also induce cell cycle arrest in G2/M-Phase and delays progression to S-Phase resulting in apoptosis
Cloretazine	Laromustine	sulfonylhydrazine alkylator	Inhibit the nucleotidyl transferase activity of purified human DNA polymerase β (Pol β), a principal enzyme of DNA base excision repair (BER)
Tosedostat		Aminopeptidase inhibitor	Inhibit aminopeptidase activity, which results in the depletion of cellular amino acid pools selectively in tumour cells that disrupts the turnover of cell cycle
CPX-351		liposomal formulation of a fixed combination of cytarabine and daunorubicin in 5:1 molar ratio	It combined the antitumor activity of cytarabine (DNA polymerase inhibitor) and anthracycline (Topoisomerase II inhibitor)
Vosaroxin		Topoisomerase II inhibitor	Inhibit topoisomerase II activity that results in replication-dependent, site-selective double-strand breaks in DNA
Quizartinib Sorafenib	Nexavar	FLT3 inhibitor	Inhibit class III receptor tyrosine kinase (FLT3) leading to inhibition of ligand- independent leukemic cell proliferation and apoptosis
Midostaurin

FLT3 = FMS-related tyrosine kinase 3