TAK-659 is an investigational, reversible, and potent dual inhibitor of SYK and FLT-3 kinases. TAK-659 inhibited the pro-survival, proliferative, chemoresistant, and activation effects promoted by the microenvironment. Combination of TAK-659 with other BCR inhibitors showed a synergistic effect in inducing apoptosis. Combination of TAK-659 and ibrutinib induced significantly higher cytotoxicity toward CLL cells. TAK-659 suppressed splenomegaly and tumor development in an LMP2A/Myc mouse model in nanomolar concentrations. In addition, TAK-659 also blocked metastasis of tumor cells into bone marrow. A phase Ib/II study of TAK-659 is underway in patients with relapsed or refractory acute myelogenous leukemia

CNDAC (TAK-109) is an analog of the nucleoside deoxycytidine with potential antineoplastic activity. CNDAC is incorporated into DNA and induces single-strand breaks, which are converted into double-strand breaks (DSBs) when cells go through a second S phase. This results in the cell cycle arrest in the S and G2/M phases, DNA fragmentation, and tumor cell apoptosis. Sapacitabine, a prodrug of CNDAC, is being developed by the US biotechnology company Cyclacel for the treatment of hemalogical cancers and solid tumors.

Rubitecan [Orathecin™] is a topoisomerase I inhibitor extracted from the bark and leaves of the Camptotheca acuminata tree, which is native to China. Rubitecan is an oral compound being developed for the treatment of pancreatic cancer and other solid tumours by SuperGen. Rubitecan binds to and inhibits the enzyme topoisomerase I and induces protein-linked DNA single-strand breaks, thereby blocking DNA and RNA synthesis in dividing cells; this agent also prevents repair of reversible single-strand DNA breaks.

Reparixin is a CXC chemokine receptor type 1 (CXCR1) and type 2 (CXCR2) inhibitor. This compound has potential antineoplastic activity. It can be administered orally, binds to CXCR1 (overexpressed on cancer stem cells) and prevents its activation by its ligand interleukin 8. This might result in the death of cancer cells and inhibition of cell progression and metastasis. Reparixin also inhibits CXCR2 activation, possibly reducing both neutrophil recruitment and vascular permeability during inflammation or injury. A phase II clinical trial evaluating the effects of orally administered reparixin on cancer stem cells in the primary tumor and the tumoral microenvironment in an early breast cancer population was terminated. Reparixin has also been suggested as a novel potential therapeutic strategy for aggressive forms of thyroid cancer, based on results of a xenotransplantation study in mice.

Hydroxypioglitazone (M-IV) is an active metabolite of the peroxisome proliferator-activated receptor γ (PPARγ) agonist pioglitazone. Experiments in vitro have shown that hydroxypioglitazone was more efficient than the parent drug in stimulating lipid synthesis.