Tosedostat is a proprietary orally bioavailable inhibitor of the M1 family of aminopeptidases with potential antineoplastic activity. Tosedostat is converted intracellularly into a poorly membrane-permeable active metabolite (CHR-79888) which inhibits the M1 family of aminopeptidases, particularly puromycin-sensitive aminopeptidase (PuSA), and leukotriene A4 (LTA4) hydrolase; inhibition of these aminopeptidases in tumor cells may result in amino acid deprivation, inhibition of protein synthesis due to a decrease in the intracellular free amino acid pool, an increase in the level of the proapoptotic protein Noxa, and cell death. There are several ongoing Phase 2 cooperative group-sponsored trials and investigator-sponsored trials evaluating the clinical activity of Tosedostat in combination with standard agents in patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS).

Gedatolisib (PF-05212384, PKI-587) is a highly potent dual inhibitor of PI3Kα, PI3Kγ and mTOR, originally being developed by Wyeth. Upon intravenous administration, gedatolisib inhibits both PI3K and mTOR kinases, which may result in apoptosis and growth inhibition of cancer cells overexpressing PI3K/mTOR. Activation of the PI3K/mTOR pathway promotes cell growth, survival, and resistance to chemotherapy and radiotherapy; mTOR, a serine/threonine kinase downstream of PI3K, may also be activated independent of PI3K. Significant antitumor efficacy and a favorable pharmacokinetic/safety profile justified clinical evaluation of Gedatolisib. Gedatolisb is in phase II clinical trials by Pfizer for the treatment of acute myeloid leukaemia. Gedatolisb is in phase I clinical trials for the treatment of solid tumours.

Emricasan (IDN- 6556 or PF-03491390) (3-[2-[(2-tert-butyl-phenylaminooxalyl)-amino]-propionylamino]-4-oxo-5-(2,3,5,6-tetrafluoro-phenoxy)-pentanoic acid) is a pan-caspase inhibitor. Testing in vitro enzyme assays demonstrated that emricasan efficiently inhibits all human caspases at low nanomolar concentrations. Preclinically, emricasan was effective in inhibiting apoptosis of sinusoidal endothelial cells. Emricasan has marked efficacy in models of liver disease after oral administration and thus, is an excellent candidate for the treatment of liver diseases characterized by excessive apoptosis. This drug is a first-in-class anti-apoptotic caspase inhibitor with demonstrated preliminary efficacy in liver-impaired patients in humans.

Indoximod is an orally available Indoleamine 2,3-dioxigenase inhibitor. It shows higher potency in reversing IDO-mediated T cell suppression. Indoximod improves the efficacy of multiple chemotherapeutics agents and some immunological checkpoints mediators in Phase I/II clinical studies for metastatic breast cancer, metastatic melanoma, non-small cell lung cancer, primary malignant brain tumors, metastatic pancreatic cancer, as well as metastatic prostate cancer.

Troxacitabine is a synthetic nucleoside analogue. It is a poor substrate for nucleoside transporters and gains entry into cells by passive diffusion. Intracellular conversion to its active triphosphate form is via deoxycytidine kinase. Incorporation of this metabolite into DNA results in immediate chain termination and apoptosis induction. It is the first nucleoside analog with anticancer activity that has an unnatural stereochemical configuration. The dose-limiting adverse reactions were stomatitis and hand–foot syndrome.

UM171 is a potent agonist of human hematopoietic stem cell renewal, independently of AhR suppression. UM171 act differently than other small molecule stimulators of hematopoiesis, such as the aryl hydrocarbon receptor (AhR) antagonist StemRegenin 1 (SR1). Addition of UM171 to cultures containing SR1 and cytokines further enhances the ex vivo expansion of normal HSCs, including CD34+ cells.

G749 is a Fms-like tyrosine receptor kinase 3 (FLT3) inhibitor and a promising next-generation drug candidate for the treatment of relapsed and refractory acute myeloid leukemia (AML) patients with various FLT3-ITD/FLT3-TKD mutants that shows the ability to overcome drug resistance. It demonstrated potent and sustained inhibition of the FLT3 wild type and mutants including FLT3-ITD, FLT3-D835Y, FLT3-ITD/N676D, and FLT3-ITD/F691L in cellular assays. G749 retained its inhibitory potency in various drug-resistance milieus such as patient plasma, FLT3 ligand surge, and stromal protection. It also displayed potent antileukemic activity in bone marrow blasts from AML patients regardless of FLT3 mutation status, including those with little or only minor responses to AC220 or PKC412. Oral administration of G749 yielded complete tumor regression and increased life span in animal models.

CPI-0610 is a small molecule inhibitor of the Bromodomain and Extra-Terminal (BET) family of proteins, with potential antineoplastic activity. Upon administration, the BET inhibitor CPI-0610 binds to the acetylated lysine recognition motifs on the bromodomain of BET proteins, thereby preventing the interaction between the BET proteins and acetylated histone peptides. This disrupts chromatin remodeling and gene expression. Prevention of the expression of certain growth-promoting genes may lead to an inhibition of tumor cell growth. CPI-0610 is currently being evaluated in three Phase 1 clinical trials in the U.S.

OTS-167 is a maternal embryonic leucine zipper kinase (MELK) inhibitor which demonstrated antitumor properties in laboratory tests. It is being developed as an anti-cancer drug. The compound has been shown to suppress the growth of breast, lung, pancreatic and prostate cancer cells that express high levels of the MELK protein. OTS167 reached phase II clinical trials in patients with AML, ALL, advanced MDSs, advanced MPNs, or advanced CML and phase I in patients with breast cancer.

Idasanutlin (RG-7388) is a second-generation, orally bioavailable, selective p53-MDM2 antagonist. MDM2 is an important negative regulator of the p 53 tumor suppressor and is expressed at high levels in a large proportion of acute myeloid leukemia (AML). Blocking the MDM2-p53 interaction stabilizes p53 and activates p-53 mediated cell death and inhibition cell growth. Idasanutlin is under clinical trial in phase III for treatment AML and in combinations with others drugs in phase I/II for treatment of multiple myeloma.