AT-406 (DEBIO-1143, SM-406), is a potent and orally bioavailable Smac mimetic and an antagonist of the inhibitor of apoptosis proteins (IAPs). AT-406 inhibits cancer cell growth in various human cancer cell lines. It has good oral bioavailability in mice, rats, non-human primates, and dogs, is highly effective in induction of apoptosis in xenograft tumors, and is capable of complete inhibition of tumor growth. Debiopharm under a licence from Ascenta Therapeutics is developing AT-406 for the treatment of cancers.

Birinapant is a parenterally administered bivalent peptidomimetic of the SMAC protein (Second Mitochondria-derived Activator of Caspases) and is therefore known as a SMAC mimetic compound. Birinapant is a particularly potent antagonist of two members of the Inhibitor of Apoptosis Proteins (IAP) family, cIAP-1, and cIAP-2. cIAP-1 and -2 are ubiquitin ligases whose expression can protect cells from apoptosis and cause pro-survival effects of TNF-α and related ligands. When Birinapant binds to cIAP-1 or -2 it causes the protein to ubiquitinate itself, which in turn drives the degradation of the protein. In this way, birinapant suppresses the levels of cIAP-1 and cIAP-2 and therefore switches cell signaling to drive tumor cell apoptosis in the presence of TNF-α. Birinapant has been shown to give rise to sustained and substantial reductions of cIAP1 levels in Peripheral Blood Mononuclear Cells (PBMCs) and tumor tissue. To date, Birinapant has been dosed in approximately 450 patients across 9 studies. The majority of studies was in oncology (one in HBV) and primarily recruited patients with refractory solid tumors & hematological malignancies (dominated by ovarian, colorectal, acute myeloid leukemia and Myelodysplastic syndromes). Overall Birinapant has shown acceptable safety and tolerability for further development in oncology indications. The current plans are to study Birinapant clinically in combination with Keytruda® for the treatment solid tumors and in an Investigator-Initiated study at UCLA for high-grade serous carcinoma (HGSC) in combination with platinum-based chemotherapy.

Alisertib (MLN8237) is an orally available selective aurora A kinase inhibitor developed by Takeda. Alisertib inhibited AAK over ABK with a selectivity of more than 200-fold in cells and produced a dose-dependent decrease in bipolar and aligned chromosomes in the HCT-116 xenograft model, a phenotype consistent with AAK inhibition. Alisertib inhibited proliferation of human tumor cell lines in vitro and produced tumor growth inhibition in solid tumor xenograft models and regressions in in vivo lymphoma models. It is currently in phase II clinical trials for acute myeloid leukaemia; B cell lymphoma; brain cancer; mesothelioma; prostate cancer; small cell lung cancer.

THIOINOSINE (Methylmercaptopurine riboside, NSC- 40774) is a purine derivative with antineoplastic and anti-angiogenic properties. THIOINOSINE is readily converted in cells to its active form, 6-methylmercaptopurine ribonucleoside 5'- monophosphate (MMPR-P), by the enzyme adenosine kinase. THIOINOSINE inhibits amidophosphoribosyltransferase, the first committed step in de novo purine synthesis, and inhibits fibroblast growth factor-2 (FGF2)-induced cell proliferation. It has been used similarly to Mercaptopurine in the treatment of Leukemia. It has being tested in clinical trials for advanced pancreatic cancer.

KW-2449, a multikinase inhibitor of FLT3, ABL, ABL-T315I, and Aurora kinase, is under investigation to treat leukaemia patients. KW-2449 is a multikinase inhibitor of FLT3, ABL, ABL-T315I, and Aurora kinase with IC50 values of 6.6nM, 14nM, 4nM and 48nM, respectively. KW-2449 has potent growth inhibitory activity against various types of leukaemia by several mechanisms of action. Kyowa Hakko Kirin Pharma Inc. (a US subsidiary of Kyowa Hakko Kirin Co) was developing KW-2449 for the treatment of acute lymphoblastic leukaemia; acute myeloid leukaemia; chronic myeloid leukaemia; myelodysplastic syndromes, but later these studies were discontinued.

Millennium Pharmaceuticals Inc's tandutinib (MLN-518), a piperazinyl derivative of quinazoline, is an orally active inhibitor of FLT3 kinase and family members PDGFR beta and c-Kit. Tandutinib inhibited FLT3 phosphorylation, downstream signaling and malignant growth in vitro and in animal models. The drug exhibited limited activity as a single agent in phase I and II clinical trials in patients with AML and myelodysplastic syndrome, but displayed promising antileukemic activity (90% complete remissions) in a phase I/II trial in patients with newly diagnosed AML when administered in combination with cytarabine and daunorubicin. Phase II clinical trials for tandutinib in patients with Glioblastoma have being discontinued. The use of tandutinib to treat AML has been granted fast-track status by the U.S. Food and Drug Administration. Phase II trials were underway., but later withwrawn.

CC-401 is a potent inhibitor of all three forms of c-Jun N-terminal Kinase (JNK) (Ki of 25 to 50 nM) and has at least 40-fold selectivity for JNK compared with other related kinases. Celgene was developing CC 401 for the treatment of cancer and inflammatory disorders. CC 401 was being developed in an IV formulation and was in a phase I trial in patients with refractory acute myelogenous leukaemia. However, trials have ended and the company is not pursuing CC 401, but will advance other JNK inhibitors.

AZ-960 is a novel inhibitor of janus-associated kinases (JAKs) that exhibits a potent inhibition against janus kinase 2 (JAK2) with the value of inhibition constant of Ki of 0.45 nmol/L. It also exhibits a lesser inhibitory effects against other JAKs family members, including JAK1, JAK3 and TYK2 as well as other kinases, including TrkA, Aurora A and FAK, with 50% inhibition concentration IC50 of around 0.1 umol/L. In recent studies, AZ-960 demonstrates potential anti-cancer activity against adult T-cell leukemia (ATL), an aggressive malignancy of CD4+ T lymphocytes, by effectively inducing growth arrest and apoptosis in human T-cell lumphotropic virus type 1 (HTLV-1) infected T cells. AZ-960 potently inhibited the clonogenic growth and induced apoptosis of freshly isolated AML cells from patients in association with cleavage of caspase 3 and downregulation of anti-apoptotic Bcl-xL proteins.

BMS-536924 is an ATP-competitive IGF-1R/IR inhibitor with IC50 of 100 nM/73 nM, modest activity for Mek, Fak, and Lck with very little activity for Akt1, MAPK1/2. BMS-536924 has been shown to inhibit the catalytic activity of IGF-1R and its down stream signaling components such as Akt and MAPK in cells; it also inhibits proliferation in a wide variety of human cancer cell lines including, colon, breast, lung, pancreas, prostate, sarcoma and multiple myeloma. In vivo, BMS-536924 inhibits tumor growth in an IGF-1R-dependent tumor model (IGF-1R Sal) as well as in a broad range of human tumor xenografts.

Pixantrone is a novel anthracenedione. It is a weak inhibitor of topoisomerase II. Pixantrone directly alkylates DNA forming stable DNA adducts and cross-strand breaks. Pixuvri is approved for the treatment of adult patients with multiply relapsed or refractory aggressive Non-Hodgkin lymphomas. It is used for patients whose cancer does not respond or has returned after they have received other chemotherapy treatments. The most frequent AE were seen in the blood (mainly neutropaenia), gastrointestinal (nausea, abdominal pain, constipation) and respiratory systems (cough, dyspnea). No drug-drug interaction studies have been submitted and no drug interactions have been reported in human subjects