PD-0325901 is an orally bioavailable inhibitor of mitogen-activated protein kinase kinases (MAPK/ERK kinases or MEK) with potential antineoplastic activity. MEK inhibitor PD325901, a derivative of MEK inhibitor CI-1040, selectively binds to and inhibits MEK, which may result in the inhibition of the phosphorylation and activation of MAPK/ERK and the inhibition of tumor cell proliferation. PD-0325901 is tested in clinical trials against non-small cell lung cancer, neurofibromatosis, melanoma and breast cancer.

AZD-5363, a novel pyrrolopyrimidine-derived compound, inhibits all AKT isoforms with a potency of <10nM, and inhibited phosphorylation of AKT substrates in cells with a potency of ~0.3 to 0.8µM. AZD5363 monotherapy inhibited the proliferation of 41/182 solid and hematologic tumour cell lines with a potency of <3µM and 25/182 with a potency of <1µM. By targeting AKT, the key node in the PIK3/AKT signaling network, AZD-5363 may be used as monotherapy or combination therapy for a variety of human cancers. There is significant relationship between the presence of PIK3CA and/or PTEN mutations and sensitivity to AZD-5363, and between RAS mutations and resistance. In xenograft studies in vivo AZD-5363 significantly reduced phosphorylation of PRAS40, GSK3β and S6. Chronic oral dosing of AZD-5363 causes dose-dependent inhibition of the growth of xenografts derived from various tumor types and AZD-5363 also significantly enhanced the antitumor activity of docetaxel, lapatinib and trastuzumab in breast cancer xenografts. Dose-response at oral doses of 50 to 150mg/kg twice daily continuous dosing and intermittent dosing in the range of 100 to 200mg/kg twice daily, 4 days on, 3 days off have led to efficacy. AZD-5363 is in phase II clinical studies for the treatment of breast cancer; gastric cancer; non-small cell lung cancer.

Nirogacestat (PF-3084014) is a tetralin imidazole gamma-secretase inhibitor. Gamma-secretase, a proteolytic enzyme complex, mediates processing of several integral membrane proteins including amyloid precursor protein and Notch. This compound can inhibit both Notch-related pathway in neoplasia and reduces amyloid-β production. Nirogacestat (PF-3084014) is under development by Pfizer for the treatment of cancer.

Estetrol is the natural human fetal selective estrogen receptor modulator. It is synthesized exclusively by the human fetal liver during pregnancy. Estetrol has a moderate affinity for human estrogen A receptor (ERa) and estrogen B receptor (ERb). Estetrol may be suitable as a potential drug for human use in applications such as hormone replacement therapy (vaginal atrophy, hot flushes), contraception and osteoporosis. The most common drug-related adverse events were lower abdominal pain, nausea, headache, dysmenorrhoea, breast enlargement and acne. Estetrol had been in clinical trials for the treatment of breast and prostate cancers.

TUCATINIB (ONT-380 or ARRY-380) is an orally active, reversible and selective small-molecule HER2 inhibitor invented by Array and licensed to Cascadian Therapeutics (previously named Oncothyreon) for development, manufacturing and commercialization. HER2, a growth factor receptor that is over-expressed in multiple cancers, including breast, ovarian, and stomach cancer. HER2 mediates cell growth, differentiation and survival, and tumors that overexpress HER2 are more aggressive and historically have been associated with poorer overall survival compared with HER2-negative cancers. ONT-380 is highly active as a single agent and in combination with both chemotherapy and Herceptin® (trastuzumab) in xenograft models of HER2+ breast cancer, including models of CNS metastases that were refractory to Tykerb® (lapatinib) or neratinib treatment. In a Phase 1 single agent clinical study, ONT-380 administered orally twice a day was well tolerated and demonstrated anti-tumor activity in heavily pre-treated HER2+ breast cancer patients with metastatic disease. Based on the strength of these preclinical and clinical trials, ONT-380 is advancing in one Phase 2 and three Phase 1b combination trials in patients with metastatic breast cancer. A second study reported the CNS activity of ONT-380 in combination with either T-DM1 or trastuzumab or capecitabine. Patients with brain metastases assessable for response were included in the combined analysis. Responses and clinical benefit in the CNS were reported with the three combinations tested, supporting future development of the drug for this particular indication.

Artenimol (dihydroartemisinin) is a derivate of antimalarial compound artemisinin. Artenimol (dihydroartemisinin) is able to reach high concentrations within the parasitized erythrocytes. Its endoperoxide bridge is thought to be essential for its antimalarial activity, causing free-radical damage to parasite membrane systems including: • Inhibition of falciparum sarcoplasmic-endoplasmic reticulum calcium ATPase, • Interference with mitochondrial electron transport • Interference with parasite transport proteins • Disruption of parasite mitochondrial function. Dihydroartemisinin in combination with piperaquine tetraphosphate (Eurartesim, EMA-approved in 2011) is indicated for the treatment of uncomplicated Plasmodium falciparum malaria. The formulation meets WHO recommendations, which advise combination treatment for Plasmodium falciparum malaria to reduce the risk of resistance development, with artemisinin-based preparations regarded as the ‘policy standard’. However, experimental testing demonstrates that, due to its intrinsic chemical instability, dihydroartemisinin is not suitable to be used in pharmaceutical formulations. In addition, data show that the currently available dihydroartemisinin preparations fail to meet the internationally accepted stability requirements.

Selinexor (KPT-330) is a first in class XPO1 antagonist being evaluated in multiple later stage clinical trials in patients with relapsed and/or refractory hematological and solid tumor malignancies.

Alpelisib (BYL719) is a PI3Kα-selective inhibitor. PI3K-AKT-mTOR pathway is frequently activated in cancer, therefore investigational PI3K inhibitor alpelisib is considered to be effective as an anticancer agent and has been in clinical development by Novartis. Alpelisib have demonstrated activity in preclinical models of solid tumors and had favorable tolerability profiles, with the most common adverse events consistent with “on-target” inhibition of PI3K in early clinical studies. There are ongoing clinical trials of alpelisib in a range of cancer types, including breast cancer, head and neck squamous cell carcinoma, non-small cell lung carcinoma, lymphoma, and glioblastoma multiforme. Combination therapy with other chemo therapeutics may be preferable.

BMN-673 (8R,9S) is the (8R,9S) enantiomer of BMN-673, known as talazoparib. BMN 673 is a novel inhibitor of nuclear enzyme poly (ADP-ribose) polymerase (PARP) with potential antineoplastic activity.

Neratinib (HKI-272) is a pan-HER inhibitor, this irreversible tyrosine kinase inhibitor binds and inhibits the tyrosine kinase activity of epidermal growth factor receptors, EGFR (or HER1), HER2 and HER4, which leads to reduced phosphorylation and activation of downstream signaling pathways. Neratinib is a modified form of the discontinued compound pelitinib, and was originally being develoAdditionally, phase II development of oral neratinib as a neoadjuvant therapy for breast cancer, as a second-line therapy for non-small cell lung cancer, and for other solid tumours is also in progress in numerous countries worldwide. ped by Wyeth (later Pfizer). Oral neratinib is awaiting approval as an extended adjuvant therapy for breast cancer in the EU and in the US. Blocking HER2 function by a small molecule kinase inhibitor, such as neratinib, represents an attractive alternate strategy for the growth inhibition of HER2-positive tumours.