LY-3039478 is an orally bioavailable, novel small molecule inhibitor of Notch signaling pathway, developed Eli Lilly and Company for cancer treatment. The Notch receptor, on the surfaces of progenitor cells and cancer cells, binds neighboring cell-surface ligands DLL or JAGGED. On ligand binding, the intramembrane protease γ-secretase cleaves the Notch intracellular domain (NICD). LY-3039478 is an exquisitely potent inhibitor of Notch-1 intracellular domain (N1ICD) cleavage with an IC50 of ∼1nM in most of the tumor cell lines tested. LY3039478 also potently inhibits mutant Notch receptor activity. Treatment with a gamma-secretase inhibitor, LY3039478, significantly inhibited the growth of 2 CCRCC(Clear cell renal cell carcinoma) cell lines in a concentration-dependent manner. LY3039478 treatment also led to decreased expression of Myc and Cyclin A1, two genes that were part of the NOTCH driven proliferative signature in murine and human model systems. LY3039478 treatment also led to G0/G1 cell cycle arrest in CCRCC cells. In a xenograft tumor model, LY3039478 inhibited N1ICD cleavage and expression of Notch-regulated genes in the tumor microenvironment. The inhibition of Notch cleavage also resulted in the induction of apoptosis in a Notch-dependent xenograft model. In immunodeficient NSG mice xenografted with 769-P CCRCC cells, LY3039478 treatment resulted in significantly increased survival and delayed tumor growth in independent cohorts of mice demonstrating in vivo efficacy in CCRCC. LY3039478 is being investigated in a clinical trial in patients with T-cell acute lymphoblastic leukemia or T-cell lymphoblastic lymphoma in combination with Dexamethasone.

Sanofi has developed SAR260301 as a selective inhibitor of the class I phosphatidylinositol 3-kinase (PI3K) beta isoform with potential antineoplastic activity. It is known that the dysregulation of the PI3K/Akt/mTOR pathway is frequently found in solid tumors and contributes to increased tumor cell growth, tumor cell survival. SAR260301 participated in phase I clinical trials in patients with advanced solid tumors. It was found that the drug had an acceptable safety profile, but exposure sufficient to inhibit the PI3K pathway was unachievable because of rapid clearance, and clinical development was terminated.

ARN-810 (GDC-0810) is a novel, orally bioavailable, estrogen receptor antagonist that induces proteasomal estrogen receptor degradation in breast cancer cell lines at picomolar concentrations and tumor regression in tamoxifen-sensitive and resistant BC xenograft models. Results from a first-in-human phase I/IIa study of ARN-810 indicate that it is tolerable and may benefit some postmenopausal women with advanced estrogen receptor-positive breast cancer. Development of ARN-810 was discontinued.

PQR-309 is an orally bioavailable pan inhibitor of phosphoinositide-3-kinases (PI3K) and inhibitor of the mammalian target of rapamycin (mTOR), with potential antineoplastic activity. PI3K/mTOR kinase inhibitor PQR-309 inhibits the PI3K kinase isoforms alpha, beta, gamma and delta and, to a lesser extent, mTOR kinase, which may result in tumor cell apoptosis and growth inhibition in cells overexpressing PI3K/mTOR. By inhibiting mTOR to a lesser extent than PI3K, PQR-309 does not interfere with the mTOR-mediated negative feedback loop on PI3K signaling. Blocking the negative feedback loop would potentially increase PI3K signaling and decrease therapeutic efficacy. PQR-309 is in phase II clinical trial for the treatment of glioblastoma, head and neck cancer, lymphoma and breast cancer. Common adverse events included fatigue, hyperglycemia, nausea, diarrhea, constipation, rash, anorexia and vomiting.

Lexanopadol is a potent ORL-1 agonist (opioid receptor like -1), nociceptin receptor agonists and opioid mu receptor agonists. Preliminary evidence suggests that targeting ORL-1 receptors may have synergistic effects with mu receptors hence enhancing the therapeutic profile of Lexanopadol in the treatment of pain. Lexanopadol is particularly suited for the management of moderate to severe chronic pain, including neuropathic pain. Lexanopadol hemicitrate is in phase II clinical trials for the treatment of pain. However there is no recent development reported.