Heather Raymon

Discovery of (S)-N-{2-[1-(3-Ethoxy-4-methoxyphenyl)-2-methanesulfonylethyl]-1,3-dioxo-2,3-dihydro-1H-isoindol-4-yl}acetamide (Apremilast), a Potent and Orally Active Phosphodiesterase 4 and Tumor Necrosis Factor-α Inhibitor

In this communication, we report the discovery of 1S (apremilast), a novel potent and orally active phosphodiesterase 4 (PDE4) and tumor necrosis factor-alpha inhibitor. The optimization of previously reported 3-(1,3-dioxo-1,3-dihydroisoindol-2-yl)-3-(3,4-dimethoxyphenyl)propionic acid PDE4 inhibitors led to this series of sulfone analogues. Evaluation of the structure-activity relationship of substitutions on the phthalimide group led to the discovery of an acetylamino analogue 1S, which is currently in clinical trials.

An activin receptor IIA ligand trap promotes erythropoiesis resulting in a rapid induction of red blood cells and haemoglobin

Sotatercept (ACE‐011), a recombinant human fusion protein containing the extracellular domain of the human Activin receptor IIA, binds to and inhibits activin and other members of the transforming growth factor ‐β (TGF‐β) superfamily. Administration of sotatercept led to a rapid and sustained increase in red blood cell (RBC) count and haemoglobin (Hb) in healthy volunteers (phase I clinical trials), but the mechanism is not fully understood. Mice treated with RAP‐011 (murine ortholog of ACE‐011) respond with a rapid (within 24 h) increase in haematocrit, Hb, and RBC count. These effects are accompanied by an equally rapid stimulation of late‐stage erythroid precursors in the bone marrow (BM). RAP‐011 also induces a significant increase in erythroid burst‐forming units and erythropoietin, which could contribute to additional, sustained effects on RBC production. Further in vitro co‐culture studies demonstrate that BM accessory cells are required for RAP‐011 effects. To better understand which TGF‐β family ligand(s) mediate RAP‐011 effects, we evaluated the impact of several of these ligands on erythroid differentiation. Our data suggest that RAP‐011 may act to rescue growth differentiation factor 11/Activin A‐induced inhibition of late‐stage erythropoiesis. These data define the mechanism of action of a novel agent that regulates RBC differentiation and provide the rationale to develop sotatercept for the treatment of anaemia and ineffective erythropoiesis.

The Synthetic Compound CC-5079 Is a Potent Inhibitor of Tubulin Polymerization and Tumor Necrosis Factor-α Production with Antitumor Activity

We have found that the synthetic compound CC-5079 potently inhibits cancer cell growth in vitro and in vivo by a novel combination of molecular mechanisms. CC-5079 inhibits proliferation of cancer cell lines from various organs and tissues at nanomolar concentrations. Its IC(50) value ranges from 4.1 to 50 nmol/L. The effect of CC-5079 on cell growth is associated with cell cycle arrest in G(2)-M phase, increased phosphorylation of G(2)-M checkpoint proteins, and apoptosis. CC-5079 prevents polymerization of purified tubulin in a concentration-dependent manner in vitro and depolymerizes microtubules in cultured cancer cells. In competitive binding assays, CC-5079 competes with [(3)H]colchicine for binding to tubulin; however, it does not compete with [(3)H]paclitaxel (Taxol) or [(3)H]vinblastine. Our data indicate that CC-5079 inhibits cancer cell growth with a mechanism of action similar to that of other tubulin inhibitors. However, CC-5079 remains active against multidrug-resistant cancer cells unlike other tubulin-interacting drugs, such as Taxol and colchicine. Interestingly, CC-5079 also inhibits tumor necrosis factor-alpha (TNF-alpha) secretion from lipopolysaccharide-stimulated human peripheral blood mononuclear cells (IC(50), 270 nmol/L). This inhibitory effect on TNF-alpha production is related to its inhibition of phosphodiesterase type 4 enzymatic activity. Moreover, in a mouse xenograft model using HCT-116 human colorectal tumor cells, CC-5079 significantly inhibits tumor growth in vivo. In conclusion, our data indicate that CC-5079 represents a new chemotype with novel mechanisms of action and that it has the potential to be developed for neoplastic and inflammatory disease therapy.

Discovery of CC-930, an orally active anti-fibrotic JNK inhibitor.

In this Letter we describe the discovery of potent, selective, and orally active aminopurine JNK inhibitors. Improving the physico-chemical properties as well as increasing the potency and selectivity of a subseries with rat plasma exposure, led to the identification of four structurally diverse inhibitors. Differentiation based on PK profiles in multiple species as well as activity in a chronic efficacy model led to the identification of 1 (CC-930) as a development candidate, which is currently in Phase II clinical trial for IPF.

CC-122, a pleiotropic pathway modifier, mimics an interferon response and has antitumor activity in DLBCL

Cereblon (CRBN), a substrate receptor of the Cullin 4 RING E3 ubiquitin ligase complex, is the target of the immunomodulatory drugs lenalidomide and pomalidomide. Recently, it was demonstrated that binding of these drugs to CRBN promotes the ubiquitination and subsequent degradation of 2 common substrates, transcription factors Aiolos and Ikaros. Here we report that CC-122, a new chemical entity termed pleiotropic pathway modifier, binds CRBN and promotes degradation of Aiolos and Ikaros in diffuse large B-cell lymphoma (DLBCL) and T cells in vitro, in vivo, and in patients, resulting in both cell autonomous as well as immunostimulatory effects. In DLBCL cell lines, CC-122-induced degradation or short hairpin RNA-mediated knockdown of Aiolos and Ikaros correlates with increased transcription of interferon (IFN)-stimulated genes independent of IFN-α, -β, and -γ production and/or secretion and results in apoptosis in both activated B-cell (ABC) and germinal center B-cell DLBCL cell lines. Our results provide mechanistic insight into the cell-of-origin independent antilymphoma activity of CC-122, in contrast to the ABC subtype selective activity of lenalidomide.

The mTOR Kinase Inhibitors, CC214-1 and CC214-2, Preferentially Block the Growth of EGFRvIII-Activated Glioblastomas

Purpose: mTOR pathway hyperactivation occurs in approximately 90% of glioblastomas, but the allosteric mTOR inhibitor rapamycin has failed in the clinic. Here, we examine the efficacy of the newly discovered ATP-competitive mTOR kinase inhibitors CC214-1 and CC214-2 in glioblastoma, identifying molecular determinants of response and mechanisms of resistance, and develop a pharmacologic strategy to overcome it. Experimental Design: We conducted in vitro and in vivo studies in glioblastoma cell lines and an intracranial model to: determine the potential efficacy of the recently reported mTOR kinase inhibitors CC214-1 (in vitro use) and CC214-2 (in vivo use) at inhibiting rapamycin-resistant signaling and blocking glioblastoma growth and a novel single-cell technology—DNA Encoded Antibody Libraries—was used to identify mechanisms of resistance. Results: Here, we show that CC214-1 and CC214-2 suppress rapamycin-resistant mTORC1 signaling, block mTORC2 signaling, and significantly inhibit the growth of glioblastomas in vitro and in vivo. EGFRvIII expression and PTEN loss enhance sensitivity to CC214 compounds, consistent with enhanced efficacy in strongly mTOR-activated tumors. Importantly, CC214 compounds potently induce autophagy, preventing tumor cell death. Genetic or pharmacologic inhibition of autophagy greatly sensitizes glioblastoma cells and orthotopic xenografts to CC214-1- and CC214-2–induced cell death. Conclusions: These results identify CC214-1 and CC214-2 as potentially efficacious mTOR kinase inhibitors in glioblastoma, and suggest a strategy for identifying patients most likely to benefit from mTOR inhibition. In addition, this study also shows a central role for autophagy in preventing mTOR-kinase inhibitor-mediated tumor cell death, and suggests a pharmacologic strategy for overcoming it. Clin Cancer Res; 19(20); 5722–32. ©2013 AACR.

Tyrosine hydroxylase expression is unstable in a human immortalized mesencephalic cell line--studies in vitro and after intracerebral grafting in vivo.

We have studied the stability of the dopaminergic phenotype in a conditionally immortalized human mesencephalic cell line, MESC2.10. Even though MESC2.10 cells exhibit features of dopaminergic neurons in vitro, none of the cells expressed tyrosine hydroxylase (TH) after transplantation into a rat model of Parkinsons disease. We examined whether this is caused by cell death or loss of transmitter phenotype. Cells were cultured in differentiation medium, then harvested and replated into the same medium where they continued to express TH, whereas replated cells fed medium lacking differentiation factors (dibutyryl cAMP and glial cell line-derived neurotrophic factor) did not. Interestingly, cultures grown in the absence of differentiation factors could regain TH expression once exposed to differentiation medium. Our data suggest that TH expression in vitro is inducible in neurons derived from the MESC2.10 cell line and that the dopaminergic phenotype of these cells in vivo might be unstable.

Emerging treatments for asthma.

Despite the availability of a great number of medications, the asthma epidemic is continuing to increase. It is obvious that a high, unmet medical need remains and innovative therapeutic agents are urgently required. Existing therapies, such as β-agonists and corticosteroids, provide relief for sufferers of mild-to-moderate asthma, reversing the acute bronchoconstriction and decreasing the inflammation. However, these therapies provide little relief for chronic asthmatics. Asthma is a manifestation of an imbalance in cytokine and signalling pathways that mediate inflammatory and structural changes within the lung. New therapies need to be developed to target these changes. Emerging treatments for asthma include strategies to alter the cytokine/chemokine balance, to skew the cytokine profile away from a T helper (Th)2 response and towards a Th1 response. Strategies designed to do this include therapeutic antibodies or small molecule inhibitors targeted towards IL-13, IL-4 or their receptors, and the Th1 cytokine IL-12. Much interest has focused on the signalling pathways involved in asthma. Among these, the mitogen-activated protein kinase (MAPK) pathway members c-Jun N-terminal kinase (JNK) and p38 have gathered much interest, in addition to the transcription factors nuclear factor kappaB (NF-κB), activator protein-1 (AP-1) and signal transducer and activator of transcription (STAT)-6. This review aims to summarise the emerging treatments for chronic asthma, from early discovery, to late clinical stages, and discuss the therapeutic rationale behind these treatments. Much is still to be learned about the mechanisms involved in the development and treatment of chronic asthma; however, much promise lies in the future of these new therapeutics.

Aminopurine based JNK inhibitors for the prevention of ischemia reperfusion injury.

In this Letter we describe the optimization of an aminopurine lead (1) with modest potency and poor overall kinase selectivity which led to the identification of a series of potent, selective JNK inhibitors. Improvement in kinase selectivity was enabled by introduction of an aliphatic side chain at the C-2 position. CC-359 (2) was selected as a potential clinical candidate for diseases manifested by ischemia reperfusion injury.

CC-223, a Potent and Selective Inhibitor of mTOR Kinase: In Vitro and In Vivo Characterization.

mTOR is a serine/threonine kinase that regulates cell growth, metabolism, proliferation, and survival. mTOR complex-1 (mTORC1) and mTOR complex-2 (mTORC2) are critical mediators of the PI3K–AKT pathway, which is frequently mutated in many cancers, leading to hyperactivation of mTOR signaling. Although rapamycin analogues, allosteric inhibitors that target only the mTORC1 complex, have shown some clinical activity, it is hypothesized that mTOR kinase inhibitors, blocking both mTORC1 and mTORC2 signaling, will have expanded therapeutic potential. Here, we describe the preclinical characterization of CC-223. CC-223 is a potent, selective, and orally bioavailable inhibitor of mTOR kinase, demonstrating inhibition of mTORC1 (pS6RP and p4EBP1) and mTORC2 [pAKT(S473)] in cellular systems. Growth inhibitory activity was demonstrated in hematologic and solid tumor cell lines. mTOR kinase inhibition in cells, by CC-223, resulted in more complete inhibition of the mTOR pathway biomarkers and improved antiproliferative activity as compared with rapamycin. Growth inhibitory activity and apoptosis was demonstrated in a panel of hematologic cancer cell lines. Correlative analysis revealed that IRF4 expression level associates with resistance, whereas mTOR pathway activation seems to associate with sensitivity. Treatment with CC-223 afforded in vivo tumor biomarker inhibition in tumor-bearing mice, after a single oral dose. CC-223 exhibited dose-dependent tumor growth inhibition in multiple solid tumor xenografts. Significant inhibition of mTOR pathway markers pS6RP and pAKT in CC-223–treated tumors suggests that the observed antitumor activity of CC-223 was mediated through inhibition of both mTORC1 and mTORC2. CC-223 is currently in phase I clinical trials. Mol Cancer Ther; 14(6); 1295–305. ©2015 AACR.