Publications by authors named "Amy Sambrone"

Fulvestrant is an FDA-approved drug with a dual mechanism of action (MOA), acting as a full antagonist and degrader of the estrogen receptor protein. A significant limitation of fulvestrant is the dosing regimen required for efficacy. Due to its high lipophilicity and poor pharmacokinetic profile, fulvestrant needs to be administered through intramuscular injections which leads to injection site soreness.

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Breast cancer remains a leading cause of cancer death in women, representing a significant unmet medical need. Here, we disclose our discovery efforts culminating in a clinical candidate, (GDC-9545 or giredestrant). is an efficient and potent selective estrogen receptor degrader (SERD) and a full antagonist, which translates into better antiproliferation activity than known SERDs (, , , and ) across multiple cell lines.

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Estrogen receptor alpha (ERα) is a well-validated drug target for ER-positive (ER+) breast cancer. Fulvestrant is FDA-approved to treat ER+ breast cancer and works through two mechanisms-as a full antagonist and selective estrogen receptor degrader (SERD)-but lacks oral bioavailability. Thus, we envisioned a "best-in-class" molecule with the same dual mechanisms as fulvestrant, but with significant oral exposure.

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Despite tremendous progress made in the understanding of the ERα signaling pathway and the approval of many therapeutic agents, ER+ breast cancer continues to be a leading cause of cancer death in women. We set out to discover compounds with a dual mechanism of action in which they not only compete with estradiol for binding with ERα, but also can induce the degradation of the ERα protein itself. We were attracted to the constrained chromenes containing a tetracyclic benzopyranobenzoxepine scaffold, which were reported as potent selective estrogen receptor modulators (SERMs).

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Herein we report identification of an imidazopyridine class of potent and selective TYK2 inhibitors, exemplified by prototype 6, through constraint of the rotatable amide bond connecting the pyridine and aryl rings of compound 1. Further optimization led to generation of compound 30 that potently inhibits the TYK2 enzyme and the IL-23 pathway in cells, exhibits selectivity against cellular JAK2 activity, and has good pharmacokinetic properties. In mice, compound 30 demonstrated dose-dependent reduction of IL-17 production in a PK/PD model as well as in an imiquimod-induced psoriasis model.

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Activated Wnt/β-catenin signaling is frequently associated with colorectal cancer. Wnt inhibitors, including tankyrase inhibitors, are being explored as potential anticancer agents. Wnt signaling is also critical for intestinal tissue homeostasis, and Wnt inhibitors have been shown to cause intestinal toxicity in mice by affecting intestinal stem cells.

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Diverse biological roles for mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) have necessitated the identification of potent inhibitors in order to study its function in various disease contexts. In particular, compounds that can be used to carry out such studies in vivo would be critical for elucidating the potential for therapeutic intervention. A structure-based design effort coupled with property-guided optimization directed at minimizing the ability of the inhibitors to cross into the CNS led to an advanced compound 13 (GNE-495) that showed excellent potency and good PK and was used to demonstrate in vivo efficacy in a retinal angiogenesis model recapitulating effects that were observed in the inducible Map4k4 knockout mice.

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Mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) is a serine/threonine kinase implicated in the regulation of many biological processes. A fragment-based lead discovery approach was used to generate potent and selective MAP4K4 inhibitors. The fragment hit pursued in this article had excellent ligand efficiency (LE), an important attribute for subsequent successful optimization into drug-like lead compounds.

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1. Modern high-throughput small molecule drug discovery requires rapid screening of the pharmacokinetic parameters of multiple candidate molecules in parallel. The mouse is often used for such screening, as are solvent-based intravenous formulations.

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A therapeutic rationale is proposed for the treatment of inflammatory diseases, such as psoriasis and inflammatory bowel diseases (IBD), by selective targeting of TYK2. Hit triage, following a high-throughput screen for TYK2 inhibitors, revealed pyridine 1 as a promising starting point for lead identification. Initial expansion of 3 separate regions of the molecule led to eventual identification of cyclopropyl amide 46, a potent lead analog with good kinase selectivity, physicochemical properties, and pharmacokinetic profile.

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Article Synopsis
  • - The study focuses on optimizing a lead molecule (compound 3) to develop stronger, selective, and orally effective inhibitors of the TYK2 enzyme, which is important for immunological responses.
  • - Through structure-based design, researchers created modifications that improved the potency of these inhibitors while ensuring selectivity against JAK1 and JAK2, leading to the discovery of compound 37.
  • - In mouse experiments, compound 37 demonstrated significant effectiveness in reducing interferon-γ levels, indicating that targeting TYK2 can effectively block the IL-12 signaling pathway in living organisms.
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Most colorectal cancers (CRC) are initiated by mutations of APC, leading to increased β-catenin-mediated signaling. However, continued requirement of Wnt/β-catenin signaling for tumor progression in the context of acquired KRAS and other mutations is less well-established. To attenuate Wnt/β-catenin signaling in tumors, we have developed potent and specific small-molecule tankyrase inhibitors, G007-LK and G244-LM, that reduce Wnt/β-catenin signaling by preventing poly(ADP-ribosyl)ation-dependent AXIN degradation, thereby promoting β-catenin destabilization.

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Granulocyte-colony stimulating factor (G-CSF) promotes mobilization of CD11b(+)Gr1(+) myeloid cells and has been implicated in resistance to anti-VEGF therapy in mouse models. High G-CSF production has been associated with a poor prognosis in cancer patients. Here we show that activation of the RAS/MEK/ERK pathway regulates G-CSF expression through the Ets transcription factor.

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Drug polymer-based amorphous solid dispersions (ASD) are widely used in the pharmaceutical industry to improve bioavailability for poorly water-soluble compounds. Spray-drying is the most common process involved in the manufacturing of ASD material. However, spray-drying involves a high investment of material quantity and time.

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It is well recognized that poor dissolution rate and solubility of drug candidates are key limiting factors for oral bioavailability. While numerous technologies have been developed to enhance solubility of the drug candidates, poor water solubility continuously remains a challenge for drug delivery. Among those technologies, amorphous solid dispersions (SD) have been successfully employed to enhance both dissolution rate and solubility of poorly water-soluble drugs.

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