19 research outputs found
Property- and Structure-Guided Discovery of a Tetrahydroindazole Series of Interleukin‑2 Inducible T‑Cell Kinase Inhibitors
Interleukin-2
inducible T-cell kinase (ITK), a member of the Tec
family of tyrosine kinases, plays a major role in T-cell signaling
downstream of the T-cell receptor (TCR), and considerable efforts
have been directed toward discovery of ITK-selective inhibitors as
potential treatments of inflammatory disorders such as asthma. Using
a previously disclosed indazole series of inhibitors as a starting
point, and using X-ray crystallography and solubility forecast index
(SFI) as guides, we evolved a series of tetrahydroindazole inhibitors
with improved potency, selectivity, and pharmaceutical properties.
Highlights include identification of a selectivity pocket above the
ligand plane, and identification of appropriate lipophilic substituents
to occupy this space. This effort culminated in identification of
a potent and selective ITK inhibitor (GNE-9822) with good ADME properties
in preclinical species
Battling Btk Mutants With Noncovalent Inhibitors That Overcome Cys481 and Thr474 Mutations
The
Bruton’s tyrosine kinase (Btk) inhibitor ibrutinib has
shown impressive clinical efficacy in a range of B-cell malignancies.
However, acquired resistance has emerged, and second generation therapies
are now being sought. Ibrutinib is a covalent, irreversible inhibitor
that modifies Cys481 in the ATP binding site of Btk and renders the
enzyme inactive, thereby blocking B-cell receptor signal transduction.
Not surprisingly, Cys481 is the most commonly mutated Btk residue
in cases of acquired resistance to ibrutinib. Mutations at other sites,
including Thr474, a gatekeeper residue, have also been detected. Herein,
we describe noncovalent Btk inhibitors that differ from covalent inhibitors
like ibrutinib in that they do not interact with Cys481, they potently
inhibit the ibrutinib-resistant Btk C481S mutant <i>in vitro</i> and in cells, and they are exquisitely selective for Btk. Noncovalent
inhibitors such as GNE-431 also show excellent potency against the
C481R, T474I, and T474M mutants. X-ray crystallographic analysis of
Btk provides insight into the unique mode of binding of these inhibitors
that explains their high selectivity for Btk and their retained activity
against mutant forms of Btk. This class of noncovalent Btk inhibitors
may provide a treatment option to patients, especially those who have
acquired resistance to ibrutinib by mutation of Cys481 or Thr474
Pyridones as Highly Selective, Noncovalent Inhibitors of T790M Double Mutants of EGFR
The rapid advancement of a series
of noncovalent inhibitors of
T790M mutants of EGFR is discussed. The optimization of pyridone <b>1</b>, a nonselective high-throughput screening hit, to potent
molecules with high levels of selectivity over wtEGFR and the broader
kinome is described herein
Tetrahydroindazoles as Interleukin‑2 Inducible T‑Cell Kinase Inhibitors. Part II. Second-Generation Analogues with Enhanced Potency, Selectivity, and Pharmacodynamic Modulation in Vivo
The medicinal chemistry community
has directed considerable efforts
toward the discovery of selective inhibitors of interleukin-2 inducible
T-cell kinase (ITK), given its role in T-cell signaling downstream
of the T-cell receptor (TCR) and the implications of this target for
inflammatory disorders such as asthma. We have previously disclosed
a structure- and property-guided lead optimization effort which resulted
in the discovery of a new series of tetrahydroindazole-containing
selective ITK inhibitors. Herein we disclose further optimization
of this series that resulted in further potency improvements, reduced
off-target receptor binding liabilities, and reduced cytotoxicity.
Specifically, we have identified a correlation between the basicity
of solubilizing elements in the ITK inhibitors and off-target antiproliferative
effects, which was exploited to reduce cytotoxicity while maintaining
kinase selectivity. Optimized analogues were shown to reduce IL-2
and IL-13 production in vivo following oral or intraperitoneal dosing
in mice
Discovery of Potent and Selective Pyrazolopyrimidine Janus Kinase 2 Inhibitors
The discovery of somatic Jak2 mutations in patients with
chronic
myeloproliferative neoplasms has led to significant interest in discovering
selective Jak2 inhibitors for use in treating these disorders. A high-throughput
screening effort identified the pyrazoloÂ[1,5-<i>a</i>]Âpyrimidine
scaffold as a potent inhibitor of Jak2. Optimization of lead compounds <b>7a</b>–<b>b</b> and <b>8</b> in this chemical
series for activity against Jak2, selectivity against other Jak family
kinases, and good in vivo pharmacokinetic properties led to the discovery
of <b>7j</b>. In a SET2 xenograft model that is dependent on
Jak2 for growth, <b>7j</b> demonstrated a time-dependent knock-down
of pSTAT5, a downstream target of Jak2
Tetrahydroindazoles as Interleukin‑2 Inducible T‑Cell Kinase Inhibitors. Part II. Second-Generation Analogues with Enhanced Potency, Selectivity, and Pharmacodynamic Modulation in Vivo
The medicinal chemistry community
has directed considerable efforts
toward the discovery of selective inhibitors of interleukin-2 inducible
T-cell kinase (ITK), given its role in T-cell signaling downstream
of the T-cell receptor (TCR) and the implications of this target for
inflammatory disorders such as asthma. We have previously disclosed
a structure- and property-guided lead optimization effort which resulted
in the discovery of a new series of tetrahydroindazole-containing
selective ITK inhibitors. Herein we disclose further optimization
of this series that resulted in further potency improvements, reduced
off-target receptor binding liabilities, and reduced cytotoxicity.
Specifically, we have identified a correlation between the basicity
of solubilizing elements in the ITK inhibitors and off-target antiproliferative
effects, which was exploited to reduce cytotoxicity while maintaining
kinase selectivity. Optimized analogues were shown to reduce IL-2
and IL-13 production in vivo following oral or intraperitoneal dosing
in mice
Discovery of GDC-0853: A Potent, Selective, and Noncovalent Bruton’s Tyrosine Kinase Inhibitor in Early Clinical Development
Bruton’s
tyrosine kinase (Btk) is a nonreceptor cytoplasmic
tyrosine kinase involved in B-cell and myeloid cell activation, downstream
of B-cell and FcÎł receptors, respectively. Preclinical studies
have indicated that inhibition of Btk activity might offer a potential
therapy in autoimmune diseases such as rheumatoid arthritis and systemic
lupus erythematosus. Here we disclose the discovery and preclinical
characterization of a potent, selective, and noncovalent Btk inhibitor
currently in clinical development. GDC-0853 (<b>29</b>) suppresses
B cell- and myeloid cell-mediated components of disease and demonstrates
dose-dependent activity in an <i>in vivo</i> rat model of
inflammatory arthritis. It demonstrates highly favorable safety, pharmacokinetic
(PK), and pharmacodynamic (PD) profiles in preclinical and Phase 2
studies ongoing in patients with rheumatoid arthritis, lupus, and
chronic spontaneous urticaria. On the basis of its potency, selectivity,
long target residence time, and noncovalent mode of inhibition, <b>29</b> has the potential to be a best-in-class Btk inhibitor for
a wide range of immunological indications
Discovery of GDC-0853: A Potent, Selective, and Noncovalent Bruton’s Tyrosine Kinase Inhibitor in Early Clinical Development
Bruton’s
tyrosine kinase (Btk) is a nonreceptor cytoplasmic
tyrosine kinase involved in B-cell and myeloid cell activation, downstream
of B-cell and FcÎł receptors, respectively. Preclinical studies
have indicated that inhibition of Btk activity might offer a potential
therapy in autoimmune diseases such as rheumatoid arthritis and systemic
lupus erythematosus. Here we disclose the discovery and preclinical
characterization of a potent, selective, and noncovalent Btk inhibitor
currently in clinical development. GDC-0853 (<b>29</b>) suppresses
B cell- and myeloid cell-mediated components of disease and demonstrates
dose-dependent activity in an <i>in vivo</i> rat model of
inflammatory arthritis. It demonstrates highly favorable safety, pharmacokinetic
(PK), and pharmacodynamic (PD) profiles in preclinical and Phase 2
studies ongoing in patients with rheumatoid arthritis, lupus, and
chronic spontaneous urticaria. On the basis of its potency, selectivity,
long target residence time, and noncovalent mode of inhibition, <b>29</b> has the potential to be a best-in-class Btk inhibitor for
a wide range of immunological indications
Cell Active Hydroxylactam Inhibitors of Human Lactate Dehydrogenase with Oral Bioavailability in Mice
A series
of trisubstituted hydroxylactams was identified as potent
enzymatic and cellular inhibitors of human lactate dehydrogenase A.
Utilizing structure-based design and physical property optimization,
multiple inhibitors were discovered with <10 ÎĽM lactate IC<sub>50</sub> in a MiaPaca2 cell line. Optimization of the series led
to <b>29</b>, a potent cell active molecule (MiaPaca2 IC<sub>50</sub> = 0.67 ÎĽM) that also possessed good exposure when
dosed orally to mice
Discovery of a Noncovalent, Mutant-Selective Epidermal Growth Factor Receptor Inhibitor
Inhibitors
targeting the activating mutants of the epidermal growth
factor receptor (EGFR) have found success in the treatment of EGFR
mutant positive non-small-cell lung cancer. A secondary point mutation
(T790M) in the inhibitor binding site has been linked to the acquired
resistance against those first generation therapeutics. Herein, we
describe the lead optimization of a series of reversible, pan-mutant
(L858R, del<sub>746–750,</sub> T790M/L858R, and T790M/del<sub>746–750</sub>) EGFR inhibitors. By use of a noncovalent double
mutant (T790M/L858R and T790M/del<sub>746–750</sub>) selective
EGFR inhibitor (<b>2</b>) as a starting point, activities against
the single mutants (L858R and del<sub>746–750</sub>) were introduced
through a series of structure-guided modifications. The in vitro ADME-PK
properties of the lead molecules were further optimized through a
number of rational structural changes. The resulting inhibitor (<b>21</b>) exhibited excellent cellular activity against both the
single and double mutants of EGFR, demonstrating target engagement
in vivo and ADME-PK properties that are suitable for further evaluation.
The reversible, noncovalent inhibitors described complement the covalent
pan-mutant EGFR inhibitors that have shown encouraging results in
recent clinical trials