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1.
J Nucl Med ; 2024 02 22.
Article in English | MEDLINE | ID: mdl-38388517

ABSTRACT

[68Ga]Ga-DPI-4452, a first-in-class carbonic anhydrase IX-binding radiolabeled peptide, is the imaging agent of a theranostic pair with [177Lu]Lu-DPI-4452, developed for selecting and treating patients with carbonic anhydrase IX-expressing tumors. Here, [68Ga]Ga-DPI-4452 imaging characteristics, dosimetry, pharmacokinetics, and safety were assessed in 3 patients with clear cell renal cell carcinoma. Methods: After [68Ga]Ga-DPI-4452 administration, patients underwent serial full-body PET/CT imaging. Blood and urine were sampled. Safety was monitored for 7 d after injection. Results: Tumor uptake was observed at all time points (15 min to 4 h). Across 36 lesions, the SUVmax at 1 h after administration ranged from 6.8 to 211.6 (mean, 64.6 [SD, 54.8]). The kidneys, liver, and bone marrow demonstrated low activity. [68Ga]Ga-DPI-4452 was rapidly eliminated from blood and urine. No clinically significant toxicity was observed. Conclusion: [68Ga]Ga-DPI-4452 showed exceptional tumor uptake in patients with clear cell renal cell carcinoma, with very high tumor-to-background ratios and no significant adverse events, suggesting potential diagnostic and patient selection applications.

2.
J Nucl Med ; 65(1): 71-78, 2024 Jan 02.
Article in English | MEDLINE | ID: mdl-38050121

ABSTRACT

In the VISION trial, [177Lu]Lu-PSMA-617 (177Lu-PSMA-617) plus protocol-permitted standard of care significantly improved overall survival and radiographic progression-free survival compared with standard of care alone in patients with prostate-specific membrane antigen-positive metastatic castration-resistant prostate cancer. This VISION dosimetry substudy quantified absorbed doses of 177Lu-PSMA-617 in the kidneys and other organs. Methods: Participants were a separate cohort of 30 nonrandomized patients receiving standard of care plus 177Lu-PSMA-617 at 7.4 GBq per cycle for up to 6 cycles. Blood samples, whole-body conjugate planar image scintigraphy, and abdominal SPECT/CT images were collected. SPECT/CT images were collected at 2, 24, 48, and 168 h after administration in cycle 1 and at a single time point 48 h after administration in cycles 2-6. Outcomes were absorbed dose per unit activity per cycle and cumulative absorbed dose over all cycles. Cumulative absorbed doses were predicted by extrapolation from cycle 1, and calculation of observed values was based on measurements of cycle 1 and cycles 2-6. Safety was also assessed. Results: Mean (±SD) absorbed doses per cycle in the kidneys were 0.43 ± 0.16 Gy/GBq in cycle 1 and 0.44 ± 0.21 Gy/GBq in cycles 2-6. The observed and predicted 6-cycle cumulative absorbed doses in the kidneys were 15 ± 6 and 19 ± 7 Gy, respectively. Observed and predicted cumulative absorbed doses were similar in other at-risk organs. Safety findings were consistent with those in the VISION study; no patients experienced renal treatment-emergent adverse events of a grade higher than 3. Conclusion: The renal cumulative absorbed 177Lu-PSMA-617 dose was below the established limit. 177Lu-PSMA-617 had a good overall safety profile, and low renal radiotoxicity was not a safety concern. Cumulative absorbed doses in at-risk organs over multiple cycles can be predicted by extrapolation from cycle 1 data in patients with metastatic castration-resistant prostate cancer receiving 177Lu-PSMA-617.


Subject(s)
Prostatic Neoplasms, Castration-Resistant , Male , Humans , Prostatic Neoplasms, Castration-Resistant/radiotherapy , Prostatic Neoplasms, Castration-Resistant/pathology , Radiopharmaceuticals/adverse effects , Dipeptides/adverse effects , Prostate-Specific Antigen , Heterocyclic Compounds, 1-Ring/adverse effects , Kidney , Lutetium/adverse effects
3.
ACS Med Chem Lett ; 10(11): 1554-1560, 2019 Nov 14.
Article in English | MEDLINE | ID: mdl-31749910

ABSTRACT

A medicinal chemistry effort focused on identifying a structurally diverse candidate for phosphoinositide 3-kinase delta (PI3Kδ) led to the discovery of clinical candidate INCB050465 (20, parsaclisib). The unique structure of 20 contains a pyrazolopyrimidine hinge-binder in place of a purine motif that is present in other PI3Kδ inhibitors, such as idelalisib (1), duvelisib (2), and INCB040093 (3, dezapelisib). Parsaclisib (20) is a potent and highly selective inhibitor of PI3Kδ with drug-like ADME properties that exhibited an excellent in vivo profile as demonstrated through pharmacokinetic studies in rats, dogs, and monkeys and through pharmacodynamic and efficacy studies in a mouse Pfeiffer xenograft model.

4.
Clin Cancer Res ; 25(1): 300-311, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30206163

ABSTRACT

PURPOSE: Bromodomain and extraterminal domain (BET) proteins regulate the expression of many cancer-associated genes and pathways; BET inhibitors have demonstrated activity in diverse models of hematologic and solid tumors. We report the preclinical characterization of INCB054329, a structurally distinct BET inhibitor that has been investigated in phase I clinical trials. EXPERIMENTAL DESIGN: We used multiple myeloma models to investigate vulnerabilities created by INCB054329 treatment that could inform rational combinations. RESULTS: In addition to c-MYC, INCB054329 decreased expression of oncogenes FGFR3 and NSD2/MMSET/WHSC1, which are deregulated in t(4;14)-rearranged cell lines. The profound suppression of FGFR3 sensitized the t(4;14)-positive cell line OPM-2 to combined treatment with a fibroblast growth factor receptor inhibitor in vivo. In addition, we show that BET inhibition across multiple myeloma cell lines resulted in suppressed interleukin (IL)-6 Janus kinase-signal transducers and activators of transcription (JAK-STAT) signaling. INCB054329 displaced binding of BRD4 to the promoter of IL6 receptor (IL6R) leading to reduced levels of IL6R and diminished signaling through STAT3. Combination with JAK inhibitors (ruxolitinib or itacitinib) further reduced JAK-STAT signaling and synergized to inhibit myeloma cell growth in vitro and in vivo. This combination potentiated tumor growth inhibition in vivo, even in the MM1.S model of myeloma that is not intrinsically sensitive to JAK inhibition alone. CONCLUSIONS: Preclinical data reveal insights into vulnerabilities created in myeloma cells by BET protein inhibition and potential strategies that can be leveraged in clinical studies to enhance the activity of INCB054329.


Subject(s)
Cell Cycle Proteins/genetics , Multiple Myeloma/drug therapy , Organic Chemicals/pharmacology , Receptors, Interleukin-6/genetics , STAT3 Transcription Factor/genetics , Transcription Factors/genetics , Animals , Cell Cycle Proteins/antagonists & inhibitors , Cell Line, Tumor , Cell Proliferation/drug effects , Gene Expression Regulation, Neoplastic/drug effects , Heterografts , Histone-Lysine N-Methyltransferase/genetics , Humans , Janus Kinases/genetics , Mice , Multiple Myeloma/genetics , Multiple Myeloma/pathology , Protein Binding/drug effects , Proteins/antagonists & inhibitors , Proteins/genetics , Proto-Oncogene Proteins c-myc/genetics , Receptor, Fibroblast Growth Factor, Type 3/genetics , Repressor Proteins/genetics , Signal Transduction/drug effects , Transcription Factors/antagonists & inhibitors
5.
J Nucl Cardiol ; 26(6): 2018-2030, 2019 12.
Article in English | MEDLINE | ID: mdl-30488323

ABSTRACT

The objectives of this study were to evaluate radiation dosimetry, biodistribution, human safety, and tolerability of 18F-labeled flurpiridaz (Flurpiridaz) in normal subjects undergoing rest and separate-day exercise or adenosine pharmacological stress PET imaging. METHODS: 12 normal subjects were injected with 58.5 to 121 MBq (1.58 to 3.27 mCi) of Flurpiridaz intravenously at rest on Day 1 and 57 to 171 MBq (1.54 to 4.61 mCi) during stress on Day 2. Sequential whole-body imaging was performed for 5 hours. Blood samples were collected for up to 8 hours. RESULTS: The heart wall received the largest mean absorbed dose with both exercise and adenosine stresses. The mean effective dose was 0.054 rem/mCi (0.015 mSv/MBq) with exercise and 0.069 rem/mCi (0.019 mSv/MBq) with adenosine pharmacological stress. The maximum dose that may be administered without exceeding 1 rem (10 mSv) effective dose was 19 mCi (685 MBq) for exercise and 15 mCi (539 MBq) for adenosine pharmacological stress. There were no drug-related adverse events, and the tracer was well tolerated in all subjects. CONCLUSION: Based on radiation dosimetry, biodistribution, and safety observations, 18F-labeled flurpiridaz is found suitable for clinical PET myocardial perfusion imaging in conjunction with either exercise or pharmacological stress testing.


Subject(s)
Adenosine/pharmacology , Exercise , Positron-Emission Tomography , Pyridazines/pharmacokinetics , Radiometry/methods , Adult , Exercise Test , Female , Healthy Volunteers , Humans , Male , Myocardial Perfusion Imaging , Patient Safety , Radiopharmaceuticals/pharmacokinetics , Whole Body Imaging , Young Adult
6.
J Learn Disabil ; 51(2): 194-208, 2018.
Article in English | MEDLINE | ID: mdl-28380307

ABSTRACT

Conventional wisdom suggests that students classified as learning disabled will exhibit difficulties with foreign language (FL) learning, but evidence has not supported a relationship between FL learning problems and learning disabilities. The simple view of reading model posits that reading comprehension is the product of word decoding and language comprehension and that there are good readers and 3 types of poor readers-dyslexic, hyperlexic, and garden variety-who exhibit different profiles of strengths and/or deficits in word decoding and language comprehension. In this study, a random sample of U.S. high school students completing first-, second-, and third-year Spanish courses were administered standardized measures of Spanish word decoding and reading comprehension, compared with monolingual Spanish readers from first to eleventh grades, and classified into reader types according to the simple view of reading. The majority of students fit the hyperlexic profile, and no participants fit the good reader profile until they were compared with first- and second-grade monolingual Spanish readers. Findings call into question the practice of diagnosing an FL "disability" before a student engages in FL study.


Subject(s)
Comprehension/physiology , Dyslexia/physiopathology , Multilingualism , Reading , Adolescent , Dyslexia/epidemiology , Female , Humans , Male , Schools , Students , United States/epidemiology
7.
ACS Med Chem Lett ; 8(5): 486-491, 2017 May 11.
Article in English | MEDLINE | ID: mdl-28523098

ABSTRACT

A data-centric medicinal chemistry approach led to the invention of a potent and selective IDO1 inhibitor 4f, INCB24360 (epacadostat). The molecular structure of INCB24360 contains several previously unknown or underutilized functional groups in drug substances, including a hydroxyamidine, furazan, bromide, and sulfamide. These moieties taken together in a single structure afford a compound that falls outside of "drug-like" space. Nevertheless, the in vitro ADME data is consistent with the good cell permeability and oral bioavailability observed in all species (rat, dog, monkey) tested. The extensive intramolecular hydrogen bonding observed in the small molecule crystal structure of 4f is believed to significantly contribute to the observed permeability and PK. Epacadostat in combination with anti-PD1 mAb pembrolizumab is currently being studied in a phase 3 clinical trial in patients with unresectable or metastatic melanoma.

9.
J Nucl Med ; 56(5): 728-36, 2015 May.
Article in English | MEDLINE | ID: mdl-25858045

ABSTRACT

UNLABELLED: Myocardial perfusion imaging has long been used off label by practitioners attending for children with cardiac aliments. To provide clinicians with evidence-based dosage recommendation, a phase I-II, open-label, nonrandomized, multicenter trial was therefore designed using (99m)Tc-sestamibi in pediatric subjects (registered under www.clinicaltrials.gov identifier no. NCT00162045). METHODS: Safety and pharmacokinetic data were collected from 78 subjects using either a 1-d imaging protocol (3.7-7.4 MBq/kg, followed by 11.1 MBq/kg) or a 2-d protocol (7.4 MBq/kg for both rest and stress). Anterior and posterior planar images were collected at 15 min, 1.5 h, 4 h, and 8 h. Blood and urine samples were collected at predetermined times. RESULTS: Subjects included 39 children (mean age ± SD, 8.5 ± 2.04 y) and 39 adolescents (mean age ± SD, 13.6 ± 1.39 y). Mean estimated organ-absorbed doses to the upper large intestine, small intestine, gallbladder wall, and lower large intestines were 0.082, 0.043, 0.042, and 0.035 mSv/MBq, respectively. All patients tolerated the radiotracer without serious adverse effects. Significant differences were observed in the liver, upper large intestine contents, and small intestine contents between rest and stress imaging. The effective dose equivalent and effective dose averages were lower in adolescents than younger children (0.011 and 0.019 mSv/MBq, respectively; P < 0.0001). Percentage injected doses (%IDs) corrected for radioactive decay in all dosimetry-evaluable subjects at 15 min and 4 h were 1.9% and 1.2% in the myocardium. Similarly in the lungs, the %ID for all dosimetry-evaluable subjects was 4.9% at 15 min after injection. At rest, the %ID in the liver decreased from a maximum of about 26% at 15 min to less than 9% at 90 min. With stress, values decreased from 15% to 7%, respectively. CONCLUSION: The estimates of radiation dosimetry, pharmacokinetic parameters, and safety profile in this study population are similar to published studies based on body-mass extrapolations from studies in adults. As such, applying current (99m)Tc-sestamibi dosing regimens for 1- and 2-d protocols based on those extrapolations will result in the expected radiation dose in children and adolescents.


Subject(s)
Safety , Technetium Tc 99m Sestamibi/adverse effects , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Male , Radiometry , Rest , Stress, Physiological , Technetium Tc 99m Sestamibi/pharmacokinetics
10.
J Nucl Med ; 55(9): 1445-51, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24994931

ABSTRACT

UNLABELLED: A novel (18)F-labeled ligand for the norepinephrine transporter (N-[3-bromo-4-(3-(18)F-fluoro-propoxy)-benzyl]-guanidine [LMI1195]) is in clinical development for mapping cardiac nerve terminals in vivo using PET. Human safety, whole-organ biodistribution, and radiation dosimetry of LMI1195 were evaluated in a phase 1 clinical trial. METHODS: Twelve healthy subjects at 3 clinical sites were injected intravenously with 150-250 MBq of LMI1195. Dynamic PET images were obtained over the heart for 10 min, followed by sequential whole-body images for approximately 5 h. Blood samples were obtained, and heart rate, electrocardiogram, and blood pressure were monitored before and during imaging. Residence times were determined from multiexponential regression of organ region-of-interest data normalized by administered activity (AA). Radiation dose estimates were calculated using OLINDA/EXM. Myocardial, lung, liver, and blood-pool standardized uptake values were determined at different time intervals. RESULTS: No adverse events due to LMI1195 were seen. Blood radioactivity cleared quickly, whereas myocardial uptake remained stable and uniform throughout the heart over 4 h. Liver and lung activity cleared relatively rapidly, providing favorable target-to-background ratios for cardiac imaging. The urinary bladder demonstrated the largest peak uptake (18.3% AA), followed by the liver (15.5% AA). The mean effective dose was 0.026 ± 0.0012 mSv/MBq. Approximately 1.6% AA was seen in the myocardium initially, remaining above 1.5% AA (decay-corrected) through 4 h after injection. The myocardium-to-liver ratio was approximately unity initially, increasing to more than 2 at 4 h. CONCLUSION: These preliminary data suggest that LMI1195 is well tolerated and yields a radiation dose comparable to that of other commonly used PET radiopharmaceuticals. The kinetics of myocardial and adjacent organ activity suggest that cardiac imaging should be possible with acceptable patient radiation dose.


Subject(s)
Fluorine Radioisotopes , Fluorobenzenes , Guanidines , Heart/innervation , Radiopharmaceuticals , Adult , Female , Fluorobenzenes/pharmacokinetics , Guanidines/pharmacokinetics , Heart/diagnostic imaging , Humans , Male , Radiometry , Radionuclide Imaging , Tissue Distribution
11.
J Nucl Med ; 54(6): 861-6, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23568366

ABSTRACT

UNLABELLED: The glutamic acid derivative (S)-4-(3-(18)F-Fluoropropyl)-l-glutamic acid ((18)F-FSPG, alias BAY 94-9392), a new PET tracer for the detection of malignant diseases, displayed promising results in non-small cell lung cancer patients. The aim of this study was to provide dosimetry estimates for (18)F-FSPG based on human whole-body PET/CT measurements. METHODS: (18)F-FSPG was prepared by a fully automated 2-step procedure and purified by a solid-phase extraction method. PET/CT scans were obtained for 5 healthy volunteers (mean age, 59 y; age range, 51-64 y; 2 men, 3 women). Human subjects were imaged for up to 240 min using a PET/CT scanner after intravenous injection of 299 ± 22.5 MBq of (18)F-FSPG. Image quantification, time-activity data modeling, estimation of normalized number of disintegrations, and production of dosimetry estimates were performed using the RADAR (RAdiation Dose Assessment Resource) method for internal dosimetry and in general concordance with the methodology and principles as presented in the MIRD 16 document. RESULTS: Because of the renal excretion of the tracer, the absorbed dose was highest in the urinary bladder wall and kidneys, followed by the pancreas and uterus. The individual organ doses (mSv/MBq) were 0.40 ± 0.058 for the urinary bladder wall, 0.11 ± 0.011 for the kidneys, 0.077 ± 0.020 for the pancreas, and 0.030 ± 0.0034 for the uterus. The calculated effective dose was 0.032 ± 0.0034 mSv/MBq. Absorbed dose to the bladder and the effective dose can be reduced significantly by frequent bladder-voiding intervals. For a 0.75-h voiding interval, the bladder dose was reduced to 0.10 ± 0.012 mSv/MBq, and the effective dose was reduced to 0.015 ± 0.0010 mSv/MBq. CONCLUSION: On the basis of the distribution and biokinetic data, the determined radiation dose for (18)F-FSPG was calculated to be 9.5 ± 1.0 mSv at a patient dose of 300 MBq, which is of similar magnitude to that of (18)F-FDG (5.7 mSv). The effective dose can be reduced to 4.5 ± 0.30 mSv (at 300 MBq), with a bladder-voiding interval of 0.75 h.


Subject(s)
Glutamates , Multimodal Imaging/methods , Neoplasms/diagnostic imaging , Positron-Emission Tomography , Tomography, X-Ray Computed , Female , Glutamates/adverse effects , Humans , Isotope Labeling , Male , Middle Aged , Radiometry , Safety
12.
J Learn Disabil ; 46(4): 304-16, 2013.
Article in English | MEDLINE | ID: mdl-22057201

ABSTRACT

Much has been written about gifted students with learning disabilities, but there have been few large-scale empirical investigations, and the concept has proven controversial. The authors reviewed the available empirical literature on these students, focusing on (a) the criteria by which the students were identified and (b) the students' performance on standardized tests of ability and achievement. In addition, the test scores of these students were aggregated to determine typical performance levels. A total of 46 empirical articles were reviewed, and major findings included wide variability in identification criteria across studies, frequent reliance on dubious methods of learning disability identification, and a lack of academic impairment among the identified students. Implications for the "gifted/LD" category are discussed.


Subject(s)
Child, Gifted/psychology , Educational Measurement/standards , Learning Disabilities/psychology , Students/psychology , Child , Child, Gifted/statistics & numerical data , Educational Measurement/statistics & numerical data , Humans , Learning Disabilities/diagnosis , Students/statistics & numerical data
13.
J Nucl Med ; 52(9): 1490-8, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21849402

ABSTRACT

UNLABELLED: (18)F-labeled BMS747158 is a novel myocardial perfusion imaging tracer that targets mitochondrial complex 1. The objectives of this phase I study were to evaluate radiation dosimetry, biodistribution, human safety, tolerability, and early elimination of (18)F activity in urine after injection of a single dose of the tracer at rest in healthy subjects. METHODS: Thirteen healthy subjects were injected with 170-244 MBq (4.6-6.6 mCi) of BMS747158 intravenously. Dynamic PET was obtained over the heart for 10 min, followed by sequential whole-body imaging for 5 h. Blood samples and urinary excretion were collected for up to 8 h. Heart rate, electrocardiogram, and blood pressure were monitored before and during imaging. The residence times were determined from multiexponential regression of organ region-of-interest data normalized by injected dose. Absorbed dose estimates for all target organs were determined using MIRD schema with OLINDA/EXM software. RESULTS: The organ receiving the largest mean absorbed dose was the kidneys at 0.066 mSv/MBq (0.24 rem/mCi), followed by the heart wall at 0.048 mSv/MBq (0.18 rem/mCi). The mean effective dose was 0.019 mSv/MBq (0.072 rem/mCi). The heart exhibited high and sustained retention of BMS747158 from the earliest images through approximately 5 h after injection. There were no drug-related adverse events, and the tracer was well tolerated in all subjects. Mean urinary excretion was 4.83 percentage injected dose (range, 0.64-12.41 percentage injected dose). CONCLUSION: These preliminary data suggest that (18)F-labeled BMS747158 appears to be well tolerated and has a unique potential for myocardial perfusion PET.


Subject(s)
Coronary Circulation/physiology , Heart/diagnostic imaging , Pyridazines , Radiopharmaceuticals , Adolescent , Adult , Algorithms , Electroencephalography , Female , Fluorine Radioisotopes/urine , Humans , Male , Positron-Emission Tomography , Pyridazines/administration & dosage , Pyridazines/pharmacokinetics , Radiometry , Radiopharmaceuticals/administration & dosage , Radiopharmaceuticals/pharmacokinetics , Tissue Distribution , Whole-Body Counting , Young Adult
14.
Eur J Nucl Med Mol Imaging ; 38(11): 2058-65, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21732107

ABSTRACT

PURPOSE: [(18)F]FEDAA1106 is a recently developed positron emission tomography (PET) radioligand for in vivo quantification of the 18 kDa translocator protein [TSPO or, as earlier called, the peripheral benzodiazepine receptor (PBR)]. TSPO imaging is expected to be useful for the clinical evaluation of neuroinflammatory diseases. The aim of this study was to provide dosimetry estimates for [(18)F]FEDAA1106 based on human whole-body PET measurements. METHODS: PET scans were performed for a total of 6.6 h after the injection of 183.8 ± 9.1 MBq of [(18)F]FEDAA1106 in six healthy subjects. Regions of interest were drawn on coronal images. Estimates of the absorbed doses of radiation were calculated using the OLINDA software. RESULTS: Peak uptake was largest in lungs, followed by liver, small intestine, kidney, spleen and other organs. Peak values of the percent injected dose (%ID) at a time after radioligand injection were calculated for the lungs (27.1%ID at 0.2 h), liver (21.1%ID at 0.6 h), small intestine (10.4%ID at 6.3 h), kidney (4.9%ID at 1.8 h) and spleen (4.6%ID at 0.6 h). The largest absorbed dose was found in the spleen (0.12 mSv/MBq), followed by kidneys (0.094 mSv/MBq). The calculated mean effective dose was 0.036 mSv/MBq. CONCLUSION: Based on the distribution and dose estimates, the estimated radiation burden of [(18)F]FEDAA1106 is moderately higher than that of [(18)F]fluorodeoxyglucose (FDG). In clinical studies, the administered activity of this radioligand ought to be adjusted in line with regional regulations. This result would be helpful for further clinical TSPO imaging studies.


Subject(s)
Acetamides/metabolism , Acetamides/pharmacokinetics , Positron-Emission Tomography , Receptors, GABA/metabolism , Whole Body Imaging , Aged , Female , Humans , Ligands , Male , Radiation Dosage , Radiometry
15.
Blood ; 115(17): 3520-30, 2010 Apr 29.
Article in English | MEDLINE | ID: mdl-20197554

ABSTRACT

Indoleamine 2,3-dioxygenase-1 (IDO1; IDO) mediates oxidative cleavage of tryptophan, an amino acid essential for cell proliferation and survival. IDO1 inhibition is proposed to have therapeutic potential in immunodeficiency-associated abnormalities, including cancer. Here, we describe INCB024360, a novel IDO1 inhibitor, and investigate its roles in regulating various immune cells and therapeutic potential as an anticancer agent. In cellular assays, INCB024360 selectively inhibits human IDO1 with IC(50) values of approximately 10nM, demonstrating little activity against other related enzymes such as IDO2 or tryptophan 2,3-dioxygenase (TDO). In coculture systems of human allogeneic lymphocytes with dendritic cells (DCs) or tumor cells, INCB024360 inhibition of IDO1 promotes T and natural killer (NK)-cell growth, increases IFN-gamma production, and reduces conversion to regulatory T (T(reg))-like cells. IDO1 induction triggers DC apoptosis, whereas INCB024360 reverses this and increases the number of CD86(high) DCs, potentially representing a novel mechanism by which IDO1 inhibition activates T cells. Furthermore, IDO1 regulation differs in DCs versus tumor cells. Consistent with its effects in vitro, administration of INCB024360 to tumor-bearing mice significantly inhibits tumor growth in a lymphocyte-dependent manner. Analysis of plasma kynurenine/tryptophan levels in patients with cancer affirms that the IDO pathway is activated in multiple tumor types. Collectively, the data suggest that selective inhibition of IDO1 may represent an attractive cancer therapeutic strategy via up-regulation of cellular immunity.


Subject(s)
Dendritic Cells/immunology , Enzyme Inhibitors/pharmacology , Indoleamine-Pyrrole 2,3,-Dioxygenase/antagonists & inhibitors , Indoleamine-Pyrrole 2,3,-Dioxygenase/immunology , Neoplasms/immunology , T-Lymphocytes/immunology , Animals , Apoptosis/drug effects , Apoptosis/immunology , B7-2 Antigen/immunology , B7-2 Antigen/metabolism , Coculture Techniques , Dendritic Cells/enzymology , Dose-Response Relationship, Drug , HeLa Cells , Humans , Immunity, Cellular/drug effects , Immunity, Cellular/immunology , Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasms/drug therapy , Neoplasms/enzymology , T-Lymphocytes/enzymology , Tryptophan Oxygenase/immunology , Tryptophan Oxygenase/metabolism
16.
Mol Cancer Ther ; 9(2): 489-98, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20124451

ABSTRACT

Malignant tumors arise, in part, because the immune system does not adequately recognize and destroy them. Expression of indoleamine-2,3-dioxygenase (IDO; IDO1), a rate-limiting enzyme in the catabolism of tryptophan into kynurenine, contributes to this immune evasion. Here we describe the effects of systemic IDO inhibition using orally active hydroxyamidine small molecule inhibitors. A single dose of INCB023843 or INCB024360 results in efficient and durable suppression of Ido1 activity in the plasma of treated mice and dogs, the former to levels seen in Ido1-deficient mice. Hydroxyamidines potently suppress tryptophan metabolism in vitro in CT26 colon carcinoma and PAN02 pancreatic carcinoma cells and in vivo in tumors and their draining lymph nodes. Repeated administration of these IDO1 inhibitors impedes tumor growth in a dose- and lymphocyte-dependent fashion and is well tolerated in efficacy and preclinical toxicology studies. Substantiating the fundamental role of tumor cell-derived IDO expression, hydroxyamidines control the growth of IDO-expressing tumors in Ido1-deficient mice. These activities can be attributed, at least partially, to the increased immunoreactivity of lymphocytes found in tumors and their draining lymph nodes and to the reduction in tumor-associated regulatory T cells. INCB024360, a potent IDO1 inhibitor with desirable pharmaceutical properties, is poised to start clinical trials in cancer patients.


Subject(s)
Amidines/pharmacology , Enzyme Inhibitors/pharmacology , Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism , Neoplasms/metabolism , Tryptophan/metabolism , Animals , Cell Line, Tumor , Dogs , Female , Humans , Immune System , Immunotherapy/methods , Indoleamine-Pyrrole 2,3,-Dioxygenase/antagonists & inhibitors , Kynurenine/pharmacology , Lymph Nodes/pathology , Lymphocytes/immunology , Mice , Mice, Inbred BALB C , Neoplasms/drug therapy , Neoplasms/pathology
17.
Neoplasia ; 12(1): 28-38, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20072651

ABSTRACT

Cytokines in the bone marrow of multiple myeloma patients activate Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways in tumor cells and promote tumor growth, survival, and drug resistance. INCB16562 was developed as a novel, selective, and orally bioavailable small-molecule inhibitor of JAK1 and JAK2 markedly selective over JAK3. The specific cellular activity of the inhibitor was demonstrated by its potent and dose-dependent inhibition of cytokine-dependent JAK/STAT signaling and cell proliferation in the absence of effects on Bcr-Abl-expressing cells. Treatment of myeloma cells with INCB16562 potently inhibited interleukin-6 (IL-6)-induced phosphorylation of STAT3. Moreover, the proliferation and survival of myeloma cells dependent on IL-6 for growth, as well as the IL-6-induced growth of primary bone marrow-derived plasma cells from a multiple myeloma patient, were inhibited by INCB16562. Induction of caspase activation and apoptosis was observed and attributed, at least in part, to the suppression of Mcl-1 expression. Importantly, INCB16562 abrogated the protective effects of recombinant cytokines or bone marrow stromal cells and sensitized myeloma cells to cell death by exposure to dexamethasone, melphalan, or bortezomib. Oral administration of INCB16562 antagonized the growth of myeloma xenografts in mice and enhanced the antitumor activity of relevant agents in combination studies. Taken together, these data suggest that INCB16562 is a potent JAK1/2 inhibitor and that mitigation of JAK/STAT signaling by targeting JAK1 and JAK2 will be beneficial in the treatment of myeloma patients, particularly in combination with other agents.


Subject(s)
Azepines/pharmacology , Janus Kinase 1/antagonists & inhibitors , Janus Kinase 2/antagonists & inhibitors , Multiple Myeloma/drug therapy , Protein Kinase Inhibitors/pharmacology , Pyridines/pharmacology , Stromal Cells/drug effects , Animals , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Apoptosis/drug effects , Azepines/administration & dosage , Azepines/chemistry , Blotting, Western , Boronic Acids/administration & dosage , Bortezomib , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cells, Cultured , Coculture Techniques , Humans , Interleukin-6/pharmacology , Janus Kinase 1/metabolism , Janus Kinase 2/metabolism , Melphalan/administration & dosage , Mice , Mice, SCID , Molecular Structure , Multiple Myeloma/metabolism , Multiple Myeloma/pathology , Phosphorylation/drug effects , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemistry , Pyrazines/administration & dosage , Pyridines/administration & dosage , Pyridines/chemistry , STAT3 Transcription Factor/metabolism , Stromal Cells/cytology , Treatment Outcome , Xenograft Model Antitumor Assays
18.
Clin Cancer Res ; 15(22): 6891-900, 2009 Nov 15.
Article in English | MEDLINE | ID: mdl-19887489

ABSTRACT

PURPOSE: Deregulation of the Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway is a hallmark for the Philadelphia chromosome-negative myeloproliferative diseases polycythemia vera, essential thrombocythemia, and primary myelofibrosis. We tested the efficacy of a selective JAK1/2 inhibitor in cellular and in vivo models of JAK2-driven malignancy. EXPERIMENTAL DESIGN: A novel inhibitor of JAK1/2 was characterized using kinase assays. Cellular effects of this compound were measured in cell lines bearing the JAK2V617F or JAK1V658F mutation, and its antiproliferative activity against primary polycythemiavera patient cells was determined using clonogenic assays. Antineoplastic activity in vivo was determined using a JAK2V617F-driven xenograft model, and effects of the compound on survival, organomegaly, body weight, and disease-associated inflammatory markers were measured. RESULTS: INCB16562 potently inhibited proliferation of cell lines and primary cells from PV patients carrying the JAK2V617F or JAK1V658F mutation by blocking JAK-STAT signaling and inducing apoptosis. In vivo, INCB16562 reduced malignant cell burden, reversed splenomegaly and normalized splenic architecture, improved body weight gains, and extended survival in a model of JAK2V617F-driven hematologic malignancy. Moreover, these mice suffered from markedly elevated levels of inflammatory cytokines, similar to advanced myeloproliferative disease patients, which was reversed upon treatment. CONCLUSIONS: These data showed that administration of the dual JAK1/2 inhibitor INCB16562 reduces malignant cell burden, normalizes spleen size and architecture, suppresses inflammatory cytokines, improves weight gain, and extends survival in a rodent model of JAK2V617F-driven hematologic malignancy. Thus, selective inhibitors of JAK1 and JAK2 represent a novel therapy for the patients with myeloproliferative diseases and other neoplasms associated with JAK dysregulation.


Subject(s)
Enzyme Inhibitors/pharmacology , Janus Kinase 1/genetics , Janus Kinase 1/metabolism , Janus Kinase 2/genetics , Janus Kinase 2/metabolism , Mutation , Animals , Antineoplastic Agents/pharmacology , Apoptosis , Cell Line, Tumor , Cell Proliferation , Humans , Inhibitory Concentration 50 , Kinetics , Mice , Neoplasm Transplantation , Polycythemia Vera/drug therapy
19.
J Learn Disabil ; 42(6): 494-510, 2009.
Article in English | MEDLINE | ID: mdl-19704046

ABSTRACT

The purpose of this study is to provide an up-to-date review of the literature on postsecondary students classified as having learning disabilities (LD). The review focused on the criteria by which students were classified as LD and the cognitive and achievement characteristics of the participants. From almost 400 studies, only 30% were empirical (data-based) investigations reporting original data. Findings showed that a wide range of criteria was used to classify students as LD, although various discrepancy criteria and registration with university offices of disability services were most often cited. Participants' mean scores on standardized intelligence and achievement tests were in the average range but somewhat lower than those of other college students. Generally, the findings show a lack of consensus among diagnosticians and researchers about how LD should be diagnosed and also show that college students classified as LD tend to have average achievement, despite scoring below their classmates.


Subject(s)
Achievement , Competency-Based Education , Education, Special , Learning Disabilities/diagnosis , Mass Screening/statistics & numerical data , Adolescent , Aptitude Tests/statistics & numerical data , Curriculum , Humans , Learning Disabilities/classification , Learning Disabilities/epidemiology , Learning Disabilities/rehabilitation , Needs Assessment/statistics & numerical data , Prognosis , Psychometrics , Reproducibility of Results , Wechsler Scales/statistics & numerical data , Young Adult
20.
J Learn Disabil ; 42(3): 230-9, 2009.
Article in English | MEDLINE | ID: mdl-19225069

ABSTRACT

This study examined the consequences of classifying postsecondary students as learning disabled (LD) using five objective sets of criteria: IQ-achievement discrepancies (1.0 to 1.49 SD, 1.5 to 1.99 SD, and >or= 2.0 SD), DSM-IV criteria, and chronic educational impairment beginning in childhood. The participants were 378 postsecondary students from two universities who had been previously classified as LD and were receiving instructional and/or testing accommodations. The agreement between diagnostic models was often low, both in terms of the proportion of students identified as well as which students were identified by the models. The discrepancy models identified the largest proportions of students as LD (10% to 42%), whereas fewer than 10% of participants met either of the other sets of criteria, and 55% of the participants were not classified as LD by any of the models. Implications for further research and practices in postsecondary settings are discussed.


Subject(s)
Education, Special , Learning Disabilities/classification , Adolescent , Adult , Curriculum , Disabled Persons/legislation & jurisprudence , Education, Special/legislation & jurisprudence , Female , Humans , Intelligence , Learning Disabilities/diagnosis , Male , Middle Aged , Models, Educational , Multilingualism , Underachievement , United States , Young Adult
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