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Dive into the research topics where Douglass Chapman is active.

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Featured researches published by Douglass Chapman.


The Journal of Infectious Diseases | 2011

Deep sequencing to infer HIV-1 co-receptor usage: application to three clinical trials of maraviroc in treatment-experienced patients.

Luke C. Swenson; Theresa Mo; Winnie Dong; Xiaoyin Zhong; Conan K. Woods; Mark A. Jensen; Alexander Thielen; Douglass Chapman; Marilyn Lewis; Ian James; Jayvant Heera; Hernan Valdez; P. Richard Harrigan

BACKGROUNDnThe Maraviroc versus Optimized Therapy in Viremic Antiretroviral Treatment-Experienced Patients (MOTIVATE) studies compared maraviroc versus placebo in treatment-experienced patients with CCR5-using (R5) human immunodeficiency virus type 1 (HIV-1), screened using the original Trofile assay. A subset with non-R5 HIV infection entered the A4001029 trial. We retrospectively examined the performance of a genotypic tropism assay based on deep sequencing of the HIV env V3 loop in predicting virologic response to maraviroc in these trials.nnnMETHODSnV3 amplicons were prepared from 1827 screening plasma samples and sequenced on a Roche/454 GS-FLX to a depth of >3000 sequences/sample. Samples were considered non-R5 if ≥2% of their viral population scored greater than or equal to -4.75 or ≤3.5 using the PSSM(x4/R5) or geno2pheno algorithms, respectively.nnnRESULTSnDeep sequencing identified more than twice as many maraviroc recipients as having non-R5 HIV, compared with the original Trofile. With use of genotyping, we determined that 49% of maraviroc recipients with R5 HIV at screening had a week 48 viral load <50 copies/mL versus 26% of recipients with non-R5. Corresponding percentages were 46% and 23% with screening by Trofile. In cases in which screening assays differed, median week 8 log₁₀ copies/mL viral load decrease favored 454. Other parameters predicted by genotyping included likelihood of changing to non-R5 tropism.nnnCONCLUSIONSnThis large study establishes deep V3 sequencing as a promising tool for identifying treatment-experienced individuals who could benefit from CCR5-antagonist-containing regimens.


AIDS | 2010

Population-based V3 genotypic tropism assay: a retrospective analysis using screening samples from the A4001029 and MOTIVATE studies.

Rachel A. McGovern; Alexander Thielen; Theresa Mo; Winnie Dong; Conan K. Woods; Douglass Chapman; Marilyn Lewis; I. James; Jayvant Heera; Hernan Valdez; P. Richard Harrigan

Background:The MOTIVATE-1 and 2 studies compared maraviroc (MVC) along with optimized background therapy (OBT) vs. placebo along with OBT in treatment-experienced patients screened as having R5-HIV (original Monogram Trofile). A subset screened with non-R5 HIV were treated with MVC or placebo along with OBT in a sister safety trial, A4001029. This analysis retrospectively examined the performance of population-based sequence analysis of HIV-1 env V3-loop to predict coreceptor tropism. Methods:Triplicate V3-loop sequences were generated using stored screening plasma samples and data was processed using custom software (‘ReCall’), blinded to clinical response. Tropism was inferred using geno2pheno (‘g2p’; 5% false positive rate). Primary outcomes were viral load changes after starting maraviroc; and concordance with prior screening Trofile results. Results:Genotype and Trofile results were available for 1164 individuals with virological outcome data (N = 169 non-R5 by Trofile). Compared with Trofile, V3 genotyping had a specificity of 92.6% and a sensitivity of 67.4% for detecting non-R5 virus. However, when compared with clinical outcome, virological responses were consistently similar between Trofile and V3 genotype at weeks 8 and 24 following the initiation of therapy for patients categorized as R5. Conclusion:Despite differences in sensitivity for predicting non-R5 HIV, week 8 and 24 week virological responses were similar in this treatment-experienced population. These findings suggest the potential utility of V3 genotyping as an accessible assay to select patients who may benefit from maraviroc treatment. Optimization of the predictive tropism algorithm may lead to further improvement in the clinical utility of HIV genotypic tropism assays.


Clinical Infectious Diseases | 2011

Deep V3 Sequencing for HIV Type 1 Tropism in Treatment-Naive Patients: A Reanalysis of the MERIT Trial of Maraviroc

Luke C. Swenson; Theresa Mo; Winnie Dong; Xiaoyin Zhong; Conan K. Woods; Alexander Thielen; Mark A. Jensen; David J.H.F. Knapp; Douglass Chapman; Simon Portsmouth; Marilyn Lewis; Ian James; Jayvant Heera; Hernan Valdez; P. Richard Harrigan

BACKGROUNDnDeep sequencing is a highly sensitive technique that can detect and quantify the proportion of non-R5 human immunodeficiency virus (HIV) variants, including small minorities, that may emerge and cause virologic failure in patients who receive maraviroc-containing regimens. We retrospectively tested the ability of deep sequencing to predict response to a maraviroc-containing regimen in the Maraviroc versus Efavirenz in Treatment-Naive Patients (MERIT) trial. Results were compared with those obtained using the Enhanced Sensitivity Trofile Assay (ESTA), which is widely used in clinical practice.nnnMETHODSnScreening plasma samples from treatment-naive patients who received maraviroc and efavirenz in the MERIT trial were assessed. Samples were extracted, and the V3 region of HIV type 1 glycoprotein 120 was amplified in triplicate and combined in equal quantities before sequencing on a Roche/454 Genome Sequencer-FLX (n = 859). Tropism was inferred from third variable (V3) sequences, with samples classified as non-R5 if ≥2% of the viral population scored ≤3.5 using geno2pheno.nnnRESULTSnDeep sequencing distinguished between responders and nonresponders to maraviroc. Among patients identified as having R5-HIV by deep sequencing, 67% of maraviroc recipients and 69% of efavirenz recipients had a plasma viral load <50 copies/mL at week 48, similar to the ESTA results: 68% and 68%, respectively.nnnCONCLUSIONSnReanalysis of the MERIT trial using deep V3 loop sequencing indicates that, had patients originally been screened using this method, the maraviroc arm would have likely been found to be noninferior to the efavirenz arm.


Annals of Allergy Asthma & Immunology | 2001

Comparative onset of action and symptom relief with cetirizine, loratadine, or placebo in an environmental exposure unit in subjects with seasonal allergic rhinitis: confirmation of a test system

James H. Day; Maureen P. Briscoe; Elizabeth Rafeiro; Douglass Chapman; Benjamin Kramer

BACKGROUNDnThe environmental exposure unit (EEU) is an instrument designed to determine onset of action of antiallergic treatment. Confirmation of test results would be useful in defining its role.nnnOBJECTIVEnThis study was intended to confirm a previous study comparing cetirizine, loratadine, and placebo in the EEU using an identical protocol design (randomized, double-blind, parallel-group comparison having the same symptom scoring system, endpoints, and statistical analyses), thus demonstrating reproducibility of studies conducted in the EEU.nnnMETHODSnOnset of action and symptom relief with once-daily cetirizine 10 mg, loratadine 10 mg, and placebo (n = 120 each group) were evaluated replicating a previous study design. Subjects meeting inclusion and exclusion criteria and qualifying symptom scores were randomized to 2 days exposure (6 to 7 hours daily) with treatment. Changes in total and major symptom complex (TSC, MSC) scores based on 14 symptoms evaluated at 30-minute intervals served as primary efficacy variables.nnnRESULTSnOnset of action again was earlier with cetirizine (at 1 hour, P < or = 0.001) versus loratadine (at 3 hours, P < or = 0.01). Cetirizine produced a 25.4% least-square mean reduction in TSC scores overall versus an 11.2% decrease with loratadine (P = 0.006) and a 4.8% increase with placebo (P < 0.001); loratadine and placebo were also significantly different (P = 0.002). Similar changes were also noted in MSC scores. Cetirizine consistently reduced TSC and MSC scores after the first dose versus placebo (P < or = 0.001) and at most time points versus loratadine (P < or = 0.05). Adverse events were reported in 1.7% of patients in each active-treatment group and in 2.5% on placebo.nnnCONCLUSIONSnCetirizine acted earlier and was more effective than loratadine or placebo in reducing symptoms of seasonal allergic rhinitis in subjects undergoing a controlled pollen challenge, replicating results from an earlier, identically designed study, demonstrating reproducibility of these assessments by the EEU.


PLOS ONE | 2012

A Genotypic Test for HIV-1 Tropism Combining Sanger Sequencing with Ultradeep Sequencing Predicts Virologic Response in Treatment-Experienced Patients

Ron M. Kagan; Erik P. Johnson; Martin Siaw; Pinaki Biswas; Douglass Chapman; Zhaohui Su; Jamie L. Platt; Rick L. Pesano

A tropism test is required prior to initiation of CCR5 antagonist therapy in HIV-1 infected individuals, as these agents are not effective in patients harboring CXCR4 (X4) coreceptor-using viral variants. We developed a clinical laboratory-based genotypic tropism test for detection of CCR5-using (R5) or X4 variants that utilizes triplicate population sequencing (TPS) followed by ultradeep sequencing (UDS) for samples classified as R5. Tropism was inferred using the bioinformatic algorithms geno2pheno[coreceptor] and PSSMx4r5. Virologic response as a function of tropism readout was retrospectively assessed using blinded samples from treatment-experienced subjects who received maraviroc (Nu200a=u200a327) in the MOTIVATE and A4001029 clinical trials. MOTIVATE patients were classified as R5 and A4001029 patients were classified as non-R5 by the original Trofile test. Virologic response was compared between the R5 and non-R5 groups determined by TPS, UDS alone, the reflex strategy and the Trofile Enhanced Sensitivity (TF-ES) test. UDS had greater sensitivity than TPS to detect minority non-R5 variants. The median log10 viral load change at week 8 was −2.4 for R5 subjects, regardless of the method used for classification; for subjects with non-R5 virus, median changes were −1.2 for TF-ES or the Reflex Test and −1.0 for UDS. The differences between R5 and non-R5 groups were highly significant in all 3 cases (p<0.0001). At week 8, the positive predictive value was 66% for TF-ES and 65% for both the Reflex test and UDS. Negative predictive values were 59% for TF-ES, 58% for the Reflex Test and 61% for UDS. In conclusion, genotypic tropism testing using UDS alone or a reflex strategy separated maraviroc responders and non-responders as well as a sensitive phenotypic test, and both assays showed improved performance compared to TPS alone. Genotypic tropism tests may provide an alternative to phenotypic testing with similar discriminating ability.


Clinical Pediatrics | 2002

The Health-Related Quality of Life Effects of Once-Daily Cetirizine HCl Syrup in Children with Seasonal Allergic Rhinitis

Sherwin A. Gillman; Mark M. Blatter; John J. Condemi; Millicent Collins; Abayomi O. Olufade; Nancy Kline Leidy; Douglass Chapman; Benjamin Kramer

Seasonal allergic rhinitis (SAR) can adversely impact childrens physical, psychological, and social functioning and well-being, that is, their health-related quality of life (HRQL). This study assessed HRQL in children 6 to 11 years treated with cetirizine HCl syrup, while concurrently assessing symptomatic relief and safety. In an open-label, non-comparative study, 544 children from 124 centers in the United States were instructed to take cetirizine HCl syrup (10 cc of 1 mg/mL) each evening for 4 weeks. Children experienced statistically significant improvements in HRQL with significant reductions in mean symptom score (p<0.001) during the treatment period. Results were consistent across age groups (6-7, 8-9, 10-11 years). These results suggest that the symptomatic relief and tolerability profile of cetirizine HCl syrup daily translates into improvements in the HRQL of children with SAR. This 4-week open label study is among the first to evaluate the effect of antihistamine treatment on HRQL outcomes in children.


Antiviral Therapy | 2011

Baseline CD4(+) T-cell counts and weighted background susceptibility scores strongly predict response to maraviroc regimens in treatment-experienced patients.

Jonathan M. Schapiro; Charles A. Boucher; Daniel R. Kuritzkes; David A. M. C. van de Vijver; Josep M. Llibre; Marilyn Lewis; Paul Simpson; Christophe Delogne; Lynn McFadyen; Douglass Chapman; Manos Perros; Hernan Valdez; Elna van der Ryst; Mike Westby

BACKGROUNDnMaraviroc-containing regimens are known to achieve virological suppression in many treatment-experienced patients. This study aimed to evaluate a more rigorous methodological approach to resistance-response analysis in large clinical studies and to better establish which subpopulations of patients were most likely to benefit from maraviroc by refining and extending previous subgroup analyses from the MOTIVATE studies.nnnMETHODSnIndividual weighted optimized background therapy (OBT) susceptibility scores were calculated by combining genotypic or phenotypic resistance testing with prior drug use information. Virological response (HIV-1 RNA<50 copies/ml at week 48) using each of these methods was compared with a commonly used method of counting active drugs. Baseline predictors of virological response, including weighted or unweighted scoring, maraviroc use, baseline CD4(+) T-cell count, HIV-1 plasma viral load and tropism, were assessed by logistic regression modelling.nnnRESULTSnGenotypic or phenotypic weighted methods were similarly predictive of virological response and better than counting active drugs. Weighted scoring and baseline CD4(+) T-cell count were the strongest predictors of virological response (P<0.0001): ≈70% of maraviroc patients with a weighted score ≥2 had a virological response, rising to ≈80% when the baseline CD4(+) T-cell count was ≥50 cells/mm(3).nnnCONCLUSIONSnApproximately 80% of patients with a CD4(+) T-cell count ≥50 cells/mm(3) receiving maraviroc with the equivalent of at least two fully active agents achieved HIV-1 RNA<50 copies/ml at week 48 in the MOTIVATE studies. Genotypic and phenotypic weighted scores were similarly predictive of virological response.


Annals of Allergy Asthma & Immunology | 2006

Comparison of cetirizine-pseudoephedrine and placebo in patients with seasonal allergic rhinitis and concomitant mild-to-moderate asthma: randomized, double-blind study

Robert A. Nathan; Albert F. Finn; Craig LaForce; Paul H. Ratner; Douglass Chapman; Emilio C. de Guia; Dial Hewlett; Ben Kramer

BACKGROUNDnAllergic rhinitis (AR) and asthma are common concurrent conditions.nnnOBJECTIVESnTo evaluate the effects of cetirizine hydrochloride (5 mg)-pseudoephedrine hydrochloride (120 mg) (cetirizine-D) twice daily on AR and asthma symptoms, pulmonary function, and asthma-related quality of life in 274 patients with confirmed seasonal AR and concomitant mild-to-moderate asthma.nnnMETHODSnIn this multicenter, randomized, double-blind, placebo-controlled study, after a 1-week screening period, patients took cetirizine-D or placebo for 4 weeks. The primary efficacy variable, AR total symptom severity complex score, was derived from patient daily diary ratings of sneezing, runny nose, itchy nose, postnasal drip, and nasal congestion. Asthma symptom severity total scores were derived from twice-daily diary ratings of wheezing, coughing, shortness of breath, and chest tightness. Pulmonary function was tested at clinic visits and by patients each morning and evening. Patients completed the Asthma Quality of Life Questionnaire at each visit. All tests were 2-sided, with statistical significance at the .05 level.nnnRESULTSnCetirizine-D reduced total symptom severity complex scores by 42.3% overall vs 23.6% with placebo (P < .001). Asthma symptom severity total scores were significantly improved with cetirizine-D at most times vs placebo. Cetirizine-D treatment was also associated with significantly improved Asthma Quality of Life Questionnaire overall scores. Pulmonary function test results were neutral. Cetirizine-D was well tolerated, with discontinuation and adverse event rates similar to placebo. Somnolence occurred in 8 patients (5.8%) taking cetirizine-D and in 1 (0.7%) taking placebo.nnnCONCLUSIONSnTreatment with cetirizine-D twice daily significantly reduced rhinitis and asthma symptoms and improved overall asthma quality of life in patients with seasonal AR and concomitant mild-to-moderate asthma.


Clinical Drug Investigation | 2013

Isolated and Spontaneous Correction of Proximal Interphalangeal Joint Contractures in Dupuytren’s Disease: An Exploratory Analysis of the Efficacy and Safety of Collagenase Clostridium histolyticum

Michael John Hayton; Ardeshir Bayat; Douglass Chapman; Robert A. Gerber; Piotr Szczypa

Background and ObjectiveDupuytren’s contractures affecting proximal interphalangeal (PIP) joints are challenging to treat. We explored the effects of collagenase Clostridium histolyticum (CCH) on PIP joint contractures after injection of an affected metacarpophalangeal (MP) joint in the same finger and after injection of an isolated PIP joint contracture.MethodsTwo patient subsets were evaluated: those with MP/PIP joints contractures in the same finger, but only the MP joint contractures were treated (Group A); and those with isolated PIP joint contractures that were treated (Group B). Endpoints included correction and improvement in contracture. Fixed-flexion contracture (FFC) and range of motion (ROM) were also assessed; adverse events (AEs) were monitored.ResultsIn Group A, 28 and 43xa0% of PIP contractures spontaneously corrected after the first and last injection of CCH, respectively, for MP contractures; 40 and 63xa0%, respectively, improved. In Group B, 31 and 39xa0% of PIP joint contractures corrected after the first and last injection of CCH, respectively, 56 and 66xa0%, respectively, improved. In Groups A and B, FFC improvements were largest after the last injection; ROM improvements were largest after the last injection in Group A and third injection in Group B. For 46 and 44xa0% of patients in Groups A and B, respectively, the first injection was the last injection. In Group B, the median (minimum, maximum) injections/joint was 1.0 (1.0, 4.0). Nearly all patients (98xa0%) experienced ≥1 AE; most were injection-site reactions.ConclusionsThe efficacy of CCH for improving PIP joint contracture was similar whether treated in isolation or after treatment of an MP joint contracture.


The Journal of Urology | 2016

Patterns of Care for Newly Diagnosed Benign Prostatic Hyperplasia in the United States

J. Quentin Clemens; Howard B. Goldman; Kelly H. Zou; Xuemei Luo; David Russell; Douglass Chapman; Canan Esinduy; Jennifer T. Anger

PURPOSEnWe examined diagnostic tests and treatment patterns in men with newxa0onset benign prostatic hyperplasia using consolidated national electronic health record data.nnnMATERIALS AND METHODSnThe Humedica® electronic health record database consists of de-identified patient records from approximately 25 million patients in the United States. Using this database, men with a new benign prostatic hyperplasia diagnosis (benign prostatic hyperplasia, bladder neck obstruction, urinary retention and incomplete bladder emptying) between July 1, 2009 and June 30, 2012 were included in study. Exclusion criteria included conditions suchxa0as genitourinary cancers, radiation cystitis, neurogenic bladder and urological pain diagnoses. Diagnostic tests and treatments were summarized andxa0stratified by age (less than 65 vs 65 years or greater) and serum prostate specific antigen level.nnnRESULTSnA total of 38,252 men met inclusion criteria. Mean followup was 1,020 days. Serum creatinine in 92% of patients, serum prostate specific antigen in 76% and urinalysis in 52% were the most common tests. Invasive testing was obtained in less than 20% of patients. Treatments included watchful waiting inxa040% of patients, pharmacological therapy in 59.4% and surgery in 2.2%. α-Blockers were prescribed in 50.7% of men. Men older than 65 years and withxa0higher prostate specific antigen levels were less likely to be treated with watchful waiting. Therapy with a 5-ARI (5-α reductase inhibitor) was prescribed in 23% to 29% of men across all prostate specific antigen categories.nnnCONCLUSIONSnThe majority of clinical care for new onset benign prostatic hyperplasia was in concordance with guideline recommendations. Based on prostate specific antigen values, 5-ARI therapy was underutilized in men with large prostates and was over utilized in men with small prostates.

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