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Dive into the research topics where Pavel Napalkov is active.

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Featured researches published by Pavel Napalkov.


Arthritis Care and Research | 2014

Risk of hospitalized bacterial infections associated with biologic treatment among US veterans with rheumatoid arthritis

Jeffrey R. Curtis; Shuo Yang; Nivedita M. Patkar; Lang Chen; Jasvinder A. Singh; Grant W. Cannon; Ted R. Mikuls; Elizabeth Delzell; Kenneth G. Saag; Monika M. Safford; Scott L. DuVall; K. Alexander; Pavel Napalkov; Kevin L. Winthrop; Mary Jane Burton; Aaron W. C. Kamauu; John W. Baddley

The comparative risk of infection associated with non–anti–tumor necrosis factor (anti‐TNF) biologic agents is not well established. Our objective was to compare risk for hospitalized infections between anti‐TNF and non–anti‐TNF biologic agents in US veterans with rheumatoid arthritis (RA).


Arthritis Care and Research | 2015

Incidence of Giant Cell Arteritis and Characteristics of Patients: Data-Driven Analysis of Comorbidities

Hans Petri; Alan Nevitt; Khaled Sarsour; Pavel Napalkov; Neil Collinson

To establish the incidence of giant cell arteritis (GCA), cumulative use of prednisolone, and comorbidities most associated with GCA.


BMC Musculoskeletal Disorders | 2012

Rheumatoid arthritis and the incidence of influenza and influenza-related complications: a retrospective cohort study

William A. Blumentals; Anna Arreglado; Pavel Napalkov; Stephen Toovey

BackgroundPatients with rheumatoid arthritis (RA) are known to be at increased risk of infection, particularly if they are taking drugs with immunomodulatory effects. There is a need for more information on the risk of influenza in patients with RA.MethodsA retrospective cohort study was carried out using data gathered from a large US commercial health insurance database (Thomson Reuters Medstat MarketScan) from 1 January 2000 to 31 December 2007. Patients were ≥18 years of age, with at least two RA claims diagnoses. The database was scanned for incidence of seasonal influenza and its complications on or up to 30 days after an influenza diagnosis in RA patients and matched controls. Other factors accounted for included medical conditions, use of disease-modifying anti-rheumatic drugs (DMARDs), use of biological agents, influenza vaccination and high- or low-dose corticosteroids. Incidence rate ratios (IRRs) were calculated for influenza and its complications in patients with RA.Results46,030 patients with RA and a matching number of controls had a median age of 57 years. The incidence of influenza was higher in RA patients than in controls (409.33 vs 306.12 cases per 100,000 patient-years), and there was a 2.75-fold increase in incidence of complications in RA. Presence or absence of DMARDs or biologics had no significant effect. The adjusted IRR of influenza was statistically significant in patients aged 60–69 years, and especially among men. A significantly increased rate of influenza complications was observed in women and in both genders combined (but not in men only) when all age groups were combined. In general, the risk of influenza complications was similar in RA patients not receiving DMARDs or biologics to that in all RA patients. Pneumonia rates were significantly higher in women with RA. Rates of stroke/myocardial infarction (MI) were higher in men, although statistical significance was borderline.ConclusionsRA is associated with increased incidence of seasonal influenza and its complications. Gender- and age-specific subgroup data indicate that women generally have a greater rate of complications than men, but that men primarily have an increased rate of stroke and MI complications. Concomitant DMARD or biological use appears not to significantly affect the rate of influenza or its complications.


Seminars in Arthritis and Rheumatism | 2015

Tocilizumab in rheumatoid arthritis: A case study of safety evaluations of a large postmarketing data set from multiple data sources

Jeffrey R. Curtis; Susana Perez-Gutthann; Samy Suissa; Pavel Napalkov; Natasha Singh; Liz Thompson; Benjamin Porter-Brown

OBJECTIVES To evaluate the magnitude of serious adverse events (SAEs) observed in postmarketing reports of tocilizumab (TCZ) for rheumatoid arthritis (RA) in relation to SAEs observed in TCZ clinical trials and external epidemiology data. METHODS A total of 64,000 patient-years (PY) of TCZ exposure was needed to determine, with 90% power, whether rates of SAEs of interest (eg, death, hepatic, gastrointestinal, and cardiovascular) were ≥50% higher (agreed with the Food and Drug Administration) than expected. Reporting rates were calculated for spontaneously reported SAEs, open-label or unblinded postmarketing clinical trials (phase 3b/4), and a Japanese postmarketing surveillance program in the global postmarketing safety database. Event rates were calculated for the registrational placebo-controlled trials and long-term extension data. External comparators for anti-tumor necrosis factor (aTNF)-treated RA patients were derived from a US-based health care insurance claims database or published literature. RESULTS The global postmarketing safety database provided 65,099 PY of TCZ exposure; the aTNF external comparator population provided 53,360 PY. Spontaneous reporting rates per 100 PY (95% confidence interval) were 8.3 (8.1, 8.5) SAEs, 0.39 (0.34, 0.44) deaths, 0.06 (0.04, 0.08) serious hepatic events, 0.15 (0.12, 0.18) serious gastrointestinal events, 0.09 (0.07, 0.12) serious myocardial infarctions, 0.15 (0.12, 0.18) serious strokes, and 0.07 (0.05, 0.09) cardiac deaths in the global postmarketing safety database. These were of similar magnitude to corresponding rates from registrational clinical trials, the aTNF external comparator population, and published literature. CONCLUSIONS SAE rates observed among postmarketing TCZ users were similar to those of various comparison populations. Predetermined design of studies to compare postmarketing AEs using multiple data sources is a useful strategy that can be applied to other medications.


Seminars in Arthritis and Rheumatism | 2016

Corticosteroid-related adverse events in patients with giant cell arteritis: A claims-based analysis ☆☆

Michael S. Broder; Khaled Sarsour; Eunice Chang; Neil Collinson; Katie Tuckwell; Pavel Napalkov; Micki Klearman

OBJECTIVE Corticosteroids (CS) are standard treatment for giant cell arteritis (GCA), but concerns persist over toxicities associated with long-term use. In this retrospective study of medical claims data, we estimated risks for adverse events (AEs) in CS-treated GCA patients. METHODS Cox regression analyses with CS use as a time-dependent variable were conducted on data from the 2003 to 2012 Truven Health Analytics MarketScan Database. Patients 50 years of age and older who had ≥2 claims of newly diagnosed GCA, ≥1 filled oral CS prescription, and no AEs before GCA diagnosis were included. The primary outcome was presence of a new CS-related AE. RESULTS In total, 2497 patients were included. Their mean age was 71.0 years, and 71% were women. Follow-up was 9680 patient-years (PY). CS treatment continued for a mean (SD) of 1.196 (729.2) days; mean (SD) prescribed cumulative CS dose was 6983.3mg (6519.9). The overall AE rate was 0.43 events/PY; the most frequent AEs were cataract and bone disease. For each 1000-mg increase in CS exposure, the hazard ratio (HR) increased by 3% (HR = 1.03; 95% CI: 1.02-1.05; P < 0.001). Additionally, statistically significant individual associations between increased CS exposure and AE risk were observed for bone-related AEs (P < 0.001), cataract (P < 0.001), glaucoma (P = 0.005), pneumonia (P = 0.003), and diabetes mellitus (P < 0.001 in a subset of patients with no previous history of diabetes). CONCLUSION CS exposure significantly increased risk for potentially serious AEs, emphasizing a need for new treatment options for GCA patients.


Seminars in Arthritis and Rheumatism | 2012

Risk of significant infection in rheumatoid arthritis patients switching anti-tumor necrosis factor-α drugs.

Bao-Anh Nguyen-Khoa; Earl L. Goehring; Kimberly Alexander; Wei Dong; Pavel Napalkov; Judith K. Jones

OBJECTIVES To describe rates of first significant infection of rheumatoid arthritis patients who switch between anti-tumor necrosis factor (aTNF) drugs. METHODS Subjects with rheumatoid arthritis who received only aTNF drugs were observed in an insurance claims database from January 2001 to December 2007. Nonswitchers (NS) remained on one aTNF throughout the study period (date of the first aTNF claim was the index date); switchers (S) received at least one other aTNF (claim date for the 2nd agent was the index date). Significant infections included those that required intravenous antibiotics or hospitalization. Two attributable risk periods were used: (1) an infection occurring ≤90 days following a claim for an aTNF (90-day) and (2) an infection occurring after the index date (ever-treated). Follow-up was censored at the first occurrence of a significant infection event, end of eligibility, or end of study period. Data were analyzed using Cox regression. RESULTS In 13,752 NS and 2293 S patients, time-stratified rates declined 2- to 3-fold between the first year versus ≥2 years. Risk of significant infection was not different for either attribution model [90-day hazard ratio (HR) = 0.93, 95CI: 0.74 to 1.17, P = 0.55; ever treated HR = 0.94, 95CI: 0.78 to 1.15, P = 0.57]. First and second year rates were similar. Predictors included age ≥50 years; history of significant or opportunistic infection, diabetes, respiratory disease; Charlson score ≥2; or prior hospitalizations. CONCLUSIONS The risk of a significant infection was not different between NS and S patients. Regardless of switching status, the rate of infection was greater in the first year. This study was limited by the lack of clinical data to determine the reason for switching.


Seminars in Arthritis and Rheumatism | 2012

Risk of mortality, fatal infection, and fatal malignancy related to use of anti-tumor necrosis factor-α biologics by rheumatoid arthritis patients.

Veena Thyagarajan; Heather Norman; Kimberly Alexander; Pavel Napalkov; Cheryl Enger

OBJECTIVE To estimate rates of all-cause mortality, fatal infection, and fatal malignancy in rheumatoid arthritis (RA) patients treated with anti-tumor necrosis factor-α (anti-TNF) biologics. METHODS A retrospective cohort study of RA patients initiating therapy with adalimumab, etanercept, or infliximab from January 2000 to December 2008 was conducted using an administrative database of a large health care insurer. Patients were followed for the occurrence of fatal events, which were identified using the National Death Index database. Overall and anti-TNF biologic-stratified incidence rates per 1000 person-years were calculated. Primary analyses were time-on-drug based on current anti-TNF biologic exposure on the outcome date for fatal infection and intent-to-treat based on the anti-TNF biologic initiated at cohort entry for fatal malignancy. RESULTS Seven thousand seven hundred thirty-four patients initiated an anti-TNF biologic with 13,296 person-years of observation. Seventy-one deaths were identified, including 12 fatal infections and 21 fatal malignancies. The all-cause mortality rate was 5.34 per 1000 person-years. Incidence rates for fatal infection were similar among anti-TNF biologic current exposure groups (0.78 to 0.88 per 1000 person-years). Incidence rates for fatal malignancy were similar among anti-TNF biologic initiator groups (1.24 to 1.84 per 1000 person-years). CONCLUSIONS The all-cause mortality rate in RA patients treated with anti-TNF biologics was lower than in previous studies in similar non-US populations, but comparable to mortality rates in the US general population. Fatal infection and fatal malignancy rates were similar across anti-TNF biologic groups. Further studies, designed to detect risk differences associated with anti-TNF biologic use and baseline risk factors, would provide additional information.


RMD Open | 2016

Malignancy rates in patients with rheumatoid arthritis treated with tocilizumab

Andrea Rubbert-Roth; Anthony Sebba; Laura Brockwell; Ariella Kelman; Benjamin Porter-Brown; Jennifer Pulley; Pavel Napalkov; Ronald F. van Vollenhoven

Objective To analyse malignancy rates in patients with rheumatoid arthritis (RA) treated with tocilizumab. Methods Patients who received tocilizumab or placebo+methotrexate/disease-modifying antirheumatic drugs in the double-blind phases of 5-phase three trials or who received at least 1 dose of tocilizumab in the long-term extension studies were analysed up to the 2 May 2012 cut-off date. Malignancies were monitored throughout the studies, analysed and adjudicated as malignant by medical review. Risk was compared with that in the general population using standardised incidence ratios (SIRs) based on data from the Surveillance Epidemiology and End Results SEER (US general population) and GLOBOCAN (non-US general population) databases. Results In total, 4009 patients in the tocilizumab all-exposure population were included. Mean treatment duration was 4.0 years (mean 5.1 (range 0.0–6.8); total observation time was 16 120.1 patient-years (PY). The adjudicated malignancy rate (95% CI) was 1.26/100 PY (1.09 to 1.44) and remained constant over time. The SIR (95% CI) for all malignancies combined, excluding non-melanoma skin cancer, was 1.36 (1.01 to 1.80) for US and 1.81 (1.44 to 2.23) for non-US populations, driven primarily by higher rates in lung and bronchus (US/non-US) malignancies and prostate cancer and non-Hodgkin lymphoma (non-US), in contrast to those for the general populations; these higher rates are in line with those expected in patients with RA or in the geographic regions studied. Conclusions Malignancy rates remained stable with long-term tocilizumab treatment, and malignancy types and rates were consistent with those expected in patients with RA.


Seminars in Arthritis and Rheumatism | 2017

Serious adverse effects associated with glucocorticoid therapy in patients with giant cell arteritis (GCA): A nested case–control analysis ☆

Jessica C. Wilson; Khaled Sarsour; Neil Collinson; Katie Tuckwell; David Musselman; Micki Klearman; Pavel Napalkov; Susan S. Jick; John H. Stone; Christoph R. Meier

OBJECTIVE Giant cell arteritis (GCA) is an inflammatory vasculitis preferentially affecting large and medium-sized arteries. High-dose oral glucocorticoids (GCs) are the mainstay of GCA therapy. Using data from the UK Clinical Practice Research Datalink (CPRD), we examined the risk of oral GC-related serious adverse events (SAEs) in a UK population of patients with giant cell arteritis (GCA). METHODS We conducted a series of nested case-control analyses in GCA patients to examine the effect of increasing dose of prednisolone on the risk of developing diabetes, glaucoma, osteoporosis, fractures, serious infection requiring hospitalization, and death. We used conditional logistic regression to calculate the unadjusted and multivariate odds ratios (ORs) with 95% CIs for the associations between prednisolone use and the risks of all outcomes of interest. We stratified the analyses by increasing cumulative prednisolone use and average daily dose. RESULTS In the multivariate analyses, we observed a trend of increasing risk of diabetes and osteoporosis with increasing cumulative dose of oral prednisolone (ptrend < 0.05). GCA patients in the highest daily dose category (30mg/d) had an increased risk of diabetes (adjusted OR, 95% CI) (4.7, 2.8-7.8), osteoporosis (1.9, 1.2-2.9), fractures (2.6, 1.6-4.3), glaucoma (3.5, 2.0-6.1), serious infection (3.3, 2.2-5.2), and death (2.1, 1.3-3.5) compared to those with lower average daily prednisolone doses (5mg/d). CONCLUSION Compared to lower average daily prednisolone doses, high average daily doses were associated with an increased risk of serious adverse effects.


Seminars in Arthritis and Rheumatism | 2017

Incidence of outcomes potentially associated with corticosteroid therapy in patients with giant cell arteritis.

Jessica C. Wilson; Khaled Sarsour; Neil Collinson; Katie Tuckwell; David Musselman; Micki Klearman; Pavel Napalkov; Susan S. Jick; John H. Stone; Christoph R. Meier

OBJECTIVE Giant cell arteritis (GCA) is an inflammatory disorder of blood vessels that preferentially affects large- and medium-sized arteries. High-dose oral corticosteroids (CS) are the mainstay of GCA therapy. Using data from the UK Clinical Practice Research Datalink, we quantified and compared the incidence of selected potentially CS-associated adverse outcomes in patients with and without GCA. METHODS We conducted a retrospective follow-up study of GCA and non-GCA patients to examine the incidence of adverse outcomes attributable to CS use. Eligibility criteria for the GCA group included a first-time diagnosis of GCA at age 50 years or older with receipt of ≥1 prescription(s) for prednisolone. GCA patients were matched to a GCA-free comparison group of equal size on age, sex, general practice, and calendar time. We estimated incidence rates and incidence rate ratios (IRRs) for diabetes, osteoporosis, glaucoma, fractures, serious infection requiring hospitalization, and death for GCA and non-GCA patients and compared all-cause hospitalizations between the two groups. RESULTS The cohort consisted of 5011 GCA and 5011 matched non-GCA patients. Approximately 74% were women, and mean age at GCA diagnosis was 72.9 years. The IR for all outcomes was greater in the GCA group than the non-GCA group. IRRs [95% confidence intervals (CIs)] were as follows: diabetes 1.4 (1.2-1.7), osteoporosis 2.4 (2.1-2.8), fractures 1.4 (1.2-1.6), glaucoma 2.0 (1.6-2.5), serious infection requiring hospitalization 1.5 (1.3-1.7), and death 1.2 (1.0-1.3). CONCLUSION Compared with age- and sex-matched non-GCA patients, patients with GCA were at increased risk for diabetes, osteoporosis, fracture, and glaucoma and at a marginally increased risk for death.

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Jeffrey R. Curtis

University of Alabama at Birmingham

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Elizabeth Delzell

University of Alabama at Birmingham

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J.R. Curtis

University of Alabama at Birmingham

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