Biomedical subjects

David Yocum

Publications and source records attributed to David Yocum.

6 recordsLinked to original sources

PubMed2006

The safety of infliximab, combined with background treatments, among patients with rheumatoid arthritis and various comorbidities: a large, randomized, placebo-controlled trial.

OBJECTIVE: To assess the risk of serious infections following 22 weeks of infliximab therapy, and to further characterize the safety profile of infliximab in combination with background treatments during 1 year in patients with rheumatoid arthritis (RA) with various comorbidities. METHODS: Patients with active RA despite receiving methotrexate (MTX) were randomly assigned to receive infusions of placebo (group 1, n=363), 3 mg/kg infliximab (group 2, n=360), or 10 mg/kg infliximab (group 3, n=361) at weeks 0, 2, 6, and 14. At week 22, patients in placebo group 1 began receiving 3 mg/kg infliximab, and patients in group 3 continued to receive an infliximab dose of 10 mg/kg. Patients in group 2 who failed to meet predefined response criteria received increasing doses of infliximab in increments of 1.5 mg/kg. RESULTS: At week 22, the relative risk of developing serious infections in groups 2 and 3, compared with group 1, was 1.0 (95% confidence interval [95% CI] 0.3-3.1, P=0.995) and 3.1 (95% CI 1.2-7.9, P=0.013), respectively. The incidence of serious adverse events was 7.8% in groups 2 and 3 compared with 7.5% in group 1. From week 22 to week 54, 11.8%, 9.9%, and 10.3% of patients in groups 1, 2, and 3, respectively, reported occurrences of serious adverse events. Through week 54, 1 patient in group 1, 2 patients in group 2, and 4 patients in group 3 developed active tuberculosis. CONCLUSION: The risk of serious infections in patients receiving the approved infliximab dose of 3 mg/kg plus MTX was similar to that in patients receiving MTX alone. Patients receiving the unapproved induction regimen of 10 mg/kg infliximab plus MTX followed by a 10 mg/kg maintenance regimen had an increased risk of serious infections through week 22.

Adult↗

PubMed2004

Does safety make a difference in selecting the right TNF antagonist?

Tumor necrosis factor (TNF) antagonists are biologic response modifiers that have significantly improved the outcomes in patients with rheumatoid arthritis (RA). At this report, safety data were collected on approximately 271,000 patients administered infliximab (as of February 2002), 121,000 patients administered etanercept (as of December 2001), and on 2400 patients who received adalimumab in trials in connection with the regulatory approval process (approval granted December 2002 in the US and September 2003 in European Union). Infliximab and etanercept have predictable and manageable safety profiles, and preliminary data suggest that the profile of adalimumab is comparable. Safety issues involving the anti-TNF agents as a class include the risk of injection-site reactions or infusion-related reactions, infection (for example, serious, opportunistic, or tubercular), malignancy, autoimmunity, and demyelinating and neurologic disorders. Injection-site and infusion-related reactions are most often easily managed and rarely lead to discontinuation of therapy. Infections can be minimized or prevented by screening and careful monitoring and follow-up; most infections respond to appropriate medical treatment. More studies are needed to evaluate the occurrence of malignancies in patients with RA to determine the potential risk posed by therapy. Antibody formation can follow the administration of any biologic agent. Although demyelinating disease has been reported with anti-TNF agents, it is not clear whether a causal relationship exists. Overall, the anti-TNF agents are well tolerated and have demonstrated a favorable benefit-to-risk profile in patients with RA.

Antirheumatic Agents↗

PubMed2004

Effective use of TNF antagonists.

Tumor necrosis factor (TNF) antagonists are biologic response modifiers that have significantly improved functional outcomes in patients with rheumatoid arthritis (RA). RA is a progressive disease in which structural joint damage can continue to develop even in the face of symptomatic relief. Before the introduction of biologic agents, the management of RA involved the use of disease-modifying antirheumatic drugs (DMARDs) early in the course of disease. This focus on early treatment, combined with the availability of the anti-TNF agents, has contributed to a shift in treatment paradigms favoring the early and timely use of DMARDs with biologic therapies. Improvement in symptom control does not always equate to a reduction in disease progression or disability. With the emergence of structure-related outcome measures as the primary means for assessing the effectiveness of antirheumatic agents, the regular use of X-rays is recommended for the continued monitoring and evaluation of patients. In addition to the control of symptoms and improvement in physical function, a reduction in erosions and joint-space narrowing should be considered among the goals of therapy, leading to a better quality of life. Adherence to therapy is an important element in optimizing outcomes. Durability of therapy with anti-TNF agents as reported from clinical trials can also be achieved in the clinical setting. Concomitant methotrexate therapy might be important in maintaining TNF antagonist therapy in the long term. Overall, the TNF antagonists have led to improvements in clinical and radiographic outcomes in patients with RA, especially those who have failed to show a complete response to methotrexate.

Antirheumatic Agents↗

PubMed2002

Hydroxychloroquine concentration-response relationships in patients with rheumatoid arthritis.

OBJECTIVE: A dose-response relationship for hydroxychloroquine (HCQ), in terms of the proportion of patients achieving the Paulus 20% criteria for improvement, had previously been observed in patients with rheumatoid arthritis (RA) receiving a 6-week loading regimen of 400, 800, or 1,200 mg HCQ daily. This present retrospective analysis was performed to investigate possible relationships between the blood HCQ and HCQ-metabolite concentrations and measures of efficacy and toxicity. In addition, we sought to ascertain whether further investigation of HCQ/HCQ-metabolite levels might lead to testing of one of these substances as a new antirheumatic drug. METHODS: Patients with active RA (n = 212) began a 6-week, double-blind trial comparing 3 different doses of HCQ at 400, 800, or 1,200 mg/day, followed by 18 weeks of open-label HCQ treatment at 400 mg/day. Patients were repeatedly evaluated for treatment efficacy and toxicity. Blood samples were available from 123 patients for analysis of HCQ, desethylhydroxychloroquine (DHCQ), desethylchloroquine (DCQ), and bisdesethylchloroquine (BDCQ) levels using high-performance liquid chromatography. Achievement of the modified Paulus 20% improvement criteria for response in RA was used as the primary efficacy parameter. Spontaneously reported adverse events were categorized and analyzed as toxicity outcome variables. The relationship between response (efficacy and toxicity) and drug levels was evaluated using logistic regression analysis. RESULTS: The subset of patients with blood concentration data was equivalent to the larger study population in all demographic and outcome characteristics. The mean HCQ, DHCQ, and DCQ elimination half-lives were 123, 161, and 180 hours, respectively. There was a positive correlation between the Paulus 20% improvement criteria response and blood DHCQ concentrations during weeks 1-6 (P < 0.001). A potential relationship between ocular adverse events and BDCQ levels was found (P = 0.036). Logistic regression analysis of adverse events data showed that adverse gastrointestinal events were associated with higher HCQ levels (P = 0.001-0.021) during weeks 1, 2, and 3. CONCLUSION: There is a weak, but predictable, relationship between blood DHCQ concentrations and efficacy of treatment with HCQ. In addition, there is an association between gastrointestinal adverse events and elevated blood HCQ concentrations. Further investigation of these relationships is warranted to see if DHCQ may be introduced as a new antirheumatic drug.

Adult↗

PubMed2002

Efficacy of tacrolimus in rheumatoid arthritis patients who have been treated unsuccessfully with methotrexate: a six-month, double-blind, randomized, dose-ranging study.

OBJECTIVE: To assess the efficacy, safety, and optimal dose of tacrolimus monotherapy in patients with rheumatoid arthritis (RA). METHODS: This phase II, randomized, double-blind, placebo-controlled monotherapy study was set in 12 community sites and 9 university-based sites. Two hundred sixty-eight patients with RA who were resistant to or intolerant of methotrexate (mean dose 15.2 mg/week) and had active disease for at least 6 months (mean tender joint count 28.2, mean erythrocyte sedimentation rate 46.5 mm/hour) were randomized to receive treatment after discontinuation of methotrexate. Those who received at least 1 dose of tacrolimus were analyzed; 141 completed the study. Stable dosages of nonsteroidal antiinflammatory drugs and low-dose prednisone were allowed during treatment. All patients were given 1, 3, or 5 mg of tacrolimus or placebo once daily for 24 weeks. The American College of Rheumatology definition of 20% improvement (ACR20) and the tender and swollen joint counts at the end of treatment were the primary outcomes. RESULTS: ACR20 response rates demonstrated a clear dose response. The ACR20 response was observed in 15.5% of patients receiving placebo (95% confidence interval [95% CI] 7.1-23.9%), 29% of the 1 mg tacrolimus group (95% CI 18.3-39.7%) (P < 0.058); 34.4% of the 3 mg group (95% CI 22.7-46.0%) (P < 0.013), and 50% of the 5 mg group (95% CI 37.8-62.3%) (P < or = 0.001). The tender joint count improved statistically significantly in all tacrolimus groups. The swollen joint count, physical function, and patient-assessed pain improved statistically significantly in the 3 mg and 5 mg groups. The incidence of creatinine elevation > or =40% above baseline levels increased in a dose-dependent manner. Dropout rates were high (41-59%) and were more common for inefficacy in the placebo patients (71.4%), whereas they were more common for toxicity in the high-dose tacrolimus groups (31-33%). Discontinuation for creatinine elevation occurred in the 3 mg (3.1%) and 5 mg (10.9%) tacrolimus groups. CONCLUSION: Tacrolimus improved disease activity in methotrexate-resistant or -intolerant patients with RA. A dose response was observed when efficacy and toxicity were assessed at different doses. The optimal dose of tacrolimus appears to be >1 mg but < or=3 mg daily.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed2002

CD4 coating, but not CD4 depletion, is a predictor of efficacy with primatized monoclonal anti-CD4 treatment of active rheumatoid arthritis.

OBJECTIVE: Double blind studies were conducted with the anti-CD4 monoclonal antibody (Mab) keliximab in patients with active, stable rheumatoid arthritis (RA), to confirm preliminary evidence of efficacy and safety from open. uncontrolled studies. METHODS: We enrolled 136 and 186 patients into 2 consecutive, randomized, double blind trials, with similar populations [apart from inclusion of disease modifying antirheumatic drug (DMARD)-naïve patients in Study 2]. Patients received 4 weeks intravenous placebo or keliximab [40, 80, 120, or 140 mg twice weekly (bw), or 240 mg once weekly (ow)]. The primary endpoint was the American College of Rheumatology (ACR) 20 response criteria, one week after the end of treatment. RESULTS: ACR 20 response rates in Study I were 19%, 42%, 51%*, and 69%* (*p < 0.05 compared to placebo), with placebo, 40, 80, or 140 mg keliximab bw, respectively. The response rates in Study 2 were 30%, 39%, 46% and 47% with placebo, 80 or 120 mg bw, or 240 mg keliximab ow, respectively. In the 2 studies, there was a dose dependent increase in peripheral blood CD4+ T cell coating with keliximab, but a different pattern of CD4 depletion was seen. While only 12% of keliximab treated patients in Study I had CD4 counts below 250 cells/mm3 at the end of the treatment period, 47% fell below this level in Study 2. Clinical response was not correlated with CD4 depletion, but was correlated with CD4+ T cell coating with keliximab. CONCLUSION: Coating of peripheral blood CD4+ T cells with keliximab, but not CD4 depletion, is a determinant of clinical response.

Adolescent↗