Building Trustworthy Generative Artificial Intelligence for Diabetes Care and Limb Preservation: A Medical Knowledge Extraction Case.

BACKGROUND: Large language models (LLMs) offer significant potential in medical information extraction but carry risks of generating incorrect information. This study aims to develop and validate a retriever-augmented generation (RAG) model that provides accurate medical knowledge about diabetes and diabetic foot care to laypersons with an eighth-grade literacy level. Improving health literacy through patient education is paramount to addressing the problem of limb loss in the diabetic population. In addition to affecting patient well-being through improved outcomes, improved physician well-being is an important outcome of a self-management model for patient health education. METHODS: We used an RAG architecture and built a question-and-answer artificial intelligence (AI) model to extract knowledge in response to questions pertaining to diabetes and diabetic foot care. We utilized GPT-4 by OpenAI, with Pinecone as a vector database. The NIH National Standards for Diabetes Self-Management Education served as the basis for our knowledge base. The model's outputs were validated through expert review against established guidelines and literature. Fifty-eight keywords were used to select 295 articles and the model was tested against 175 questions across topics. RESULTS: The study demonstrated that with appropriate content volume and few-shot learning prompts, the RAG model achieved 98% accuracy, confirming its capability to offer user-friendly and comprehensible medical information. CONCLUSION: The RAG model represents a promising tool for delivering reliable medical knowledge to the public which can be used for self-education and self-management for diabetes, highlighting the importance of content validation and innovative prompt engineering in AI applications.

A Randomized, Double-Blind, Efficacy and Safety Study of PF-05280586 (a Rituximab Biosimilar) Compared with Rituximab Reference Product (MabThera®) in Subjects with Previously Untreated CD20-Positive, Low-Tumor-Burden Follicular Lymphoma (LTB-FL).

BACKGROUND: Biosimilars are highly similar to the licensed biologic ("reference product"), with no clinically meaningful differences in safety, purity, or potency between the two products. OBJECTIVE: This comparative 52-week clinical study evaluated the efficacy, safety, immunogenicity, pharmacokinetics (PK), and pharmacodynamics (PD) of PF-05280586 (Ruxience™ [a rituximab biosimilar]) versus rituximab reference product sourced from the EU (MabThera®; rituximab-EU). PATIENTS AND METHODS: Subjects with CD20-positive, low-tumor-burden follicular lymphoma (LTB-FL) and an Eastern Cooperative Oncology Group performance status 0-1 were randomized (1:1) to PF-05280586 or rituximab-EU (375 mg/m2 intravenously [once weekly for 4 weeks at days 1, 8, 15, and 22]), stratified using the Follicular Lymphoma International Prognostic Index 2 classification. The primary endpoint was overall response rate (ORR) at week 26 (percentage of subjects achieving complete response [CR] or partial response [PR]). Therapeutic equivalence was concluded if the two-sided 95% confidence interval (CI) for the difference in ORR between groups was within the prespecified margin (± 16%). Secondary endpoints included progression-free survival (PFS), CR rate, safety, immunogenicity, PK, and PD. RESULTS: A total of 394 subjects were randomized: PF-05280586 (n = 196) or rituximab-EU (n = 198). ORR at week 26 was 75.5% (PF-05280586) versus 70.7% (rituximab-EU), for a difference of 4.66%; 95% CI (- 4.16 to 13.47), which was entirely within the prespecified equivalence margin. Rates of CR were 29.3% (PF-05280586) versus 31.0% (rituximab-EU). Estimated 1-year PFS rates were 78.2% (95% CI 70.2-84.2) and 83.0% (95% CI 75.0-88.6) for PF-05280586 and rituximab-EU, respectively. Safety, immunogenicity, and mean serum concentrations were similar between groups. CONCLUSIONS: The efficacy, safety, immunogenicity, PK, and PD of PF-05280586 and rituximab-EU were similar up to week 52 in subjects with previously untreated CD20-positive LTB-FL. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02213263 and EudraCT (2014-000132-41).

Efficacy of Calcium Channel Blockers Versus Other Classes of Antihypertensive Medication in the Treatment of Hypertensive Patients With Previous Stroke and/or Coronary Artery Disease: A Systematic Review and Meta-Analysis.

Hypertensive patients, such as those with established coronary artery disease (CAD) or those who have suffered a stroke, are at increased risk of morbidity and mortality. This systematic literature review and meta-analysis assesses the long-term effects of calcium channel blockers (CCBs) compared with other classes of antihypertensive medications on major cardiovascular (CV) outcomes in these high-risk subgroups of hypertensive patients. Randomized, active controlled parallel group trials were included if they compared CCBs with α-blockers, ß-blockers, angiotensin II receptor blockers, angiotensin-converting enzyme inhibitors, or diuretics, had a follow-up of ≥6 months, and had assessments of blood pressure (BP) and CV events [all-cause death, CV death, major CV events (myocardial infarction, MI; congestive heart failure, CHF; stroke; and CV death), MI, stroke, or CHF] in patients with baseline systolic/diastolic BP ≥140/≥90 mm Hg with either concomitant previous stroke and/or CAD. The final dataset included 19 publications reporting on 7 unique trials. In hypertensive patients with previous stroke, there was no difference between CCBs and comparators for any CV outcome. In those with CAD, there was no difference for all-cause death, CV death, major CV events, and MI for CCBs relative to comparators; however, a reduction in the risk of stroke and an increase in the risk of CHF were seen. For BP lowering, CCBs were at least as efficacious as comparators. The findings of our systematic review and analysis add to the body of evidence for the use of CCBs for the long-term treatment of hypertension in difficult-to-treat high CV risk populations.

Parasitological Clearance Rates and Drug Concentrations of a Fixed Dose Combination of Azithromycin-Chloroquine in Asymptomatic Pregnant Women with Plasmodium Falciparum Parasitemia: An Open-Label, Non-Comparative Study in Sub-Saharan Africa.

BACKGROUND: Malaria remains one of the most important causes of morbidity and mortality in pregnant women and their newborn babies in sub-Saharan Africa. Intermittent preventive treatment in pregnancy (IPTp) is recommended by the World Health Organization (WHO) to reduce the burden of disease and improve maternal and neonatal survival and general health. Due to the growing resistance to sulfadoxine-pyrimethamine (SP), the current WHO-recommended drug for IPTp, identification of new and effective drugs is an urgent priority. METHODS AND FINDINGS: This was an open-label, non-comparative study (NCT01103713) in 5 countries in East and sub-Saharan Africa (Benin, Kenya, Malawi, Tanzania, and Uganda) to assess parasitological response and drug concentrations of a single, 3-day course of four tablets of a fixed-dose combination of azithromycin-chloroquine (AZCQ) 250/155 mg given during the second or third trimester to women with asymptomatic Plasmodium falciparum parasitemia in their first or second pregnancy. Parasitemia was determined by microscopy and molecular genotyping was performed to characterize parasites relative to the baseline infection. Weekly follow-up visits took place until day 42 after first dose and additional follow-up occurred after delivery. Systemic concentrations of azithromycin (AZ), chloroquine (CQ), and the CQ metabolite, desethyl CQ (DECQ) were evaluated at Day 0 (pre-dose), at Day 2 (pre-dose, 2 and 8 hours) and randomly at Days 7 and 14. Systemic concentrations of CQ and DECQ were also measured randomly at Day 21 and Day 28. In total, 404 women were screened for eligibility and 168 were treated, 155 of whom completed the study. PCR-adjusted parasitological response in the modified intent-to-treat population at day 28 (the primary efficacy endpoint) was estimated by the Kaplan-Meier method as 99.35% (95% confidence interval [CI]: 97.76, 100.00). PCR-adjusted parasitological response remained high at day 42 (95.19%; 95% CI: 91.35, 99.03). In general, the mean concentrations of serum AZ, plasma CQ, and plasma DECQ showed large CV% values (ranges of 33-156%, 42-228%, and 57-109%, respectively). There were 157 live births, three stillbirths, and eight pregnancies of unknown outcome: 7 due to withdrawal of participant consent and 1 lost to follow-up. The most frequent treatment-emergent adverse events were vomiting (20.8%) and dizziness (19.6%). CONCLUSIONS: These results suggest that a 3-day course of AZCQ can lead to an adequate 28-day parasitological response.

Efficacy and Safety of Azithromycin-Chloroquine versus Sulfadoxine-Pyrimethamine for Intermittent Preventive Treatment of Plasmodium falciparum Malaria Infection in Pregnant Women in Africa: An Open-Label, Randomized Trial.

BACKGROUND: The World Health Organization recommends intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) in African regions with moderate to high malaria transmission. However, growing resistance to SP threatens the effectiveness of IPTp-SP, and alternative drugs are needed. This study tested the efficacy, tolerability, and safety of a fixed-dose combination azithromycin-chloroquine (AZCQ; 250 mg AZ/155 mg CQ base) for IPTp relative to IPTp-SP. METHODS AND FINDINGS: A randomized, Phase 3, open-label, multi-center study was conducted in sub-Saharan Africa (Benin, Kenya, Malawi, Tanzania, and Uganda) between October 2010 and November 2013. Pregnant women received 3 IPTp courses with AZCQ (each course: 1,000/620 mg AZCQ QD for 3 days) or SP (each course 1,500/75 mg SP QD for 1 day) at 4- to 8-week intervals during the second and third trimester. Long-lasting insecticide-treated bednets were also provided at enrollment. Study participants were followed up until day 28 post delivery (time window: day 28-42). The primary endpoint was the proportion of participants with sub-optimal pregnancy outcomes (a composite endpoint comprising live-borne neonates with low birth weight [LBW, <2,500 g], premature birth [<37 weeks], still birth [>28 weeks], abortion [≤28 weeks], lost to follow-up prior to observation of pregnancy outcome, or missing birth weight). The study was terminated early after recruitment of 2,891 of the planned 5,044 participants, due to futility observed in a pre-specified 35% interim analysis. In the final intent-to-treat dataset, 378/1,445 (26.2%) participants in the AZCQ and 342/1,445 (23.7%) in the SP group had sub-optimal pregnancy outcomes, with an estimated risk ratio (RR) of 1.11 (95% CI: 0.97, 1.25; p = 0.12). There was no significant difference in the incidence of LBW between treatment groups (57/1138 [5.0%] in the AZCQ group, 68/1188 [5.7%] in the SP group, RR 0.87 [95% CI: 0.62, 1.23]; p = 0.44). IPTp-AZCQ was less well-tolerated in mothers than IPTp-SP. Occurrences of congenital anomalies, deaths, and serious adverse events were comparable in neonates for both groups. Limitations included the open-label design and early study termination. CONCLUSIONS: IPTp-AZCQ was not superior to IPTp-SP in this study and alternatives for IPTp-SP remain to be identified. The proportions of sub-optimal pregnancy outcomes and LBW were lower than expected, which may be linked to insecticide-treated bednet use throughout the study. Reduced incidences of symptomatic malaria infection and peripheral parasitemia in the AZCQ group relative to SP suggest that AZCQ warrants further investigation as an alternative treatment of uncomplicated malaria. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01103063).

Comparison of azithromycin plus chloroquine versus artemether-lumefantrine for the treatment of uncomplicated Plasmodium falciparum malaria in children in Africa: a randomized, open-label study.

BACKGROUND: This randomized, open-label study was conducted to establish the non-inferiority of a combination of azithromycin (AZ) and chloroquine (CQ) to artemether-lumefantrine (AL) for treatment of uncomplicated malaria in children from six sites in sub-Saharan Africa. METHODS: Children with uncomplicated Plasmodium falciparum malaria between six and 59 months of age were randomized 1:1 to either AZCQ (30 mg/kg AZ + 10 mg/kg CQ base) or AL per prescribing information for three days (Days 0, 1, 2). Each site could enrol in the study population once the treatment of uncomplicated malaria in five children five to 12 years of age was deemed to be effective and well tolerated. The primary efficacy evaluation was the proportion of subjects in both the modified intent-to-treat (MITT) and per-protocol (PP) populations with an adequate clinical and parasitological response (PCR corrected) at Day 28. Non-inferiority was concluded if the lower bound of the 95% confidence interval comparing the two groups was 10 percentage points or greater. RESULTS: A total of 255 children were enrolled in the efficacy analysis (AZCQ, n = 124; AL, n = 131). The PCR corrected clearance rates were 89% (AZCQ) versus 98% (AL) for MITT, a difference of -9.10 (95% confidence interval; -16.02, -2.18) and 93% (AZCQ) versus 99% (AL) for PP, a difference of -6.08 (-12.10, -0.05). Early and late treatment failures were more common in subjects receiving AZCQ. Adverse events were more common in subjects treated with AZCQ. Drug concentrations obtained at specified time points following AZCQ administration had a large coefficient of variation partially due to sparse sampling with sample collection time window. CONCLUSIONS: In this study, non-inferiority of AZCQ to AL was not demonstrated. TRIAL REGISTRATION: ClinicalTrials.gov NCT00677833 .

A Systematic Review on the Efficacy of Amlodipine in the Treatment of Patients With Hypertension With Concomitant Diabetes Mellitus and/or Renal Dysfunction, When Compared With Other Classes of Antihypertensive Medication.

The long-term cardiovascular (CV) effects of calcium channel blockers, with special focus on amlodipine, were compared with other classes of antihypertensive medications in high-risk hypertensive patient subgroups. A systematic literature review and meta-analysis was undertaken of 38 unique randomized, active-controlled, parallel-group trials comparing amlodipine/calcium channel blockers with diuretics, ß-blockers, α-blockers, angiotensin-converting enzyme inhibitors, or angiotensin II receptor blockers, with ≥6-month follow-up, and which had included assessment of blood pressure (BP) and CV events [all-cause death, CV death, myocardial infarction (MI), stroke, congestive heart failure (CHF), or major CV events (MACE: MI, CHF, stroke, and CV death)], in hypertensive patients (baseline systolic/diastolic BP ≥140/≥90 mm Hg) with either concomitant diabetes and/or renal dysfunction. In hypertensive patients with diabetes, no difference was found for amlodipine versus comparators with respect to all-cause death, CV death, MACE, and MI; a decrease in stroke risk, and an increase in CHF risk, was seen. In hypertensive patients with renal dysfunction, no difference was found for amlodipine versus comparators with respect to all-cause death, CV death, MACE, MI, and CHF; a decrease in stroke risk was seen. Amlodipine was found to be at least as efficacious as all the other classes of antihypertensive agents in reducing systolic and diastolic BP. Long-term control of BP is critical for avoiding complications of hypertension in high-risk patients, particularly CV and cerebrovascular events such as stroke. This analysis has provided evidence that amlodipine is an appealing therapeutic option in the long-term management of hypertension in both diabetic and renal dysfunction patients.

Incremental Blood Pressure-Lowering Effect of Titrating Amlodipine for the Treatment of Hypertension in Patients Including Those Aged ≥55 Years.

Small reductions in blood pressure reduce the risk of cardiovascular events. Here, we report 2 post hoc pooled analyses assessing the antihypertensive effect of amlodipine in patients who had not responded to 5 mg and were uptitrated to 10 mg. The first analysis assessed subgroups of patients aged either younger than 55 years or 55 years or older and the second analysis pooled all patients irrespective of age. Of 706 patients in the age-related analysis, a statistically significant decrease in blood pressure from baseline was observed {for younger than 55 years [N = 253]: systolic blood pressure = -12.8 [standard error (SE) = 0.90] mm Hg, diastolic blood pressure = -8.0 [SE = 0.55] mm Hg; for 55 years or older [N = 453]: systolic blood pressure = -12.1 [SE = 0.66] mm Hg, diastolic blood pressure = -6.7 [SE = 0.39] mm Hg; all P < 0.0001}. In total, 45.8% and 39.3% of patients aged younger than 55 and 55 years or older, respectively, achieved their blood pressure goals. Adverse events were experienced by 62 (24.5%) patients aged younger than 55 years and 136 (30.0%) patients aged 55 years or older. Similar efficacy and safety results were seen in the all patient pooled analysis. Titration of amlodipine from 5 mg to 10 mg significantly decreased blood pressure in older hypertensive patients, which is clinically relevant because increased age is associated with hypertension and cardiovascular events.

Uptitrating amlodipine significantly reduces blood pressure in diabetic patients with hypertension: a retrospective, pooled analysis.

Diabetic patients with hypertension are approximately twice as likely to develop cardiovascular disease as non-diabetic patients with hypertension. Given that hypertension affects ∼60% of patients with diabetes, effective blood pressure (BP) management is important in this high-risk population. This post-hoc analysis pooled data from six clinical studies to quantify additional BP efficacy achieved when titrating hypertensive diabetic patients from amlodipine 5 mg to 10 mg. Approximately half of the diabetic patients were male (44/98; 44.9%) with a mean (standard deviation [SD]) age of 60.6 (9.6) years and a baseline mean (standard error [SE]) systolic blood pressure/diastolic blood pressure (SBP/DBP) of 150.8 (1.30)/87.5 (0.94) mmHg while on amlodipine 5 mg (159.1 [1.40]/92.6 [0.94] mmHg prior to treatment). In comparison, 350/610 (57.4%) non-diabetic patients were male with a mean (SD) age of 58.7 (11.1) years and baseline mean (SE) SBP/DBP of 150.3 (0.62)/90.9 (0.41) mmHg while on amlodipine 5 mg (160.0 [0.67]/96.2 [0.45] mmHg prior to treatment). Increasing amlodipine from 5 mg to 10 mg lowered sitting SBP by -12.5 mmHg (95% confidence interval (CI): -15.5, -9.5; P<0.0001) and DBP by -6.0 mmHg (-7.4, -4.6; P<0.0001) in diabetic patients; and SBP by -12.4 mmHg (-13.5, -11.3; P<0.0001) and DBP by -7.3 mmHg (-8.0, -6.7; P<0.0001) in non-diabetic patients. In total, 12.0% (95% CI: 6.4, 20.0) of diabetic patients achieved their BP goal versus 46.4% (42.4, 50.4) of non-diabetic patients after titration to amlodipine 10 mg. Overall, 22.0% of diabetic patients experienced 31 adverse events (AEs) and 28.9% of non-diabetic patients experienced 282 AEs. Serious AEs were reported by one (1.0%) diabetic and five (0.8%) non-diabetic patients. In this analysis, increasing amlodipine from 5 mg to 10 mg produced a clinically significant reduction in the BP of diabetic hypertensive patients, similar to non-diabetic patients, highlighting the importance of optimizing amlodipine titration in this high-risk population.

Efficacy and safety of a combination of azithromycin and chloroquine for the treatment of uncomplicated Plasmodium falciparum malaria in two multi-country randomised clinical trials in African adults.

BACKGROUND: Given increasing rates of resistance to existing therapy, new options for treatment and prophylaxis of malaria are needed. METHODS: Two randomised, comparative, non-inferiority studies were conducted in Africa, one double-blinded and one open-label. Adults with fever, a positive peripheral blood smear, and a positive rapid diagnostic test for Plasmodium falciparum were randomised in both studies to either azithromycin (AZ) 1,000 mg plus chloroquine (CQ) 600-mg base (AZCQ 1,000 mg) once daily for three days or mefloquine hydrochloride (MQ) 1,250 mg (split dose). In the first study, an additional regimen of AZ 500 mg plus CQ 600-mg base (AZCQ 500 mg) once daily for three days was included. All study participants were hospitalised until three consecutive daily blood smears were negative for asexual P. falciparum parasitaemia. Study participants were evaluated weekly for 42 days, with Day 28 polymerase chain reaction (PCR)-corrected parasitological clearance rate as primary endpoint. RESULTS: A total of 467 subjects were randomised in the two studies. At 28 days' follow-up, PCR-corrected parasitological clearance rates in the per protocol population in the first study were 101/103 (98%) with AZCQ 1,000 mg compared with 102/103 (99%) with MQ (95% confidence interval [CI]: -5.2, 3.3). The AZCQ 500-mg regimen was stopped during an interim study review (six [86%] clearance of seven evaluable; two lost to follow-up). In the second study, clearance rates were similar: AZCQ 1,000 mg 107/107 (100%) vs MQ 111/112 (99%; 95% CI: -1.8, 3.6). Among the participating countries, in vitro CQ resistance based on pfcrt mutation frequency in the baseline isolates across both studies ranged from 20.8% (Zambia) to 96.1% (Uganda). Serious adverse events (AEs; all causality) were observed more frequently with MQ compared with AZCQ (four vs one, respectively), though discontinuations for AEs were similar (four vs three, respectively). Common AEs in the AZ-containing arms included pruritus, vomiting, dizziness, and headache. CONCLUSIONS: Among adults with symptomatic uncomplicated falciparum malaria in Africa, the combination of AZ 1,000 mg and CQ 600-mg base once daily for three days resulted in Day 28 PCR-corrected parasitological clearance rates of ≥98% and was non-inferior to treatment with MQ. AZCQ was well tolerated. TRIAL REGISTRATION: ClinicalTrials.gov identifiers NCT00082576 and NCT00367653.

Titration of amlodipine to higher doses: a comparison of Asian and Western experience.

In this retrospective analysis, data pooled from two Phase III/IV open-label Asian studies were used to quantify the additional blood pressure efficacy achieved when titrating amlodipine from 5 mg to 10 mg in mild/moderate hypertensive patients, and compared to data pooled from three Western studies. The primary efficacy end point was the change from baseline in sitting systolic blood pressure (SBP) and diastolic blood pressure (DBP) to the specified time point (4-8 weeks, depending on the trial). For the Asian analysis (n=174), both mean SBP and DBP were significantly decreased at the final visit (SBP -13.3 mmHg, 95% confidence interval [CI] -15.5 to -11.0; DBP -9.2 mmHg, 95% CI -10.6 to -7.8; both P<0.0001). These results were similar to the Western analysis (n=369; SBP -11.5 mmHg, 95% CI -13.1 to -10.0; DBP -6.3, 95% CI -7.1 to -5.5; both P<0.0001). In summary, titration of amlodipine from 5 mg to 10 mg significantly decreased both SBP and DBP in Asian patients with mild-to-moderate hypertension.

Creative solutions to extraordinary challenges in clinical trials: methodology of a phase III trial of azithromycin and chloroquine fixed-dose combination in pregnant women in Africa.

BACKGROUND: Malaria in pregnancy is one of the most common preventable causes of maternal and neonatal morbidity and mortality in sub-Saharan Africa. To prevent its adverse effects, such as maternal anaemia, placental parasitaemia and low birth weight (LBW) neonates, the World Health Organization recommends effective malaria case management, use of insecticide-treated bed nets and intermittent preventive therapy in pregnancy (IPTp). Sulphadoxine-pyrimethamine (SP) has been the standard for IPTp in several countries, but parasite resistance to SP is growing. Therefore, new IPTp therapies are urgently needed. One candidate being evaluated for IPTp is a fixed-dose combination of azithromycin and chloroquine (AZCQ). This paper describes the challenges and the innovative solutions implemented in designing and conducting a pivotal AZCQ-IPTp trial, sponsored by Pfizer Inc and co-funded by Pfizer Inc and the Medicines for Malaria Venture. METHODS: The AZCQ-IPTp pivotal trial is a multicentre, multicountry, phase III, open-label, randomized superiority study of AZCQ-IPTp versus SP-IPTp in pregnant women of sub-Saharan Africa. The trial was designed to meet stringent regulatory agency scientific advice and IPTp policy makers' recommendations, and incorporates an innovative adaptive design to manage programme risk, maintain the operating characteristics of the study and optimize resources. The trial's novel composite primary endpoint is the proportion of participants with a suboptimal pregnancy outcome (abortion [≤28 weeks], stillbirths [>28 weeks], premature [<37 weeks] deliveries, LBW [<2,500 g] live neonates, missing neonatal birth weight data or loss to follow-up). The study employs a prospective group sequential design with three unblinded analyses when 50%, 70% and 100% of participants achieve the primary endpoint; the study team will remain blinded to the analyses until after the completion of the study. The number of participants randomized will be adaptive, based on the blinded review of the observed pooled primary endpoint data across the two treatment arms, when approximately 1,000 participants complete the primary endpoint assessments. RESULTS: This study is ongoing and expected to complete in 2014. CONCLUSION: This report describes the unique challenges and innovative solutions implemented in designing and conducting this pivotal AZCQ-IPTp trial, which may serve as a prototype for future IPTp and other studies involving similar conditions.

Protein kinase C depresses cardiac myocyte power output and attenuates myofilament responses induced by protein kinase A.

Following activation by G-protein-coupled receptor agonists, protein kinase C (PKC) modulates cardiac myocyte function by phosphorylation of intracellular targets including myofilament proteins cardiac troponin I (cTnI) and cardiac myosin binding protein C (cMyBP-C). Since PKC phosphorylation has been shown to decrease myofibril ATPase activity, we hypothesized that PKC phosphorylation of cTnI and cMyBP-C will lower myocyte power output and, in addition, attenuate the elevation in power in response to protein kinase A (PKA)-mediated phosphorylation. We compared isometric force and power generating capacity of rat skinned cardiac myocytes before and after treatment with the catalytic subunit of PKC. PKC increased phosphorylation levels of cMyBP-C and cTnI and decreased both maximal Ca(2+) activated force and Ca(2+) sensitivity of force. Moreover, during submaximal Ca(2+) activations PKC decreased power output by 62 %, which arose from both the fall in force and slower loaded shortening velocities since depressed power persisted even when force levels were matched before and after PKC. In addition, PKC blunted the phosphorylation of cTnI by PKA, reduced PKA-induced spontaneous oscillatory contractions, and diminished PKA-mediated elevations in myocyte power. To test whether altered thin filament function plays an essential role in these contractile changes we investigated the effects of chronic cTnI pseudo-phosphorylation on myofilament function using myocyte preparations from transgenic animals in which either only PKA phosphorylation sites (Ser-23/Ser-24) (PP) or both PKA and PKC phosphorylation sites (Ser-23/Ser-24/Ser-43/Ser-45/T-144) (All-P) were replaced with aspartic acid. Cardiac myocytes from All-P transgenic mice exhibited reductions in maximal force, Ca(2+) sensitivity of force, and power. Similarly diminished power generating capacity was observed in hearts from All-P mice as determined by in situ pressure-volume measurements. These results imply that PKC-mediated phosphorylation of cTnI plays a dominant role in depressing contractility, and, thus, increased PKC isozyme activity may contribute to maladaptive behavior exhibited during the progression to heart failure.

Dosing celecoxib in pediatric patients with juvenile rheumatoid arthritis.

The objective was to derive dosing recommendations for the use of celecoxib in patients with juvenile rheumatoid arthritis (JRA) using pharmacokinetic (PK) and exposure-response data. PK and efficacy data from a randomized, double-blind, 12-week study of celecoxib dosed at 3 and 6 mg/kg twice a day (bid) as an investigational suspension formulation in 152 JRA patients aged 2 to 17 years, PK data from 36 adult RA patients, and relative bioavailability data in healthy adults comparing suspension or capsule sprinkles with the commercial capsule were analyzed. Typical oral clearance (L/h) values were 40% and 24% lower in patients weighing 10 and 25 kg, respectively, compared with a 70-kg patient. Longitudinal, logistic pharmacodynamic models incorporating linear effects of dose/area under the plasma concentration-time curve (AUC) over 0 to 12 hours (AUC(0-12)) suggested that the percentage of responders increased with celecoxib exposure. Systemic exposures (AUC) were similar for the suspension, capsule sprinkles, and intact capsule. Administration of a 50-mg bid capsule (or sprinkles) for patients weighing 10 to 25 kg and 100 mg bid for patients >25 kg was predicted to yield similar exposures and response rates as those observed in the JRA trial. Doses and dosage forms not studied in the JRA trial were approved based on the results of this analysis.

Celecoxib in the treatment of primary dysmenorrhea: results from two randomized, double-blind, active- and placebo-controlled, crossover studies.

BACKGROUND: Celecoxib, a cyclooxygenase-2 inhibitor, has established analgesic efficacy for the treatment of acute pain resulting from a variety of causes. OBJECTIVE: This article describes 2 studies designed to assess the efficacy and tolerability of celecoxib in patients with primary dysmenorrhea. METHODS: Two identical, 3-day, multiple-dose, randomized, double-blind, active- and placebo-controlled, crossover studies were carried out in women aged 18 to 44 years with primary dysmenorrhea (studies 1 and 2). The studies employed a 6-sequence, 3-period, complete-block crossover design over 3 menstrual cycles. Patients received celecoxib 400 mg, followed by celecoxib 200 mg no sooner than 12 hours after first dose (day 1), then celecoxib 200 mg q12h as necessary (days 2 and 3); naproxen sodium 550 mg followed by naproxen sodium 550 mg no sooner than 12 hours after first dose (day 1), then naproxen sodium 550 mg q12h as necessary (days 2 and 3); or placebo. Primary efficacy measures were time-weighted sum of total pain relief and time-weighted sum of pain intensity difference at 8 hours after administration of the first dose of study medication (TOTPAR[8] and SPID[8], respectively). Tolerability was assessed using routine physical examination, including vital sign measurements, and clinical laboratory analyses at screening and end of study. RESULTS: In total, 149 and 154 patients were randomized to 1 of the 6 treatment sequences in studies 1 and 2, respectively. Across treatment sequences, mean age ranges were 23.4 to 26.9 years (study 1) and 28.3 to 34.1 years (study 2). Mean weight ranges were 62.7 to 74.5 kg (study 1) and 69.2 to 86.7 kg (study 2). Most patients (96.6% in study 1, 80.5% in study 2) were white. Mean TOTPAR[8] values with celecoxib (study 1/study 2, 18.28/17.98) and naproxen sodium (20.59/21.27) were significantly greater than with placebo (12.82/12.98) (all, P < 0.001). Mean SPID[8] values were significantly greater with celecoxib (10.06/9.60) and naproxen sodium (11.48/11.71) than with placebo (5.96/6.41) (all, P < 0.001). Naproxen sodium was significantly different from celecoxib in TOTPAR[8] (study 2 only) and SPID[8] (both studies) (all, P < 0.001). In both studies, the adverse-events (AEs) profile was not significantly different between treatments, with the majority of AEs being related to primary dysmenorrhea and not medication. Less than 10% of patients experienced severe AEs in any treatment period. CONCLUSIONS: In these 2 identically designed studies in women aged 18 to 44 years, celecoxib 400 mg (followed by 200 mg q12h) was more effective, as measured using pain scores, in the treatment of primary dysmenorrhea compared with placebo. In each study, the primary efficacy measures-TOTPAR[8] and SPID[8] scores-were significantly improved with celecoxib and naproxen sodium compared with placebo. SPID[8] in both studies and TOTPAR[8] in study 2 were significantly improved with naproxen sodium compared with celecoxib. Both celecoxib and naproxen sodium were well tolerated and provided relief from menstrual pain within 1 hour of administration.

A prospective study comparing celecoxib with naproxen in children with juvenile rheumatoid arthritis.

OBJECTIVE: To compare the efficacy and safety of celecoxib and naproxen in children with juvenile rheumatoid arthritis (JRA). METHODS: In this multicenter, randomized, double-blind, noninferiority study, subjects with JRA were randomized to receive a target dose of celecoxib 3 mg/kg bid or 6 mg/kg bid, or a target dose of naproxen 7.5 mg/kg bid for 12 weeks (maximum allowed dose=600 mg total daily dose). The primary efficacy measure was the percentage of responders at Week 12 attaining the American College of Rheumatology pediatric 30% improvement criterion (ACR Pediatric-30). RESULTS: Both celecoxib doses were at least as effective as naproxen at Week 12 [ACR Pediatric-30 treatment differences: celecoxib 3 mg/kg bid-naproxen=1.36% (95% CI -13.08 to 15.80); celecoxib 6 mg/kg bid-naproxen=13.02% (95% CI -0.22 to 26.25)]. Celecoxib 6 mg/kg bid had a numerically higher response rate than celecoxib 3 mg/kg bid at all postrandomization visits and a numerically higher response rate than naproxen 7.5 mg/kg bid at Weeks 4, 8, and 12. Improvement in each ACR Pediatric-30 core set measure was comparable to or numerically higher for celecoxib 6 mg/kg bid than naproxen or celecoxib 3 mg/kg bid. Adverse event rates were similar for all treatment groups, except that gastrointestinal adverse events were more common in the naproxen group, although the difference was not statistically significant. CONCLUSION: Celecoxib 3 mg/kg bid and 6 mg/kg bid were at least as effective as naproxen 7.5 mg/kg bid in treating the signs and symptoms of JRA over 12 weeks. All treatments were generally well tolerated.

Preliminary development of a responder index for chronic low back pain.

OBJECTIVE: One of the greatest obstacles to identifying the most effective therapy for chronic low back pain (CLBP) is the lack of standardized outcome measures for assessing treatment effect in clinical trials. The aim of the OMERACT Special Interest Group was to discuss the development and validation of a preliminary responder index in CLBP. METHODS: Patient data from 5 clinical trials of celecoxib and valdecoxib use in CLBP were used to assess the reliability and validity of multiple items in the outcome domains of pain, functioning, and overall impression of health. Candidate preliminary responder indices were selected on the basis of effect size, high chi-square test values, and a placebo response rate < or = 25%. RESULTS: Candidate indices comprised improvements in single outcome measures and combinations of improvements and/or avoidance of worsening in multiple measures. The preliminary choice for the responder index was at least 30% improvement in pain, with an improvement of at least 30% in patient global assessment and no worsening in function. CONCLUSION: Further studies are needed to refine a responder index for CLBP trials that is clinically relevant, reliable, and easy to administer for standardizing assessments across clinical trials.

Long-term efficacy and safety of celecoxib in Alzheimer's disease.

BACKGROUND/AIMS: Cyclooxygenase-2 (COX-2) may play an important role in the neuropathology of Alzheimer's disease (AD). The efficacy and safety of celecoxib (200 mg bid), a COX-2 selective inhibitor, were assessed in patients > or =50 years with established mild-to-moderate AD to determine whether treatment was effective in retarding deterioration of cognitive function. METHODS: This was a 52-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group study. The primary efficacy end points were the change from baseline to week 52 in the Alzheimer's Disease Assessment Scale-Cognitive Behavior (ADAS-cog) composite score and the week 52 Clinician's Interview-Based Impression of Change Plus (CIBIC+). RESULTS: At 52 weeks, change in ADAS-cog scores from baseline was similar for placebo and celecoxib 200 mg bid groups (5.00 and 4.39, respectively). CIBIC+ scores were also similar (4.83 and 4.92). Two extension studies were conducted but were terminated early based on these efficacy results. Safety data from all 3 studies indicated that celecoxib was generally well-tolerated. CONCLUSION: Celecoxib 200 mg bid did not slow the progression of AD in this study, and the occurrence of adverse events was as expected for an elderly population with a complex chronic medical condition.

Celecoxib is efficacious and well tolerated in treating signs and symptoms of ankylosing spondylitis.

OBJECTIVE: To evaluate the efficacy and safety of celecoxib in patients with ankylosing spondylitis (AS). METHODS: This was a 12-week randomized, double-blind, placebo-controlled study with 4 treatment arms: celecoxib 200 mg qd, celecoxib 400 mg qd, naproxen 500 mg bid, and placebo. Patients (age 18-75 yrs) requiring daily treatment with nonselective nonsteroidal antiinflammatory drugs, and with a pain intensity on visual analog scale (VAS) > or = 50 mm worsening by 30% compared with a preinclusion visit (14 days prior) were studied. Primary endpoints were least-squares mean changes from baseline in pain intensity, disease activity (patient global assessment VAS), and functional impairment [Bath Ankylosing Spondylitis Functional Index (BASFI)]. Adverse events were monitored throughout the study. RESULTS: Of 611 randomized patients, 137 were allocated to celecoxib 200 mg, 161 to celecoxib 400 mg, 157 to naproxen, and 156 to placebo. Improvements in least-squares mean pain intensity, disease activity, and BASFI scores were significantly greater in the celecoxib 200 mg, celecoxib 400 mg, and naproxen groups than in the placebo group (p < or = 0.001) at Week 12 and the interim timepoints, Weeks 1, 3, and 6. Celecoxib 400 mg was as effective as naproxen; however, naproxen was more effective than celecoxib 200 mg. Celecoxib was well tolerated, with an adverse event profile similar to placebo. However, 3 naproxen-treated patients experienced serious treatment-related gastrointestinal (GI) adverse events (one severe gastric ulcer, one moderate GI hemorrhage, one severe GI hemorrhage). CONCLUSION: In this 12-week study, celecoxib 200 mg qd and 400 mg qd were efficacious and well tolerated in treating signs and symptoms of AS.