¿Ensayos clínicos de superioridad, equivalencia o no inferioridad? / ¿Clinical trials of superiority, non-inferiority or equivalence?

La eficacia de una nueva intervención se establece generalmente a través de ensayos clínicos (EC) con asignación aleatoria (AA). Sin embargo, entre otros tantos desafíos metodológicos, el especificar la hipótesis de un EC con AA, sigue siendo un problema complejo de resolver para los investigadores clínicos. En este manuscrito discutimos las características de tres variantes de los EC con AA: EC de superioridad (ECS), EC de no-inferioridad (ECNI), y EC de equivalencia (ECE). Estos tres tipos de EC tienen supuestos diferentes sobre los efectos de una intervención, por lo que plantear hipótesis y definir objetivos requiere conocer algunos supuestos subyacentes a estos EC, incluso hasta elementos relacionados con la estimación del tamaño de muestra para cada cual. El objetivo de este manuscrito fue describir las diferencias metodológicas entre ECS, ECNI y ECE.

Efficacy and effectivity of new interventions are generally established through randomized clinical trials (RCTs). However, among many other methodological challenges, specifying the hypothesis of a RCT remains complex problem for clinical researchers. In this manuscript we discuss the characteristics of three variants of RCTs: superiority RCT (SRCT), non-inferiority RCT (NIRCT), and equivalence RCT (ERCT). These three types of RCT have different assumptions about the effects of an intervention, so setting hypotheses and defining objectives requires knowing some assumptions underlying these RCTs, including elements related to the estimation of the sample size for each one. The aim of this manuscript was to describe methodological differences between SRCT, NIRCT and ERCT.

Skyline view of the patella does not increase fracture detection: A non-inferiority diagnostic study.

PURPOSE: Patella fractures are frequent injuries in the adult population. Initial study is made by plain radiographs and the standard set includes the skyline view of patella. Recommendation for use of this projection is variable among the experts, without data that support its performance in the diagnosis of patella fractures. The main purpose of this study was to determine the sensitivity of the antero-posterior and lateral view of the knee, without skyline view, in the diagnosis of patella fracture. METHODS: A retrospective non-inferiority diagnostic study was designed with all the knee trauma adult patients of an Emergency Department in a single center in five years. A random sample of all the consecutive patella fracture cases were taken to elaborate the case group. The control group was matched by sex and age. Two blinded orthopedic surgeons reviewed the cases and control radiographs and defined the presence of fracture, with or without skyline view, with a wash-out time of three weeks between the two evaluations. Non-inferiority was defined a priori at 90% of minimum sensitivity. RESULTS: 140 patients were evaluated (70 cases and 70 controls). Sensitivity of the set without skyline view was 92.86% (CI 95% 0.90 - 0.96) and the standard set was 97.86% (CI 95% 0.96 - 0.99), without significant differences (p = 0.1) CONCLUSION: Sensitivity of the plain radiograph set without skyline view is non-inferior to the standard set. The routine use of skyline view when suspecting patella fractures is questionable.

Magnetic Waves vs. Electric Shocks: A Non-Inferiority Study of Magnetic Seizure Therapy and Electroconvulsive Therapy in Treatment-Resistant Depression.

Treatment-resistant depression (TRD), characterized by the failure to achieve symptomatic remission despite multiple pharmacotherapeutic treatments, poses a significant challenge for clinicians. Electroconvulsive therapy (ECT) is an effective but limited option due to its cognitive side effects. In this context, magnetic seizure therapy (MST) has emerged as a promising alternative, offering comparable antidepressant efficacy with better cognitive outcomes. However, the clinical outcomes and cognitive effects of MST require further investigation. This double-blinded, randomized, non-inferiority study aims to compare the efficacy, tolerability, cognitive adverse effects, and neurophysiological biomarkers of MST with bilateral ECT (BT ECT) in patients with TRD. This study will employ multimodal nuclear magnetic resonance imaging (MRI) and serum neurotrophic markers to gain insight into the neurobiological basis of seizure therapy. Additionally, neurophysiological biomarkers will be evaluated as secondary outcomes to predict the antidepressant and cognitive effects of both techniques. The study design, recruitment methods, ethical considerations, eligibility criteria, interventions, and blinding procedures are described. The expected outcomes will advance the field by offering a potential alternative to ECT with improved cognitive outcomes and a better understanding of the underlying pathophysiology of depression and antidepressant therapies.

A non-inferiority study evaluating a new extended-release preparation of tilmicosin injected subcutaneously vs. ceftiofur administered intramammary, as dry-cow therapy in Holstein Friesian cows.

BACKGROUND: A new, extended long-acting tilmicosin (TLAe) preparation was tested against intramammary ceftiofur (CEF) using a non-inferiority trial model during dry-cow therapy (DCT) in a farm with high bovine population density and deficient hygiene application. OBJECTIVES: To evaluate the possibility that TLAe administered parenterally can achieve non-inferiority status compared to CEF administered intramammary for DCT. METHODS: Cows were randomly assigned to TLAe (20 mg/kg subcutaneous; n = 53) or CEF (CEF-HCl, 125 mg/quarter; n = 38 cows) treatment groups. California mastitis testing, colony-forming unit assessment (CFU/mL), and number of cases positive for Staphylococcus aureus were quantified before DCT and 7 d after calving. A complete cure was defined as no bacteria isolated; partial cure when CFU/mL ranged from 150 to 700, and cure-failure when CFU/mL was above 700. RESULTS: TLAe and CEF had overall cure rates of 57% and 53% (p > 0.05) and S. aureus cure rates of 77.7% and 25%, respectively (p < 0.05). The pathogens detected at DCT and 7 days after calving were S. aureus (62.71% and 35.55%), Staphylococcus spp. (22.03% and 35.55%), Streptococcus uberis (10.16% and 13.33%), and Escherichia coli (5.08% and 15.55%). Non-inferiority and binary logistic regression analyses revealed a lack of difference in overall efficacies of TLAe and CEF. Apart from S. aureus, S. uberis was the predominant pathogen found in both groups. CONCLUSIONS: This study is the first successful report of parenteral DCT showing comparable efficacy as CEF, the gold-standard. The extended long-term pharmacokinetic activity of TLAe explains these results.

Etifoxine is non-inferior than clonazepam for reduction of anxiety symptoms in the treatment of anxiety disorders: a randomized, double blind, non-inferiority trial.

OBJECTIVE: To determine whether etifoxine, a non-benzodiazepine drug of the benzoxazine family, is non-inferior compared with clonazepam in the treatment of anxiety disorders. METHOD: A randomized controlled double blind trial with parallel groups was conducted. A total of 179 volunteer patients with a diagnosis of anxiety disorder (DSM-IV), between 18 and 64 years of age, participated in this study. The experimental group received 150 mg/day of etifoxine and the control 1 mg/day of clonazepam, both in three daily doses for 12 weeks. This treatment was completed by 87 participants, and 70 were available for follow-up at 24 weeks from start of treatment. The primary objective was a non-inferiority comparison between etifoxine and clonazepam in the decrease of anxiety symptoms (HAM-A) at 12 weeks of treatment. Secondary outcomes included the evaluation of medication side effects (UKU), anxiety symptoms at 24 weeks of treatment, and clinical improvement (CGI). Data analysis included multiple imputation of missing data. The effect of etifoxine on the HAM-A, UKU, and CGI was evaluated with the intention of treatment, and a sensitivity analysis of the results was conducted. Non-inferiority would be declared by a standardized mean difference (SMD) between clonazepam and etifoxine not superior to 0.31 in favour of clonazepam. RESULTS: Using imputed data, etifoxine shows non-inferiority to clonazepam on the reduction of anxiety symptoms at the 12-week (SMD = 0.407; 95% CI, 0.069, 0.746) and 24-week follow-ups (SMD = 0.484; 95% CI, 0.163, 0.806) and presented fewer side effects (SMD = 0.58; 95% CI, 0.287, 0.889). LOCF analysis shows that etifoxine is non-inferior to clonazepam on reduction of anxiety symptoms and adverse symptoms even when no change was assigned as result to participant whom withdrew. Non-inferiority could be declared for clinical improvement (SMD = 0.326; 95% CI, - 0.20, 0.858). CONCLUSION: Etifoxine was non-inferior to clonazepam on reduction of anxiety symptoms, adverse effects, and clinical improvement.

Non-inferiority comparative clinical trial between early oral REFEEDING and usual oral REFEEDING in predicted mild acute biliary pancreatitis.

BACKGROUND: The aim of the study was to compare the onset of oral feeding in the first 24 h after hospital admission with usual oral refeeding and determine whether the timing of the onset of oral feeding influences the recurrence of pain or alters the blood levels of pancreatic enzymes in patients with predicted mild acute biliary pancreatitis. METHODS: This non-inferiority randomized controlled trial was carried out between September 2018 and June 2019 after receiving authorization from the ethics committee for health research. Patients with a diagnosis of predicted mild acute biliary pancreatitis were divided into Group A (early oral refeeding, EOR) and Group B (usual oral refeeding, UOR). Outcome measures included pancreatic lipase levels, the systemic inflammatory response (concentrations of leukocytes), feasibility (evaluated by abdominal pain recurrence), the presence and recurrence of gastrointestinal symptoms and the length of hospital stay. RESULTS: Two patients in the EOR group experienced pain relapse (3.2%), and four patients in the UOR group experienced pain relapse (6.77%) after oral refeeding (p = 0.379). The presence of nausea or vomiting after the onset of oral refeeding was not different between the two groups (p = 0.293). The onset of oral refeeding was approximately 48 h later in the UOR group. The length of hospital stay was 5 days in the EOR group and 8 days in the UOR group (p = 0.042), and this difference was also manifested in higher hospital costs in the UOR group (p = 0.0235). CONCLUSION: Compared with usual oral refeeding, early oral refeeding is safe in predicted mild acute biliary pancreatitis patients, does not cause adverse gastrointestinal events, and reduces the length of hospital stay and costs. TRIAL REGISTRATION: Early oral refeeding in mild acute pancreatitis (EORVsUOR). NCT04168801 , retrospectively registered (November 19, 2019).

Randomized controlled trial comparing mini-sling with transobturator sling for the treatment of stress urinary incontinence.

INTRODUCTION AND HYPOTHESIS: Stress urinary incontinence (SUI) is the involuntary loss of urine on effort and is a condition that negatively interferes with various aspects of a woman's life. This study aimed to demonstrate the non-inferiority of the less invasive single-incision mini-sling (SIMS) method in objective and subjective cures in relation to tension-free transobturator tape (TOT) in two analyses, per protocol and intention to treat, and secondarily to evaluate complications and quality of life. METHODS: This study was a randomized controlled trial (RCT). Participants in this study included 105 women with a clinical diagnosis of stress predominant urinary incontinence and urodynamic results demonstrating SUI and absence of detrusor overactivity. Patients were evaluated pre- and postoperatively through anamnesis, physical examination, urinalysis, urine culture and susceptibility testing, simplified pad test, the Urinary Incontinence-Specific Quality of Life Instrument (I-QOL) and Urogenital Distress Inventory Short Form (UDI-6). RESULTS: Regarding the objective cure, SIMS was non-inferior to TOT (p < 0.05). However, the same was not found for the subjective cure (p > 0.05). There were no differences in the complication rates (p > 0.05). However, in the TOT group, bladder perforation (2.4%), tape exposure (2.4%) and urinary retention occurred, lasting > 7 days (2.4%). In both groups, there was improvement in quality of life after surgery, without significant differences (p > 0.05). CONCLUSIONS: The non-inferiority of SIMS in relation to TOT was only demonstrated in the objective cure. There were no significant differences between groups regarding complications and quality of life.

Tamaño de muestra de protocolos clínicos.

El cálculo del tamaño de muestra en los protocolos clínicos que se revisan en el comité institucional del Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán tiene básicamente tres tipos de problemas: datos insuficientes para recalcular el tamaño de la muestra, uso de ecuaciones obsoletas que no toman en cuenta el error beta y uso de una ecuación que no corresponde al diseño del estudio. En este documento discutimos los cuatro datos que deben ser incluidos en los protocolos de los estudios clínicos aleatorizados que comparan medicamentos versus placebo en los estudios de superioridad y versus control activo en los estudios de no inferioridad.Sample size calculation in clinical protocols submitted to the review board of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán frequently has three types of problems: insufficient data for sample size recalculation, use of obsolete equations that do not take the beta error into account, and use of equations that do not correspond to the study design. In this document, we discuss the four data that should be included in the clinical protocols of randomized controlled trials that compare drugs versus placebo in superiority trials, and versus active controls in non-inferiority studies.

Design and statistical considerations for studies evaluating the efficacy of a single dose of the human papillomavirus (HPV) vaccine.

Cervical cancer is a leading cause of cancer mortality in women worldwide. Human papillomavirus (HPV) types 16 and 18 cause about 70% of all cervical cancers. Clinical trials have demonstrated that three doses of either commercially available HPV vaccine, Cervarix ® or Gardasil ®, prevent most new HPV 16/18 infections and associated precancerous lesions. Based on evidence of immunological non-inferiority, 2-dose regimens have been licensed for adolescents in the United States, European Union, and elsewhere. However, if a single dose were effective, vaccine costs would be reduced substantially and the logistics of vaccination would be greatly simplified, enabling vaccination programs in developing countries. The National Cancer Institute (NCI) and the Agencia Costarricense de Investigaciones Biomédicas (ACIB) are conducting, with support from the Bill & Melinda Gates Foundation and the International Agency for Research on Cancer (IARC), a large 24,000 girl study to evaluate the efficacy of a 1-dose regimen. The first component of the study is a four-year non-inferiority trial comparing 1- to 2-dose regimens of the two licensed vaccines. The second component is an observational study that estimates the vaccine efficacy (VE) of each regimen by comparing the HPV infection rates in the trial arms to those in a contemporaneous survey group of unvaccinated girls. In this paper, we describe the design and statistical analysis for this study. We explain the advantage of defining non-inferiority on the absolute risk scale when the expected event rate is near 0 and, given this definition, suggest an approach to account for missing clinic visits. We then describe the problem of estimating VE in the absence of a randomized placebo arm and offer our solution.

A phase III, randomized, non-inferiority study comparing the efficacy and safety of biosimilar filgrastim versus originator filgrastim for chemotherapy-induced neutropenia in breast cancer patients

OBJECTIVES: To compare the efficacy and safety of two filgrastim formulations for controlling chemotherapy-induced neutropenia and to evaluate the non-inferiority of the test drug relative to the originator. METHODS: This phase III non-inferiority study had a randomized, multicenter, and open-label design. The patients were randomized at a ratio of 1:1 with a follow-up period of 6 weeks for each patient. In both study arms, filgrastim was administered subcutaneously at a daily dose of 5 mg/kg body weight. The primary endpoint was the rate of grade 4 neutropenia in the first treatment cycle. The secondary endpoints were the duration of grade 4 neutropenia, the generation of anti-filgrastim antibodies, and the rates of adverse events, laboratory abnormalities, febrile neutropenia, and neutropenia of any grade. RESULTS: The primary efficacy analysis demonstrated the non-inferiority of the test drug compared with the originator drug; the upper limit of the 90% confidence interval (CI) for the rate of neutropenia between the two groups (12.61%) was lower than the established margin of non-inferiority. The two treatments were similar with respect to the secondary endpoints and safety. CONCLUSION: The efficacy and safety profile of the test drug were similar to those of the originator product based on the rate of grade 4 neutropenia in the first treatment cycle. This study supports Anvisa’s approval of the first biosimilar drug manufactured by the Brazilian industry (Fiprima¯).

Mometasone furoate in the treatment of mild, moderate, or severe persistent allergic rhinitis: a non-inferiority study (PUMA) / Furoato de mometasona no tratamento de rinite alérgica persistente leve, moderada ou grave: estudo de não inferioridade (PUMA)

ABSTRACT INTRODUCTION: Allergic rhinitis is considered the most prevalent respiratory disease in Brazil and worldwide, with great impact on quality of life, affecting social life, sleep, and also performance at school and at work. OBJECTIVE: To compare the efficacy and safety of two formulations containing mometasone furoate in the treatment of mild, moderate, or severe persistent allergic rhinitis after four weeks of treatment. METHODS: Phase III, randomized, non-inferiority, national, open study comparing mometasone furoate in two presentations (control drug and investigational drug). The primary endpoint was the percentage of patients with reduction of at least 0.55 in nasal index score (NIS) after four weeks of treatment. Secondary outcomes included total nasal index score score after four and 12 weeks of treatment; individual scores for symptoms of nasal obstruction, rhinorrhea, sneezing, and nasal pruritus; as well as score for pruritus, lacrimation, and ocular redness after four and 12 weeks of treatment. The study was registered at clinicaltrials.gov with the reference number NCT01372865. RESULTS: The efficacy primary analysis demonstrated non-inferiority of the investigational drug in relation to the control drug, since the upper limit of the confidence interval (CI) of 95% for the difference between the success rates after four weeks of treatment (12.6%) was below the non-inferiority margin provided during the determination of the sample size (13.7%). Adverse events were infrequent and with mild intensity in most cases. CONCLUSION: The efficacy and safety of investigational drug in the treatment of persistent allergic rhinitis were similar to the reference product, demonstrating its non-inferiority.

Resumo Introdução: A rinite alérgica é considerada a doença respiratória mais prevalente no Brasil e em todo o mundo, com grande impacto na qualidade de vida; além de, afetar a vida social, o sono e também o desempenho na escola e no trabalho. Objetivo: Comparar a eficácia e segurança de duas formulações contendo furoato de mometasona no tratamento da rinite alérgica persistente leve, moderada ou grave por um período de quatro semanas. Método: Trata-se de um estudo nacional aberto de fase III, randomizado, de não inferioridade de comparação do furoato de mometasona em duas apresentações (medicação de controle e fármaco sob investigação). O ponto final primário foi o percentual de pacientes com redução mínima de 0,55 no escore de índice nasal (EIN) após quatro semanas de tratamento. Os desfechos secundários foram: escore NIS total após 4 e 12 semanas de tratamento; escores individuais para sintomas de obstrução nasal, rinorréia, espirros e prurido nasal, bem como escores para prurido, lacrimejamento e hiperemia conjuntival após 4 e 12 semanas de tratamento. O estudo foi registrado em clinicaltrials.gov com o número de referência NCT01372865. Resultados: A análise de eficácia primária demonstrou não inferioridade do fármaco sob investigação em relação à medicação de controle, visto que o limite superior do intervalo de confiança (IC) de 95% para a diferença entre os percentuais de sucesso após quatro semanas de tratamento (12,6%) situava-se abaixo da margem de não inferioridade proporcionada durante a determinação do tamanho da amostra (13,7%). Eventos adversos foram pouco frequentes e de leve intensidade na maioria dos casos. Conclusão: A eficácia e a segurança de um fármaco experimental no tratamento da rinite alérgica persistente foram similares às do produto de referência, o que demonstrou sua não inferioridade.

Mometasone furoate in the treatment of mild, moderate, or severe persistent allergic rhinitis: a non-inferiority study (PUMA).

INTRODUCTION: Allergic rhinitis is considered the most prevalent respiratory disease in Brazil and worldwide, with great impact on quality of life, affecting social life, sleep, and also performance at school and at work. OBJECTIVE: To compare the efficacy and safety of two formulations containing mometasone furoate in the treatment of mild, moderate, or severe persistent allergic rhinitis after four weeks of treatment. METHODS: Phase III, randomized, non-inferiority, national, open study comparing mometasone furoate in two presentations (control drug and investigational drug). The primary endpoint was the percentage of patients with reduction of at least 0.55 in nasal index score (NIS) after four weeks of treatment. Secondary outcomes included total nasal index score score after four and 12 weeks of treatment; individual scores for symptoms of nasal obstruction, rhinorrhea, sneezing, and nasal pruritus; as well as score for pruritus, lacrimation, and ocular redness after four and 12 weeks of treatment. The study was registered at clinicaltrials.gov with the reference number NCT01372865. RESULTS: The efficacy primary analysis demonstrated non-inferiority of the investigational drug in relation to the control drug, since the upper limit of the confidence interval (CI) of 95% for the difference between the success rates after four weeks of treatment (12.6%) was below the non-inferiority margin provided during the determination of the sample size (13.7%). Adverse events were infrequent and with mild intensity in most cases. CONCLUSION: The efficacy and safety of investigational drug in the treatment of persistent allergic rhinitis were similar to the reference product, demonstrating its non-inferiority.

Trastuzumab subcutaneo en el tratamiento del cancer de mama HER2 positivo / Subcutaneous trastuzumab in breastcancer treatment of her2 positive

La sobreexpresión o amplificación del receptor HER2 seobserva en el 20% de pacientes con cáncer de mama y seasocia con un pronóstico adverso. El agente anti HER2más ampliamente utilizado en la clínica es el trastuzumab,anticuerpo monoclonal. El tratamiento adyuvante tieneuna duración de 12 meses y en cáncer de mama metastásicose continúa más allá de la progresión. La mayoría delos pacientes recibirá trastuzumab durante 1 año, muchosrecibirán 2 a 3 años, y algunos han recibido/recibirán más de8 años. Surge así un interés creciente por la vía subcutánea(SC) de administración: menos invasiva, menos costosay más cómoda. El estudio HannaH, ensayo de fase III,abierto y aleatorizado, utilizó una dosis fija subcutánea de600 mg de trastuzumab en combinación con quimioterapianeoadyuvante y la comparó con la vía de administraciónendovenosa (EV) aprobada. Se incluyeron pacientes concáncer de mama HER2 (+) operable, localmente avanzado einflamatorio. Los objetivos primarios fueron: concentraciónsérica mínima predosis del ciclo 8 y respuesta patológicacompleta. Se aleatorizaron 299 pacientes a trastuzumab EVy 297 a trastuzumab SC. La concentración sérica mínimamedia fue 57.8 μ/ml en el grupo EV y 78.7 en el grupo SC.El 40.7% de los pacientes en el grupo EV y el 45.4% en elgrupo SC logró respuesta patológica completa. TrastuzumabSC resultó no inferior para ambos objetivos primarios.La incidencia de eventos adversos grados 3 a 5 fue similar enambos grupos. La demostración de no-inferioridad sugiereque el trastuzumab SC ofrece una válida y más convenientealternativa al trastuzumab EV.

Overexpression or amplification of HER2 is found in 20%of patients with breast cancer and is associated with anunfavourable prognosis. Trastuzumab is the anti HER2agent most widely used in clinical practice. Adjuvanttreatment should be given during 12 months, and in themetastatic setting treatment should continue beyond progression.Most patients will receive treatment during oneyear, many will be treated during 2 to 3 years, and somepatients will remain in treatment for more than 8 years.In this context, a subcutaneous route of administrationbecomes an attractive option: less invasive, less costly,and more comfortable for patients. The HannaH study is a phase III, open, randomized clinical trial that used a fixedsubcutaneous dose of 600 mg of trastuzumab in combinationwith neoadjuvant chemotherapy and compared it tothe approved intravenous (IV) route of administration.Patients with HER2 (+) operable, locally advanced andinflammatory breast cancer were included in the study.Primary endpoints included: serum trough concentrationpre-dose cycle 8 and pathologic complete response. Twohundred and ninety-nine patients were randomized to IVtrastuzumab and 297 to SC trastuzumab. Mean serumtrough concentration was 57.8 μ/ml in the IV group and78.7 in the SC group. In the IV group 40.7% of patientsachieved pathologic complete response, and 45.4% in the SCgroup. The SC formulation resulted non-inferior for bothprimary objectives. Incidence of grade 3-5 adverse eventswas similar in both groups. The non-inferior results suggestthat SC trastuzumab is a valid and more convenientalternative to IV trastuzumab.

Evaluation of the immunogenicity of the quadrivalent HPV vaccine using 2 versus 3 doses at month 21: An epidemiological surveillance mechanism for alternate vaccination schemes.

The cost of HPV vaccines and the need for 3 doses remains a barrier for their inclusion in routine vaccination schedules for girls in low and middle income countries. In a non-inferiority study, we aimed to compare the immunogenicity of a standard 3 doses and a 2 doses schedule. We enrolled 450 participants in an open-label non-randomized clinical trial to evaluate the immunogenicity induced at different ages by the licensed HPV6/11/16/18 quadrivalent vaccine in a 2 doses schedule (0-6 months, n = 150 girls aged 9-10 y) and 3 doses schedule (0, 2, and 6 months; n = 150 girls aged 9-10 y and n=150 women aged 18 to 24 years). To assess the antibody response, blood samples were obtained at Month 7 and 21 after the first vaccination from participants in all study groups. cLIA testing was performed at Merck Research Laboratories. Antibody levels were expressed as milli-Merck units (mMU) per ml. Primary outcome was non-inferiority (95% CI, lower bound >0.5) of the geometric mean titers (GMT) ratios for HPV6, HPV11, HPV16 and HPV18 antibodies 7 and 21 months after the first dose among girls receiving 2 doses compared with young women and girls receiving 3 doses. All vaccinees were seropositive for both HPV16 and HPV18 antibodies at month 7. At month 21, 98.5 and 56.6% of women 18-24 y old were seropositive for HPV16 and 18, respectively. For girls in the three doses group, seropositivity rates were 99.3 and 86.3% for HPV16 and 18, respectively. For girls in the two doses group rates were 99.3 and 70.2% for HPV16 and 18, respectively. The two doses schedule was non-inferior compared to the 3 doses schedule in same-age girls and to the group of adult women after 21 months of the first vaccine dose. Our results are in agreement with similar trials evaluating the immune response of a 2 doses schedule of both HPV vaccines, supporting the recent WHO recommendation as well as the Mexican policy to incorporate the 2 doses schedule for girls aged 9-11 y.

Sample size considerations in active-control non-inferiority trials with binary data based on the odds ratio.

This paper presents an approximate closed form sample size formula for determining non-inferiority in active-control trials with binary data. We use the odds-ratio as the measure of the relative treatment effect, derive the sample size formula based on the score test and compare it with a second, well-known formula based on the Wald test. Both closed form formulae are compared with simulations based on the likelihood ratio test. Within the range of parameter values investigated, the score test closed form formula is reasonably accurate when non-inferiority margins are based on odds-ratios of about 0.5 or above and when the magnitude of the odds ratio under the alternative hypothesis lies between about 1 and 2.5. The accuracy generally decreases as the odds ratio under the alternative hypothesis moves upwards from 1. As the non-inferiority margin odds ratio decreases from 0.5, the score test closed form formula increasingly overestimates the sample size irrespective of the magnitude of the odds ratio under the alternative hypothesis. The Wald test closed form formula is also reasonably accurate in the cases where the score test closed form formula works well. Outside these scenarios, the Wald test closed form formula can either underestimate or overestimate the sample size, depending on the magnitude of the non-inferiority margin odds ratio and the odds ratio under the alternative hypothesis. Although neither approximation is accurate for all cases, both approaches lead to satisfactory sample size calculation for non-inferiority trials with binary data where the odds ratio is the parameter of interest.

Overcoming barriers to HPV vaccination: non-inferiority of antibody response to human papillomavirus 16/18 vaccine in adolescents vaccinated with a two-dose vs. a three-dose schedule at 21 months.

For middle and low-income countries, the cost of HPV vaccines remains challenging. We conducted an open-label nonrandomized clinical trial evaluating immune response to the HPV-16/18 AS04-adjuvanted vaccine administered on a standard (months (M) 0-1-6) versus extended schedule (M 0-6-60) at 7, 21, 60, 72 and 120 months post-vaccination. Participants were females recruited in Morelos, Mexico: 474 girls aged 9-10 years and 500 women aged 18-24 years receiving a standard schedule, and 1026 girls aged 9-10 years receiving an extended schedule (currently the girls in the extended schedule had received only the first 2 doses). This report presents the interim analysis results for non-inferiority between the regimes conducted with the current available data at 21 months after the first dose, with serum antibodies assessed by ELISA. A pre-stated margin of non-inferiority was defined by post-vaccination geometric mean titer (GMT) ratio (upper 95% confidence interval [CI]≤2.0) between the standard and the two-dose schedule in girls at month 21. Immune response to the vaccine was strongest in adolescent girls and in the 3-dose group. Statistical non-inferiority of the two-dose versus three-dose groups was demonstrated. At 21 months, comparing the adolescent 2-dose versus 3-dose groups, the GMT ratio and 95% CI were 1.66 (1.55-1.81) and 1.67 (1.51-1.86) for HPV16 and 18, respectively. The two-dose regimen was non-inferior when compared to the three-dose response in same-age girls and with women aged 18-24 years after 21 months of follow-up. The reduction in the number of doses from the current three-dose schedule may lower overall costs associated with the vaccination and increase accessibility and compliance with the recommended dosing of the HPV vaccine.

Fluticasone/formoterol dry powder versus budesonide/formoterol in adults and adolescents with uncontrolled or partly controlled asthma.

UNLABELLED: This 12-week study compared the efficacy and safety of a fixed combination of fluticasone propionate plus formoterol (FL/F) 250/12 µg b.i.d. administered via a dry powder inhaler (DPI) (Libbs Farmacêutica, Brazil) to a combination of budesonide plus formoterol (BD/F) 400/12 µg b.i.d. After a 2-week run-in period (in which all patients were treated exclusively with budesonide plus formoterol), patients aged 12-65 years of age (N = 196) with uncontrolled asthma were randomized into an actively-controlled, open-labeled, parallel-group, multicentre, phase III study. The primary objective was to demonstrate non-inferiority, measured by morning peak expiratory flow (mPEF). The non-inferiority was demonstrated. A statistically significant improvement from baseline was observed in both groups in terms of lung function, asthma control, and the use of rescue medication. FL/F demonstrated a statistical superiority to BD/F in terms of lung function (FEV(1)) (p = 0.01) and for asthma control (p = 0.02). Non-significant between-group differences were observed with regards to exacerbation rates and adverse events. In uncontrolled or partly controlled asthma patients, the use of a combination of fluticasone propionate plus formoterol via DPI for 12-weeks was non-inferior and showed improvements in FEV(1) and asthma control when compared to a combination of budesonide plus formoterol. ( CLINICAL TRIAL NUMBER: ISRCTN60408425).

Vacunas anti neumocócicas / Pneumococcal vaccines

Existen vacunas contra el Streptococcus pneumoniae. Una de polisacáridos capsulares con 23 antígenos y las vacunas conjugadas, denominadas así, porque los polisacáridos están conjugados a una mutante no tóxica de la toxina diftérica o a la proteína D delHaemophilus influenzae no tipificable, a una proteína transportadora del toxoide tetánico y otra de toxoide diftérico. La vacuna de 23 antígenos se recomienda en niños con edad igual y mayor de 24 meses, con alto riesgo para enfermedad neumocócica invasiva y complicaciones, debidas a enfermedades subyacentes y se administra en esquema mixto con vacunas anti neumocócica conjugadas. En 2002, la Organización Mundial de la Salud determinó que la vacuna anti neumocócica heptavalente (Prevenar® 7) es el estándar de oro, con la cual debían ser comparada toda nueva vacuna conjugada, por lo que definieron, necesarios para su aprobación, dos criterios de no inferioridad. Primer criterio: Una vez administrada la vacuna se registren títulos de anticuerpos medidos por ELISA iguales o mayoresde 0,35 μg/mL para los serotipos comunes a ambas vacunas y los adicionales. Segundo criterio: Los anticuerpos deben tener capacidadfuncional, lo cual se establece mediante la cuantificación de la actividad opsonofagocítica que debe ser igual o mayor de 1:8. Las vacunas conjugadas 10valente (Synflorix®) y 13 valente (Prevenar® 13) cumplen ambos criterios. De no ser posible completar el esquema o administrar refuerzo, con el mismo tipo de vacuna conjugada inicial, puede hacerse con cualquier otra vacuna

Several vaccines against Streptococcus pneumoniae are available. One made of capsular polysaccharides with 23 antigens and the conjugated vaccines, thus denominated, because the polysaccharides are conjugated to a nontoxic mutant of the diphteric toxin or to the D protein of the nontipificable Haemophilus influenzae, to a transporting protein of tetanic and diphteric toxoids. The 23 antigens vaccine is recommended for children 24 months of age and older, with high risk for invasive pneumococcal disease and complications due to underlying diseases. It is administered in a mixed scheme with anti pneumococcal conjugated vaccines. In 2002, the World Health Organization (WHO) determined that the heptavalent vaccine (Prevenar® 7) is the gold standard, with which all new conjugated vaccineshould be compared. For this reason, they defined two non inferiority criteria as necessary for the approval. First criterion: Once administered the vaccine and measured the amount of antibodies by ELISA, these must be equal or above 0.35 μg/mL for the common serotypes to both vaccines and to the additional serotypes. Second criterion: The antibodies must have functional capacity, which is determined by the opsonophagocitic activity that must be equal or greater than 1:8. The 10 valent (Synflorix®) and the 13 valent(Prevenar® 13) conjugated vaccines fulfill both criteria. If it is not possible to complete the vaccine scheme or to administer a booster dose, with the same type of conjugated vaccine, this may be done with any other vaccine

Requerimentos mínimos para o planejamento e análise de estudos clínicos de não inferioridade: [revisão] / Minimum requirements for planning and analyzing non-inferiority clinical trials: [review]

JUSTIFICATIVA E OBJETIVOS: Estudos de não inferioridade, de uso crescente em pesquisa clínica, são metodologicamente distintos dos estudos tradicionais de superioridade e são particularmente úteis quando existem impedimentos éticos para estudos placebo controlados. O objetivo deste estudo foi rever os critérios mínimos a serem observados no planejamento, condução e análise dos estudos de não inferioridade. CONTEÚDO: Os seguintes determinantes críticos dos estudos de não inferioridade são apresentados e discutidos: margem de não inferioridade, sensibilidade de ensaio, tamanho da amostra, estratégias de análise, algoritmo de inferência e condições que suportam conclusão de superioridade. CONCLUSÃO: Os estudos de não inferioridade possuem um conjunto particular de vieses a serem controlados e o uso correto desta metodologia é orientado por algumas diretrizes regulatórias internacionais. A observância de certo número de requerimentos mínimos é condição necessária para assegurar a validade das conclusões dos estudos de não inferioridade.

BACKGROUND AND OBJECTIVES: Non-inferiority trials with increasing utilization in clinical research have different properties in relation to traditional superiority trials. They are particular useful in situations where placebo controlled studies are considered unethical. This study is a brief review of basic criteria to be observed for planning, executing and analyzing non-inferiority studies. CONTENTS: The following critical issues of non-inferiority studies are discussed: non-inferiority margin, essay sensitivity, sample size determination, strategies for analysis, rules of inference and conditions for switching to claim of superiority. CONCLUSION: Non-inferiority designs are subject to a particular set of bias and some international guidelines are available. Clinical investigators should be aware of basic requirements to ensure validity of conclusions from non-inferiority studies.