Real time monitoring and prediction of time to endpoint maturation in clinical trials.

In clinical trials, almost all key milestone dates can be defined in terms of time to endpoint maturation (TTEM). The real time monitoring and accurate prediction of TTEM have a significant impact on clinical trial planning and execution and can bring significant value to clinical trial practitioners. TTEM is defined as the time to achieve or observe a certain number or percentage of some endpoint of interest. It is a combination of time to site initiation, time to subject enrollment after site initiation and time to event of interest after subject enrollment. To better predict TTEM during the trial, the future site initiation and subject enrollment have to be taken into account while predicting the number of events. In this article, we propose a novel simulation-based framework combining time to site initiation, time to subject enrollment and time to event in order to predict TTEM. A nonhomogeneous Poisson process with a quadratic time-varying rate function is used to model site initiation and subject enrollment and more advanced time to event models had been explored and integrated on top of them, such as Weibull, piecewise exponential, and model averaging which is equivalent to a Bayesian model selection strategy. To evaluate the predictive performance of the proposed methodology, we conducted extensive simulations and applied the methodology to 14 randomly selected real oncology phase 2 and phase 3 studies in both solid tumor and hematology with a total 31 study-endpoint combinations. The predictive performance of the proposed methodology was then compared with popular and commonly available commercial software, for example, East (Cytel, Cambridge, MA, USA). From both simulation and real data, the proposed methodology can significantly improve the prediction accuracy by up to 54% compared to the commonly available method.

Efficacy and Safety of MEDI2070, an Antibody Against Interleukin 23, in Patients With Moderate to Severe Crohn's Disease: A Phase 2a Study.

BACKGROUND & AIMS: MEDI2070 is a human monoclonal antibody that selectively inhibits interleukin 23 (IL23), a cytokine implicated in the pathogenesis of Crohn's disease (CD). We analyzed its safety and efficacy in treatment of CD in a phase 2a study. METHODS: We conducted a double-blind, placebo-controlled study of 119 adults with moderate to severe CD failed by treatment with tumor necrosis factor antagonists. Patients were randomly assigned (1:1) to groups given MEDI2070 (700 mg) or placebo intravenously at weeks 0 and 4. Patients received open-label MEDI2070 (210 mg) subcutaneously every 4 weeks from weeks 12 to 112. The CD Activity Index was used to measure disease activity. RESULTS: The primary outcome, clinical response (either a 100-point decrease in CD Activity Index score from baseline or clinical remission, defined as CD Activity Index score <150) at week 8 occurred in 49.2% of patients receiving MEDI2070 (n = 59) compared with 26.7% receiving placebo (n = 60; absolute difference, 22.5%; 95% confidence interval, 5.6%-39.5%; P = .010). Clinical response at week 24 occurred in 53.8% of patients who continued to receive open-label MEDI2070 and in 57.7% of patients who had received placebo during the double-blind period and open-label MEDI2070 thereafter. The most common adverse events were headache and nasopharyngitis. Higher baseline serum concentrations of IL22, a cytokine whose expression is induced by IL23, were associated with greater likelihood of response to MEDI2070 compared with placebo. CONCLUSIONS: In a phase 2a trial of patients with moderate to severe Crohn's disease who had failed treatment with tumor necrosis factor antagonists, 8 and 24 weeks of treatment with MEDI2070 were associated with clinical improvement. ClinicalTrials.gov ID: NCT01714726.

A Bayesian paradigm for decision-making in proof-of-concept trials.

Decision-making is central to every phase of drug development, and especially at the proof of concept stage where risk and evidence must be weighed carefully, often in the presence of significant uncertainty. The decision to proceed or not to large expensive Phase 3 trials has significant implications to both patients and sponsors alike. Recent experience has shown that Phase 3 failure rates remain high. We present a flexible Bayesian quantitative decision-making paradigm that evaluates evidence relative to achieving a multilevel target product profile. A framework for operating characteristics is provided that allows the drug developer to design a proof-of-concept trial in light of its ability to support decision-making rather than merely achieve statistical significance. Operating characteristics are shown to be superior to traditional p-value-based methods. In addition, discussion related to sample size considerations, application to interim futility analysis and incorporation of prior historical information is evaluated.

Tradeoff-based optimization criteria in clinical trials with multiple objectives and adaptive designs.

The article discusses clinical trial optimization problems in the context of mid- to late-stage drug development. Using the Clinical Scenario Evaluation approach, main objectives of clinical trial optimization are formulated, including selection of clinically relevant optimization criteria, identification of sets of optimal and nearly optimal values of the parameters of interest, and sensitivity assessments. The paper focuses on a class of optimization criteria arising in clinical trials with several competing goals, termed tradeoff-based optimization criteria, and discusses key considerations in constructing and applying tradeoff-based criteria. The clinical trial optimization framework considered in the paper is illustrated using two case studies based on a clinical trial with multiple objectives and a two-stage clinical trial which utilizes adaptive decision rules.

Viral clearance is associated with improved insulin resistance in genotype 1 chronic hepatitis C but not genotype 2/3.

OBJECTIVES: Genotype-specific associations between hepatitis C virus (HCV) and insulin resistance (IR) have been described, but a causal relationship remains unclear. This study investigated the association between a sustained virological response (SVR) and IR after chronic HCV therapy. METHODS: 2255 treatment-naive patients with chronic HCV genotype 1 or 2/3 were enrolled in two phase 3 trials of albinterferon alpha-2b versus pegylated interferon alpha-2a for 48 or 24 weeks, respectively. IR was measured before treatment and 12 weeks after treatment using homeostasis model assessment (HOMA)-IR. RESULTS: Paired HOMA-IR measurements were available in 1038 non-diabetic patients (497 with genotype 1; 541 with genotype 2/3). At baseline the prevalence of HOMA-IR >3 was greater in patients with genotype 1 than 2/3 (33% vs 27%; p=0.048). There was a significant reduction in the prevalence of IR in patients with genotype 1 achieving SVR (δ 10%; p<0.001), but not in genotype 1 non-responders or those with genotype 2/3. Multivariate analysis indicated that SVR was associated with a significant reduction in mean HOMA-IR in patients with genotype 1 (p=0.004), but not in those with genotype 2/3, which was independent of body mass index, alanine transaminase, γ-glutamyl transpeptidase and lipid level changes. CONCLUSIONS: SVR is associated with a reduction in HOMA-IR in patients with HCV genotype 1 but not in those with genotype 2/3. Genotype 1 may have a direct effect on the development of IR, independent of host metabolic factors, and may be partially reversed by viral eradication.

Steatosis is an independent predictor of relapse following rapid virologic response in patients with HCV genotype 3.

BACKGROUND & AIMS: It is recommended that patients with chronic hepatitis C virus (HCV) genotype 3 infections receive 24 weeks of treatment. A rapid virologic response (RVR; at week 4) predicts a sustained virologic response (SVR), although not all patients with an RVR achieve an SVR. We explored the relationships among hepatic steatosis, level of HCV RNA, relapse, and RVR in a phase 3 randomized controlled trial of 932 patients infected with HCV genotype 2 (n = 427) or 3 (n = 505) who received 24 weeks of therapy with interferon-α. METHODS: In patients with an RVR (HCV RNA <43 IU/mL), the presence of an SVR was modeled using multivariate logistic regression as a function of age, sex, weight, body mass index, insulin resistance, steatosis, and levels of γ-glutamyl transpeptidase, alanine aminotransferase, liver fibrosis, and baseline HCV RNA. RESULTS: RVR, SVR, and relapse rates among patients with HCV genotype 3 were 79.6%, 79.2%, and 15.6%, respectively; corresponding rates among patients with HCV genotype 2 were 86.7%, 84.3%, and 10.1%. An RVR had high predictive value for an SVR in patients with HCV genotypes 2 (88.9%) and 3 (88.1%). The strongest independent predictors of relapse in patients with genotype 3 and an RVR were steatosis (odds ratio 3.0; P = .003) and HCV RNA ≥400,000 IU/mL (odds ratio 2.5; P = .04). Relapse rates in patients with steatosis were 17.4% and 20.9% for low and high baseline levels of HCV RNA, respectively; corresponding rates in those without steatosis were 2.5% and 8.8%. CONCLUSIONS: Steatosis was associated with significantly higher rates of relapse, irrespective of viral load, in patients infected with HCV genotype 3 who had an RVR. Further studies are needed to determine if longer treatment durations are effective in patients with an RVR and these risk factors.

Albinterferon Alfa-2b was not inferior to pegylated interferon-α in a randomized trial of patients with chronic hepatitis C virus genotype 1.

BACKGROUND & AIMS: The current standard of care for patients with chronic hepatitis C virus (HCV) genotype 1 is once-weekly pegylated interferon-α (Peg-IFNα) plus daily ribavirin for 48 weeks. We evaluated the efficacy/safety of albinterferon alfa-2b (albIFN), a novel, long-acting, genetic fusion polypeptide of albumin and IFNα-2b. METHODS: In the phase 3 ACHIEVE-1 trial, 1331 patients were assigned equally to 3 open-label, 48-week treatment groups: Peg-IFNα-2a 180 µg every week, or albIFN 900 or 1200 µg every 2 weeks administered subcutaneously, with weight-based oral ribavirin 1000-1200 mg/day. During the study, the data monitoring committee recommended dose modification for all patients receiving albIFN 1200 µg to 900 µg because of increased pulmonary adverse events (AEs) in the 1200-µg arms of both ACHIEVE studies. Main outcome measure was sustained virologic response (SVR; undetectable serum HCV RNA at week 72). RESULTS: Intention-to-treat SVR rates were 51.0% (225/441), 48.2% (213/442), and 47.3% (208/440) with Peg-IFNα-2a, and albIFN 900 and 1200 µg, respectively. The primary objective of showing noninferiority of albIFN 900 µg (P < .001) and 1200 µg (P = .003) vs Peg-IFNα-2a for SVR was achieved. Multivariate modeling indicated consistency of treatment effect across subgroups. Serious/severe AE rates were 23.1%, 24.0%, 28.2%; treatment discontinuation rates because of AEs were 4.1%, 10.4%, 10.0%; discontinuation rates because of respiratory AEs were 0%, 0.9%, 1.6%; with Peg-IFNα-2a, and albIFN 900 and 1200 µg, respectively. Hematologic abnormality rates were comparable across the Peg-IFNα-2a and albIFN 900-µg groups. CONCLUSIONS: albIFN 900 µg every 2 weeks showed comparable efficacy, with similar serious/severe AE rates, although with a higher discontinuation rate, vs Peg-IFNα-2a in patients with chronic HCV genotype 1.

Albinterferon Alfa-2b was not inferior to pegylated interferon-α in a randomized trial of patients with chronic hepatitis C virus genotype 2 or 3.

BACKGROUND & AIMS: A phase 3 active-controlled study was conducted to assess the efficacy/safety of albinterferon alfa-2b (albIFN), a novel, long-acting, genetic fusion polypeptide of recombinant human albumin and interferon alfa-2b, in patients with chronic hepatitis C virus (HCV) genotype 2/3. METHODS: In all, 933 patients were randomized to open-label subcutaneous treatment with pegylated interferon-alfa-2a (Peg-IFNalfa-2a) 180 µg/wk, or albIFN 900 or 1200 µg every 2 weeks for 24 weeks, each administered with oral ribavirin 800 mg/day. The primary end point of the study was sustained virologic response (SVR) (HCV-RNA level, <15 IU/mL at week 48). During the study, the data monitoring committee recommended dose modification for all patients receiving albIFN 1200 µg to 900 µg, impacting 38% of this treatment arm. RESULTS: By intention-to-treat analysis, SVR rates were 84.8% (95% confidence interval, 80.4%-88.6%), 79.8% (95% confidence interval, 74.9%-84.1%), and 80.0% (95% confidence interval, 75.1%-84.3%) with Peg-IFNalfa-2a, and albIFN 900 and 1200 µg, respectively. The primary hypothesis of noninferiority of SVR was established for albIFN 900 µg (P = .009) and 1200 µg (P = .006). Independent positive predictors of SVR by multivariate regression analysis were pretreatment HCV-RNA level less than 400,000 IU/mL, age younger than 45 years, body mass index less than 30 kg/m(2), genotype 2, normal γ-glutamyl transpeptidase and increased alanine aminotransferase levels at baseline, fibrosis stage F0-F2, no steatosis, and Asian geographic region (Peg-IFNalfa-2a only). The 3 treatment groups showed similar rates of serious (7%-8%) and severe (13%-16%) adverse events, and discontinuations owing to adverse events (3.6%-5.5%). CONCLUSION: Albinterferon alfa-2b 900 µg every 2 weeks provides an alternative efficacious treatment option in patients with chronic HCV genotype 2 or 3.

Insulin resistance is independently associated with significant hepatic fibrosis in Asian chronic hepatitis C genotype 2 or 3 patients.

BACKGROUND AND AIM: The role of insulin resistance (IR) and hepatic steatosis in fibrogenesis in chronic hepatitis C infection (CHC) has yielded conflicting data and few studies have been performed in Asian-region populations. We retrospectively investigated the relationship between host metabolic variables, including IR and hepatic steatosis, to hepatic fibrosis in Asian-region CHC genotype 2/3 patients. METHODS: A total of 303 treatment-naïve Asian-region patients with CHC genotype 2/3 were enrolled in a multicenter phase 3 study of albinterferon alfa-2b plus ribavirin for 24 weeks. IR was defined as Homeostasis Model for Assessment of IR (HOMA-IR) > 2. Baseline liver biopsy was evaluated by a single expert histopathologist. Post hoc subgroup logistic regression modeling selected for independent variables associated with significant fibrosis (METAVIR stage F2-F4). RESULTS: Insulin resistance was available in 263 non-diabetic Asian-region patients (hepatitis C virus-2 [HCV-2] = 171, HCV-3 = 92), and 433 non-Asian region patients (407 "Caucasian"); METAVIR fibrosis prevalence F0-F1 (minimal fibrosis)= 201 (77%) and F2-F4 (significant fibrosis) = 59 (23%), and steatosis prevalence of grade 0 = 169 (65%), grade 1 = 64 (25%), grade 2/3 = 27 (10%). Median HOMA-IR was 1.8 (interquartile range: 1.2-2.7); 100 (38%) patients had HOMA-IR > 2. Factors independently associated with significant fibrosis included HOMA-IR (odds ratio [OR]= 8.42), necro-inflammatory grade (OR = 3.17), age (OR = 1.07) and serum total cholesterol levels (OR = 0.008). This was similar to non-Asian region patients, but steatosis was not associated with significant fibrosis in either cohort. CONCLUSIONS: In this subgroup study of Asian-region HCV genotype 2 or 3 patients, insulin resistance, along with age, cholesterol levels and necro-inflammation, but not steatosis may be associated with significant hepatic fibrosis.

Positive and negative prediction of sustained virologic response at weeks 2 and 4 of treatment with albinterferon alfa-2b or peginterferon alfa-2a in treatment-naïve patients with genotype 1, chronic hepatitis C.

BACKGROUND/AIMS: Albinterferon alfa-2b is a novel, long-acting, fusion polypeptide that is dosed q2wk or q4wk. The predictive value of early virologic response during albinterferon alfa-2b or peginterferon alfa-2a treatment was investigated in interferon-naïve patients with genotype 1, chronic hepatitis C. METHODS: Four hundred and fifty-eight patients were randomized to: albinterferon 900 or 1200 microg q2wk, or 1200 microg q4wk, or peginterferon 180 microg qwk. HCV RNA was measured by real-time PCR. A linear exhaustive search algorithm was used to determine the best SVR prediction algorithm in the per-protocol population (n=368), with inclusion of key ITT analyses to assess impact. RESULTS: SVR rate: 54-67% (P=NS between arms). Rapid initial virologic response rate at week 2 (RIVR; viral decline >2 log(10)IU/mL) was 32-50% and gave rise to positive predictive value of 88-97% for SVR. No initial virologic response at week 4 (NIVR; viral decline <2 log(10)IU/mL; viral load >5.5 log(10)IU/mL) demonstrated a 100% negative predictive value for SVR. A sequential prediction algorithm based on viral kinetics at weeks 2 and 4 identified four prediction groups that reliably predicted SVR, positively or negatively, in 65-72% of patients. CONCLUSIONS: Improved SVR prediction was obtained by integrating absolute levels and reduction of HCV RNA at treatment week 2 and 4. Patients with RIVR had a high likelihood of achieving SVR.

Safety and antiviral activity of albinterferon alfa-2b in prior interferon nonresponders with chronic hepatitis C.

BACKGROUND & AIMS: Pegylated interferon alfa-2a/2b is used in combination with ribavirin to treat patients with chronic hepatitis C (CHC), although many do not achieve a sustained virologic response (SVR). Albinterferon alfa-2b, a recombinant protein consisting of interferon alfa-2b fused to human albumin, may increase drug exposure. This phase 2 study evaluated the safety/efficacy of albinterferon in CHC patients who had not responded to interferon-based regimens. METHODS: A total of 115 patients were assigned to 5 groups given 1200 microg albinterferon every 4 weeks or 900, 1200, 1500, or 1800 microg every 2 weeks, plus oral ribavirin, for 48 weeks. The primary efficacy end point was achievement of an SVR after 24 weeks. Treatment was extended to 72 weeks for 6 slow responders who were negative for hepatitis C virus RNA after 24 weeks. RESULTS: The types of adverse events were similar across groups; the overall discontinuation rate as a result of adverse events was 10.4%. Reductions in absolute neutrophil counts were less frequent in the every 4 weeks group and comparable among the every 2 weeks groups. The overall SVR rate was 17% (11% for previous nonresponders to pegylated interferon-alfa/ribavirin with genotype 1 infection). An SVR occurred in 3 of 6 slow responders by 72 weeks. The greatest reductions in hepatitis C virus RNA in nonresponders to pegylated interferon-alfa/ribavirin with genotype 1 infection were observed in the 1800-microg group. CONCLUSIONS: In patients with CHC who did not respond to interferon-based regimens, higher doses of albinterferon had significant early antiviral activity and a low incidence of adverse events, with the types of adverse events similar to those observed with interferon.

Albinterferon alfa-2b dosed every two or four weeks in interferon-naïve patients with genotype 1 chronic hepatitis C.

UNLABELLED: The efficacy and safety of albinterferon alfa-2b (alb-IFN), a novel recombinant protein consisting of interferon alfa-2b genetically fused to human albumin, was evaluated in a phase 2b, open-label study of patients with genotype 1, chronic hepatitis C. In all, 458 IFN-alfa treatment-naïve patients were randomized to 48-week treatment with peginterferon alfa (PEG-IFNalpha)-2a 180 microg one time per week (qwk), or alb-IFN 900 or 1,200 microg once every two weeks (q2wk), or 1,200 microg once every four weeks (q4wk), administered subcutaneously, plus weight-based oral ribavirin 1,000 or 1,200 mg/day. Hepatitis C virus RNA was measured by real-time polymerase chain reaction (limit of detection: 10 IU/mL). The primary efficacy endpoint was sustained virologic response (hepatitis C virus RNA <10 IU/mL 24 weeks after the end of treatment). By intention-to-treat analysis, sustained virologic response rates were 58.5% (69/118) with alb-IFN 900 microg q2wk, 55.5% (61/110) with 1,200 microg q2wk, and 50.9% (59/116) with 1,200 microg q4wk, and 57.9% (66/114) with PEG-IFNalpha-2a (P = 0.64 for overall test). Discontinuation rates due to adverse events were 9.3% with alb-IFN 900 microg q2wk, 18.2% with 1,200 microg q2wk and 12.1% with 1,200 microg q4wk, and 6.1% with PEG-IFNalpha-2a (P = 0.04). Hematologic reductions were lowest in the q4wk group and comparable across other groups. At week 12, mean treatment-associated missed workdays were significantly lower with alb-IFN 900 mug q2wk versus PEG-IFNalpha-2a (1.1 versus 4.3 days; P = 0.006). CONCLUSION: Alb-IFN administered q2wk or q4wk may offer comparable efficacy, with an improved dosing schedule, compared with PEG-IFNalpha-2a.

Early prediction of sustained virological response at day 3 of treatment with albinterferon-alpha-2b in patients with genotype 2/3 chronic hepatitis C.

BACKGROUND: Albinterferon-alpha-2b (albIFN) is a long-acting fusion polypeptide composed of albumin and IFN-alpha-2b. In a phase 2 study of albIFN 1500 mug q2wk or q4wk in patients with genotype 2/3 chronic hepatitis C, albIFN demonstrated sustained virological response (SVR) rates of 62-77% (intent-to-treat population). AIMS: To assess the association of initial viral kinetics during albIFN therapy with baseline factors and SVR prediction. METHODS: In all, 43 patients were treated with albIFN 1500 mug (q2wk/q4wk) plus ribavirin (RBV) 800 mg/day for 24 weeks. Hepatitis C virus (HCV)-RNA levels were measured by real-time polymerase chain reaction, insulin resistance by homeostasis model assessment of insulin resistance (HOMA-IR) and serum albIFN levels by enyzme-linked immunosorbent assay. Prediction analysis was performed in a per protocol 28-patient subset who were > or =80% adherent to albIFN/RBV and had HCV-RNA levels measured at treatment day 3. RESULTS: Day-3 HCV-RNA level and first-phase viral decline as well as second-phase slope of viral decline were significantly associated with SVR. In adherent patients, 82.1% had a day-3 viral load <4.2 log(10) IU/ml or first-phase decline >1.25 log(10) IU/ml, which was predictive of SVR, both positively (95.7%; sensitivity: 100%) and negatively (100%; specificity: 83.3%). As low first-phase decline was associated with a high pretreatment HOMA-IR index (P=0.004) and a low day-3 serum albIFN level (P=0.01). CONCLUSIONS: First-phase viral decline with albIFN/RBV was predictive of SVR in this study and may be modulated in part by IR.

Safety and antiviral activity of albinterferon alfa-2b dosed every four weeks in genotype 2/3 chronic hepatitis C patients.

BACKGROUND & AIMS: A phase 2, randomized, multicenter, open-label study evaluated the safety and efficacy of albinterferon alfa-2b in interferon-alpha treatment-naïve patients with genotype 2/3, chronic hepatitis C virus infection. METHODS: Forty-three patients were randomly assigned in a 1:1 ratio to receive subcutaneous albinterferon alfa-2b 1500 microg every 4 weeks (q4wk) or every 2 weeks (q2wk) with oral ribavirin 800 mg/day for 24 weeks. Primary efficacy end point was sustained virologic response (undetectable hepatitis C virus RNA 24 weeks after completion of treatment). Insulin resistance was also assessed. RESULTS: The safety of albinterferon alfa-2b was acceptable, with a similar adverse event profile in both treatment arms. Discontinuation as a result of adverse events occurred in 4.5% and 14.3% of patients in the q4wk and q2wk arms, respectively. No dose reductions caused by adverse events were reported in the q4wk arm versus 9.5% in the q2wk arm. Rapid viral response rates at week 4 were 68.2% and 76.2% for the q4wk and q2wk arms, respectively; the corresponding sustained virologic response rates were 77.3% and 61.9%. Insulin resistance at baseline was significantly associated with lower sustained virologic response rates independent of body mass index. CONCLUSIONS: Albinterferon alfa-2b administered at 4-week intervals was safe and well-tolerated and demonstrated significant antiviral activity in patients with genotype 2/3, chronic hepatitis C virus. Insulin resistance appeared to have an independent effect on treatment response.

Ethical Considerations in Adaptive Design Clinical Trials.

Adaptive design clinical trial methodologies offer both opportunities and challenges for observing basic ethical principles in human subject research. Using both published and unpublished adaptive design clinical trials, we have selected and reviewed examples of clinical trials with different design adaptations to discuss the ethical obstacles presented and often successfully resolved by these approaches, including (1) confirmatory trials for treatments widely accepted on the basis of uncontrolled case series or open-label trials (clinical equipoise and "justice" in the sense of which trial groups will "receive the benefits of research and bear its burdens") (infantile hemangioma/propranolol); (2) interim results analysis by unblinded data monitoring committees ("withholding information necessary to make a considered judgment" ["respect for persons"] versus compromising the trial's scientific basis) (BIG 1-98); (3) adaptations involving sample size reassessment or dose adjustment via dropping or adding treatment arms, allowing fewer subjects to produce statistically significant results, fewer subjects treated with ineffective/toxic doses, and more subjects given doses showing tolerance and treatment activity ("beneficence" or "protecting from harm and making efforts to secure wellbeing") (ECMO, Neuromyelitis Optica); (4) adaptive randomization inferential problems balanced against ethical benefits (trastuzumab vs taxane in advanced gastric cancer; ADVENT); (5) more efficient allocation of societal resources for research, in both public and commercial realms, versus uncertain regulatory acceptance (indicaterol; VALOR); and (6) platform, umbrella, and basket trials offering additional efficiencies (I-SPY II, BATTLE, Lung-MAP). The importance of careful design, meticulous planning, and rigorous ethical review of adaptive design trials on a case-by-case basis cannot be overemphasized.

Statistical Considerations for an Adaptive Design for a Serious Rare Disease.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) is a rare, disabling autoimmune disorder of the central nervous system. Clinical trials in NMOSD present unique design and statistical challenges to adequately determine treatment effect and to minimize risk. METHODS: The N-MOmentum trial (NCT02200770) is evaluating the efficacy and safety of MEDI-551, an anti-CD 19 B-cell depleting monoclonal antibody, in patients with NMOSD and employs a number of unique design features. Patients are randomized (3:1) to receive MEDI-551 or placebo for up to 197 days. NMOSD attacks are evaluated by the investigator and confirmed by an independent adjudication committee. The primary endpoint is time to first relapse as determined by adjudication committee. Sample size re-estimation and futility analyses are planned interim analyses. Novel multiplicity adjustment methods are developed to control the study-wise type I error. Methods for assessing inter- and intrarater reliability are proposed. CONCLUSIONS: The N-MOmentum study minimizes exposure to placebo for individual patients. The application of several statistical methods in the N-MOmentum trial is novel in NMOSD and aims to achieve a balance between minimizing risk and maintaining scientific integrity.

Phenotypes of interferon-α-induced thyroid dysfunction among patients treated for hepatitis C are associated with pretreatment serum TSH and female sex.

CONTEXT: Thyroid dysfunction is a common complication of interferon-α (IFNα) therapy, with many phenotypic patterns and the potential for significant morbidity. OBJECTIVE: Our objective was to gain mechanistic insight and predict clinical presentations by determining the risk factors for distinct subtypes of IFNα-induced thyroid dysfunction. DESIGN: ACHIEVE-1, a randomized trial conducted from 2005-2009, compared long-acting preparations of IFNα in 1323 patients with hepatitis C, genotype 1. SETTING: A total of 149 outpatient clinics in North America, Europe, and Australia participated. PATIENTS: We studied 1233 patients who were euthyroid at baseline. This population is 60% male and 82% Caucasian. INTERVENTIONS: Patients were treated with pegylated IFNα2a weekly or albumin-IFNα2b every 2 wk for 48 wk. Serum TSH and free T(4) were measured before therapy and 12 or more times over 60 weeks. MAIN OUTCOME MEASURES: Thyroid dysfunction was defined as a TSH outside the normal range during the course of therapy. Low serum TSH indicated thyrotoxicosis, elevated TSH indicated hypothyroidism, and both abnormalities occurred in biphasic thyroiditis. RESULTS: Of previously euthyroid patients, 16.7% developed abnormal TSH values during therapy, including 24 with TSH below 0.1 mU/liter, 69 with TSH over 5.5 mU/liter, and 76 with biphasic thyroiditis. Biphasic thyroiditis was over 8-fold more common among women than men using multivariate logistic regression analysis [odds ratio (OR) = 8.4; 95% confidence interval (CI) = 4.5-15.8]. Thyrotoxicosis was most strongly associated with a lower pretreatment TSH (OR = 4.1 per -1 mU/liter decline; 95% CI = 1.9-9), whereas hypothyroidism was strongly associated with higher pretreatment TSH (OR = 3.9 per 1 mU/liter increase; 95% CI = 3-5.2). CONCLUSIONS: Biphasic thyroiditis is common among women treated for hepatitis C with IFNα. Lower and higher pretreatment serum TSH are associated with greater likelihood of thyrotoxicosis and hypothyroidism, respectively. Antithyroid antibody levels were not available for the cohort, and thus we cannot clarify the role of pretreatment thyroid autoimmunity as a risk factor. Our results do show that readily identifiable patient characteristics are risk factors for specific patterns of IFN-induced thyroid dysfunction. These findings suggest that distinct mechanisms may underlie subtypes of thyroid dysfunction associated with immune-modulatory therapy for hepatitis C.

FibroSURE and FibroScan in relation to treatment response in chronic hepatitis C virus.

AIM: To compare histological endpoint assessment using noninvasive alternatives to biopsy during treatment in a chronic hepatitis C virus (HCV) cohort. METHODS: Patients with chronic HCV were randomized to receive interferon-based therapy for 24 (genotypes 2/3) or 48 (genotype 1) wk. FibroSURE™ (FS) was assessed at baseline and at week-12 post-treatment follow-up. Baseline biopsy for METAVIR was assessed by a single pathologist. FibroScan(®) transient elastography (TE) was performed during treatment in a patient subset. RESULTS: Two thousand and sixty patients (n = 253 in Asia) were classified as METAVIR F0-1 (n = 1682) or F2-4 (n = 378). For F2-4, FS (n = 2055) had sensitivity and specificity of 0.87 and 0.61, respectively, with area under the receiver-operating curve of 0.82; corresponding values for TE (n = 214) and combined FS/TE (n = 209) were 0.77, 0.88 and 0.88, and 0.93, 0.68 and 0.88. Overall FS/TE agreement for F2-4 was 71% (κ = 0.41) and higher in Asians vs non-Asians (κ = 0.86 vs 0.35; P < 0.001). Combined FS/TE had 97% accuracy in Asians (n = 33). Baseline FS (0.38 vs 0.51, P < 0.001) and TE (8.0 kPa vs 11.9 kPa, P = 0.006) scores were lower in patients with sustained virological response than in nonresponders, and were maintained through follow-up. CONCLUSION: FS and TE may reliably differentiate mild from moderate-advanced disease, with a potential for high diagnostic accuracy in Asians with chronic HCV.

Changes in B-lymphocyte stimulator protein levels during treatment with albinterferon alfa-2b in patients with chronic hepatitis C who have failed previous interferon therapy.

AIM: The pharmacodynamics of albinterferon alfa-2b (alb-IFN), a novel recombinant protein consisting of interferon-α-2b genetically fused to human albumin, was evaluated in patients with chronic hepatitis C with a previous non-response to interferon-α-based therapy. B-lymphocyte stimulator (BLyS) is an essential in vivo regulator of B-lymphocyte homeostasis. This analysis examined the relationship between serum BLyS level and virologic response across a range of alb-IFN doses. METHODS: In all, 115 patients were randomized initially to three alb-IFN treatment arms (900 and 1200 µg every two weeks [q2wk], and 1200 µg every four weeks) with weight-based ribavirin, followed by sequential enrollment in two higher dose arms (1500 and 1800 µg q2wk). Serum BLyS level was assessed by enzyme-linked immunosorbent assay. RESULTS: Serum BLyS levels at baseline were lower in African-Americans (P < 0.001). Significant BLyS inductions were observed at weeks 12 and 24 versus pretreatment; in general, serum BLyS levels returned to pretreatment levels following treatment completion. Induction of BLyS was greater in the highest dose group; a significant dose-response trend was observed at weeks 12 (P = 0.002) and 24 (P < 0.001), as well as a significant time trend, with further BLyS induction increases at week 24 versus 12 (P < 0.001). Week 24 BLyS level change correlated with hepatitis C virus RNA reduction (r = -0.28; P = 0.006), driven primarily by patients with BLyS increases > 400%, but did not correlate with sustained virologic response. CONCLUSION: Higher alb-IFN doses demonstrated dose-related BLyS increases, although the correlation with virologic response was modest.

Goodness-of-fit tests for ordinal response regression models.

It is well documented that the commonly used Pearson chi-square and deviance statistics are not adequate for assessing goodness-of-fit in logistic regression models when continuous covariates are modelled. In recent years, several methods have been proposed which address this shortcoming in the binary logistic regression setting or assess model fit differently. However, these techniques have typically not been extended to the ordinal response setting and few techniques exist to assess model fit in that case. We present the modified Pearson chi-square and deviance tests that are appropriate for assessing goodness-of-fit in ordinal response models when both categorical and continuous covariates are present. The methods have good power to detect omitted interaction terms and reasonable power to detect failure of the proportional odds assumption or modelling the wrong functional form of a continuous covariate. These tests also provide immediate information as to where a model may not fit well. In addition, the methods are simple to understand and implement, and are non-specific. That is, they do not require prespecification of a type of lack-of-fit to detect.