Sample size calculation in clinical trials with two co-primary endpoints including overdispersed count and continuous outcomes.

Count outcomes are collected in clinical trials for new drug development in several therapeutic areas and the event rate is commonly used as a single primary endpoint. Count outcomes that are greater than the mean value are termed overdispersion; thus, count outcomes are assumed to have a negative binomial distribution. However, in clinical trials for treating asthma and chronic obstructive pulmonary disease (COPD), a regulatory agency has suggested that a continuous endpoint related to lung function must be evaluated as a primary endpoint in addition to the event rate.

Cautionary note on regional consistency evaluation in multiregional clinical trials with binary outcomes.

Multiregional clinical trials (MRCTs) have become increasingly common during the development of new drugs to obtain simultaneous drug approvals worldwide. When planning MRCTs, a major statistical challenge is determination of the regional sample size. In general, the regional sample size must be determined as the sample size such that the regional consistency probability, defined as the probability of meeting the regional consistency criterion, is greater than a prespecified value.

Efficacy and safety of the sodium-glucose co-transporter-2 inhibitor empagliflozin in elderly Japanese adults (≥65 years) with type 2 diabetes: A randomized, double-blind, placebo-controlled, 52-week clinical trial (EMPA-ELDERLY).

Aim: Use of sodium-glucose co-transporter-2 inhibitors (SGLT2is) for glycaemic control is increasing in individuals with type 2 diabetes (T2D) for their additional benefits on heart failure and chronic kidney disease. However, SGLT2is generally reduce body weight, which might promote sarcopenia in older individuals. We evaluated the effects of the SGLT2i empagliflozin on muscle mass and strength in addition to glucose control in elderly adults with T2D.

Usefulness of the placebo lead-in design for clinical trials with binary outcomes.

Background: In placebo-controlled clinical trials to develop new drugs for the treatment of psychiatric or neurological disorders, a high and sometimes greater-than-expected placebo response makes it difficult to show the superiority of an investigational drug over a corresponding placebo. To avoid such difficulty, a placebo lead-in design has been presented, but its usefulness has been open to discussion. Although the statistical properties of the placebo lead-in design are investigated in the context of continuous outcomes, whether these properties can be generalized for binary or ordinal cases remains unclear.

Ramucirumab Plus Erlotinib Versus Placebo Plus Erlotinib in Patients With Untreated Metastatic -Mutated NSCLC: RELAY Japanese Subset.

Introduction: The phase 3 RELAY global study (NCT02411448) revealed significant improvement in progression-free survival (PFS) with ramucirumab plus erlotinib (RAM + ERL) compared with placebo plus ERL (PL + ERL) in untreated -mutated metastatic NSCLC (hazard ratio [HR] = 0.59 [95% confidence interval (CI): 0.46-0.

Phase 2 randomized placebo-controlled study of lasmiditan for the acute treatment of migraine in Japanese patients.

Objective: To evaluate the efficacy and safety of lasmiditan in Japanese adults with migraine.

Background: Global clinical studies have demonstrated the efficacy and safety of lasmiditan in the acute treatment of migraine.

Methods: This was a multicenter, randomized, double-blind, placebo-controlled, phase 2 study in Japan (NCT03962738), which enrolled adults with migraine with or without aura.

Quality of Life Associated with Ramucirumab Treatment in Patients with Advanced Gastric Cancer in Japan: Exploratory Analysis from the Phase III RAINBOW Trial.

Background And Objective: Gastric cancer has been associated with notable geographic heterogeneity in previous multi-regional studies. In particular, patients from Japan have better outcomes compared with patients from other regions. Here, we assess patient-focused outcomes for the subgroup of Japanese patients in the global RAINBOW study.

Ramucirumab or placebo plus erlotinib in EGFR-mutated, metastatic non-small-cell lung cancer: East Asian subset of RELAY.

In the global phase III RELAY study, ramucirumab plus erlotinib (RAM + ERL) demonstrated superior progression-free survival (PFS) to placebo plus erlotinib (PL + ERL) in untreated patients with epidermal growth factor receptor (EGFR) mutation-positive metastatic non-small-cell lung cancer (NSCLC) (hazard ratio (HR) [95% CI]: 0.59 [0.46-0.

Ramucirumab after prior sorafenib in patients with advanced hepatocellular carcinoma and elevated alpha-fetoprotein: Japanese subgroup analysis of the REACH-2 trial.

Background: The global, randomized, phase 3 REACH-2 study (ClinicalTrials.gov identifier: NCT02435433) found significantly longer overall survival (OS) for second-line ramucirumab versus placebo (hazard ratio [HR]: 0.710, 95% confidence interval [CI] 0.

Sequential parallel comparison design with two coprimary endpoints.

A placebo-controlled randomized clinical trial is required to demonstrate that an experimental treatment is superior to its corresponding placebo on multiple coprimary endpoints. This is particularly true in the field of neurology. In fact, clinical trials for neurological disorders need to show the superiority of an experimental treatment over a placebo in two coprimary endpoints.

Sequential parallel comparison design for "gold standard" noninferiority trials with a prespecified margin.

Three-arm noninferiority trials (involving an experimental treatment, a reference treatment, and a placebo)-called the "gold standard" noninferiority trials-are conducted in patients with mental disorders whenever feasible, but often fail to show superiority of the experimental treatment and/or the reference treatment over the placebo. One possible reason is that some of the patients receiving the placebo show apparent improvement in the clinical condition. An approach to addressing this problem is the use of the sequential parallel comparison design (SPCD).

A simple test for the treatment effect in clinical trials with a sequential parallel comparison design and negative binomial outcomes.

In placebo-controlled, double-blinded, randomized clinical trials, the presence of placebo responders reduces the effect size for comparison of the active drug group with the placebo group. An attempt to resolve this problem is to use the sequential parallel comparison design (SPCD). Although there are SPCDs with dichotomous or continuous outcomes, an SPCD with negative binomial outcomes-with which investigators deal eg, in clinical trials involving multiple sclerosis, where the investigators are still concerned about the presence of placebo responders-has not yet been discussed.