Phase 1 trial of zolbetuximab in Japanese patients with CLDN18.2+ gastric or gastroesophageal junction adenocarcinoma.

Zolbetuximab is a chimeric monoclonal antibody that targets claudin-18.2, a candidate biomarker in patients with advanced gastric/gastroesophageal cancer. This nonrandomized phase 1 study (NCT03528629) enrolled previously treated Japanese patients with claudin-18.2-positive locally advanced/metastatic gastric/gastroesophageal cancer in two parts: Safety (Arms A and B, n = 3 each) and Expansion (n = 12). Patients received intravenous zolbetuximab 800 mg/m2 on cycle 1, day 1 followed by 600 mg/m2 every 3 weeks (Q3W; Safety Part Arm A and Expansion) or 1000 mg/m2 Q3W (Safety Part Arm B). For the Safety Part, the primary endpoint was safety (i.e., dose-limiting toxicities [DLTs]) and a secondary endpoint was objective response rate (ORR) by investigator. For the Expansion Part, the primary endpoint was ORR by investigator and secondary endpoints included ORR by central review and safety. Additional secondary endpoints for both the Safety and Expansion Parts were disease control rate (DCR), overall survival (OS), progression-free survival (PFS), duration of response, pharmacokinetics, and immunogenicity. In 18 patients, no DLTs (Safety Part) or drug-related treatment-emergent adverse events (TEAEs) grade ≥3 were observed. Most TEAEs were gastrointestinal. In 17 patients with measurable lesions, best overall response was stable disease (64.7%) or progressive disease (35.3%). The DCR was 64.7% (95% confidence interval 38.3-85.8). In Arm A and Expansion combined (n = 15), median OS was 4.4 months (2.6-11.4) and median PFS was 2.6 months (0.9-2.8). In Arm B (n = 3), median OS was 6.4 months (2.9-6.8) and median PFS was 1.7 months (1.2-2.1). Zolbetuximab exhibited no new safety signals with limited single-agent activity in Japanese patients.

The net benefit for time-to-event outcome in oncology clinical trials with treatment switching.

BACKGROUND: The net benefit is an effect measure for any type of endpoint, including the time-to-event outcome, and can provide intuitive and clinically meaningful interpretation. It is defined as the probability of a randomly selected subject from the experimental arm surviving by at least a clinically relevant time longer than a randomly selected subject from the control arm. In oncology clinical trials, an intercurrent event such as treatment switching is common, which potentially causes informative censoring; nevertheless, conventional methods for the net benefit are not able to deal with it. In this study, we proposed a new estimator using the inverse probability of censoring weighting (IPCW) method and illustrated an oncology clinical trial with treatment switching (the SHIVA study) to apply the proposed method under the estimand framework. METHODS: The net benefit can be estimated using the survival functions of each treatment group. The proposed estimator was based on the survival functions estimated by the inverse probability of the censoring weighting method that can handle covariate-dependent censoring. The simulation study was undertaken to evaluate the operating characteristics of the proposed estimator under several scenarios; we varied the shapes of the survival curves, treatment effect, covariates effect on censoring, proportion of the censoring, threshold of the net benefit, and sample size. We also applied conventional methods (the scoring rules by Péron or Gehan) and the proposed method to the SHIVA study. RESULTS: Our simulation study showed that the proposed estimator provided less biased results under the covariate-dependent censoring than existing estimators. When applying the proposed method to the SHIVA study, we were able to estimate the net benefit by incorporating the information of the covariates with different estimand strategies to address the intercurrent event of the treatment switching. However, the estimates of the proposed method and those of the aforementioned conventional methods were similar under the hypothetical strategy. CONCLUSIONS: We proposed a new estimator of the net benefit that can include covariates to account for the possibly informative censoring. We also provided an illustrative analysis of the proposed method for the oncology clinical trial with treatment switching using the estimand framework. Our proposed new estimator is suitable for handling the intercurrent events that can potentially cause covariate-dependent censoring.

Post hoc analysis of clinical characteristics of patients with radiographic progression in a Japanese phase 3 trial of peficitinib and methotrexate treatment (RAJ4).

OBJECTIVE: To determine the efficacy of peficitinib in reducing joint damage and predictive factors affecting treatment response in Japanese patients with rheumatoid arthritis. METHODS: This post hoc analysis used data from a placebo-controlled, phase 3 trial (RAJ4) of peficitinib in patients with rheumatoid arthritis and inadequate response to methotrexate. Erosion and joint space narrowing (JSN) were assessed at baseline and at Week 28/early termination of treatment using the van der Heijde-modified Sharp method. A univariate logistic regression analysis of change from baseline in a modified total Sharp score identified predictive factors with significant treatment interaction; the effects of these factors on treatment response were further evaluated using a multivariate model. RESULTS: The analyses included 481 patients. For most joint groups, peficitinib demonstrated a reduced change from baseline at Week 28/early termination in erosion and JSN scores versus placebo; a numerically greater effect was observed with peficitinib 150 mg versus 100 mg. Baseline C-reactive protein (CRP) and prednisolone dose were identified as clinically significant negative predictive factors: the treatment effect decreased as CRP or prednisolone dose increased for both peficitinib doses. CONCLUSIONS: Peficitinib 100 mg and 150 mg reduced joint damage versus placebo, across almost all joint groups. Higher baseline CRP and/or prednisolone dose were associated with reduced peficitinib efficacy. CLINICALTRIALS.GOV IDENTIFIER: NCT02305849.

Impact of age on the efficacy and safety of peficitinib (ASP015K) for the treatment of rheumatoid arthritis.

OBJECTIVES: To evaluate peficitinib efficacy and safety in Asian patients with rheumatoid arthritis (RA), stratified by age (≥20-<50, ≥50-<65, and ≥65 years). METHODS: Efficacy data from two Phase 3 studies were analysed. Safety data from one Phase 2, two Phase 3, and one open-label extension study were pooled. Incidence rates per 100 patient-years of adverse events of special interest were calculated, and Cox proportional hazard analysis was conducted. RESULTS: 1052 patients received peficitinib for 2 years (median). Peficitinib demonstrated efficacy improvements versus placebo across all age categories. Incidence rates (95% confidence interval) per 100 patient-years for ≥20-<50, ≥50-<65, and ≥65 years were 0.8 (0.4, 1.9), 2.6 (1.8, 3.7), and 4.7 (3.1, 7.0) for serious infections and 3.7 (2.5, 5.4), 6.4 (5.0, 8.2), and 11.2 (8.5, 14.7) for herpes zoster-related disease, respectively. Twenty patients reported malignancies in pooled Phase 2/3 studies. Incidences of serious infections and herpes zoster-related disease increased significantly with age, but there was no association with baseline estimated glomerular filtration rate. CONCLUSIONS: Peficitinib was efficacious in adult Asian RA patients of all ages. Age, but not estimated glomerular filtration rate, was associated with serious infections and herpes zoster-related disease, demonstrating the importance of an appropriate RA treatment strategy in older patients.

A pooled analysis of serious infections and herpes zoster-related disease in Asian patients with rheumatoid arthritis treated with peficitinib (ASP015K) over a median of 3 years.

OBJECTIVE: To analyse serious infection (SI) and herpes zoster-related disease (HZD) during long-term treatment of rheumatoid arthritis with the oral Janus kinase inhibitor, peficitinib (ASP015K). METHODS: This was a post hoc analysis of pooled data from one Phase 2b study and two Phase 3 studies and final data from a long-term extension study of peficitinib in Asian rheumatoid arthritis patients. Two pooled datasets were analysed (Phase 3 studies and Phase 2/3 studies). Univariate and multivariate Cox regression analyses explored relationships between exposure-adjusted incidence rate of SI and HZD, peficitinib dose, and baseline factors. RESULTS: Total peficitinib exposure for 1052 patients receiving once-daily peficitinib in the pooled Phase 2/3 Asian studies was 2998.9 patient-years. Exposure-adjusted incidence rates (95% confidence interval) of SI and HZD were 2.7 (2.2, 3.4) and 6.9 (6.0, 8.0) per 100 patient-years, respectively, in pooled Phase 2/3 studies. Advanced age was prognostic for SI and HZD, while baseline prednisolone dose was prognostic for SI. There was no temporal relationship between either adverse event and prolonged peficitinib administration. CONCLUSIONS: As expected in this peficitinib-treated population, older patients had increased risk of SI and HZD, and those receiving higher prednisolone doses had increased risk of SI.

A pooled safety analysis of peficitinib (ASP015K) in Asian patients with rheumatoid arthritis treated over a median of 2 years.

OBJECTIVE: To evaluate the safety of peficitinib for the treatment of rheumatoid arthritis (RA) in Asian patients. METHODS: Safety data from one Phase 2b, two Phase 3, and one open-label long-term extension study [data cut-off 31 May 2018] were pooled into Phase 3 studies (peficitinib 100 and 150 mg/day, and placebo) and Phase 2/3 studies (all peficitinib-treated patients). Incidence rates per 100 patient-years (PY) of adverse events (AEs) of special interest were calculated. RESULTS: Overall, 1052 patients received peficitinib for 2336.3 PY of exposure (median 2.1 years); four deaths occurred, including one death after the studies. AE incidence was similar across peficitinib 100 and 150 mg/day groups (Phase 3 studies). Respective peficitinib and placebo incidence rates (95% confidence interval) per 100 PY were 2.9 (1.9, 4.6) and 0.0 for serious infections, 5.7 (4.2, 7.9) and 2.3 (0.6, 9.4) for herpes zoster-related disease, and 0.6 (0.2, 1.6) and 1.2 (0.2, 8.3) for malignancies (excluding non-melanoma skin cancer) (Phase 3 studies), and 0.1 (0.0, 0.3) for venous thromboembolism in all peficitinib-treated patients (Phase 2/3 studies). CONCLUSION: Peficitinib was well tolerated in Asian patients with RA over a median of 2 years, with no observed dose or temporal dependency for AEs with prolonged administration.

A phase 1 study of oral ASP5878, a selective small-molecule inhibitor of fibroblast growth factor receptors 1-4, as a single dose and multiple doses in patients with solid malignancies.

ASP5878 is a selective small-molecule inhibitor of fibroblast growth factor receptors (FGFRs). This study investigated safety, tolerability, and antitumor effect of single and multiple oral doses of ASP5878 in patients with solid tumors. This phase 1, open label, first-in-human study comprised dose-escalation and dose-expansion parts. Primary objectives of the dose-escalation part were to identify the dose-limiting toxicity (DLT), maximum tolerated dose, and recommended dose of ASP5878 for the dose-expansion part. Nine dose cohorts of ASP5878 were evaluated (0.5─2 mg once daily; 2─40 mg twice daily [BID]). A single dose of ASP5878 was followed by a 2-day pharmacokinetic collection, and then either 28-day cycles of daily dosing (ASP5878 ≤ 10 mg BID) or 5-day dosing/2-day interruption (ASP5878 ≥ 20 mg BID). The primary objective of the dose-expansion part was to determine the safety of ASP5878 (16 mg BID) administered in 28-day cycles of 5-day dosing/2-day interruption in patients with urothelial carcinoma, hepatocellular carcinoma, or squamous cell lung carcinoma with FGFR genetic alterations. Safety was assessed by monitoring adverse events (AEs). Thirty-five patients were enrolled and 31 discontinued in the dose-escalation part; 51 patients were enrolled and 51 discontinued in the dose-expansion part. In the dose-escalation part, 66.7% of patients in the 20 mg BID 5-day dosing/2-day interruption group reported DLTs of hyperphosphatemia. The recommended dose for the dose-expansion part was 16 mg BID. Common AEs included retinal detachment, diarrhea, and increased alanine aminotransferase. One death occurred that was not related to ASP5878. ASP5878 was well tolerated with manageable toxicities including hyperphosphatemia.

The Number of Events per Confounder for Valid Estimation of Risk Difference Using Modified Least-Squares Regression.

Risk difference is a relevant effect measure in epidemiologic research. Although it is well known that when there are few events per confounder, logistic regression is not suitable for confounding control, it is not clear how many events per confounder are required for valid estimation of risk difference using linear binomial models. Because the maximum likelihood method has a convergence problem, we investigated the number of events per confounder necessary to validly estimate risk difference using modified least-squares regression in a simulation. We simulated 864 scenarios, according to the number of confounders (2-20), the number of events per confounder (2-12), marginal risk (0.5%-40%), exposure proportion (20% and 40%), and 3 sizes of risk difference. Our simulation showed that modified least-squares regression provided unbiased risk difference-regardless of the number of events per confounder-and reliable confidence intervals when more than 5 events were expected in the exposed and in the unexposed, irrespective of the number of events per confounder. We illustrated the modified least-squares regression analysis using perinatal epidemiologic data. Modified least-squares regression is considered to be a useful analytical tool for rare binary outcomes relative to the number of confounders.

Meta-analysis of randomized clinical trials in the era of individual patient data sharing.

BACKGROUND: Individual patient data (IPD) meta-analysis is considered to be a gold standard when the results of several randomized trials are combined. Recent initiatives on sharing IPD from clinical trials offer unprecedented opportunities for using such data in IPD meta-analyses. METHODS: First, we discuss the evidence generated and the benefits obtained by a long-established prospective IPD meta-analysis in early breast cancer. Next, we discuss a data-sharing system that has been adopted by several pharmaceutical sponsors. We review a number of retrospective IPD meta-analyses that have already been proposed using this data-sharing system. Finally, we discuss the role of data sharing in IPD meta-analysis in the future. RESULTS: Treatment effects can be more reliably estimated in both types of IPD meta-analyses than with summary statistics extracted from published papers. Specifically, with rich covariate information available on each patient, prognostic and predictive factors can be identified or confirmed. Also, when several endpoints are available, surrogate endpoints can be assessed statistically. CONCLUSIONS: Although there are difficulties in conducting, analyzing, and interpreting retrospective IPD meta-analysis utilizing the currently available data-sharing systems, data sharing will play an important role in IPD meta-analysis in the future.

Patient- and physician-reported outcomes from two phase 3 randomized studies (RAJ3 and RAJ4) of peficitinib (ASP015K) in Asian patients with rheumatoid arthritis.

BACKGROUND: Peficitinib (ASP015K), a novel oral Janus kinase inhibitor, has demonstrated efficacy and safety in the treatment of patients with rheumatoid arthritis (RA). This study evaluated the effect of peficitinib on patient- and physician-reported outcomes in Asian patients with RA and an inadequate response to prior disease-modifying antirheumatic drugs (DMARDs). METHODS: Patients from two randomized, placebo-controlled, double-blind, phase 3 trials (RAJ3 and RAJ4) received once-daily peficitinib 100 mg, peficitinib 150 mg, or placebo, alone or in combination with DMARDs (RAJ3), or in combination with methotrexate (RAJ4). Mean changes in Work Productivity and Activity Impairment (WPAI) questionnaire domain scores from baseline, and percentages of patients achieving minimal clinically important differences (MCIDs) for patient- and physician-reported outcomes (WPAI, Health Assessment Questionnaire - Disability Index [HAQ-DI], and Subject's Global Assessment of Pain [SGAP]), and Physician's Global Assessment of disease activity (PGA) were evaluated at weeks 4, 8, 12, and 12/early termination (ET). RESULTS: Data from 1025 patients were analyzed. At week 12/ET in both studies, patients who received peficitinib 100 mg or 150 mg reported significantly improved WPAI domain scores from baseline (except for absenteeism in RAJ4) compared with placebo (both doses, p<0.05). A higher proportion of peficitinib- versus placebo-treated patients achieved MCID in WPAI, HAQ-DI, SGAP, and PGA in studies RAJ3 and RAJ4. Significant differences with peficitinib versus placebo were evident in both studies as early as week 4 in HAQ-DI (peficitinib 150 mg only), SGAP, and PGA, and week 8 in WPAI loss of work productivity and daily activity impairment. At week 12/ET, significantly higher proportions of patients receiving peficitinib versus placebo achieved MCID in HAQ-DI, SGAP, PGA, and WPAI domains of presenteeism (RAJ3 only), loss of work productivity (RAJ3 only), and daily activity impairment (p<0.05 for all comparisons). CONCLUSIONS: Peficitinib 100 mg or 150 mg administered daily over 12 weeks resulted in clinically meaningful improvements in outcomes that are important to RA patients, including pain, physical function, and work productivity and activity. These observations were reinforced through similar improvements in physicians' rating of disease activity. TRIAL REGISTRATION: RAJ3: ClinicalTrials.gov, NCT02308163 , registered 4 December 2014. RAJ4: ClinicalTrials.gov, NCT02305849 , registered 3 December 2014.