Combination of Itacitinib or Parsaclisib with Pembrolizumab in Patients with Advanced Solid Tumors: A Phase I Study.

PURPOSE: This phase Ib open-label, multicenter, platform study (NCT02646748) explored safety, tolerability, and preliminary activity of itacitinib (Janus kinase 1 inhibitor) or parsaclisib (phosphatidylinositol 3-kinase δ inhibitor) in combination with pembrolizumab [programmed death-1 (PD-1) inhibitor]. EXPERIMENTAL DESIGN: Patients with advanced or metastatic solid tumors with disease progression following all available therapies were enrolled and received itacitinib (Part 1 initially 300 mg once daily) or parsaclisib (Part 1 initially 10 mg once daily; Part 2 all patients 0.3 mg once daily) plus pembrolizumab (200 mg every 3 weeks). RESULTS: A total of 159 patients were enrolled in the study and treated with itacitinib (Part 1, n = 49) or parsaclisib (Part 1, n = 83; Part 2, n = 27) plus pembrolizumab. The maximum tolerated/pharmacologically active doses were itacitinib 300 mg once daily and parsaclisib 30 mg once daily. Most common itacitinib treatment-related adverse events (TRAE) were fatigue, nausea, and anemia. Most common parsaclisib TRAEs were fatigue, nausea, diarrhea, and pyrexia in Part 1, and fatigue, maculopapular rash, diarrhea, nausea, and pruritus in Part 2. In patients receiving itacitinib plus pembrolizumab, four (8.2%) achieved a partial response (PR) in Part 1. Among patients receiving parsaclisib plus pembrolizumab, 5 (6.0%) achieved a complete response and 9 (10.8%) a PR in Part 1; 5 of 27 (18.5%) patients in Part 2 achieved a PR. CONCLUSIONS: Although combination of itacitinib or parsaclisib with pembrolizumab showed modest clinical activity in this study, the overall response rates observed did not support continued development in patients with solid tumors. SIGNIFICANCE: PD-1 blockade combined with targeted therapies have demonstrated encouraging preclinical activity. In this phase I study, patients with advanced solid tumors treated with pembrolizumab (PD-1 inhibitor) and either itacitinib (JAK1 inhibitor) or parsaclisib (PI3Kδ inhibitor) experienced limited clinical activity beyond that expected with checkpoint inhibition alone and showed little effect on T-cell infiltration in the tumor. These results do not support continued development of these combinations.

Efficacy and safety of itacitinib versus placebo in combination with corticosteroids for initial treatment of acute graft-versus-host disease (GRAVITAS-301): a randomised, multicentre, double-blind, phase 3 trial.

BACKGROUND: Acute graft-versus-host disease (GVHD) is a common and life-threatening complication of allogeneic haematopoietic stem cell transplantation (HSCT); there is an urgent unmet need for effective therapies. We aimed to evaluate the Janus kinase 1 inhibitor itacitinib versus placebo, both in combination with corticosteroids, for initial treatment of acute GVHD. METHODS: GRAVITAS-301 was an international, double-blind, adaptive (group sequential design) phase 3 study conducted at 129 hospitals and community practices in 19 countries. Eligible patients were aged 18 years or older, had previously received allogeneic HSCT for a haematological malignancy, developed grades II-IV acute GVHD, and received up to 2 days of systemic corticosteroids. Patients were stratified by clinical standard-risk or high-risk acute GVHD and randomly assigned (1:1), via a centralised interactive voice response system, to receive either oral itacitinib (200 mg) or placebo once daily, both in addition to corticosteroids. The primary endpoint was overall response rate (ORR) at day 28 (defined as the proportion of patients with complete response, very good partial response, or partial response 28 days after the start of treatment). For sample size determination, an absolute improvement in ORR at day 28 over standard therapy of 16% was considered clinically meaningful. Efficacy analyses were performed in the intention-to-treat population; safety analyses included patients who received at least one dose of study drug. GRAVITAS-301 is registered with ClinicalTrials.gov (NCT03139604) and is complete. FINDINGS: Between July 19, 2017, and Oct 3, 2019, 439 patients were randomly assigned to receive either itacitinib plus corticosteroids (n=219; itacitinib group) or placebo plus corticosteroids (n=220; placebo group). 173 (39%) patients were female and 390 (89%) were White. At baseline, 107 (24%) of 439 patients (itacitinib 51 [23%] of 219; placebo 56 [25%] of 220) had clinical high-risk acute GVHD. The ORR at day 28 was 74% (95% CI 67·6-79·7; 162 of 219; complete response 53% [116 of 219]) for itacitinib and 66% (59·7-72·6; 146 of 220; complete response, 40% [89 of 220]) for placebo (odds ratio for ORR 1·45, 95% CI 0·96-2·20; two-sided p=0·078). Grade 3 or worse adverse events occurred in 185 (86%) of 215 itacitinib recipients and 178 (82%) of 216 placebo recipients, and most commonly included thrombocytopenia or platelet count decreased (78 [36%] vs 68 [31%]), neutropenia or neutrophil count decreased (49 [23%] vs 45 [21%]), anaemia (42 [20%] vs 26 [12%]), and hyperglycaemia (26 [12%] vs 28 [13%]). Treatment-related deaths occurred in three of 215 patients (1%) in the itacitinib group and four of 216 (2%) in the placebo group. INTERPRETATION: The observed improvement in ORR at day 28 with the addition of itacitinib versus placebo to corticosteroids did not reach the prespecified significance level. Further studies might provide additional insight into the utility of selective JAK1 inhibition for the treatment of acute GVHD. FUNDING: Incyte.

First-in-human, phase I study of PF-06647263, an anti-EFNA4 calicheamicin antibody-drug conjugate, in patients with advanced solid tumors.

PF-06647263, a novel antibody-drug conjugate consisting of an anti-EFNA4 antibody linked to a calicheamicin payload, has shown potent antitumor activity in human xenograft tumor models, including triple-negative breast cancer (TNBC). In the dose-escalation part 1 of this multicenter, open-label, phase I study (NCT02078752), successive cohorts of patients (n, 48) with advanced solid tumors and no available standard therapy received PF-06647263 every 3 weeks (Q3W) or every week (QW), following a modified toxicity probability interval (mTPI) method (initial dosing: 0.015 mg/kg Q3W). Primary objective in part 1 was to estimate the maximum tolerated dose (MTD) and select the recommended phase 2 dose (RP2D). In part 2 (dose-expansion cohort), 12 patients with pretreated, metastatic TNBC received PF-06647263 at the RP2D to further evaluate tumor response and overall safety. PF-06647263 QW administration (n, 23) was better tolerated than the Q3W regimen (n, 25) with only 1 DLT reported (thrombocytopenia). The most common AEs with the QW regimen (fatigue, nausea, vomiting, mucosal inflammation, thrombocytopenia, and diarrhea) were mostly mild to moderate in severity. The MTD was not estimated. PF-06647263 exposures increased in a dose-related manner across the doses evaluated. The RP2D was determined to be 0.015 mg/kg QW. Six (10%) patients achieved a confirmed partial response and 22 (36.7%) patients had stable disease. No correlations were observed between tumor responses and EFNA4 expression levels. Study findings showed manageable safety and favorable PK for PF-06647263 administered QW at the RP2D, with preliminary evidence of limited antitumor activity in patients with TNBC and ovarian cancer.

Bayesian methods for the design and analysis of noninferiority trials.

The gold standard for evaluating treatment efficacy of a medical product is a placebo-controlled trial. However, when the use of placebo is considered to be unethical or impractical, a viable alternative for evaluating treatment efficacy is through a noninferiority (NI) study where a test treatment is compared to an active control treatment. The minimal objective of such a study is to determine whether the test treatment is superior to placebo. An assumption is made that if the active control treatment remains efficacious, as was observed when it was compared against placebo, then a test treatment that has comparable efficacy with the active control, within a certain range, must also be superior to placebo. Because of this assumption, the design, implementation, and analysis of NI trials present challenges for sponsors and regulators. In designing and analyzing NI trials, substantial historical data are often required on the active control treatment and placebo. Bayesian approaches provide a natural framework for synthesizing the historical data in the form of prior distributions that can effectively be used in design and analysis of a NI clinical trial. Despite a flurry of recent research activities in the area of Bayesian approaches in medical product development, there are still substantial gaps in recognition and acceptance of Bayesian approaches in NI trial design and analysis. The Bayesian Scientific Working Group of the Drug Information Association provides a coordinated effort to target the education and implementation issues on Bayesian approaches for NI trials. In this article, we provide a review of both frequentist and Bayesian approaches in NI trials, and elaborate on the implementation for two common Bayesian methods including hierarchical prior method and meta-analytic-predictive approach. Simulations are conducted to investigate the properties of the Bayesian methods, and some real clinical trial examples are presented for illustration.

Bayesian probability of success for clinical trials using historical data.

Developing sophisticated statistical methods for go/no-go decisions is crucial for clinical trials, as planning phase III or phase IV trials is costly and time consuming. In this paper, we develop a novel Bayesian methodology for determining the probability of success of a treatment regimen on the basis of the current data of a given trial. We introduce a new criterion for calculating the probability of success that allows for inclusion of covariates as well as allowing for historical data based on the treatment regimen, and patient characteristics. A new class of prior distributions and covariate distributions is developed to achieve this goal. The methodology is quite general and can be used with univariate or multivariate continuous or discrete data, and it generalizes Chuang-Stein's work. This methodology will be invaluable for informing the scientist on the likelihood of success of the compound, while including the information of covariates for patient characteristics in the trial population for planning future pre-market or post-market trials.

Bayesian methods for design and analysis of safety trials.

Safety assessment is essential throughout medical product development. There has been increased awareness of the importance of safety trials recently, in part due to recent US Food and Drug Administration guidance related to thorough assessment of cardiovascular risk in the treatment of type 2 diabetes. Bayesian methods provide great promise for improving the conduct of safety trials. In this paper, the safety subteam of the Drug Information Association Bayesian Scientific Working Group evaluates challenges associated with current methods for designing and analyzing safety trials and provides an overview of several suggested Bayesian opportunities that may increase efficiency of safety trials along with relevant case examples.

The asthma disease activity score: a discriminating, responsive measure predicts future asthma attacks.

BACKGROUND: Classifying asthma severity or activity has evolved, but there are no published weighted composite measures of asthma disease activity that account for the relative importance of the many individual clinical variables that are widely used. OBJECTIVES: We sought to develop a weighted and responsive measure of asthma disease activity. METHODS: Discriminant and multiple regression analyses based on 2 previously conducted clinical trials were used to develop the Asthma Disease Activity Score (ADAS-6). RESULTS: The ADAS-6 demonstrated content validity because its components assess different manifestations of asthma: FEV(1) (percent predicted), Asthma Quality of Life Questionnaire-Symptom domain, rescue ß-agonist use, nocturnal awakenings, peak expiratory flow diurnal variability, and rescue ß-agonist use diurnal variability. The ADAS-6 demonstrated cross-sectional and longitudinal validity. It was discriminating: it distinguished levels of disease activity and response to different treatment intensities (P < .0001). Similar results were obtained with an independent clinical trial. The ADAS-6 was highly responsive to treatment effects, with a standardized effect size exceeding that of other widely used outcome measures. Using ADAS-6 as the primary end point in the montelukast pivotal trials would have significantly reduced the sample size needed to detect a comparable change in outcome. Furthermore, increments in the ADAS-6 predicted the risk of future asthma attacks. A simplified Asthma Disease Activity Score 4-variable version (ADAS-4) demonstrated similar measurement properties. CONCLUSIONS: The ADAS-6 and ADAS-4 are novel, weighted, and responsive measures of asthma disease activity. Use of these measures in clinical trials might better separate treatment effects, predict future asthma attacks, and substantially reduce sample size.

Airway obstruction lability helps distinguish levels of disease activity in asthma.

Classifying disease activity in asthma relies on clinical and physiological variables, but these variables do not capture all aspects of asthma that distinguish levels of disease activity. We used data from two pivotal trials of montelukast in asthma to classify disease activity as "high" or "low". We performed a principal component analysis (PCA) of disease activity using 21 efficacy outcome variables, including several novel derived outcome variables reflecting clinical and airway obstruction lability. Then we performed discriminant analysis (DA) based on disease activity classification. PCA revealed 6 factors (daytime asthma control, nighttime-predominant asthma control, airway obstruction, exacerbations, clinical lability, airway obstruction lability) that explained 76% of the variance between outcome variables. Although airway obstruction lability (comprising both diurnal variability in peak expiratory flow and diurnal variability in ß-agonist use) accounted for only 6% of the explained variance in PCA, in DA it was more accurate (canonical coefficient 0.75) than traditional measures of asthma severity such as obstruction (-0.54) and daytime control (-0.56) in distinguishing between high and low disease activity. We conclude that airway obstruction lability, a parameter not typically captured in clinical trials, may contribute to more complete assessment of asthma disease activity and may define an emerging clinical target of future therapy.

Development and validation of a composite score based on clinically meaningful events for the opioid-related symptom distress scale.

PURPOSE: To develop and validate a composite score based on clinically meaningful events (CMEs) for the opioid-related symptom distress scale (OR-SDS) that would be appropriate for use in postoperative clinical trials. METHODS: Secondary analysis of data from 2 multi-site Phase III randomized clinical safety trials: a general surgery trial (N = 1,050) and a coronary artery bypass graft surgery trial (N = 1,636). Validating measures include daily opioid consumption and physician and patient global evaluations of study medication. We empirically defined CMEs for each symptom, using factor analysis and an area under the receiver-operating characteristic analysis of the severity and frequency items of the OR-SDS. Construct validity was examined by testing hypotheses of relationships between composite CME scores and opioid consumption and physician and patient evaluations of study medication. RESULTS: Hypotheses supporting the construct validity of the CME-based composite score were confirmed. Significant associations were found between higher numbers of CMEs with greater opioid consumption and lower likelihood of a positive evaluation of the study medication. CONCLUSIONS: The OR-SDS CME-based composite score demonstrates evidence of construct validity and appears appropriate for use in evaluating patients' opioid-related side effect burden in future postoperative clinical trials.

Validity of 24-h recall ratings of pain severity: biasing effects of "Peak" and "End" pain.

Despite the frequent use of pain recall ratings in clinical research, there remains doubt about the ability of individuals to accurately recall their pain. In particular, previous research indicates the possibility that the most pain experienced during a recall period and the most recent pain experienced (known as peak and end effects, respectively) might bias recall ratings. The current study used data from a published clinical trial to determine the relative validity of a 24-h recall rating of average post-operative pain and the nature and extent of any biasing influence of peak and end effects on nine separate 24-h recall ratings. The results supported a statistically significant but small biasing influence of both peak and end pain. Also, the influence of peak pain was stronger than that of end pain. However, the biasing impact of both peak and end pain together was very small, suggesting that 24-h recall ratings are adequately valid indicants of average pain for patients participating in post-surgery clinical pain trials.

Therapeutic dosing with anti-interleukin-13 monoclonal antibody inhibits asthma progression in mice.

In vivo models have demonstrated that interleukin-13 (IL-13) plays an important role in asthma; however, few studies have evaluated the effect of inhibition of IL-13 on established and persistent disease. In the present study, we have investigated the effect of a therapeutic dosing regimen with an anti-IL-13 monoclonal antibody (mAb) in a chronic mouse model of persistent asthma. BALB/c mice were sensitized to allergen [ovalbumin (OVA); on days 1 and 8] and challenged with OVA weekly from day 22. Anti-IL-13 mAb or vehicle dosing was initiated following two OVA challenges when disease was established. At this time, mice exhibited airway hyperresponsiveness (AHR), increased mucus production, inflammation, and initiation of subepithelial fibrosis compared with saline-challenged mice. Mice received four additional OVA challenges. Treatment with anti-IL-13 mAb inhibited AHR and prevented the further development of subepithelial fibrosis and progression of inflammation. Furthermore, mAb treatment reversed the mucus hyperplasia to basal levels. These effects were associated with an inhibition of cytokines, chemokines, and matrix metalloproteinase-9. These data demonstrate that neutralization of IL-13 can inhibit the progression of established disease in the presence of repeated allergen exposures.