Futility Interim Analysis Based on Probability of Success Using a Surrogate Endpoint.

In clinical trials with time-to-event data, the evaluation of treatment efficacy can be a long and complex process, especially when considering long-term primary endpoints. Using surrogate endpoints to correlate the primary endpoint has become a common practice to accelerate decision-making. Moreover, the ethical need to minimize sample size and the practical need to optimize available resources have encouraged the scientific community to develop methodologies that leverage historical data. Relying on the general theory of group sequential design and using a Bayesian framework, the methodology described in this paper exploits a documented historical relationship between a clinical "final" endpoint and a surrogate endpoint to build an informative prior for the primary endpoint, using surrogate data from an early interim analysis of the clinical trial. The predictive probability of success of the trial is then used to define a futility-stopping rule. The methodology demonstrates substantial enhancements in trial operating characteristics when there is a good agreement between current and historical data. Furthermore, incorporating a robust approach that combines the surrogate prior with a vague component mitigates the impact of the minor prior-data conflicts while maintaining acceptable performance even in the presence of significant prior-data conflicts. The proposed methodology was applied to design a Phase III clinical trial in metastatic colorectal cancer, with overall survival as the primary endpoint and progression-free survival as the surrogate endpoint.

Treatment sequences and prognostic/predictive factors in metastatic pancreatic ductal adenocarcinoma: univariate and multivariate analyses of a real-world study in Europe.

BACKGROUND: Real-world data on treatment patterns/outcomes for metastatic pancreatic cancer (mPAC) are limited. This study aims to assess real-world treatment patterns, survival outcomes, and prognostic/predictive factors in patients with mPAC. METHODS: Retrospective, observational, chart-review involving medical oncologists and gastroenterologists from five European countries. Physicians reported information on disease and patient characteristics, diagnosis, and treatment for patients diagnosed with mPAC from January-October 2016. Outcomes included median progression-free survival (mPFS), median overall survival (mOS), and the impact of baseline performance status on survival. Univariate/multivariate regression analyses were undertaken to identify prognostic/predictive factors. RESULTS: Three hundred four physicians and 3432 patients were included. First-line therapies included modified (m)FOLFIRINOX (28.4%), gemcitabine + nab-paclitaxel (28.0%), and gemcitabine monotherapy (23.0%). Frequent second-line therapies were gemcitabine monotherapy (25.0%), fluorouracil (5-FU) + oxaliplatin (21.8%), and gemcitabine + nab-paclitaxel (16.7%). Most frequent first- to second-line treatment sequences were gemcitabine + nab-paclitaxel followed by fluoropyrimidine combinations. Longest unadjusted estimated mOS was observed with (m)FOLFIRINOX followed by gemcitabine-based combinations (19.1 months). Multivariate analysis identified significant prognostic/predictive factors for OS and PFS including performance status and carbohydrate antigen 19-9 (CA 19-9) levels. CONCLUSIONS: Treatment and treatment sequences were generally in accordance with guidelines at the time of the study. Identification of prognostic/predictive factors for survival may help inform the individualised management of mPAC patients in the future.

Liposomal irinotecan with fluorouracil and leucovorin after gemcitabine-based therapy in Japanese patients with metastatic pancreatic cancer: additional safety analysis of a randomized phase 2 trial.

BACKGROUND: Nanoliposomal irinotecan (nal-IRI) was recently authorized in Japan for unresectable pancreatic cancer after disease progression following chemotherapy. Physicians now consider certain aspects of nal-IRI safety profile as slightly different from conventional irinotecan. This report aims to explore additional aspects of the nal-IRI safety in Japanese phase 2 study. METHODS: We analyzed the incidence, time to first onset, and time to resolution for adverse events that require special attention and other selected toxicities in the nal-IRI combination group (n = 46). RESULTS: Leukopenia/neutropenia (76.1%/71.7%), diarrhea (58.7%) and hepatic dysfunction (41.3%) were the most commonly reported treatment-emergent adverse events, with a median time to onset of 21.0 days (range: 8, 97), 9.0 days (1, 61) and 22.0 days (2, 325), respectively, and a median time to resolution of 8.0 days (95% confidence intervals: 8, 9), 4.0 days (4, 8) and 40.0 days (9, -), respectively. Eight patients experienced Grade ≥ 3 diarrhea and their symptoms were well controlled by dose modification except one patient who had drug withdrawal. The median time to resolution for Grade ≥ 3 and Grade ≤ 2 diarrhea was 17.5 days (95% confidence intervals: 1, 31) and 4 days (3, 7), respectively. Anorexia occurred in 28/46 patients (60.9%) with a median time to onset of 4.0 days (range: 2, 132) and a median time to resolution of 12.0 days (95% confidence intervals: 6, 26). CONCLUSIONS: We explored safety profile of nal-IRI combination regimen recognized as effective and tolerable treatment for Japanese unresectable pancreatic cancer patients. Although the treatment-emergent adverse events occurred were controllable, patients with prolonged toxicities should be closely managed.

Oral ixazomib maintenance following autologous stem cell transplantation (TOURMALINE-MM3): a double-blind, randomised, placebo-controlled phase 3 trial.

BACKGROUND: Maintenance therapy following autologous stem cell transplantation (ASCT) can delay disease progression and prolong survival in patients with multiple myeloma. Ixazomib is ideally suited for maintenance therapy given its convenient once-weekly oral dosing and low toxicity profile. In this study, we aimed to determine the safety and efficacy of ixazomib as maintenance therapy following ASCT. METHODS: The phase 3, double-blind, placebo-controlled TOURMALINE-MM3 study took place in 167 clinical or hospital sites in 30 countries in Europe, the Middle East, Africa, Asia, and North and South America. Eligible participants were adults with a confirmed diagnosis of symptomatic multiple myeloma according to International Myeloma Working Group criteria who had achieved at least a partial response after undergoing standard-of-care induction therapy followed by high-dose melphalan (200 mg/m2) conditioning and single ASCT within 12 months of diagnosis. Patients were randomly assigned in a 3:2 ratio to oral ixazomib or matching placebo on days 1, 8, and 15 in 28-day cycles for 2 years following induction, high-dose therapy, and transplantation. The initial 3 mg dose was increased to 4 mg from cycle 5 if tolerated during cycles 1-4. Randomisation was stratified by induction regimen, pre-induction disease stage, and response post-transplantation. The primary endpoint was progression-free survival (PFS) by intention-to-treat analysis. Safety was assessed in all patients who received at least one dose of ixazomib or placebo, according to treatment actually received. This trial is registered with ClinicalTrials.gov, number NCT02181413, and follow-up is ongoing. FINDINGS: Between July 31, 2014, and March 14, 2016, 656 patients were enrolled and randomly assigned to receive ixazomib maintenance therapy (n=395) or placebo (n=261). With a median follow-up of 31 months (IQR 27·3-35·7), we observed a 28% reduction in the risk of progression or death with ixazomib versus placebo (median PFS 26·5 months [95% CI 23·7-33·8] vs 21·3 months [18·0-24·7]; hazard ratio 0·72, 95% CI 0·58-0·89; p=0·0023). No increase in second malignancies was noted with ixazomib therapy (12 [3%] patients) compared with placebo (eight [3%] patients) at the time of this analysis. 108 (27%) of 394 patients in the ixazomib group and 51 (20%) of 259 patients in the placebo group experienced serious adverse events. During the treatment period, one patient died in the ixazomib group and none died in the placebo group. INTERPRETATION: Ixazomib maintenance prolongs PFS and represents an additional option for post-transplant maintenance therapy in patients with newly diagnosed multiple myeloma. FUNDING: Millennium Pharmaceuticals, a wholly owned subsidiary of Takeda Pharmaceutical Company.

Adverse event management in the TOURMALINE-MM3 study of post-transplant ixazomib maintenance in multiple myeloma.

The phase 3, double-blind, placebo-controlled TOURMALINE-MM3 study (NCT02181413) demonstrated improved progression-free survival with ixazomib maintenance versus placebo post autologous stem cell transplant (ASCT) in multiple myeloma patients. We report additional safety data from TOURMALINE-MM3 to inform adverse event (AE) management recommendations. Patients were randomized 3:2 to receive ixazomib (n = 395) or placebo (n = 261) on days 1, 8, and 15 of 28-day cycles for ~ 2 years or until progressive disease/toxicity. The initial 3-mg ixazomib dose was escalated to 4 mg in cycle 5, if tolerated in cycles 1-4. Safety was a secondary endpoint assessed in all treated patients; AEs were graded using Common Terminology Criteria for AEs v4.03. The rate of grade ≥ 3 AEs was higher in the ixazomib arm (19%) than in the placebo arm (5%), but the rate of discontinuation due to AEs was similar (7% vs. 5%). For AEs of clinical interest, rates were higher with ixazomib versus placebo: nausea 39% versus 15%, vomiting 27% versus 11%, diarrhea 35% versus 24%, thrombocytopenia 13% versus 3%, and peripheral neuropathy 19% versus 15%. However, the majority of events were low-grade, manageable with supportive therapy or dose reduction, and reversible, and did not result in discontinuation. There was no evidence of cumulative, long-term, or late-onset toxicity with ixazomib maintenance. Ixazomib is an efficacious and tolerable option for post-ASCT maintenance. AEs associated with ixazomib maintenance can be managed in the context of routine post-ASCT supportive care due to the limited additional toxicity. ClinicalTrials.gov NCT02181413.

Seamless phase 2/3 oncology trial design with flexible sample size determination.

Conventional seamless phase 2/3 design with fixed sample size determination (SSD) has gained its popularity in oncology drug development due to attractive features such as significantly shortening the development timeline, minimizing sample size, as well as early decision making. However, this design is not immune to inaccurate treatment effect assumption when only limited efficacy data are available at study design stage. We propose an innovative seamless phase 2/3 study design with flexible SSD for oncology trials, in which the trial is designed under a distribution of treatment effect instead of one single assumption due to huge uncertainty of treatment effect at design stage and the sample size for end of phase 3 analysis is not predetermined at design stage, but rather dynamically determined based on observed treatment effect at phase 2 portion. Some practical sample size determination rules for end of phase 3 analysis will be discussed. The proposed design can lead to reduced sample size or/and improved power compared with conventional seamless phase 2/3 design with fixed SSD. This innovative study design can be especially useful for programs with aggressive development strategy to expedite the process in delivering efficacious treatment to patients.

Phase 2 study of all-oral ixazomib, cyclophosphamide and low-dose dexamethasone for relapsed/refractory multiple myeloma.

There is a need for efficacious, convenient treatments with long-term tolerability for patients with relapsed/refractory multiple myeloma (RRMM). This phase 2 study evaluated the all-oral combination of ixazomib, cyclophosphamide and dexamethasone (ICd). Patients with RRMM received ixazomib 4 mg and cyclophosphamide 300 mg/m2 on days 1, 8 and 15, and dexamethasone 40 mg on days 1, 8, 15 and 22 in 28-day cycles. The primary endpoint was overall response rate (ORR). Seventy-eight patients were enrolled (median age 63·5 years). At data cut-off, patients had received a median of 12 treatment cycles; 31% remained on treatment. ORR was 48% [16% very good partial response or better (≥VGPR)]. ORR was 64% and 32% in patients aged ≥65 and <65 years (25% and 16% ≥VGPR), respectively. At a median follow-up of 15·2 months, median progression-free survival (PFS) was 14·2 months, with a trend towards better PFS in patients aged ≥65 years vs. <65 years (median 18·7 months vs. 12·0 months; hazard ratio 0·62, P = 0·14). ICd was well tolerated. The most common treatment-emergent adverse events were diarrhoea (33%), nausea (24%), upper respiratory tract infection (24%), and thrombocytopenia (22%); 10 patients (13%) had peripheral neuropathy (one grade 3). This study is registered at ClinicalTrials.gov (NCT02046070).

Ixazomib maintenance therapy in newly diagnosed multiple myeloma: An integrated analysis of four phase I/II studies.

OBJECTIVES: To evaluate the safety and efficacy of maintenance therapy with the oral proteasome inhibitor ixazomib in patients with newly diagnosed multiple myeloma (NDMM) not undergoing transplantation. METHODS: Data were pooled from four NDMM phase I/II studies; patients received induction therapy with once- or twice-weekly ixazomib plus lenalidomide-dexamethasone (IRd), melphalan-prednisone (IMP), or cyclophosphamide-dexamethasone (ICd), followed by single-agent ixazomib maintenance, given at the last tolerated dose during induction, until disease progression, death, or unacceptable toxicity. RESULTS: A total of 121 patients achieved stable disease or better after induction (weekly IRd, n = 25; twice-weekly IRd, n = 18; weekly or twice-weekly IMP, n = 35; weekly ICd, n = 43) and received ≥ 1 dose of ixazomib maintenance. Grade ≥ 3 drug-related adverse events occurred in 24% of patients during maintenance; each event was reported in ≤2% of patients. Rates of complete response were 22% after induction and 35% after maintenance. A total of 28 patients (23%) improved their response during maintenance. CONCLUSIONS: Ixazomib maintenance following ixazomib-based induction is associated with deepening of responses and a positive safety profile with no cumulative toxicity in patients with NDMM not undergoing transplantation, suggesting that ixazomib is feasible for long-term administration. Phase III investigation of ixazomib maintenance is ongoing.

Optimal seamless phase 2/3 oncology trial designs based on Probability of Success (PoS).

In recent years, there has been an increasing trend in conducting seamless phase 2/3 clinical trials for drug development in the pharmaceutical industry due to the visible advantages compared with traditional approaches for separate phase 2 and 3 development. Innovative study designs have been proposed for seamless phase 2/3 trials, which mainly focus on the traditional aspects of study design, such as how to control the Type I error rate, sample size re-estimation after the phase 2 portion, and how to make treatment selection at the end of the phase 2 portion. However, there are still some questions unresolved such as how to determine the go/no-go boundary and how to plan the phase 2 portion sample size. In this paper, we discuss how to determine the phase 2 portion and phase 3 portion sample sizes as well as the corresponding go/no-go criteria for a seamless phase 2/3 oncology trial based on Probability of Success. In addition, we further expand the methodology to include designs with an interim look within the phase 2 portion to speed up the go/no-go decision-making process. In case of overwhelming efficacy, this design would further shorten the overall trial duration. In case of inefficacy, this design can stop the trial earlier without exposing more patients to inefficacious treatment.

Unified additional requirement in consideration of regional approval for multiregional clinical trials.

To speed up the process of bringing a new drug to the market, more and more clinical trials are being conducted simultaneously in multiple regions. After demonstrating the overall drug's efficacy across regions, the regulatory and drug sponsor may also want to assess the drug's effect in specific region(s). Most of the recent approaches imposed a uniform criterion to assess the consistency of treatment effects between the interested region(s) and the entire study population regardless of the number of regions in multiregional clinical trials (MRCT). As a result, the needed sample size to achieve the desired probability of satisfying the regional requirement could be huge and implausible for the trial sponsors to implement. In this paper, we propose a unified additional requirement for regional approval by differing the parameters in the additional requirement depending on the number of planned regions. In particular, the values of the parameters are determined by a reasonable sample size increase with the desired probability satisfying the additional requirement. Considering the practicality of the global trial or sample size increase, we recommend specific values of the parameters for a different number of planned regions. We also introduce the assurance probability curve to evaluate the performance of different regional requirements.

Association of sex steroids, gonadotrophins, and their trajectories with clinical cardiovascular disease and all-cause mortality in elderly men from the Framingham Heart Study.

BACKGROUND: Emerging data from longitudinal studies suggest that low sex steroid concentrations in men are associated with increased cardiovascular risk and mortality. The impact of longitudinal trajectory patterns from serial sex steroid and gonadotrophin measurements on the observed associations is unknown to date. METHODS: We prospectively evaluated 254 elderly men (mean age, 75·5 years) of the Framingham Heart Study with up to four serial measurements of serum total testosterone (TT), dehydroepiandrosterone sulphate (DHEAS), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and total estradiol (EST); and constructed age- and multivariable-adjusted Cox proportional hazard regression models relating baseline hormone concentrations and their mean, slope and variation over time (modelled as continuous and categorized into quartiles) to the incidence of clinical cardiovascular disease (CVD) and all-cause mortality at 5- and 10-year follow-up. RESULTS: We observed no association between baseline concentrations of sex steroids, gonadotrophins and their trajectories with incident clinical CVD over 5- and 10-year follow-up. Although higher baseline TT concentrations were associated with lower mortality risk at 5 years (hazard ratio per quartile increment, 0·74; 95% confidence interval, 0·56-0·98), correction for multiple statistical testing (P < 0·005) rendered this association statistically nonsignificant. Repeat analyses at the 10-year follow-up time point also demonstrated no significant association between sex steroids, gonadotrophins or their trajectories and mortality. CONCLUSION: Investigating longitudinal trajectory patterns of serial sex steroid and gonadotrophin measurements, the present study found no consistent associations with incident clinical CVD and all-cause mortality risk in elderly men from the community.

Deepening responses associated with improved progression-free survival with ixazomib versus placebo as posttransplant maintenance in multiple myeloma.

In the TOURMALINE-MM3 study, post-autologous stem cell transplantation maintenance therapy with the oral proteasome inhibitor ixazomib versus placebo significantly improved progression-free survival (PFS), with a favorable safety profile. With ixazomib versus placebo maintenance, deepening responses occurred in 139/302 (46%) versus 60/187 (32%) patients with very good partial response or partial response (VGPR/PR) at study entry (relative risk 1.41, P = 0.004), and median time to best confirmed deepened response was 19.9 versus 30.8 months (24-month rate: 54.2 versus 41.4%; hazard ratio (HR): 1.384; P = 0.0342). Median PFS in patients with VGPR/PR at study entry was 26.2 versus 18.5 months (HR: 0.636, P < 0.001) with ixazomib versus placebo; in a pooled analysis across arms, in patients with versus without deepening responses, the median PFS was not reached versus 15.9 months (HR: 0.245, P < 0.001). In patients with deepening responses, 24-month PFS rate was 77.4 versus 68.3% with ixazomib versus placebo (HR: 0.831; P = 0.466); in patients without deepening responses, median PFS was 17.9 versus 14.1 months (HR: 0.741; P = 0.028). These analyses demonstrate the significantly higher rate of deepening responses with ixazomib versus placebo maintenance and the association between deepening response and prolonged PFS.

All-oral ixazomib, cyclophosphamide, and dexamethasone for transplant-ineligible patients with newly diagnosed multiple myeloma.

BACKGROUND: Novel efficacious treatments with long-term tolerability are needed for transplant-ineligible, newly diagnosed multiple myeloma (NDMM) patients. This phase 2 study evaluated the safety and efficacy of all-oral ixazomib-cyclophosphamide-dexamethasone (ICd) followed by single-agent ixazomib maintenance. PATIENTS AND METHODS: Patients were randomised (1:1) to receive 4.0 mg of ixazomib, 300 (Arm A) or 400 (Arm B) mg/m2 of cyclophosphamide (days 1, 8, and 15), and 40 mg of dexamethasone (days 1, 8, 15, and 22) as induction (up to 13 × 28-day cycles), followed by single-agent ixazomib maintenance (28-day cycles) until progressive disease, death, or unacceptable toxicity. Primary end-point was complete response (CR) + very good partial response (VGPR) rate for ICd induction. RESULTS: Seventy patients were enrolled (n = 36 Arm A; n = 34 Arm B); median age was 73 years (range, 61-87). At data cut-off, 66% of patients had completed 13 induction cycles followed by ixazomib maintenance. Median overall treatment duration was 19 cycles (range, 1-29); 21% of patients discontinued treatment during induction and 3% during maintenance due to adverse events (AEs). During induction, among 67 response-evaluable patients, CR+VGPR rate was 25%, and overall response rate (ORR) was 73%. Including the maintenance phase, CR+VGPR rate was 33%, and ORR was 76%. Median progression-free survival was 23.5 months (median follow-up: 26.1 months). The most common all-grade AE was neutropenia (31%). Grade ≥3 AEs were reported by 73% of patients. Five on-study deaths occurred (not treatment-related). CONCLUSIONS: ICd treatment followed by ixazomib maintenance is tolerable and active in elderly, transplant-ineligible NDMM patients. TRIAL REGISTRATION NUMBER: NCT02046070.

Model-Informed Drug Development for Ixazomib, an Oral Proteasome Inhibitor.

Model-informed drug development (MIDD) was central to the development of the oral proteasome inhibitor ixazomib, facilitating internal decisions (switch from body surface area (BSA)-based to fixed dosing, inclusive phase III trials, portfolio prioritization of ixazomib-based combinations, phase III dose for maintenance treatment), regulatory review (model-informed QT analysis, benefit-risk of 4 mg dose), and product labeling (absolute bioavailability and intrinsic/extrinsic factors). This review discusses the impact of MIDD in enabling patient-centric therapeutic optimization during the development of ixazomib.

Model-Based Meta-Analysis for Multiple Myeloma: A Quantitative Drug-Independent Framework for Efficient Decisions in Oncology Drug Development.

The failure rate for phase III trials in oncology is high; quantitative predictive approaches are needed. We developed a model-based meta-analysis (MBMA) framework to predict progression-free survival (PFS) from overall response rates (ORR) in relapsed/refractory multiple myeloma (RRMM), using data from seven phase III trials. A Bayesian analysis was used to predict the probability of technical success (PTS) for achieving desired phase III PFS targets based on phase II ORR data. The model demonstrated a strongly correlated (R2 = 0.84) linear relationship between ORR and median PFS. As a representative application of the framework, MBMA predicted that an ORR of ∼66% would be needed in a phase II study of 50 patients to achieve a target median PFS of 13.5 months in a phase III study. This model can be used to help estimate PTS to achieve gold-standard targets in a target product profile, thereby enabling objectively informed decision-making.

Prospective Relation of Circulating Adipokines to Incident Metabolic Syndrome: The Framingham Heart Study.

BACKGROUND: Adipokines are elaborated by adipose tissue and are associated with glycemic, lipid, and vascular traits. We hypothesized that in a cross-sectional analysis circulating adipokines are altered among subsets of obesity stratified by presence versus absence of metabolic syndrome (MetS) and prospectively predict the incidence of MetS. METHODS AND RESULTS: Participants in the community-based Framingham Third Generation Cohort who attended examination cycle 1 were included in the study (2002-2005; N=3777, mean age, 40 years; 59% women). Circulating adiponectin, leptin, leptin receptor, fetuin-A, fatty acid-binding protein 4, and retinol binding protein 4 were assayed and related to incident MetS in follow-up (mean 6 years). The adipokines were compared among individuals with excess body weight (body mass index ≥25 kg/m2) and prevalent MetS, excess body weight without MetS (metabolically healthy obese), and normal-weight with MetS (metabolically obese, normal-weight) with normal-weight participants without MetS as a referent. Metabolically healthy obese individuals (n=1467) had higher circulating levels of fetuin-A and fatty acid-binding protein 4 but lower levels of leptin, leptin receptor, and adiponectin (P<0.001 for all). The adipokine panel was associated with incident MetS (263 new-onset cases; P=0.002). Higher circulating concentrations of retinol-binding protein 4 and fetuin-A were associated with incidence of MetS (odds ratio per 1-SD increment log marker, 1.21; 95% CI, 1.03-1.41 [P=0.02] and 1.17; 95% CI, 1.01-1.34 [P=0.03], respectively). CONCLUSIONS: In our community-based sample of young to middle-aged adults, metabolically healthy obese individuals demonstrated an adverse adipokine profile. Higher circulating levels of retinol-binding protein 4 and fetuin-A marked future cardiometabolic risk.