Liver stiffness thresholds to predict disease progression and clinical outcomes in bridging fibrosis and cirrhosis.

OBJECTIVE: In retrospective studies, liver stiffness (LS) by vibration-controlled transient elastography (VCTE) is associated with the risk of liver decompensation in patients with non-alcoholic steatohepatitis (NASH), but prospective data in biopsy-confirmed cohorts with advanced fibrosis are limited. We aimed to establish thresholds for LS by VCTE that predict progression to cirrhosis among patients with bridging fibrosis and hepatic decompensation among patients with cirrhosis due to NASH. DESIGN: We used data from four randomised placebo-controlled trials of selonsertib and simtuzumab in participants with advanced fibrosis (F3-F4). The trials were discontinued due to lack of efficacy. Liver fibrosis was staged centrally at baseline and week 48 (selonsertib study) or week 96 (simtuzumab study). Associations between LS by VCTE with disease progression were determined using Cox proportional hazards regression analysis. RESULTS: Progression to cirrhosis occurred in 16% (103/664) of participants with bridging fibrosis and adjudicated liver-related events occurred in 4% (27/734) of participants with baseline cirrhosis. The optimal baseline LS thresholds were ≥16.6 kPa for predicting progression to cirrhosis, and ≥30.7 kPa for predicting liver-related events. Baseline LS ≥16.6 kPa (adjusted HR 3.99; 95% CI 2.66 to 5.98, p<0.0001) and a ≥5 kPa (and ≥20%) increase (adjusted HR 1.98; 95% CI 1.20 to 3.26, p=0.008) were independent predictors of progression to cirrhosis in participants with bridging fibrosis, while baseline LS ≥30.7 kPa (adjusted HR 10.13, 95% CI 4.38 to 23.41, p<0.0001) predicted liver-related events in participants with cirrhosis. CONCLUSION: The LS thresholds identified in this study may be useful for risk stratification of NASH patients with advanced fibrosis.

Cirrhosis regression is associated with improved clinical outcomes in patients with nonalcoholic steatohepatitis.

BACKGROUND AND AIMS: Surrogate endpoints that predict complications are necessary for assessment and approval of NASH therapies. We assessed associations between histologic and noninvasive tests (NITs) of fibrosis with liver-related complications in patients with NASH cirrhosis. APPROACH AND RESULTS: Patients with compensated cirrhosis due to NASH were enrolled in two placebo-controlled trials of simtuzumab and selonsertib. Liver fibrosis at baseline and week 48 (W48) was staged by NASH Clinical Research Network (CRN) and Ishak classifications and a machine learning (ML) approach, hepatic collagen and alpha-smooth muscle actin (α-SMA) expression were quantified by morphometry, liver stiffness (LS) was measured by transient elastography, and serum NITs (enhanced liver fibrosis [ELF], NAFLD fibrosis score [NFS], and Fibrosis-4 index [FIB-4]) were calculated. Cox regression determined associations between these parameters at baseline and their changes over time with adjudicated liver-related clinical events. Among 1,135 patients, 709 (62%) had Ishak stage 6 fibrosis, and median ELF and LS were 10.66 and 21.1 kPa, respectively. During a median follow-up of 16.6 months, 71 (6.3%) had a liver-related event; associated baseline factors included Ishak stage 6 fibrosis, and higher hepatic collagen, α-SMA expression, ML-based fibrosis parameters, LS, ELF, NFS, and FIB-4. Cirrhosis regression observed in 16% (176/1,135) between BL and W48 was associated with a lower risk of events versus nonregression (1.1% [2/176] vs. 7.2% [69/957]; HR, 0.16; 95% CI, 0.04, 0.65 [p = 0.0104]). Conversely, after adjustment for baseline values, increases in hepatic collagen, α-SMA, ML-based fibrosis parameters, NFS, and LS were associated with an increased risk of events. CONCLUSIONS: In patients with compensated cirrhosis due to NASH, regression of fibrosis is associated with a reduction in liver-related complications. These data support the utility of histologic fibrosis regression and NITs as clinical trial endpoints for NASH cirrhosis.

A Machine Learning Approach to Liver Histological Evaluation Predicts Clinically Significant Portal Hypertension in NASH Cirrhosis.

BACKGROUND AND AIMS: The hepatic venous pressure gradient (HVPG) is the standard for estimating portal pressure but requires expertise for interpretation. We hypothesized that HVPG could be extrapolated from liver histology using a machine learning (ML) algorithm. APPROACH AND RESULTS: Patients with NASH with compensated cirrhosis from a phase 2b trial were included. HVPG and biopsies from baseline and weeks 48 and 96 were reviewed centrally, and biopsies evaluated with a convolutional neural network (PathAI, Boston, MA). Using trichrome-stained biopsies in the training set (n = 130), an ML model was developed to recognize fibrosis patterns associated with HVPG, and the resultant ML HVPG score was validated in a held-out test set (n = 88). Associations between the ML HVPG score with measured HVPG and liver-related events, and performance of the ML HVPG score for clinically significant portal hypertension (CSPH) (HVPG ≥ 10 mm Hg), were determined. The ML-HVPG score was more strongly correlated with HVPG than hepatic collagen by morphometry (ρ = 0.47 vs. ρ = 0.28; P < 0.001). The ML HVPG score differentiated patients with normal (0-5 mm Hg) and elevated (5.5-9.5 mm Hg) HVPG and CSPH (median: 1.51 vs. 1.93 vs. 2.60; all P < 0.05). The areas under receiver operating characteristic curve (AUROCs) (95% CI) of the ML-HVPG score for CSPH were 0.85 (0.80, 0.90) and 0.76 (0.68, 0.85) in the training and test sets, respectively. Discrimination of the ML-HVPG score for CSPH improved with the addition of a ML parameter for nodularity, Enhanced Liver Fibrosis, platelets, aspartate aminotransferase (AST), and bilirubin (AUROC in test set: 0.85; 95% CI: 0.78, 0.92). Although baseline ML-HVPG score was not prognostic, changes were predictive of clinical events (HR: 2.13; 95% CI: 1.26, 3.59) and associated with hemodynamic response and fibrosis improvement. CONCLUSIONS: An ML model based on trichrome-stained liver biopsy slides can predict CSPH in patients with NASH with cirrhosis.

Combination Therapies Including Cilofexor and Firsocostat for Bridging Fibrosis and Cirrhosis Attributable to NASH.

BACKGROUND AND AIMS: Advanced fibrosis attributable to NASH is a leading cause of end-stage liver disease. APPROACH AND RESULTS: In this phase 2b trial, 392 patients with bridging fibrosis or compensated cirrhosis (F3-F4) were randomized to receive placebo, selonsertib 18 mg, cilofexor 30 mg, or firsocostat 20 mg, alone or in two-drug combinations, once-daily for 48 weeks. The primary endpoint was a ≥1-stage improvement in fibrosis without worsening of NASH between baseline and 48 weeks based on central pathologist review. Exploratory endpoints included changes in NAFLD Activity Score (NAS), liver histology assessed using a machine learning (ML) approach, liver biochemistry, and noninvasive markers. The majority had cirrhosis (56%) and NAS ≥5 (83%). The primary endpoint was achieved in 11% of placebo-treated patients versus cilofexor/firsocostat (21%; P = 0.17), cilofexor/selonsertib (19%; P = 0.26), firsocostat/selonsertib (15%; P = 0.62), firsocostat (12%; P = 0.94), and cilofexor (12%; P = 0.96). Changes in hepatic collagen by morphometry were not significant, but cilofexor/firsocostat led to a significant decrease in ML NASH CRN fibrosis score (P = 0.040) and a shift in biopsy area from F3-F4 to ≤F2 fibrosis patterns. Compared to placebo, significantly higher proportions of cilofexor/firsocostat patients had a ≥2-point NAS reduction; reductions in steatosis, lobular inflammation, and ballooning; and significant improvements in alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, bile acids, cytokeratin-18, insulin, estimated glomerular filtration rate, ELF score, and liver stiffness by transient elastography (all P ≤ 0.05). Pruritus occurred in 20%-29% of cilofexor versus 15% of placebo-treated patients. CONCLUSIONS: In patients with bridging fibrosis and cirrhosis, 48 weeks of cilofexor/firsocostat was well tolerated, led to improvements in NASH activity, and may have an antifibrotic effect. This combination offers potential for fibrosis regression with longer-term therapy in patients with advanced fibrosis attributable to NASH.

A Machine Learning Approach Enables Quantitative Measurement of Liver Histology and Disease Monitoring in NASH.

BACKGROUND AND AIMS: Manual histological assessment is currently the accepted standard for diagnosing and monitoring disease progression in NASH, but is limited by variability in interpretation and insensitivity to change. Thus, there is a critical need for improved tools to assess liver pathology in order to risk stratify NASH patients and monitor treatment response. APPROACH AND RESULTS: Here, we describe a machine learning (ML)-based approach to liver histology assessment, which accurately characterizes disease severity and heterogeneity, and sensitively quantifies treatment response in NASH. We use samples from three randomized controlled trials to build and then validate deep convolutional neural networks to measure key histological features in NASH, including steatosis, inflammation, hepatocellular ballooning, and fibrosis. The ML-based predictions showed strong correlations with expert pathologists and were prognostic of progression to cirrhosis and liver-related clinical events. We developed a heterogeneity-sensitive metric of fibrosis response, the Deep Learning Treatment Assessment Liver Fibrosis score, which measured antifibrotic treatment effects that went undetected by manual pathological staging and was concordant with histological disease progression. CONCLUSIONS: Our ML method has shown reproducibility and sensitivity and was prognostic for disease progression, demonstrating the power of ML to advance our understanding of disease heterogeneity in NASH, risk stratify affected patients, and facilitate the development of therapies.

Selonsertib for patients with bridging fibrosis or compensated cirrhosis due to NASH: Results from randomized phase III STELLAR trials.

BACKGROUND & AIMS: Apoptosis signal-regulating kinase 1 (ASK1) plays a key role in hepatocyte injury, inflammation, and fibrosis in non-alcoholic steatohepatitis (NASH). We evaluated the safety and antifibrotic effect of selonsertib, a selective inhibitor of ASK1, in patients with advanced fibrosis due to NASH. METHODS: We conducted 2 randomized, double-blind, placebo-controlled, phase III trials of selonsertib in patients with NASH and bridging fibrosis (F3, STELLAR-3) or compensated cirrhosis (F4, STELLAR-4). Patients were randomized 2:2:1 to receive selonsertib 18 mg, selonsertib 6 mg, or placebo once daily for 48 weeks. Liver biopsies were performed at screening and week 48 and non-invasive tests of fibrosis (NITs) were evaluated. The primary efficacy endpoint was the proportion of patients with ≥1-stage improvement in fibrosis without worsening of NASH at week 48. Additional endpoints included changes in NITs, progression to cirrhosis (in STELLAR-3), and liver-related clinical events. RESULTS: Neither trial met the primary efficacy endpoint. In STELLAR-3, fibrosis improvement without worsening of NASH was observed in 10% (31/322, p = 0.49 vs. placebo), 12% (39/321, p = 0.93 vs. placebo), and 13% (21/159) of patients in the selonsertib 18 mg, selonsertib 6 mg, and placebo groups, respectively. In STELLAR-4, the primary endpoint was achieved in 14% (51/354; p = 0.56), 13% (45/351; p = 0.93), and 13% (22/172) of patients, respectively. Although selonsertib led to dose-dependent reductions in hepatic phospho-p38 expression indicative of pharmacodynamic activity, it had no significant effect on liver biochemistry, NITs, progression to cirrhosis, or adjudicated clinical events. The rates and types of adverse events were similar among selonsertib and placebo groups. CONCLUSIONS: Forty-eight weeks of selonsertib monotherapy had no antifibrotic effect in patients with bridging fibrosis or compensated cirrhosis due to NASH. LAY SUMMARY: Patients with non-alcoholic steatohepatitis (NASH) can develop scarring of the liver (fibrosis), including cirrhosis, which increases the risks of liver failure and liver cancer. We tested whether 48 weeks of treatment with selonsertib reduced fibrosis in patients with NASH and advanced liver scarring. We did not find that selonsertib reduced fibrosis in these patients. TRIAL REGISTRATION DETAILS: Clinicaltrials.gov numbers NCT03053050 and NCT03053063.

The Natural History of Advanced Fibrosis Due to Nonalcoholic Steatohepatitis: Data From the Simtuzumab Trials.

Progression of nonalcoholic steatohepatitis (NASH) is incompletely characterized. We analyzed data on longitudinal changes in liver histology, hepatic venous pressure gradient (HVPG), and serum markers of fibrosis in 475 patients with NASH with bridging fibrosis (F3) or compensated cirrhosis (F4) enrolled in two phase 2b, placebo-controlled trials of simtuzumab. The trials were terminated after 96 weeks because of lack of efficacy, so data from treatment groups were combined. Liver biopsies and HVPG measurements (only for patients with F4 fibrosis) were collected at screening and at weeks 48 and 96. Patients were assessed for Ishak fibrosis stage, hepatic collagen content and alpha-smooth muscle actin (by morphometry), NAFLD Activity Score (NAS), and serum markers of fibrosis. Associations with progression to cirrhosis (in patients with F3 fibrosis) and liver-related clinical events (in patients with F4 fibrosis) were determined. Progression to cirrhosis occurred in 22% (48/217) of F3 patients, and liver-related clinical events occurred in 19% (50/258) of patients with cirrhosis. Factors significantly associated with progression to cirrhosis included higher baseline values of and greater increases in hepatic collagen content, level of alpha-smooth muscle actin, and Enhanced Liver Fibrosis score. Similar factors, plus lack of fibrosis stage improvement (hazard ratio, 9.30; 95% confidence interval, 1.28-67.37), higher HVPG at baseline, and greater increase in HVPG over time, were associated with an increased risk of liver-related clinical events in patients with cirrhosis. Disease progression was not associated with the NAS at baseline or changes in NAS during treatment after adjustment for fibrosis stage. Conclusion: In patients with advanced fibrosis due to NASH, the primary determinant of clinical disease progression is fibrosis and its change over time.

Simtuzumab for Primary Sclerosing Cholangitis: Phase 2 Study Results With Insights on the Natural History of the Disease.

Lysyl oxidase like-2 (LOXL2) plays a central role in fibrogenesis and is elevated in the serum and liver of patients with primary sclerosing cholangitis (PSC). We evaluated the safety and efficacy of simtuzumab, a monoclonal antibody directed against LOXL2, in patients with PSC. Patients with compensated liver disease caused by PSC were randomized 1:1:1 to receive weekly subcutaneous injections of simtuzumab 75 mg, simtuzumab 125 mg, or placebo for 96 weeks. The primary efficacy endpoint was mean change in hepatic collagen content assessed by morphometry between baseline and week 96. Additional endpoints included change in Ishak fibrosis stage and the frequency of PSC-related clinical events. Overall, 234 patients were randomized and started treatment. At week 96, the mean change from baseline in hepatic collagen content was -0.5% for patients receiving simtuzumab 75 mg (P = 0.73 versus placebo), +0.5% for patients receiving simtuzumab 125 mg (P = 0.33 versus placebo), and 0.0 for patients receiving placebo. Compared with placebo, neither dose of simtuzumab led to significant reductions in Ishak fibrosis stage, progression to cirrhosis, or frequency of clinical events. Overall, 80 (34%) patients had fibrosis progression and 47 (20%) experienced PSC-related clinical events. In a multivariate model of baseline factors, PSC-related clinical events were more frequent in patients with advanced fibrosis (hazard ratio [HR], 2.03; 95% confidence interval [CI], 1.02-4.06; P = 0.045), higher alkaline phosphatase (HR per 10 U/L, 1.01; 95% CI, 1.00-1.02; P = 0.015), and higher enhanced liver fibrosis score (HR per unit, 1.26; 95% CI, 0.98-1.61; P = 0.073). Overall, rates of adverse events and laboratory abnormalities were similar between groups. Conclusion: Treatment with the LOXL2 inhibitor simtuzumab for 96 weeks did not provide clinical benefit in patients with PSC.

Noninvasive Tests Accurately Identify Advanced Fibrosis due to NASH: Baseline Data From the STELLAR Trials.

Accurate noninvasive tests (NITs) are needed to replace liver biopsy for identifying advanced fibrosis caused by nonalcoholic steatohepatitis (NASH). We analyzed screening data from two phase 3 trials of selonsertib to assess the ability of NITs to discriminate advanced fibrosis. Centrally read biopsies from the STELLAR studies, which enrolled patients with bridging fibrosis and compensated cirrhosis, were staged according to the NASH Clinical Research Network classification. We explored associations between fibrosis stage and NITs, including the nonalcoholic fatty liver disease fibrosis score (NFS), fibrosis-4 (FIB-4) index, Enhanced Liver Fibrosis (ELF) test, and liver stiffness by vibration-controlled transient elastography (LS by VCTE). The performance of these tests to discriminate advanced fibrosis, either alone or in combinations, was evaluated using areas under the receiver operating characteristic curve (AUROCs) with 5-fold cross-validation repeated 100 times. Of the 4,404 patients screened for these trials, 3,202 had evaluable biopsy data: 940 with F0-F2 fibrosis and 2,262 with F3-F4 fibrosis. Significant differences between median values of NITs for patients with F0-F2 versus F3-F4 fibrosis were observed: -0.972 versus 0.318 for NFS, 1.18 versus 2.20 for FIB-4, 9.22 versus 10.39 for ELF, and 8.8 versus 16.5 kPa for LS by VCTE (all P < 0.001). AUROCs ranged from 0.75 to 0.80 to discriminate advanced fibrosis. FIB-4 followed by an LS by VCTE or ELF test in those with indeterminate values (FIB-4 between 1.3 and 2.67) maintained an acceptable performance while reducing the rate of indeterminate results. Conclusion: Among patients being considered for enrollment into clinical trials, NITs alone or in combination can reduce the need for liver biopsy to discriminate advanced fibrosis caused by NASH. The predictive value of these tests for general screening will require confirmation in a real-world population.

Simtuzumab Is Ineffective for Patients With Bridging Fibrosis or Compensated Cirrhosis Caused by Nonalcoholic Steatohepatitis.

BACKGROUND & AIMS: Lysyl oxidase-like 2 contributes to fibrogenesis by catalyzing cross-linkage of collagen. We evaluated the safety and efficacy of simtuzumab, a monoclonal antibody against lysyl oxidase-like 2, in two phase 2b trials of patients with advanced fibrosis caused by nonalcoholic steatohepatitis. METHODS: We performed a double-blind study of 219 patients with bridging fibrosis caused by nonalcoholic steatohepatitis who were randomly assigned (1:1:1) to groups given weekly subcutaneous injections of simtuzumab (75 or 125 mg) or placebo for a planned duration of 240 weeks. We performed a separate study of 258 patients with compensated cirrhosis randomly assigned (1:1:1) to groups given intravenous infusions of simtuzumab (200 or 700 mg) or placebo every other week. The studies were performed from January 2013 through July 2014 at 80 sites in North America and Europe. Biopsy specimens were collected and analyzed at screening and at weeks 48 and 96; clinical information and serum levels of fibrosis biomarkers were collected throughout the study. The primary end point was change from baseline to week 96 in hepatic collagen content, measured by morphometry of liver specimens, in patients with bridging fibrosis; for patients with cirrhosis, the primary end point was change in hepatic venous pressure gradient from baseline to week 96. RESULTS: The 2 studies were stopped after week 96 because of lack of efficacy. All 3 groups of patients with bridging fibrosis-including those given placebo-had significant decreases in hepatic collagen content, but there was no statistically significant difference in decrease between patients receiving simtuzumab 75 mg and those receiving placebo (-0.2%, 95% confidence interval [CI] -1.3 to 1.0, P = .77) or between patients receiving simtuzumab 125 mg and those receiving placebo (-0.4%, 95% CI -1.5 to 0.8, P = .52). In patients with cirrhosis, the mean difference in hepatic venous pressure gradient between the 2 simtuzumab groups and the placebo group was 0.1 mm Hg (95% CI -1.2 to 1.5, P = .84 for 200 mg; 95% CI -1.2 to 1.4, P = .88 for 700 mg). Simtuzumab did not significantly decrease fibrosis stage, progression to cirrhosis in patients with bridging fibrosis, or liver-related clinical events in patients with cirrhosis. Rates of adverse events were similar among groups. CONCLUSION: In two phase 2b trials of patients with bridging fibrosis or compensated cirrhosis associated with nonalcoholic steatohepatitis, simtuzumab was ineffective in decreasing hepatic collagen content or hepatic venous pressure gradient, respectively. Clinicaltrials.govNCT01672866 and NCT01672879.

Neurologic adverse events in patients with relapsed/refractory acute lymphoblastic leukemia treated with blinatumomab: management and mitigating factors.

Neurologic events (NEs) have been reported during treatment with blinatumomab, a bispecific T cell engager (BiTE®) construct. We evaluated the occurrence, severity, and management of NEs; the relationship between NEs and blinatumomab dose; and the potential clinical risk factors in an open-label, single-arm, phase 2 study (N = 189). Patients had Philadelphia chromosome-negative, relapsed/refractory acute lymphoblastic leukemia (ALL) and ≥ 10% bone marrow blasts. The relationship between blinatumomab exposure and NE incidence and severity was assessed. Clinical risk factors for NEs were assessed in a post hoc multivariate analysis. Overall, 98 patients (52%) experienced NEs: most frequently, dizziness, tremor, confusional state, and encephalopathy. NEs occurred predominantly during cycle 1 (median onset, 9 days) and were usually grades 1 or 2. Grade ≥ 3 NEs (13-17% incidence), serious NEs (16-19% incidence), and recurring NEs were managed with infusion interruptions or dexamethasone treatment. The incidence of NEs increased with increasing blinatumomab exposure at a given dose, but exposure appeared unrelated to NE severity. NEs were more frequent in patients ≥ 65 years than < 65 years (72 vs 49%). In a multivariate analysis, race other than white (hazard ratio [HR], 2.11; P = 0.009), > 2 prior salvage therapies (HR, 2.48; P = 0.006), and prior NEs (HR, 1.65; P = 0.020) were risk factors for time to first on-study NE. Although the mechanism underlying NEs associated with blinatumomab treatment in patients with relapsed/refractory ALL remains unclear, NEs tended to occur early during treatment and were often resolved by interrupting treatment and with dexamethasone. Additional research is warranted to investigate the risk factors for NEs.

Blinatumomab treatment of older adults with relapsed/refractory B-precursor acute lymphoblastic leukemia: Results from 2 phase 2 studies.

BACKGROUND: Older adults with relapsed/refractory B-precursor acute lymphoblastic leukemia (r/r ALL) are reported to have a poor prognosis and few therapeutic options. In the current study, the authors evaluated treatment with single-agent blinatumomab in adults aged ≥65 years with r/r ALL. METHODS: A total of 261 adults with r/r ALL who were examined across two phase 2 studies received blinatumomab in cycles of 4-week continuous infusion and 2-week treatment-free intervals. The primary endpoint in each study was complete remission (CR) or CR with partial hematologic recovery (CRh) during the first 2 cycles. Data were pooled and analyzed according to patient age at screening (aged ≥65 years vs aged <65 years). RESULTS: Of 36 older adults, 56% (95% confidence interval [95% CI], 38%-72%) achieved CR/CRh during the first 2 cycles compared with 46% (225 patients) (95% CI, 40%-53%) of younger adults. Complete minimal residual disease responses were 60% in older and 70% in younger responders. Three older responders (15%) and 61 younger responders (59%) proceeded to allogeneic hematopoietic stem cell transplantation. Kaplan-Meier curves overlapped for relapse-free and overall survival for both age groups. Older adults were found to have a similar incidence of grade ≥3 adverse events (AEs) as younger adults (86% vs 80%) but more grade ≥3 neurologic events (28% vs 13%). Cytokine release syndrome occurred in 7 older (19%) (1 case of grade 3) and 23 younger (10%) (4 cases of grade ≥3) adults. There were no treatment-related fatal AEs reported. CONCLUSIONS: Older adults with r/r ALL who were treated with single-agent blinatumomab were found to have similar hematologic response rates and incidence of grade ≥3 AEs compared with younger adults but had more neurologic events, which were reversible and primarily resolved with treatment interruption. Cancer 2016;122:2178-85. © 2016 American Cancer Society.

Safety and activity of blinatumomab for adult patients with relapsed or refractory B-precursor acute lymphoblastic leukaemia: a multicentre, single-arm, phase 2 study.

BACKGROUND: Adults with relapsed or refractory B-precursor acute lymphoblastic leukaemia have an unfavourable prognosis. Blinatumomab is a bispecific T-cell engager antibody construct targeting CD19, an antigen consistently expressed on B-lineage acute lymphoblastic leukaemia cells. We aimed to confirm the activity and safety profile of blinatumomab for acute lymphoblastic leukaemia. METHODS: In a multicentre, single-arm, open-label phase 2 study, we enrolled adult patients with Philadelphia-chromosome-negative, primary refractory or relapsed (first relapse within 12 months of first remission, relapse within 12 months after allogeneic haemopoietic stem-cell transplantation [HSCT], or no response to or relapse after first salvage therapy or beyond) leukaemia. Patients received blinatumomab (9 µg/day for the first 7 days and 28 µg/day thereafter) by continuous intravenous infusion over 4 weeks every 6 weeks (up to five cycles), per protocol. The primary endpoint was complete remission (CR) or CR with partial haematological recovery of peripheral blood counts (CRh) within the first two cycles. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, number NCT01466179. FINDINGS: Between Jan 13, 2012, and Oct 10, 2013, 189 patients were enrolled and treated with blinatumomab. After two cycles, 81 (43%, 95% CI 36-50) patients had achieved a CR or CRh: 63 (33%) patients had a CR and 18 (10%) patients had a CRh. 32 (40%) of patients who achieved CR/CRh underwent subsequent allogeneic HSCT. The most frequent grade 3 or worse adverse events were febrile neutropenia (48 patients, 25%), neutropenia (30 patients, 16%), and anaemia (27 patients, 14%). Three (2%) patients had grade 3 cytokine release syndrome. Neurologic events of worst grade 3 or 4 occurred in 20 (11%) and four (2%) patients, respectively. Three deaths (due to sepsis, Escherichia coli sepsis, and Candida infection) were thought to be treatment-related by the investigators. INTERPRETATION: Single-agent blinatumomab showed antileukaemia activity in adult patients with relapsed or refractory B-precursor acute lymphoblastic leukaemia characterised by negative prognostic factors. Further assessment of blinatumomab treatment earlier in the course of the disease and in combination with other treatment approaches is warranted. FUNDING: Amgen.

Hypothesis testing for two-stage designs with over or under enrollment.

Simon's two-stage designs are widely used in cancer phase II clinical trials for assessing the efficacy of a new treatment. However in practice, the actual sample size for the second stage is often different from the planned sample size, and the original inference procedure is no longer valid. Previous work on this problem has certain limitations in computation. In this paper, we attempt to maximize the unconditional power while controlling for the type I error for the modified second stage sample size. A normal approximation is used for computing the power, and the numerical results show that the approximation is accurate even under small sample sizes. The corresponding confidence intervals for the response rate are constructed by inverting the hypothesis test, and they have reasonable coverage while preserving the type I error.

Development and validation of a model to predict platelet response to romiplostim in patients with lower-risk myelodysplastic syndromes.

Low endogenous erythropoietin levels and limited red blood cell transfusion history can predict response to erythropoiesis-stimulating agents in anaemic patients with myelodysplastic syndromes (MDS). The relationship between endogenous thrombopoietin (THPO) levels and platelet response to romiplostim is unknown. Variables including baseline endogenous THPO levels, transfusion needs, and platelet response were analysed in a randomized trial of 250 thrombocytopenic, lower-risk MDS patients (International Prognostic Scoring System low/intermediate-1). A predictive scoring system was developed based on log-likelihood ratios and logistic coefficients. Patients with HI-P (haematological improvement - platelets) responses had lower mean baseline THPO levels (P = 0·0497) and were more likely to have <6 platelet units transfused in the past year (P = 0·0027), as did patients with platelet responses ≥50% of weeks on romiplostim (P = 0·001 and P = 0·0037, respectively). A model for predicting response to romiplostim was developed and validated in a separate MDS cohort (N = 72). Patients in low-, intermediate-, and high-response groups had response rates of 17·4%, 29·6%, and 50·7%, respectively, for HI-P, and 17·4%, 33·8%, and 65·2%, respectively, for ≥50% response. For thrombocytopenic patients with lower-risk MDS, lower baseline THPO levels (<500 pg/ml) and limited platelet transfusion history predicted a greater likelihood of a subsequent platelet response to romiplostim.

Bayesian design of superiority clinical trials for recurrent events data with applications to bleeding and transfusion events in myelodyplastic syndrome.

In many biomedical studies, patients may experience the same type of recurrent event repeatedly over time, such as bleeding, multiple infections and disease. In this article, we propose a Bayesian design to a pivotal clinical trial in which lower risk myelodysplastic syndromes (MDS) patients are treated with MDS disease modifying therapies. One of the key study objectives is to demonstrate the investigational product (treatment) effect on reduction of platelet transfusion and bleeding events while receiving MDS therapies. In this context, we propose a new Bayesian approach for the design of superiority clinical trials using recurrent events frailty regression models. Historical recurrent events data from an already completed phase 2 trial are incorporated into the Bayesian design via the partial borrowing power prior of Ibrahim et al. (2012, Biometrics 68, 578-586). An efficient Gibbs sampling algorithm, a predictive data generation algorithm, and a simulation-based algorithm are developed for sampling from the fitting posterior distribution, generating the predictive recurrent events data, and computing various design quantities such as the type I error rate and power, respectively. An extensive simulation study is conducted to compare the proposed method to the existing frequentist methods and to investigate various operating characteristics of the proposed design.

Multivariate recurrent events in the presence of multivariate informative censoring with applications to bleeding and transfusion events in myelodysplastic syndrome.

We propose a general novel class of joint models to analyze recurrent events that has a wide variety of applications. The focus in this article is to model the bleeding and transfusion events in myelodysplastic syndrome (MDS) studies, where patients may die or withdraw from the study early due to adverse events or other reasons, such as consent withdrawal or required alternative therapy during the study. The proposed model accommodates multiple recurrent events and multivariate informative censoring through a shared random-effects model. The random-effects model captures both within-subject and within-event dependence simultaneously. We construct the likelihood function for the semiparametric joint model and develop an expectation-maximization (EM) algorithm for inference. The computational burden does not increase with the number of types of recurrent events. We utilize the MDS clinical trial data to illustrate our proposed methodology. We also conduct a number of simulations to examine the performance of the proposed model.

Thermal styling: efficacy, convenience, damage tradeoffs.

We introduce a simple method to explore the efficacy of thermal styling, By using a temperature gradient curling iron we rapidly explore a range of thermal treatment conditions. The thermodynamic literature on the glass transition in keratin fibers explains the surprisingly limited role of elevated temperature in improvements in the efficacy of holding the styled curvature of the fibers. The onset of damage, however, is strongly temperature dependent. This combination of measurements of damage and efficacy shows the range of conditions over which thermal protection products must be functional.