The flavonoid fustin exerts anti-inflammatory effect in a model of carrageenan-induced paw oedema

Carrageenan-induced paw oedema is a widely used model of acute inflammation. The objective of this study was to assess the effect of the flavonoid fustin on carrageenan-induced acute paw inflammation in rats. Thirty male Wistar rats were distributed equally between three groups – control, F10, and F20. In the course of 1 week, animals were treated once daily by intragastric gavage as follows: control group – with distilled water (10 mL kg−1) containing 50 μL Tween 80; groups F10 and F20 – with 10 mL kg−1 suspensions containing fustin in two doses (10 mg kg−1 and 20 mg kg−1, respectively) and 50 μL Tween 80. After the treatment period, carrageenan was injected in the left hind paw and paw oedema was evaluated 0, 30, 60, 120, 180, 240, and 300 min after the injection using a plethysmometer. In the control group, paw oedema increased gradually and peaked at the 180th minute. Fustin treatment reduced the oedema in all time intervals and the effect was significant on the 30th and 60th minute after the injection. The present study indicated that fustin could suppress acute inflammation.

TTI-622-01: A phase 1a/1b dose-escalation and expansion trial of TTI-622 in patients with advanced hematologic malignancies, including diffuse large B-cell lymphoma (DLBCL)

TPS7595

Background: CD47 is an innate immune checkpoint that binds signal regulatory protein alpha (SIRPα) and delivers a "don’t eat me" signal to suppress macrophage phagocytosis. Overexpression of CD47 on cancer cells serves as a mechanism of immune surveillance evasion, and is associated with poor prognosis in both hematologic and solid malignancies. TTI-622 is a fusion protein consisting of the CD47-binding domain of human SIRPα linked to the Fc region of human IgG4. It is designed to enhance phagocytosis and antitumor activity by preventing CD47 from delivering its inhibitory signal as well as generating a moderate pro-phagocytic signal via IgG4 Fc. Importantly, unlike many CD47-blocking agents, TTI-622 does not bind to human red blood cells. Preclinical studies demonstrate that TTI-622 induces macrophage-mediated phagocytosis of different malignant cell lines, including DLBCL cells, decreases tumor growth and improves survival in a DLBCL xenograft tumor model. Anti-CD47 antibody enhances rituximab stimulated macrophage-mediated phagocytosis of non-GCB DLBCL cell lines (Bouwstra et al, Cancer Immunol Res. 2019). The ongoing phase 1a part of this study has been previously described. Here we describe 2 cohorts within the phase 1b part of the study that are intended to determine the safety and preliminary efficacy of TTI-622 when given in combination with anti-CD20 targeting agent in patients with CD20+ relapsed/refractory (RR) DLBCL. Methods: TTI-622-01 is a multi-center Phase 1a/1b study. Phase 1a was designed to determine the MTD, pharmacokinetics (PK), pharmacodynamics, and preliminary antitumor activity of QW, Q2W, and Q3W single-agent TTI-622 in R/R lymphoma using a 3+3 dose escalation schema. Phase 1b, ongoing, will determine the safety, recommended dose and preliminary efficacy of TTI-622 in combination with select approved anticancer treatments for patients with hematological malignancies including, but not limited to anti-CD20 therapy in patients with CD20+ RR DLBCL. Secondary objectives are to further characterize safety, PK and immunogenicity of TTI-622 when combined with approved therapies. Patients will be enrolled in 2 cohorts exploring different doses of TTI-622 in combination with anti-CD20 therapy. Cohorts will open in a staggered manner. In each cohort 3 patients will be dosed and followed for 28 days before expanding enrolment to additional 27 patients per cohort. Key eligibility criteria include: age ≥18 years; relapsed and/or refractory disease after ≥1 prior line of therapy; not eligible for or have progressed after high dose chemotherapy (HDT)/auto-SCT; ≥1 site of measurable disease (Lugano 2014 classification); ECOG PS ≤2; adequate organ functions, no known CNS involvement; no prior anti-CD47 or anti-SIRPα therapy. Patient recruitment is planned or ongoing at 40 sites worldwide. Clinical trial information: NCT03530683.

Promising La2Mo2O9-La2Mo3O12 Composite Oxygen-Ionic Electrolytes: Interphase Phenomena

The La₂Mo₂O₉-La₂Mo₃O₁₂ composite materials represent a novel class of highly conductive materials demonstrating increased oxygen-ion conductivity. Extensive research of (100 - x)La₂Mo₂O₉-xLa₂Mo₃O₁₂ composites over a wide range of concentrations (x = 5, 10, 15, 20, 30, and 100) was carried out for the first time. An increase in conductivity, oxygen surface exchange coefficient, and oxygen diffusivity is observed for composites compared to individual oxides, which is associated with the segregation of different ions on the surface of the grains and the formation of a La₅Mo₃O₁₆ new phase at the contact boundary of La₂Mo₂O₉ and La₂Mo₃O₁₂. 3D-modeling of the composite microstructure was performed on the basis of SEM-image analysis data in order to estimate the conductivity of the interphase layer between the La₂Mo₂O₉ and La₂Mo₃O₁₂ grains containing La₅Mo₃O₁₆. The electrical conductivity values of the composite materials calculated from a 3D-simulated microstructure and the experimentally measured conductivity correlate and demonstrate a composite effect.

456 A phase 1b/2 umbrella study of anti-PD-1 sasanlimab in combination with other therapies for patients with stage IIIB/IV non-small cell lung cancer (NSCLC): The LANDSCAPE 1011 trial in progress

Background

Programmed cell death protein 1 (PD-1) inhibitors as monotherapy or in combination with chemotherapy have become a standard of care first-line therapy for Stage IIIB/IV non-small cell lung cancer (NSCLC). However, many patients experience disease progression and require subsequent therapy within the first year of treatment.1 For patients requiring salvage chemotherapy, prognosis is poor, with a median progression-free survival (PFS) and overall survival (OS) of 4.0 and 8.5 months, respectively.2 Combinations of PD-1 blockade using sasanlimab (PF-06801591) and other immune and/or targeted therapies may be able to achieve clinical response in patients who have progressed on standard chemoimmunotherapy.

Methods

LANDSCAPE 1011 (NCT04585815) is a prospective, open-label, multi-center, parallel group, phase 1b/2 umbrella study evaluating the safety, efficacy, pharmacokinetics, and pharmacodynamics of sasanlimab in combination with other therapies, in patients with Stage IIIB/IV NSCLC. The study is expected to enrol ~375 patients age 18 years or older diagnosed with stage IIIB/IV NSCLC. During phase 1b, the safety of each sub-study combination with subcutaneous sasanlimab will be assessed and the recommended phase 2 dose determined for each combination. Phase 2 will further evaluate safety and anti-tumor activity of each combination using the respective recommended phase 2 dose (figure 1). Up to 5 parallel sub-studies are planned. Currently, 2 sub-studies are ongoing. Sub-Study A will investigate sasanlimab, encorafenib (a BRAF inhibitor), and binimetinib (a MEK inhibitor) in patients with BRAF^V600E mutations (only including treatment-naïve patients in phase 2). Sub-Study B will investigate sasanlimab, axitinib (a vascular endothelial growth factor receptor inhibitor), and SEA-TGT (an anti-TIGIT antibody). In phase 2, this will involve treatment-naïve patients without oncogene drivers who have PD ligand 1-positive tumors or whose disease has progressed on prior immune checkpoint inhibitor-containing regimens. The primary phase 1b endpoint is the dose-limiting toxicity during the first cycle (28 days). The primary phase 2 endpoint in Sub-Study A is durable objective response (OR) defined as confirmed complete response or partial response lasting 10 or more months; and in Sub-Study B, OR defined as confirmed complete response or partial response, according to Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Secondary endpoints include adverse events and laboratory abnormalities, duration of response, time to tumor response, PFS, OS, OR by PD-L1 expression at baseline, pharmacokinetic parameters, incidence of anti-drug antibodies and neutralizing antibodies, and health-related quality of life. The first patient was enrolled in November 2020.

Abstract 456 Figure 1

LANDSCAPE 1011 study overview

Acknowledgements

This study was sponsored by Pfizer. Medical writing and editorial support was provided by Simon Stones at Engage Scientific Solutions, and funded by Pfizer. The authors would like to acknowledge the late Aron Thall, who was highly devoted to the execution and success of this study.

Trial Registration

ClinicalTrials.

gov NCT04585815

References

Gandhi L, Rodriguez-Abreu D, Gadgeel S, et al. Pembrolizumab plus Chemotherapy in Metastatic Non-Small-Cell Lung Cancer. N Engl J Med 2018;378:2078–92.

Herbst RS, Baas P, Kim DW, et al. Pembrolizumab versus docetaxel for previously treated, PD-L1-positive, advanced non-small-cell lung cancer (KEYNOTE-010): a randomised controlled trial. Lancet 2016;387:1540–50.

Ethics Approval

The study is approved at each study site according to local regulations.

Avelumab plus standard-of-care chemoradiotherapy versus chemoradiotherapy alone in patients with locally advanced squamous cell carcinoma of the head and neck: a randomised, double-blind, placebo-controlled, multicentre, phase 3 trial

BACKGROUND

Chemoradiotherapy is the standard of care for unresected locally advanced squamous cell carcinoma of the head and neck. We aimed to assess if addition of avelumab (anti-PD-L1) to chemoradiotherapy could improve treatment outcomes for this patient population.

METHODS

In this randomised, double-blind, placebo-controlled, phase 3 study, patients were recruited from 196 hospitals and cancer treatment centres in 22 countries. Patients aged 18 years or older, with histologically confirmed, previously untreated, locally advanced squamous cell carcinoma of the oropharynx, hypopharynx, larynx, or oral cavity (unselected for PD-L1 status), an Eastern Cooperative Oncology Group performance status score of 0 or 1, and who could receive chemoradiotherapy were eligible. Patients were randomly assigned (1:1) centrally by means of stratified block randomisation with block size four (stratified by human papillomavirus status, tumour stage, and nodal stage, and done by an interactive response technology system) to receive 10 mg/kg avelumab intravenously every 2 weeks plus chemoradiotherapy (100 mg/m2 cisplatin every 3 weeks plus intensity-modulated radiotherapy with standard fractionation of 70 Gy [35 fractions during 7 weeks]; avelumab group) or placebo plus chemoradiotherapy (placebo group). This was preceded by a single 10 mg/kg avelumab or placebo lead-in dose given 7 days previously and followed by 10 mg/kg avelumab or placebo every 2 weeks maintenance therapy for up to 12 months. The primary endpoint was progression-free survival by investigator assessment per modified Response Evaluation Criteria in Solid Tumors, version 1.1, in all randomly assigned patients. Adverse events were assessed in patients who received at least one dose of avelumab or placebo. This trial is registered with ClinicalTrials.gov, NCT02952586. Enrolment is no longer ongoing, and the trial has been discontinued.

FINDINGS

Between Dec 12, 2016, and Jan 29, 2019, from 907 patients screened, 697 patients were randomly assigned to the avelumab group (n=350) or the placebo group (n=347). Median follow-up for progression-free survival was 14·6 months (IQR 8·5-19·6) in the avelumab group and 14·8 months (11·6-18·8) in the placebo group. Median progression-free survival was not reached (95% CI 16·9 months-not estimable) in the avelumab group and not reached (23·0 months-not estimable) in the placebo group (stratified hazard ratio 1·21 [95% CI 0·93-1·57] favouring the placebo group; one-sided p=0·92). The most common grade 3 or worse treatment-related adverse events were neutropenia (57 [16%] of 348 patients in the avelumab group vs 52 [15%] of 344 patients in the placebo group), mucosal inflammation (50 [14%] vs 45 [13%]), dysphagia (49 [14%] vs 47 [14%]), and anaemia (41 [12%] vs 44 [13%]). Serious treatment-related adverse events occurred in 124 (36%) patients in the avelumab group and in 109 (32%) patients in the placebo group. Treatment-related deaths occurred in two (1%) patients in the avelumab group (due to general disorders and site conditions, and vascular rupture) and one (<1%) in the placebo group (due to acute respiratory failure).

INTERPRETATION

The primary objective of prolonging progression-free survival with avelumab plus chemoradiotherapy followed by avelumab maintenance in patients with locally advanced squamous cell carcinoma of the head and neck was not met. These findings may help inform the design of future trials investigating the combination of immune checkpoint inhibitors plus CRT.

FUNDING

Pfizer and Merck KGaA, Darmstadt, Germany.

P1572 The role of 3D echocardiography in the evaluation of left ventricular remodeling

Purpose

to assess the left ventricular (LV) remodeling with using transthoracic 3D Echo and MRI in young athletes.

Materials

for the period from October 2015 to April 2018, 88 athletes (61 men and 27 women) were examined. Mean age was 20.8 ± 3.9 years. Group A (professionals) – 65 athletes (4 or more training days a week, experience in sports for at least 7 years, the presence of at least the 1st sports category). Group B (Amateurs) – 23 athletes (3 or less training days a week). By types of loads were identified 4 groups: 1st - high-static, low-dynamic (climbing); 2nd - medium-static, medium-dynamic (volleyball, Rugby, sports dancing); 3rd - medium-static, high-dynamic (badminton, orienteering, hockey); 4th - high-static, high-dynamic (triathlon, water polo, rowing).

Methods

2D-, 3D-Echo was performed on Vivid E9 XDclear 4D (GE, USA). With the help of software package for processing 3D arrays (4D auto LVQ and 4D Strain and LV-mass) in automatic and semi-automatic mode was obtained end diastolic and end systolic volumes (EDV, ESV), ejection fraction (EF) and LV mass. The device was used for MRI - Avanto (Siemens) - 1.5 T, using: sensors for breathing and synchronization with ECG, standard surface coil Body Matrix. Visualization of the mobile myocardium was carried out by SSFP protocols in standard two-and four-chamber view, as well as on the short axis. In addition, the black-blood Protocol was performed in axial projection for visualization of mediastinal organs and chest. Evaluation of the results was performed on a workstation Syngo Via VB10B (Siemens) using a worker thread MR Cardiac analisis.

Results

There were significant differences in the types of loads (p &lt; 0.001): 22% of men in Group B had 1st type, 2nd type - 78% of men and 93% of women in group B, 3rd type - 45% of men and 36% of women in group A, 4th type - 39% of men and 21% of women in group A. In the evaluation of LV remodeling and its relationship with the type of loads revealed significant differences (p &lt; 0.01): 87.5% had LV remodeling (95.4% - aggregate type load 1, 2, 3), 6.8% - concentric remodeling (21.7% of all type 4), and 4.5% eccentric hypertrophy (8.7% of all type 4), 1.1 per cent of concentric hypertrophy (4.4% of all type 4). Consequently, most athletes with loads of type 4 had different types of LV remodeling. Comparing 3D Echo and MRI, high-grade positive correlations were obtained in indicators: EDV (R 0.82, p &lt; 0.0001), ESV (R 0.80, p &lt; 0.0001), LV mass (R 0.85, p &lt; 0.0001), as well as moderate positive the index of EDV (R 0.54, p &lt; 0.037) and unreliable for the EF.

Conclusions

three-dimensional visualization allows to carry out a reliable assessment of the volumetric parameters of the heart chambers, comparable with MRI data and to identify the signs and type of LV remodeling.

Requires further study of the performance of 3D Echo in athletes, given the lack of normative data on the modern stage.

10-million-elements-per-second printing of infrared-resonant plasmonic arrays by multiplexed laser pulses

We report on high-quality infrared (IR)-resonant plasmonic nanoantenna arrays fabricated on a thin gold film by tightly focused femtosecond (fs) laser pulses coming at submegahertz repetition rates at a printing rate of 10 million elements per second. To achieve this, the laser pulses were spatially multiplexed by fused silica diffractive optical elements into 51 identical submicrometer-sized laser spots arranged into a linear array at periodicity down to 1 μm. The demonstrated high-throughput nanopatterning modality indicates fs laser maskless microablation as an emerging robust, flexible, and competitive lithographic tool for advanced fabrication of IR-range plasmonic sensors for environmental sensing, chemosensing, and biosensing.

Phase 1b/3 study of avelumab-based combination regimens in patients with relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL)

TPS7575

Background: Approximately 50% of patients (pts) with advanced DLBCL are refractory to or relapse following first line R-CHOP therapy. Pts with R/R DLBCL have limited treatment options and a poor prognosis. This study assesses immunotherapy-based regimens containing avelumab (a fully human IgG1 anti–PD-L1 antibody) in combination with utomilumab (a novel 4-1BB agonist), azacitidine, rituximab, and/or conventional chemotherapy (CT; bendamustine) in pts with R/R DLBCL. Methods: JAVELIN DLBCL (NCT02951156) is a global, multicenter, randomized, open-label, 2-component(phase 1b followed by phase 3) study of avelumab-based combination regimens in R/R DLBCL. In phase 1b, up to 84 pts will be randomized 1:1:1 to receive avelumab/rituximab/utomilumab, or avelumab/azacitidine/utomilumab, or avelumab/rituximab/bendamustine. The primary phase 1b objectives are preliminary assessments of dose-limiting toxicities (n = 6 per arm) and efficacy (objective response [OR]; n = 28 per arm). One regimen from phase 1b will be selected for phase 3 evaluation in 220 additional pts randomized 1:1 to the chosen regimen or investigator’s choice CT (rituximab/bendamustine or rituximab/gemcitabine/oxaliplatin). The primary phase 3 objective is to demonstrate progression-free survival (PFS) superiority of the avelumab-based regimen over CT. Overall survival is a key secondary endpoint. Eligible pts have completed up to 4 lines of prior rituximab/multiagent CT, and/or have failed autologous stem cell transplantation (ASCT), or are not eligible for intensive CT or ASCT. Other eligibility criteria include ECOG PS ≤1 and no prior therapy with a checkpoint inhibitor. Treatment with avelumab, utomilumab, and azacitidine will be continued until the pt no longer receives clinical benefit; rituximab and bendamustine are limited to 8 and 6 cycles, respectively. OR and PFS will be assessed per Lugano disease classification criteria. Other secondary efficacy endpoints include disease control, duration of response, time to response, and minimal residual disease burden. Safety, PK, immunogenicity, pt-reported outcomes, and biomarkers will also be evaluated. Clinical trial information: NCT02951156.

The research of electroconvulsive therapy effect on cognitive function in rats with depressive-like disorder formed by ultrasound

Electroconvulsive therapy (ECT) is effective method of resistant depression treatment. ECT activates neurotransmitter systems, increases neurotrophic factors production, induces neurogenesis. Nevertheless, ECT side effects, expressed as temporary amnesia, limit its application in clinical practice.

The objective of our work was to estimate rat's memory after ECT in the behavioral test: “Object recognition”, “Morris water-maze”.

The aim of the work was to research the effect of ECT on cognitive function in rats with depressive-like disorder and in normal rats.

Methods

The research was conducted with Sprague-Dawley rats (n = 41, 2 month age). Experimental stages:

– control group (n = 10) compared to control + ECT group ([70 mA, 50 Hz, 500 μsec; 10 days] n = 10);

– control group (n = 9) compared to group with depressive-like disorder, formed by ultrasound ([20–45 kHz; 21days] US, n = 6) and group with depressive-like disorder received ECT (n = 6).

Memory was estimated in the “Object recognition” and “Morris water-maze” tests.

Results

(1) ECT did not decrease cognitive function in the “Object recognition” test in normal rats (P = 0.1217). Also, it did not lead to cognitive impairments in the “Morris water-maze” test: time of platform searching did not differ significantly from the control group (P = 0.8573).

(2) ECT produced recovering effect on memory impairments of the US group in the “Object recognition” test (P = 0.0066). In the “Morris water-maze” ECT decreased time of platform searching by 7 times compared to the US group (P = 0.0025). That demonstrates the absence of ECT negative effect on rat's memory.

Conclusion

ECT does not produce negative effect on cognitive function in rats with depressive-like disorder and even recovers memory impairments.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Long-term evaluation of cardiac and vascular toxicity in patients with Philadelphia chromosome-positive leukemias treated with bosutinib

Vascular and cardiac safety during tyrosine kinase inhibitor (TKI) therapy is an emerging issue. We evaluated vascular/cardiac toxicities associated with long-term bosutinib treatment for Philadelphia chromosome-positive (Ph+) leukemia based on treatment-emergent adverse events (TEAEs) and changes in QTc intervals and ejection fraction in two studies: a phase 1/2 study of second-/third-/fourth-line bosutinib for Ph+ leukemia resistant/intolerant to prior TKIs (N = 570) and a phase 3 study of first-line bosutinib (n = 248) versus imatinib (n = 251) in chronic phase chronic myeloid leukemia. Follow-up time was ≥48 months (both studies). Incidences of vascular/cardiac TEAEs in bosutinib-treated patients were 7%/10% overall with similar incidences observed with first-line bosutinib (5%/8%) and imatinib (4%/6%). Few patients had grade ≥3 vascular/cardiac events (4%/4%) and no individual TEAE occurred in >2% of bosutinib patients. Exposure-adjusted vascular/cardiac TEAE rates (patients with events/patient-year) were low for second-line or later bosutinib (0.037/0.050) and not significantly different between first-line bosutinib (0.015/0.024) and imatinib (0.011/0.017; P ≥ 0.267). Vascular/cardiac events were managed mainly with concomitant medications (39%/44%), bosutinib treatment interruptions (18%/21%), or dose reductions (4%/8%); discontinuations due to these events were rare (0.7%/1.0%). Based on logistic regression modelling, performance status >0 and history of vascular or cardiac disorders were prognostic of vascular/cardiac events in relapsed/refractory patients; hyperlipidemia/hypercholesterolemia and older age were prognostic of cardiac events. In newly diagnosed patients, older age was prognostic of vascular/cardiac events; history of diabetes was prognostic of vascular events. Incidences of vascular and cardiac events were low with bosutinib in the first-line and relapsed/refractory settings following long-term treatment in patients with Ph+ leukemia. Am. J. Hematol. 91:606-616, 2016. © 2016 Wiley Periodicals, Inc.

Bosutinib versus imatinib in newly diagnosed chronic-phase chronic myeloid leukaemia: results from the 24-month follow-up of the BELA trial

Bosutinib is an oral, dual SRC/ABL1 tyrosine kinase inhibitor for resistant/intolerant chronic myeloid leukaemia (CML). We assessed the efficacy and safety of bosutinib 500 mg/d (n = 250) versus imatinib 400 mg/d (n = 252) after >24 months from accrual completion in newly diagnosed chronic phase (CP)-CML (Bosutinib Efficacy and Safety in Newly Diagnosed CML trial [BELA]). Cumulative complete cytogenetic response (CCyR) rates by 24 months were similar (bosutinib, 79%; imatinib, 80%); cumulative major molecular response (MMR) rates were 59% for bosutinib and 49% for imatinib. Responses were durable; 151/197 vs. 172/204 and 125/153 vs. 117/131 responders remained on treatment and maintained CCyR and MMR, respectively. Since the 12-month primary analysis, no new accelerated-/blast-phase transformations occurred with bosutinib; four occurred with imatinib. Early response (BCR-ABL1/ABL1 ≤ 10%, 3 months) was associated with better CCyR and MMR rates by 12 and 24 months (both arms). Gastrointestinal events and liver function test elevations were more common, and neutropenia, musculoskeletal events and oedema were less common with bosutinib. Discontinuations due to adverse events were more common with bosutinib versus imatinib (most commonly alanine aminotransferase elevation: 4% vs. <1%); most occurred within the first 12 months. Cardiovascular adverse events were similar in both arms. Bosutinib continues to demonstrate good efficacy and manageable tolerability in newly diagnosed CP-CML patients.

Safety of bosutinib versus imatinib in the phase 3 BELA trial in newly diagnosed chronic phase chronic myeloid leukemia

Bosutinib, an orally active, Src/Abl tyrosine kinase inhibitor, has demonstrated clinical activity and acceptable tolerability in chronic phase chronic myeloid leukemia (CP CML). This updated analysis of the BELA trial assessed the safety profile and management of toxicities of bosutinib versus imatinib in adults with newly diagnosed (≤6 months) CP CML after >30 months from accrual completion. Among patients randomized to bosutinib 500 mg/d (n = 250) or imatinib 400 mg/d (n = 252), 248 and 251, respectively, received ≥1 dose of study treatment. Adverse events (AEs; any grade) with bosutinib versus imatinib were significantly more common for certain gastrointestinal events (diarrhea, 70% vs. 26%; P < 0.001; vomiting, 33% vs. 16%; P < 0.001), alanine aminotransferase (33% vs. 9%; P < 0.001) and aspartate aminotransferase (28% vs. 10%; P < 0.001) elevations, and pyrexia (19% vs. 12%; P = 0.046). AEs significantly less common with bosutinib included edema (periorbital, 2% vs. 14%; P < 0.001; peripheral, 5% vs. 12%; P = 0.006), musculoskeletal (myalgia, 5% vs. 12%; P = 0.010; muscle cramps, 5% vs. 22%; P < 0.001; bone pain, 4% vs. 11%; P = 0.003), increased creatine phosphokinase (8% vs. 20%; P < 0.001), neutropenia (13% vs. 30%; P < 0.001), and leukopenia (9% vs. 22%; P < 0.001). Between-group differences in the incidence of cardiac and vascular AEs were not significant. Diarrhea was typically transient, mostly Grade 1/2, occurring early during treatment, and was manageable with antidiarrheal medication. Despite higher rates of aminotransferase elevation with bosutinib, events were managed in most patients with dose modification and/or concomitant medication. Bosutinib had a manageable safety profile distinct from that of imatinib in patients with newly diagnosed CP CML. Am. J. Hematol. 89:947–953, 2014. © 2014 The Authors. American Journal of Hematology Published by Wiley Periodicals, Inc.

Deciphering the binding of caveolin-1 to client protein endothelial nitric-oxide synthase (eNOS): scaffolding subdomain identification, interaction modeling, and biological significance

Caveolin-1 (Cav-1) gene inactivation interferes with caveolae formation and causes a range of cardiovascular and pulmonary complications in vivo. Recent evidence suggests that blunted Cav-1/endothelial nitric-oxide synthase (eNOS) interaction, which occurs specifically in vascular endothelial cells, is responsible for the multiple phenotypes observed in Cav-1-null animals. Under basal conditions, Cav-1 binds eNOS and inhibits nitric oxide (NO) production via the Cav-1 scaffolding domain (CAV; amino acids 82-101). Although we have recently shown that CAV residue Phe-92 is responsible for eNOS inhibition, the "inactive" F92A Cav-1 mutant unexpectedly retains its eNOS binding ability and can increase NO release, indicating the presence of a distinct eNOS binding domain within CAV. Herein, we identified and characterized a small 10-amino acid CAV subsequence (90-99) that accounted for the majority of eNOS association with Cav-1 (Kd = 49 nM), and computer modeling of CAV(90-99) docking to eNOS provides a rationale for the mechanism of eNOS inhibition by Phe-92. Finally, using gene silencing and reconstituted cell systems, we show that intracellular delivery of a F92A CAV(90-99) peptide can promote NO bioavailability in eNOS- and Cav-1-dependent fashions. To our knowledge, these data provide the first detailed analysis of Cav-1 binding to one of its most significant client proteins, eNOS.

Axitinib with or without dose titration for first-line metastatic renal cell carcinoma (mRCC): Unblinded results from a randomized phase II study

LBA349

Background: Patients receiving the 5-mg twice daily (BID) axitinib starting dose exhibit variable drug exposure; prior pharmacokinetic analyses indicate higher exposure is associated with better outcomes in mRCC. Dose titration based on individual tolerability may optimize exposure and improve efficacy. Methods: Patients (N=213) with treatment-naïve mRCC received axitinib 5 mg BID for a 4-week lead-in period. Then, patients with 2 consecutive weeks of blood pressure ≤150/90 mmHg, no axitinib-related toxicities >grade 2, no dose reductions, and ≤2 antihypertensive medications were randomized (double-blind) to axitinib 5 mg BID + dose titration to 10 mg BID maximum with axitinib or placebo. Those not eligible for randomization continued axitinib 5 mg BID or lower. Primary endpoint was objective response rate (ORR) in randomized arms. Progression-free survival (PFS), overall survival, and safety were secondary endpoints. Assuming response rate under the null hypothesis is 0.15, this study had ≥80% power (1-sided type I error 10%) to detect a ≥25% absolute improvement in ORR with active vs placebo titration. Results: In all, 56 patients each were randomized to active and placebo titration arms, 91 were not randomized, and 10 withdrew during the lead-in period. As of Oct 12, 2012, ORR (95% confidence interval [CI]) was 54% (40–67) in the active titration arm vs 34% (22–48) in the placebo titration arm (1-sided P=0.019), and 59% (49–70) in the non-randomized arm. Median PFS (95% CI) from first dose was 14.5 mo (9.2–24.5) in the active titration arm vs 15.7 mo (8.3–19.4) in the placebo titration arm (hazard ratio favored active titration, 0.85; 95% CI, 0.54–1.35; 1-sided P=0.244), and 16.6 mo (11.2–22.5) in the non-randomized arm. Most frequent all-grade, all-causality adverse events in active titration, placebo titration, and non-randomized arms, respectively, were diarrhea (61% vs 63% vs 63%), hypertension (61% vs 43% vs 82%), and fatigue (45% vs 46% vs 54%). Conclusions: Axitinib is effective and well tolerated in first-line mRCC with prolonged median PFS in all treatment arms compared to historical controls. Axitinib dose titration significantly improved ORR vs placebo. Clinical trial information: NCT00835978.

Phase III randomized clinical trial comparing tremelimumab with standard-of-care chemotherapy in patients with advanced melanoma

PURPOSE

In phase I/II trials, the cytotoxic T lymphocyte-associated antigen-4-blocking monoclonal antibody tremelimumab induced durable responses in a subset of patients with advanced melanoma. This phase III study evaluated overall survival (OS) and other safety and efficacy end points in patients with advanced melanoma treated with tremelimumab or standard-of-care chemotherapy.

PATIENTS AND METHODS

Patients with treatment-naive, unresectable stage IIIc or IV melanoma were randomly assigned at a ratio of one to one to tremelimumab (15 mg/kg once every 90 days) or physician's choice of standard-of-care chemotherapy (temozolomide or dacarbazine).

RESULTS

In all, 655 patients were enrolled and randomly assigned. The test statistic crossed the prespecified futility boundary at second interim analysis after 340 deaths, but survival follow-up continued. At final analysis with 534 events, median OS by intent to treat was 12.6 months (95% CI, 10.8 to 14.3) for tremelimumab and 10.7 months (95% CI, 9.36 to 11.96) for chemotherapy (hazard ratio, 0.88; P = .127). Objective response rates were similar in the two arms: 10.7% in the tremelimumab arm and 9.8% in the chemotherapy arm. However, response duration (measured from date of random assignment) was significantly longer after tremelimumab (35.8 v 13.7 months; P = .0011). Diarrhea, pruritus, and rash were the most common treatment-related adverse events in the tremelimumab arm; 7.4% had endocrine toxicities. Seven deaths in the tremelimumab arm and one in the chemotherapy arm were considered treatment related by either investigators or sponsor.

CONCLUSION

This study failed to demonstrate a statistically significant survival advantage of treatment with tremelimumab over standard-of-care chemotherapy in first-line treatment of patients with metastatic melanoma.

BELA trial update: Bosutinib (BOS) versus imatinib (IM) in patients (pts) with newly diagnosed chronic phase chronic myeloid leukemia (CP CML) after 30 months of follow-up

6512

Background: The BELA study compared the efficacy and safety of BOS (dual Src/Abl kinase inhibitor) with IM in newly diagnosed CP CML. Methods: 502 pts with newly diagnosed CP CML were randomized to BOS 500 mg/d (n = 250) or IM 400 mg/d (n = 252) and stratified by Sokal risk group and geographic region. Efficacy analyses included all randomized pts (ITT); safety analyses included all treated pts (BOS, n = 248; IM, n = 251). Data described below are for ≥24 mo of follow-up; updated data for ≥30 mo of follow-up will be presented. Results: Median treatment duration was 27.5 mo in both cohorts; 63% of BOS pts and 71% of IM pts were still receiving treatment. The primary reason for BOS discontinuation was a treatment-emergent adverse event (TEAE; 24% vs 7% with IM); the primary reason for IM discontinuation was disease progression (13% vs 4% with BOS). Cumulative complete cytogenetic response (CCyR) rates by 24 mo were 79% for BOS and 80% for IM. Cumulative major molecular response (MMR) rates by 24 mo were 59% for BOS and 49% for IM (P = 0.019), including 16% and 12% of pts with complete molecular response (4.0-log sensitivity). On-treatment transformation to accelerated/blast phase occurred in 4 (2%) BOS pts and 13 (5%) IM pts. Deaths were reported for 7 BOS pts (6 due to CML progression) and 13 IM pts (10 due to CML progression); 24-mo Kaplan-Meier overall survival estimates were 97% (BOS) and 95% (IM). BOS was associated with higher incidences of gastrointestinal events than IM (diarrhea [70% vs 25%], vomiting [32% vs 16%]; primarily transient), but lower incidences of edema (13% vs 40%) and musculoskeletal events (cramps [4% vs 22%], bone pain [4% vs 10%]). Grade ≥3 TEAEs in ≥2% of BOS or IM pts were diarrhea (12% vs 1%), vomiting (3% vs 0%), and rash (2% vs 1%). Grade ≥3 lab abnormalities (≥15% of pts) with BOS and IM were neutropenia (10% vs 24%), thrombocytopenia (14% vs 15%), elevated alanine aminotransferase (23% vs 4%), and hypophosphatemia (6% vs 20%). Conclusions: BOS was effective for newly diagnosed CP CML and had a distinct toxicity profile. With continued follow-up both on-treatment transformation to accelerated/blast phase and overall survival continue to favor BOS versus IM.

Phase I/II trial of tremelimumab in patients with metastatic melanoma

PURPOSE

Cytotoxic T lymphocyte-associated antigen 4 (CTLA4) blockade with tremelimumab (CP-675,206), a fully human anti-CTLA4 monoclonal antibody, was tolerated and demonstrated antitumor activity in a single dose, dose-escalation phase I trial in patients with solid tumors. This phase I/II trial was conducted to examine safety of multiple doses of tremelimumab, to further assess efficacy, and to identify an appropriate dosing regimen for further development.

PATIENTS AND METHODS

Twenty-eight patients with metastatic melanoma received monthly intravenous infusions of tremelimumab at 3, 6, or 10 mg/kg for up to 1 year to determine recommended monthly phase II dose. During phase II, 89 patients received tremelimumab 10 mg/kg once every month or 15 mg/kg every 3 months.

RESULTS

No dose-limiting toxicity was observed in phase I once every month dosing. In phase II, 8 (10%) of 84 response-assessable patients attained objective antitumor responses; best overall objective response was one complete response and three partial responses in each dosing regimen. Most responses were durable (range, 3 to 30+ months). Most frequent treatment-related adverse events (AEs) were diarrhea, rash, and pruritus. Frequency of grade 3/4 AEs was 13% in the 15 mg/kg every 3 months arm and 27% in the 10 mg/kg once every month. Serious AEs were also less frequent in the 15 mg/kg once every 3 months cohort (9% v 23% in 10 mg/kg arm).

CONCLUSION

Multiple infusions of tremelimumab were generally tolerable and demonstrated single-agent antitumor activity. Both phase II regimens generated durable tumor responses. Based on its more favorable safety profile, 15 mg/kg every 3 months was selected for further clinical testing.

Familial hypertrophic cardiomyopathy-related cardiac troponin C mutation L29Q affects Ca2+ binding and myofilament contractility

The cardiac troponin C (cTnC) mutation, L29Q, has been found in a patient with familial hypertrophic cardiomyopathy. We previously showed that L29, together with neighboring residues, Asp2, Val28, and Gly30, plays an important role in determining the Ca(2+) affinity of site II, the regulatory site of mammalian cardiac troponin C (McTnC). Here we report on the Ca(2+) binding characteristics of L29Q McTnC and D2N/V28I/L29Q/G30D McTnC (NIQD) utilizing the Phe(27) --> Trp (F27W) substitution, allowing one to monitor Ca(2+) binding and release. We also studied the effect of these mutants on Ca(2+) activation of force generation in single mouse cardiac myocytes using cTnC replacement, together with sarcomere length (SL) dependence. The Ca(2+)-binding affinity of site II of L29Q McTnC(F27W) and NIQD McTnC(F27W) was approximately 1.3- and approximately 1.9-fold higher, respectively, than that of McTnC(F27W). The Ca(2+) disassociation rate from site II of L29Q McTnC(F27W) and NIQD McTnC(F27W) was not significantly different than that of control (McTnC(F27W)). However, the rate of Ca(2+) binding to site II was higher in L29Q McTnC(F27W) and NIQD McTnC(F27W) relative to control (approximately 1.5-fold and approximately 2.0-fold respectively). The Ca(2+) sensitivity of force generation was significantly higher in myocytes reconstituted with L29Q McTnC (approximately 1.4-fold) and NIQD McTnC (approximately 2-fold) compared with those reconstituted with McTnC. Interestingly, the change in Ca(2+) sensitivity of force generation in response to an SL change (1.9, 2.1, and 2.3 mum) was significantly reduced in myocytes containing L29Q McTnC or NIQD McTnC. These results demonstrate that the L29Q mutation enhances the Ca(2+)-binding characteristics of cTnC and that when incorporated into cardiac myocytes, this mutant alters myocyte contractility.

Survival of patients (pts) with metastatic melanoma treated with the anti-CTLA4 monoclonal antibody (mAb) CP-675,206 in a phase I/II study

8524

Background: The fully human anti-CTLA4 mAb CP-675,206 has demonstrated clinical activity in pts with metastatic melanoma. Prolonged survival was observed in a prior single-dose phase I study, even in pts who did not achieve objective tumor responses. Methods: A multidose phase I/II trial was conducted in pts (N = 119) with histologically confirmed stage IIIc (unresectable) or stage IV recurrent metastatic melanoma and ECOG PS = 1. The study consisted of a phase I, open-label, multidose study (3, 6, and 10 mg/kg) and a phase I expansion cohort for HLA-A2.1+ pts (10 mg/kg monthly [Q1M]), followed by a phase II open-label study of 2 dosing regimens: 10 mg/kg Q1M and 15 mg/kg every 3 months (Q3M). The primary endpoint was safety in phase I, immune monitoring in the expansion cohort, and response in phase II. Survival was analyzed as a secondary endpoint. Results: In the phase I study, Kaplan-Meier estimates of median overall survival were 17.6 months for all dose groups combined (n = 28). In the phase II study, median survival was 10.3 months in the 10 mg/kg arm and 11.0 months in the 15 mg/kg arm. Survival outcomes were favorable, compared with historical median survival of 7 months, independent of whether pts achieved an objective response. Updated survival data will be presented. Conclusions: Patients participating in a multiple dose study of CP-675,206 showed a survival time that was greater than expected on historic controls. These observations support the endpoints of an ongoing randomized phase III study in melanoma to further evaluate survival in the frontline setting.

[Table: see text]

[Table: see text]

Results of a phase II clinical trial of 2 doses and schedules of CP-675,206, an anti-CTLA4 monoclonal antibody, in patients (pts) with advanced melanoma

3000

Background: CP-675,206 has antitumor activity in pts with metastatic melanoma. A 2-stage, 2-arm phase II trial was conducted to choose the optimal dosing regimen for pivotal clinical trial testing. Methods: Eligible pts had measurable melanoma (stage IIIc or IV) progressing on or after prior therapy with ECOG PS = 1. In stage 1, 18 pts per arm were randomized to either 10 mg/kg monthly (10 Q1M) or 15 mg/kg every 3 months (15 Q3M). If 3 or more pts in either arm had CR or PR, then 25 more pts were entered to that arm. Primary endpoint was objective tumor response, and secondary endpoints were safety and survival. Results: 89 pts received at least 1 dose (44 at 10 Q1M, 45 at 15 Q3M), with both study arms moving to stage 2. 96% of pts had stage IV disease, and 57% had elevated LDH. There were no significant differences in age, sex, stage, or baseline LDH levels between study groups. A median of 3 doses (range, 1 to 26) at 10 Q1M and 1 dose (range, 1 to 9) at 15 Q3M were administered with 100% compliance. Dose delays occurred in 30% of pts treated at 10 Q1M and 16% at 15 Q3M. 2 pts at 10 Q1M and 5 pts at 15 Q3M continued on study beyond 12 months (mo). To date, 6 pts at 10 Q1M have been discontinued due to toxicity (3 diarrhea/colitis [1 requiring colectomy], Grave’s ophthalmopathy, pancreatitis, hypersensitivity reaction) and 2 pts at 15 Q3M (colitis and pancreatitis, diarrhea) (P = 0.14). There were no toxic deaths. 15 Q3M was associated with lower incidence of grade 3 or 4 AEs (31% vs 41% at 10 Q1M; P = 0.42). Responses by investigator assessment were 1 CR and 3 PRs at 10 Q1M, and 1 CR and 2 PRs at 15 mg/kg Q3M, including responses in skin, LN, bone, liver, lung, and adrenal glands. To date, only 1 pt with PR at 10 Q1M has relapsed, and the remaining responses are ongoing (18+ to 28+ mo). Median survival is 10.3 mo at 10 Q1M and 11.0 mo at 15 Q3M (P = NS). Conclusions: The 15 mg/kg Q3M regimen was chosen for further clinical testing based on comparable antitumor efficacy and a trend to improved feasibility and safety compared with 10 mg/kg Q1M. CP-675,206 at this dose and schedule is being examined in pivotal phase II and III clinical trials for pts with melanoma, and in early phase II trials in pts with CRC and NSCLC.

No significant financial relationships to disclose.

A phase II study of the anti-CTLA4 monoclonal antibody (mAb), CP-675,206, in patients with refractory metastatic adenocarcinoma of the colon or rectum

3035

Background: The antitumor activity of antibodies to cytotoxic T lymphocyte-associated antigen 4 (CTLA4) has been demonstrated in a variety of murine tumor models, including rejection of established tumors and secondary exposure to tumor cells. This suggests that blockade of the inhibitory effects of CTLA4 can promote effective antitumor immune responses. CP-675,206 has also been shown to induce durable tumor responses in patients (pts) with metastatic melanoma in phase 1 and phase 2 clinical studies. The purpose of this study was to assess safety and efficacy of CTLA4 blockade with the fully human mAb CP-675,206 as single-agent therapy in pts with relapsed/ refractory colorectal cancer. Methods: A single-arm, multicenter, phase II trial of CP-675,206 was conducted in pts with measurable adenocarcinoma of the colon or rectum failing standard treatments and with an ECOG performance status of 0 or 1. Patients received 15 mg/kg Q90 days via IV infusion until disease progression. The primary objective was response rate by RECIST criteria. Secondary objectives included safety, duration of response, progression-free survival, and overall survival. Results: A total of 47 pts who received a median of 4 previous therapies (range, 1 to 9) were treated, and 46 experienced disease progression or death because of disease before reaching the planned second dose at 3 months. Grade 3 or 4 adverse events attributed to study drug were limited to diarrhea (n = 3, 6.4%) and idiopathic thrombocytopenia purpura (n = 1, 2.1%). Four pts (8.5%) had grade 2 diarrhea. Four pts received steroids and 2 received infliximab. One patient was removed for toxicity (diarrhea in the setting of what appeared to be treatment-related ulcerative colitis that was responsive to steroids). One patient (2%; 95% CI = 0%, 11%) had a stable ovarian mass and a substantial regression in an adrenal mass. This patient is continuing on study and has received a second dose. Conclusions: In heavily pretreated pts with colorectal cancer and good performance status, CP- 675,206 was tolerable. However, in this setting, CP-675,206 at 15 mg/kg did not demonstrate substantial single-agent activity.

No significant financial relationships to disclose.

Clearance of monoclonal antibody (mAb) CP-675,206 by therapeutic plasma exchange (TPE) or plasmapheresis

13515

Background: CP-675,206 is a fully human, cytotoxic T lymphocyte-associated antigen 4 (CTLA4) blocking mAb with immune stimulating properties under development for the treatment of metastatic melanoma. The pharmacokinetics of CP-675,206 is similar to endogenous IgG, with a long plasma half-life (22 days). We explored the use of TPE in two patients (pts) receiving CP-675,206, postulating that TPE could be used to remove mAb in cases where toxicities are thought to result from persistence of mAb in circulation. Methods: For both pts, five TPEs were performed over 7 days using a Cobe Spectra blood cell separator (TPE daily x 3, 2 days rest, and TPE daily x 2). One plasma volume was processed per TPE and replaced with a 60%/40% albumin/saline solution. Plasma CP-675,206 concentration was measured at baseline and after the 3rd and 5th TPE. Results: Patient 1 was a 62 year-old with metastatic melanoma who received 8 monthly doses of CP-675,206 (10 mg/kg). Six days after the last dose, the pt was found to have elevated ALT and bilirubin and detectable anti- smooth muscle and anti-microsomal antibodies. Based on a suspicion of therapy-related autoimmune hepatitis, the pt underwent TPE. Plasma CP-675,206 concentration declined by 96% following the 5th TPE, and ALT and bilirubin normalized over the 4 weeks following TPE with no other evidence of clinical hepatitis. Patient 2 was a 78 year-old with in-transit melanoma who received 3 monthly doses of CP-675,206 (10 mg/kg) and was responding to therapy. Two weeks after the last dose the pt developed diffuse bilateral arthralgias. The pt was diagnosed with rheumatoid factor-negative rheumatoid arthritis, presumably related to therapy with CP-675,206, and underwent TPE. Pre- and post-TPE plasma CP-675,206 concentrations are pending. The arthralgias persisted, and the pt subsequently received oral methotrexate with slow improvement in symptoms over the next 6 months. Conclusions: TPE is highly effective for reducing the plasma concentration of CP-675,206 and may be useful to avert the progression of drug-related adverse events. Clinical benefit from TPE may vary depending on the interval from dosing and may be limited by slow reversibility of T-cell immunostimulation.

[Table: see text]

Natural history of diarrhea associated with the anti-CTLA4 monoclonal antibody CP-675,206

3038

Background: Diarrhea resulting from immune activation has been associated with CTLA4 blockade. For example, in patients (pts) with stage IV melanoma receiving ipilimumab (MDX-010), a number of pts developed grade 3/4 autoimmune enterocolitis and severe diarrhea (Attia et al, 2005). In a single-dose phase I trial of CP-675,206 at doses up to 15 mg/kg in pts with solid tumors (n = 39), 9 instances of diarrhea were reported including 3 grade 3 events (Ribas et al, 2005). The incidence and severity of diarrhea was assessed in pts receiving CP- 675,206 in a large phase I/II study. Methods: An open-label phase I/II trial of CP-675,206 was conducted in pts with stage III (unresectable) or stage IV melanoma and an ECOG PS = 1. Diarrhea was assessed in pts treated at the phase II doses: 10 mg/kg monthly (Q1M) in phase I (n = 22), or 10 mg/kg Q1M (n = 44) or 15 mg/kg every 3 months (Q3M, n = 45) in phase II. Results: Medians of 3.5 doses (range, 1 to 18) at 10 mg/kg Q1M in phase I, 3 doses (range, 1 to 26) at 10 mg/kg Q1M in phase II, and 1 dose (range, 1 to 9) at 15 mg/kg Q3M were administered with 100% dose compliance. Treatment-related diarrhea was reported by 43 (39%) of 111 pts, and grade 3 diarrhea occurred in 14 (13%) pts. One patient had grade 4 colitis resulting in a colectomy. Diarrhea (all grades) occurred with similar frequency in each dose group; however, grade 3 treatment-related diarrhea occurred in 8% of pts treated with 15 mg/kg Q3M compared with 18% of pts treated with 10 mg/kg Q1M in phase I and 14% of pts treated with 10 mg/kg Q1M in phase II. Among 9 pts with an objective response, 8 experienced diarrhea (3 of which were grade 3). The majority of cases (65%) were mild to moderate in severity with a median time to onset of 51 days (range, 1 to 583 days) and resolution of 8 days (range, 1 to 182 days). More than half of pts who reported serious events of diarrhea were treated with steroids. Conclusions: Diarrhea associated with CP-675,206 was primarily mild to moderate in severity, transient, and manageable. In addition, 15 mg/kg Q3M may be better tolerated than 10 mg/kg Q1M. Ongoing clinical trials in pts with advanced melanoma will provide further information about the incidence, severity, and optimal management of diarrhea associated with CP-675,206.

No significant financial relationships to disclose.

Comorbidities and the risk of late-stage prostate cancer

The degree to which comorbidities affect the diagnosis of prostate cancer is not clear. The purpose of this study was to determine how comorbidities affect the stage at which prostate cancer is diagnosed in elderly white and black men. We obtained data from the Surveillance, Epidemiology, and End Results program of the National Cancer Institute merged with Medicare claims data. For each patient, we estimated associations between stage of disease at diagnosis and each of the 27 comorbidities. The sample included 2,489 black and 2,587 white men with staged prostate cancer. Coronary artery disease, benign hypertension, and dyslipidemia reduced the odds of late-stage prostate cancer. A prior diagnosis of peripheral vascular disease, severe renal disease, or substance abuse increased the odds of being diagnosed with late-stage disease. The study shows some effect modification by race, particularly among white men with substance abuse, cardiac conduction disorders, and other neurologic conditions. The strongest predictors of late-stage prostate cancer diagnosis for both white and black men were age at diagnosis of at least 80 years and lack of PSA screening. Comorbidities do affect stage at diagnosis, although in different ways. Four hypotheses are discussed to explain these findings.

Ex vivo blood stimulation assay as a translational research tool in the development of the ticilimumab (CP-675,206)

2542

Background: Cytotoxic T Lymphocyte-associated Antigen 4 (CTLA4) is an activation-induced T lymphocyte negative costimulatory receptor which down-regulates cellular immune responses. CTLA4 blockade may break peripheral immunological tolerance, leading to an effective immune response to cancer. Tools for assessing the effects of such a blockade are limited, as CTLA4 is not constitutively expressed on circulating T cells, and because activated lymphocytes are difficult to access in vivo. Therefore, we have employed ex vivo blood stimulation assays to define pharmacodynamic properties of the anti-CTLA4 antibody, ticilimumab. Methods: Ex vivo blood stimulation assays employed staphylococcal enterotoxin A (SEA) to stimulate isolated peripheral blood mononuclear cells (PBMC) or whole blood. Stimulation was monitored by production of interleukin 2 (IL-2). This assay was used preclinically to predict in vivo responses in animal models and in samples from cancer patients, as a batch release assay for production runs of ticilimumab, and clinically as a pharmacodynamic measurement in clinical trials of ticilimumab. Results: Screening experiments using the SEA assay allowed us to identify the lead candidate mAb with optimal CTLA4 blockade activity, ticilimumab. Dose-dependent increases in IL-2 production were observed in PBMC and whole blood samples up to an in vitro concentration of 100 ug/mL of ticilimumab, with 10 ug/mL identified as the minimum predicted efficacious concentration (Ceff). This functional potency assay was adapted for qualification of production lots of ticilimumab. Whole blood taken from cynomolgus monkeys dosed with ticilimumab demonstrated significant enhancement of IL-2 production at the same magnitude observed in in vitro experiments. Additionally, longitudinal samples taken from healthy volunteers and cancer patients suggested that an enhancement of 2.8 fold would be indicative of a pharmacodynamic effect of ticilimumab. Conclusions: The SEA assay provides a functional assessment of ticilimumab activity and can be used to guide the clinical development of this agent. Our data suggest that T cell reactivity is enhanced in the presence of ticilimumab in vitro, in primate models and in humans.

[Table: see text]

Dose and schedule selection for the anti-CTLA4 monoclonal antibody ticilimumab in patients (pts) with metastatic melanoma

8032

Background: Ticilimumab therapy has demonstrated anti-tumor activity in pts with metastatic melanoma. Its indirect, immune-mediated antitumor effects pose unique challenges for dose/regimen selection. Methods: It was our original intention to select the clinical dose/regimen of ticilimumab based on (1) clinical safety and tolerability and (2) attainment of target plasma concentrations derived from pre-clinical work using an ex vivo assay of ticilimumab-induced enhancement of cytotoxic T-cell function. Because numerous pts with metastatic melanoma experienced clinical benefit (i.e., durable objective responses [OR] and/or long-term survival) in early clinical trials of ticilimumab, we are using (1) safety and tolerability and (2) clinical benefit to guide dose/regimen selection. Data for evaluating these criteria come from a single-dose Phase 1 trial (0.01, 0.1, 1, 3, 6, 10 and 15 mg/kg) and an ongoing multiple-dose Phase 1/2 trial in pts with melanoma (Phase 1 portion: 3, 6 and 10 mg/kg Q1M; Phase 2 portion: 10 mg/kg Q1M and 15 mg/kg Q3M). Results: In the single-dose Phase 1 trial, 10 mg/kg was the Protocol-defined MTD but a high rate of clinical benefit was seen in the 15 mg/kg dose cohort (6/6 pts). Because the DLTs seen at 15 mg/kg (Gr 3 diarrhea, Gr 3 rash) were moderate and resolved completely within 3 months of dosing, 15 mg/kg Q3M was proposed as a safe and tolerable dose and is being studied in the Phase 2 portion of the multiple-dose Phase 1/2 trial. The Phase 1 portion of the multiple-dose Phase 1/2 trial revealed that 10 mg/kg is safe and tolerable with monthly dosing so 10 mg/kg Q1M is also being studied in the Phase 2 portion of the trial. At the end of the Simon Optimum-defined Stage 1 of the Phase 2 portion of the ongoing trial, the OR rate (3/18 pts) is the same for both dosing regimens. However, with 15 mg/kg Q3M, Gr 3/4 adverse events were less frequent (6% versus 34%). Conclusions: 15 mg/kg Q3M is proposed as the clinical dose/regimen for ticilimumab in metastatic melanoma. This dose/regimen appears to have anti-tumor activity approximately equal to 10 mg/kg Q1M but it appears to have a superior safety profile.

[Table: see text]

Phase I clinical trials of ticilimumab: Tumor responses are sufficient but not necessary for prolonged survival

8036

Background: Clinical studies examining anti-CTLA4 monoclonal antibodies (mAb) provide evidence of the biologic and clinical activity of this class of agents. Two Phase 1 studies with ticilimumab, a fully human anti-CTLA4 mAb, have been reported previously. In both studies, objective responses (OR) were seen in some patients (pts) with melanoma. In addition, we observed highly favorable outcomes among several pts who did not experience objective responses. This may indicate a positive impact of ticilimumab on melanoma in these pts, not well reflected by traditional response criteria. Long-term follow-up data on survival for pts enrolled in these Phase 1 studies is now reported. Methods: We studied the safety, pharmacokinetics, immunostimulatory activity, and clinical activity of ticilimumab in 53 pts with solid malignancies. Ticilimumab was administered, as a single agent, at single dose levels ranging from 0.01 to 15 mg/kg and at multiple dose levels ranging from 3 to 15 mg/kg. The dosing regimens included either a single dose, multiple doses given q3 months, or multiple doses given q1 month. Results: The two studies included 43 pts with measurable melanoma. Ticilimumab proved safe and overall was well tolerated (Ribas et al. ProcASCO 2005, and JCO Dec2005). Of the 43 pts with measurable melanoma, 18 were alive at >12 months (range: 13 - 42+) after initial treatment with ticilimumab. This includes 5 pts with an OR who continue on ticilimumab, either on-study or as part of a single IND, and 13 pts without an objective response. Among the pts who did not experience an OR, 5 had surgical resection of metastatic lesions and remain relapse free, and 8 are alive with disease. Conclusions: In pts with melanoma treated with ticilimumab, long-term survival has been achieved by all 5 pts who experienced an OR and in 13 pts who did not experience an OR. These findings suggest that lack of objective response is a poor predictor of long-term survival following ticilimumab therapy.

[Table: see text]

Antitumor Activity in Melanoma and Anti-Self Responses in a Phase I Trial With the Anti-Cytotoxic T Lymphocyte–Associated Antigen 4 Monoclonal Antibody CP-675,206

Purpose

Cytotoxic T lymphocyte–associated antigen 4 (CTLA4) blockade with CP-675,206, a fully human anti-CTLA4 monoclonal antibody, may break peripheral immunologic tolerance leading to effective immune responses to cancer in humans. A phase I trial was conducted to test the safety of CP-675,206.

Patients and Methods

Thirty-nine patients with solid malignancies (melanoma, n = 34; renal cell, n = 4; colon, n = 1) received an intravenous (IV) infusion of CP-675,206 at seven dose levels. The primary objective was to determine the maximum-tolerated dose and the recommended phase II dose.

Results

Dose-limiting toxicities and autoimmune phenomena included diarrhea, dermatitis, vitiligo, panhypopituitarism and hyperthyroidism. Two patients experienced complete responses (maintained for 34+ and 25+ months), and there were two partial responses (26+ and 25+ months) among 29 patients with measurable melanoma. There have been no relapses thus far after objective response to therapy. Four other patients had stable disease at end of study evaluation (16, 7, 7, and 4 months). Additionally, five patients had extended periods without disease progression (36+, 35+, 26+, 24+, and 23+ months) after local treatment of progressive metastases. Longer systemic exposure to CP-675,206 achieved in higher dose cohorts predicted for a higher probability of response.

Conclusion

CP-675,206 can be administered safely to humans as a single IV dose up to 15 mg/kg, resulting in breaking of peripheral immune tolerance to self-tissues and antitumor activity in melanoma.

Comorbidity as a predictor of stage of illness for patients with breast cancer

OBJECTIVE

The purpose of this research was to determine whether comorbidity affects the stage at which breast cancer is diagnosed.

METHODS

Data from the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute (NCI) was merged with Medicare claims for 17,468 women diagnosed with breast cancer from 1993 to 1995.

RESULTS

Women with cardiovascular disease, musculoskeletal disorders, mild-to-moderate gastrointestinal disease, and nonmalignant benign breast disease had a 13%, 7%, 14%, and 24% lower odds, respectively, of being diagnosed with advanced breast cancer. Women with diabetes, other endocrine disorders, psychiatric disorders, or hematologic disorders increased the odds of a late-stage diagnosis by 19%, 11%, 20%, and 19% respectively. Mammography screening and contact with the medical care system decreased the odds of late-stage diagnosis.

DISCUSSION

Four hypotheses are suggested to explain this link between comorbid illness and stage at diagnosis: (1) the "surveillance" hypothesis, (2) the "physiological" hypothesis, (3) the "competing demand" hypothesis, and (4) the "death from other causes" hypothesis.

CONCLUSIONS

Comorbidity may complicate the diagnostic decision-making process for breast cancer. The results suggest that contact with the medical care system improves the odds of early-stage diagnosis. Thus, barriers to access for people with chronic conditions may exacerbate those chronic conditions and increase the odds of late-stage breast cancer.

Potentially pathogenic features of heterotrophic plate count bacteria isolated from treated and untreated drinking water

Heterotrophic plate counts (HPCs) are commonly used to assess the general microbiological quality of drinking water. Drinking water quality specifications worldwide recommend HPC limits from 100 to 500 cfu ml(-1). A number of recent studies revealed evidence that these bacteria may not be as harmless as generally accepted. It appears that immuno-compromised individuals are particularly at risk. This would include the very young and very old patients with diseases such as AIDS and patients on therapy for purposes such as organ transplantation and cancer treatment. In this study, 339 bacterial colonies were isolated at random from selected treated and untreated drinking water in South Africa using routine heterotrophic plate count tests. In a first step to screen for potentially pathogenic properties, 188 (55.5%) of the isolates showed alpha- or beta-haemolysis on human- and horse-blood agar media. Subsequent analysis of the haemolytic isolates for enzymatic properties associated with pathogenicity revealed the presence of chondroitinase in 5.3% of the isolates, coagulase in 16.0%, DNase in 60.6%, elastase in 33.0%, fibrinolysin in 53.7%, gelatinase in 62.2%, hyaluronidase in 21.3%, lecithinase in 47.9%, lipase in 54.8% and proteinase in 64.4%. Fluorescein and pyocyanin were not produced by any of the isolates. Among the haemolytic isolates, 77.7% were resistant to oxacillin 1 microg, 59.6% to penicillin G 2 units, 47.3% to penicillin G 10 units, 54.3% to ampicillin 10 microg and 43.1% to ampicillin 25 microg. Cell culture studies revealed that 96% of haemolytic isolates were cytotoxic to HEp-2 cells, and 98.9% of the 181 cytotoxic isolates adhered to HEp-2 or Caco-2 cells. HEp-2 cells were invaded by 43.6%, and Caco-2 cells by 49.7%, of the 181 cytotoxic isolates. The invasion index on HEp-2 cells ranged from 1.9 x 10(-1) to 8.9 x 10(-6), whereas the invasion index on Caco-2 cells varied between 7.7 x 10(-2) and 8.3 x 10(-6). The most commonly isolated genera with these potentially pathogenic features were Aeromonas, Acinetobacter, Aureobacterium, Bacillus, Chryseobacterium, Corynebacterium, Klebsiella, Moraxella, Pseudomonas, Staphylococcus, Tsukamurella and Vibrio. The results obtained in this study support earlier findings on potentially pathogenic features of bacteria detected by routine HPCs on drinking water. These findings are in agreement with some epidemiological studies, which indicated an association between HPCs in drinking water and the incidence of gastroenteritis in consumers. However, the extent of the health risk concerned needs to be defined in more detail for meaningful revision of quality guidelines for HPCs in drinking water.

The development and validation of a comorbidity index for prostate cancer among Black men

BACKGROUND AND OBJECTIVES

The purpose of this study was to develop a comorbidity index specific to Black Men with prostate cancer, because certain comorbidities and prostate cancer are particularly prevalent among this racial group.

METHODS

This research used the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database to develop an index of comorbidity burden based on survival, and the presence/absence of comorbid illness in 2,931 Black males diagnosed with prostate cancer. Comorbidity burden was recognized using inpatient, outpatient, and physician claims for a 2-year period prior to the diagnosis of prostate cancer. We compared five different statistical models, each with two-way, three-way, and/or four-way interactions among the comorbidities, and selected the model with only two-way interactions as the optimal choice. We demonstrated the utility of refining the simplest model, with 27 comorbidity categories only, by adjusting for the number of different diagnoses within statistically significant categories.