Synthesis and evaluation of druglike parameters via in silico techniques for a series of heterocyclic monosquarate-amide derivatives as potential carboxylic acid bioisosteres

Herein, we present a synthetic compound library comprising of 13 structurally diverse heterocyclic monosquarate-amide derivatives. The compounds featured in this library were designed as potential bioisosteric replacements carboxylic acid moiety's. A good selection of the compounds presented exhibit unique molecular architecture and have shown promising results following in silico evaluation of 'druglike properties' using Swiss ADME. The research presented in this work focuses on the preparation of derivatives of 3,4-dihydroxycyclobut-3-ene-1,2-dione, a known carboxylic acid bioisostere.

Chronic rhinosinusitis: microbiology and treatment of acute exacerbations in patients after endoscopic surgery

Objective

Antibiotics are the mainstay of therapy for acute exacerbation of chronic rhinosinusitis. However, no treatment guidelines exist. Most clinicians follow the recommendations for acute bacterial rhinosinusitis, usually caused by Haemophilus influenzae, Streptococcus pneumoniae or Moraxella catarrhalis, and treat with amoxicillin or amoxicillin-clavulanate.

Method

Medical data of 810 patients who had undergone endoscopic sinus surgery were analysed retrospectively. The results of bacterial cultures and treatment course were assessed in 152 patients who presented with acute exacerbation of chronic rhinosinusitis within 6 months of endoscopic sinus surgery.

Results

The most common bacterial species present were Staphylococcus aureus (36 per cent), Pseudomonas aeruginosa (13 per cent) and Escherichia coli (11 per cent). Most of the isolates showed resistance or intermediate sensitivity to amoxicillin-clavulanate. Targeted antibiotic therapy was significantly more effective than empiric therapy (71 per cent versus 42 per cent). The most effective antibiotics were fluoroquinolones.

Conclusion

Acute exacerbation of chronic rhinosinusitis shows different microbiology than acute bacterial rhinosinusitis and requires a different therapeutic approach. It is optimally treated with culture-directed antibiotic therapy.

Activity and safety of crizotinib in patients with alveolar soft part sarcoma with rearrangement of TFE3: European Organization for Research and Treatment of Cancer (EORTC) phase II trial 90101 'CREATE'

Background

Alveolar soft part sarcoma (ASPS) is an orphan malignancy associated with a rearrangement of transcription factor E3 (TFE3), leading to abnormal MET gene expression. We prospectively assessed the efficacy and safety of the MET tyrosine kinase inhibitor crizotinib in patients with advanced or metastatic ASPS.

Patients and methods

Eligible patients with reference pathology-confirmed ASPS received oral crizotinib 250 mg bd. By assessing the presence or absence of a TFE3 rearrangement, patients were attributed to MET+ and MET- sub-cohorts. The primary end point was the objective response rate (ORR) according to local investigator. Secondary end points included duration of response, disease control rate (DCR), progression-free survival (PFS), progression-free rate, overall survival (OS) and safety.

Results

Among 53 consenting patients, all had a centrally confirmed ASPS and 48 were treated. A total of 45 were eligible, treated and assessable. Among 40 MET+ patients, 1 achieved a confirmed partial response (PR) that lasted 215 days and 35 had stable disease (SD) as best response (ORR: 2.5%, 95% CI 0.6% to 80.6%). Further efficacy end points in MET+ cases were DCR: 90.0% (95% CI 76.3% to 97.2%), 1-year PFS rate: 37.5% (95% CI 22.9% to 52.1%) and 1-year OS rate: 97.4% (95% CI 82.8% to 99.6%). Among 4 MET- patients, 1 achieved a PR that lasted 801 days and 3 had SD (ORR: 25.0%, 95% CI 0.6% to 80.6%) for a DCR of 100% (95% CI 39.8% to 100.0%). The 1-year PFS rate in MET- cases was 50% (95% CI 5.8% to 84.5%) and the 1-year OS rate was 75% (95% CI 12.8% to 96.1%). One patient with unknown MET status due to technical failure achieved SD but stopped treatment due to progression after 17 cycles. The most common crizotinib-related adverse events were nausea [34/48 (70.8%)], vomiting [22/48 (45.8%)], blurred vision [22/48 (45.8%)], diarrhoea (20/48 (41.7%)] and fatigue [19/48 (39.6%)].

Conclusion

According to European Organization for Research and Treatment of Cancer (EORTC) efficacy criteria for soft tissue sarcoma, our study demonstrated that crizotinib has activity in TFE3 rearranged ASPS MET+ patients.

Clinical trial number

EORTC 90101, NCT01524926.

Activity and safety of crizotinib in patients with advanced clear-cell sarcoma with MET alterations: European Organization for Research and Treatment of Cancer phase II trial 90101 'CREATE'

Background

Clear-cell sarcoma (CCSA) is an orphan malignancy, characterized by a specific t(12;22) translocation, leading to rearrangement of the EWSR1 gene and overexpression of MET. We prospectively investigated the efficacy and safety of the tyrosine kinase inhibitor crizotinib in patients with advanced or metastatic CCSA.

Patients and methods

Patients with CCSA received oral crizotinib 250 mg twice daily. Primary end point was objective response rate (ORR), secondary end points included duration of response, disease control rate (DCR), progression-free survival (PFS), progression-free rate (PFR), overall survival (OS), OS rate and safety. The study design focused on MET+ disease with documented rearrangement of the EWSR1 gene by fluorescence in situ hybridization.

Results

Among 43 consenting patients with the local diagnosis of CCSA, 36 had centrally confirmed CCSA, 28 of whom were eligible, treated and assessable. Twenty-six out of the 28 patients had MET+ disease, of whom one achieved a confirmed partial response and 17 had stable disease (SD) (ORR 3.8%, 95% confidence interval: 0.1-19.6). Further efficacy end points in MET+ CCSA were DCR: 69.2% (48.2% to 85.7%), median PFS: 131 days (49-235), median OS: 277 days (232-442). The 3-, 6-, 12- and 24-month PFR was 53.8% (34.6-73.0), 26.9% (9.8-43.9), 7.7% (1.3-21.7) and 7.7% (1.3-21.7), respectively. Among two assessable MET- patients, one had stable disease and one had progression. The most common treatment-related adverse events were nausea [18/34 (52.9%)], fatigue [17/34 (50.0%)], vomiting [12/34 (35.3%)], diarrhoea [11/34 (32.4%)], constipation [9/34 (26.5%)] and blurred vision [7/34 (20.6%)].

Conclusions

The PFS with crizotinib in MET+ CCSA is similar to results achieved first-line in non-selected metastatic soft tissue sarcomas with single-agent doxorubicin. The PFS is similar to results achieved with pazopanib in previously treated sarcoma patients.

Clinical trial number

EORTC 90101, EudraCT number 2011-001988-52, NCT01524926.

Effect of Propionibacterium acnes (PA) injection on intervertebral disc degeneration in a rat model: Does it mimic modic changes?

INTRODUCTION

Multiple reports of bacterial isolates in human disc tissue have suggested a role of low-grade infection on intervertebral disc degeneration and modic changes (MC) generation. Animal models have been extensively used to study IDD; however, until recently, no consideration had been given to eventual infectious processes. To reproduce the phenomena by inoculating an infecting agent would support the infectious hypothesis. Therefore, we studied the effect of Propionibacterium acnes (PA) inoculation on rat-tails and determined whether it would produce MCs on the adjacent endplates.

HYPOTHESIS

Disc infection with PA would accelerate IDD compared with the standard model and would also lead to MCs on the adjacent endplates.

METHODS

Twelve Sprague-Dawley rats were randomized to receive a needle puncture in a caudal tail disc with either saline (control) or an inoculum of 5×10⁷ CFU of strain 1a PA. Twelve weeks later, the rats were euthanized and the tails were analyzed. The main assessment criteria were obtained from the post-mortem MRI: T2 values of punctured discs and adjacent endplates, as well as disc volumes. A histological grading score for IDD was also used, measuring the morphology and cellularity of the nucleus and annulus, as well as endplate disruption.

RESULTS

The median T2 value and disc volume were smaller in PA-punctured discs [T2 value: 30ms (23-44) vs. 61ms (38-132), respectively, P=0.01; 0.01mm³ (0.01-0.05) vs. 0.5mm³ (0.01-5.35), respectively; P=0.049]. There was no change in the adjacent endplates. There was no significant difference in histological grading between the test and control [13 (10-14) vs. 10.5 (6-13); P=0.05].

DISCUSSION

Inoculation of caudal discs with PA generated increased degeneration; however, no MCs were observed on the adjacent endplates. A better understanding of low-grade disc infections is still needed.

LEVEL OF EVIDENCE

V (animal study).

Influence of Cytochrome P450, ABC and SLC Gene Polymorphisms on Imatinib Therapy Outcome of Patients with Gastrointestinal Stromal Tumours (GIST)

The efficacy of imatinib-based therapy depends on the proteins involved in its metabolism and transportation. Therefore, the aim of our study was to investigate the possible correlation of selected P450, ABC and SLC polymorphic variants and the outcome of imatinib therapy. A total of 101 patients with advanced, KIT/PDGFRA(+) GIST treated with imatinib were enrolled to the study. DNA was extracted from peripheral blood samples and genotypes were determined by PCR-RFLP and direct sequencing. Deviation from the Hardy-Weinberg equilibrium was only observed for rs2740574. None of the studied SNPs was associated with GIST time to progression. No significant correlation between any specific variant and time to progression was found in the group with KIT exon 11 mutation. However, individuals of at least three potentially unfavourable genotypes presented significantly shorter time to progression in comparison to patients with two or less unfavourable genotypes.

Effects of body temperature on post-anoxic oxidative stress from the perspective of postnatal physiological adaptive processes in rats

It is well known that decrease in body temperature provides protection to newborns subjected to anoxia/ischemia. We hypothesized that the normal body temperature of 33°C in neonatal rats (4°C below normal body temperature in adults) is in fact a preadaptation to protect CNS from anoxia and further reductions as well as elevations in temperature may be counterproductive. Our experiments aimed to examine the effect of changes in body temperature on oxidative stress development in newborn rats exposed to anoxia. Two-day-old Wistar rats were divided into 4 temperature groups: i. hypothermic at body temperature of 31°C, ii. maintaining physiological neonatal body temperature of 33°C, iii. forced to maintain hyperthermic temperature of 37°C, and i.v. forced to maintain hyperthermic temperature of 39°C. The temperature was controlled starting 15 minutes before and afterword during 10 minutes of anoxia as well as for 2 hours post-anoxia. Cerebral concentrations of lipid peroxidation products malondialdehyde (MDA) and conjugated dienes (CD) and the activities of antioxidant enzymes had been determined post mortem: immediately after anoxia was finished and 3, 7, and 14 days later. There were no post-anoxic changes in the concentration of MDA, CD and in antioxidant enzymes activity in newborn rats kept at their physiological body temperature of 33°C. In contrast, perinatal anoxia at body temperature elevated to 37°C or 39°C as well as under hypothermic conditions (31°C) intensified post-anoxic oxidative stress and depleted the antioxidant pool. Overall, these findings suggest that elevated body temperature (hyperthermia or fever), as well as exceeding cooling beyond the physiological level of body temperature of newborn rats, may extend perinatal anoxia-induced brain lesions. Our findings provide new insights into the role of body temperature in anoxic insult in vivo.

Plasmodium knowlesi as a Threat to Global Public Health

Malaria is a tropical disease caused by protozoans of the Plasmodium genus. Delayed diagnosis and misdiagnosis are strongly associated with higher mortality. In recent years, a greater importance is attributed to Plasmodium knowlesi, a species found mainly in Southeast Asia. Routine parasitological diagnostics are associated with certain limitations and difficulties in unambiguous determination of the parasite species based only on microscopic image. Recently, molecular techniques have been increasingly used for predictive diagnosis. The aim of the study is to draw attention to the risk of travelling to knowlesi malaria endemic areas and to raise awareness among personnel involved in the therapeutic process.

Defining pseudoprogression in glioblastoma multiforme

BACKGROUND AND PURPOSE

Pseudoprogression is a frequent phenomenon observed since the introduction of postoperative therapy with radiotherapy and temozolomide (RT/TMZ) in glioblastoma multiforme (GBM) patients. However, the criteria defining pseudoprogression, its incidence, the time of occurrence and its impact on therapy and outcome remain poorly defined.

METHODS

The objective of this study is to compare two sets of criteria (liberal and stringent), defining pseudoprogression, in a cohort of patients treated before and after the introduction of RT/TMZ in the standard postoperative treatment. This retrospective review includes 136 unselected and consecutively treated patients with pathologically diagnosed GBM.

RESULTS

Pseudoprogression was observed in 10 (12%) cases applying the stringent criteria, and in 18 (23%) patients when using the liberal criteria, in the cohort treated with RT/TMZ. Pseudoprogression was observed in only one patient treated with RT alone. The median time to pseudoprogression was 4 weeks after the end of RT. Patients with pseudoprogression had a median survival time of 28 months, compared with 12 months for patients without pseudoprogression.

CONCLUSIONS

The incidence of pseudoprogression after RT/TMZ strongly depends on the applied criteria. However, regardless of the stringency of the criteria, the impact on survival remains the same.

Whole-body cryostimulation and oxidative stress in rowers: the preliminary results

INTRODUCTION

The effect of whole-body cryostimulation (WBC) on the biomarkers of oxidative stress, lysosomal enzymes, creatine kinase and cortisol was studied.

MATERIAL AND METHODS

The rowers underwent two 6-day training cycles: with pre-training daily WBC (temperature: from -125°C to -150°C) and without cryostimulation (control). Blood samples were taken before and after the third and sixth day of training.

RESULTS

The activity of superoxide dismutase and glutathione peroxidase was lower (by 44% and 42%, respectively) after the third day of training with WBC than without WBC. The concentration of lipid peroxidation products was also lower after the training preceded by WBC. Moreover, the acid phosphatase activity was 50% lower after the third day of training with WBC than training without WBC. Considering the antioxidant enzymes activity during training without WBC, the increase of superoxide dismutase and glutathione peroxidase activity was observed after the third day of training (by about 74% and 100%, respectively). The level of lipid peroxidation products also increased after the training without WBC. No statistically significant changes were observed in creatine kinase activity after the training preceded with WBC, while after the training without WBC activity of this enzyme was two-fold higher than before the training.

CONCLUSIONS

The use of WBC prior to training may reduce the risk of oxidative stress and the extent of muscle fibre injuries provoked by intense exercise. The WBC seems to be an effective and safe method for limiting exercise-induced damage; thus it may be used in biological regeneration of sportsmen.

The activity of cathepsin D and alpha-1 antitrypsin in hip and knee osteoarthritis

The progress of cartilage decay during joint degeneration is not well monitored with biochemical methods. The role of cathepsin D (CAT-D) in articular cartilage deterioration remains unclear. The aim of this study is to assess the activity of CAT-D and alpha-1 antitrypsin (AAT) in blood in patients with hip or knee osteoarthritis. The activity of CAT-D and AAT in blood serum of 40 women and 21 men with hip or knee osteoarthritis was determined before total joint replacement, on the tenth day after surgery, and once in 54 healthy patients. The preoperative activity of CAT-D in patients with osteoarthritis was lower by 53.6% (11.00 ± 4.54 10(-2) nM released tyrosine/mg protein/min, P < 0.001) and after surgery by 55.0% (10.67 ± 4.64 10(-2) nM released tyrosine/mg protein/min, P < 0.001) when compared to its activity in healthy patients. There was no significant statistical difference between CAT-D activity before the surgery and its activity on the tenth day after it in the analyzed group (P< 0.496). Simultaneously, the preoperative activity of AAT in the OA (osteoarthritis) patients was by 25.5% (0.93 ± 0.32 mg inhibited trypsin/ml blood serum, P < 0.001) and postoperative was by 44.9% higher (1.26 ± 0.36 mg inhibited trypsin/ml blood serum, P < 0.001) than in healthy patients. The low CAT-D activity in osteoarthritis of big joints is associated with a decrease of cartilage cells during the degenerative process. The higher activity of acute phase protein AAT in OA patients' blood serum confirms the inflammatory component in the osteoarthritis process.

The activity of cathepsin D and alpha-1 antitrypsin in hip and knee osteoarthritis

The progress of cartilage decay during joint degeneration is not well monitored with biochemical methods. The role of cathepsin D (CAT-D) in articular cartilage deterioration remains unclear. The aim of this study is to assess the activity of CAT-D and alpha-1 antitrypsin (AAT) in blood in patients with hip or knee osteoarthritis. The activity of CAT-D and AAT in blood serum of 40 women and 21 men with hip or knee osteoarthritis was determined before total joint replacement, on the tenth day after surgery, and once in 54 healthy patients. The preoperative activity of CAT-D in patients with osteoarthritis was lower by 53.6% (11.00 ± 4.54 10(-2) nM released tyrosine/mg protein/min, P < 0.001) and after surgery by 55.0% (10.67 ± 4.64 10(-2) nM released tyrosine/mg protein/min, P < 0.001) when compared to its activity in healthy patients. There was no significant statistical difference between CAT-D activity before the surgery and its activity on the tenth day after it in the analyzed group (P< 0.496). Simultaneously, the preoperative activity of AAT in the OA (osteoarthritis) patients was by 25.5% (0.93 ± 0.32 mg inhibited trypsin/ml blood serum, P < 0.001) and postoperative was by 44.9% higher (1.26 ± 0.36 mg inhibited trypsin/ml blood serum, P < 0.001) than in healthy patients. The low CAT-D activity in osteoarthritis of big joints is associated with a decrease of cartilage cells during the degenerative process. The higher activity of acute phase protein AAT in OA patients' blood serum confirms the inflammatory component in the osteoarthritis process.

[The assessment of metabolism of bone tissue as changes in concentration of biochemical markers of bone turnover in inpatient alcohol dependent women]

AIM

The aim of this study was the assessment to of metabolism of bone tissue as changes in concentration of biochemical markers of bone turnover in inpatient alcohol dependent women.

METHODS

The studied group consisted of 50 alcohol dependent female patients who were divided in two groups: one with an activity ofAST or ALT above referential values and level of bilirubin and the second one with the activity oftransaminases and level ofbilirubin within referential values. The level of sex hormones and markers of bone turnover such as osteocalcin and collagen cross laps (ctx) were indicated.

RESULTS

In the group with an AST, ALT or BIL above referential values, the concentration of FSH in the ovulation phase and luteal phase as well as LH in luteal phase was significantly higher, while ctx and osteocalcin was lower compared to the group with AST, ALT or BIL within referential values. The mean concentrations ofFSH in follicular phase and luteal phase as well as LH in the luteal phase and progesterone in the follicular phase were increased in the group of patients with AST, ALT or BIL above referential values. The positive correlation between levels ofctx and osteocalcin was found which suggests a balance between processes. of bone formation and bone resorption in the whole group while a lack of such correlation was observed in patients with AST, ALT or BIL above referential values.

CONCLUSIONS

The results obtained indicate the multidirectional and mutual relations between the alcohol abuse, liver function, bone turnover and activity of endocrine system.

Evasion of host immunity by virulent Salmonella: implications for vaccine design

Dendritic cells (DCs) are professional antigen presenting cells (APCs) capable of linking innate and adaptive immunity during infection. After recognition of pathogen-associated molecular patterns (PAMPs), DCs can engulf, process and present bacteria-derived antigens on MHC molecules to T cells. Because of the key role that DCs play on the initiation of innate and adaptive immunity, alterations in their function could render the host susceptible to bacterial dissemination. Consistent with this notion, is the observation that several pathogenic bacteria have evolved mechanisms to impair the DC capacity to prime naïve T cells. One of such bacteria is Salmonella enterica serovar Typhimurium, which causes a typhoid-like disease in mice and gastroenteritis in humans. Recent studies have shown that virulent Salmonella can use intestinal DCs to spread inside the host, evading T cell priming. The avoidance of T cell recognition by Salmonella is in large part achieved by the activity of gene products encoded on Salmonella Pathogenicity Islands -1 and - 2. The understanding of some of the remarkable molecular virulence mechanisms displayed by Salmonella has contributed to the design of new vaccines capable of inducing protective immunity against this pathogen in mouse models. Here we describe recent data underscoring the virulence mechanisms used by Salmonella to exploit DC function and discuss strategies based on this new knowledge aimed at the design of new efficient and safe vaccines against this pathogen.

Safety of central venous catheter placement at diagnosis of acute lymphoblastic leukemia in children

BACKGROUND

Central venous catheters (CVC) facilitate the management of patients with cancer. Optimal timing for placement of a CVC is controversial. We sought to determine whether early placement in children with acute lymphoblastic leukemia (ALL), a group at high risk for infection and thrombosis, was associated with an increased rate of surgical complications.

PROCEDURE

We evaluated the incidence and risk factors for early surgical complications in children with ALL diagnosed between 2004 and 2009 at a single pediatric cancer center.

RESULTS

One hundred seventy-two patients were studied. There were 17 episodes of bloodstream infection, for a 30-day incidence of 9.8% (95% CI, 5.9-15%). There were no surgical site infections and no CVC was removed due to infection. Early thrombosis occurred in only one patient, 3 days after CVC placement. Infection was not influenced by catheter type, patient age, body mass index, or fever at the time of placement. The infection rate was not statistically higher when the ANC was <500/mm(3) at the time of CVC placement (14.2% vs. 6.8%; P = 0.12).

CONCLUSION

Early CVC placement at the time of diagnosis of ALL was associated with a low surgical complication rate with no catheters requiring removal due to infection. Utilizing our current methods of preoperative preparation, surgical management and postoperative CVC care, early placement of a CVC is safe in children with ALL even when their ANC is <500/mm(3) , but larger cohort studies would be helpful to further clarify this issue.

Validation of the Joensuu risk criteria for primary resectable gastrointestinal stromal tumour - the impact of tumour rupture on patient outcomes

BACKGROUND

Approval of imatinib for adjuvant treatment of gastrointestinal stromal tumours (GIST) raised discussion about accuracy of prognostic factors in GIST and the clinical significance of the available risk stratification criteria.

METHODS

We studied the influence of a new modification of the NIH Consensus Criteria (the Joensuu risk criteria), NCCN-AFIP criteria, and several clinicopathological factors, including tumour rupture, on relapse-free survival (RFS) in a prospectively collected tumour registry series consisting of 640 consecutive patients with primary, resectable, CD117-immunopositive GIST. The median follow-up time after tumour resection was 39 months. None of the patients received adjuvant imatinib.

RESULTS

The median RFS time after surgery was 50 months. In univariable analyses, high Joensuu risk group, tumour mitotic count >5/50 HPF, size >5 cm, non-gastric location, tumour rupture (7% of cases; P = 0.0014) and male gender had adverse influence on RFS. In a multivariable analysis mitotic count >5/50HPF, tumour size >5 cm and non-gastric location were independent adverse prognostic factors. Forty, 151, 86 and 348 patients were assigned according to the Joensuu criteria to very low, low, intermediate and high risk groups and had 5-year RFS of 94%, 94%, 86% and 29%, respectively.

CONCLUSION

The Joensuu criteria, which include 4 prognostic factors (tumour size, site, mitotic count and rupture) and 3 categories for the mitotic count, were found to be a reliable tool for assessing prognosis of operable GIST. The Joensuu criteria identified particularly well high risk patients, who are likely the proper candidates for adjuvant therapy.

Prognostic value of KIT/PDGFRA mutations in gastrointestinal stromal tumours (GIST): Polish Clinical GIST Registry experience

BACKGROUND

Majority of gastrointestinal stromal tumours (GISTs) are characterised by KIT-immunopositivity and the presence of KIT/platelet-derived growth factor receptor alpha (PDGFRA) activating mutations.

PATIENTS AND METHODS

Spectrum and frequency of KIT and PDGFRA mutations were investigated in 427 GISTs. Univariate and multivariate analysis of relapse-free survival (RFS) was conducted in relation to tumours' clinicopathologic features and genotype.

RESULTS

Mutations were found in 351 (82.2%) cases, including 296 (69.3%) KIT and 55 (12.9%) PDGFRA isoforms. Univariate analysis revealed higher 5-year RFS rate in women (37.9%; P = 0.028) and in patients with gastric tumours (46.3%; P < 0.001). In addition a better 5-year RFS correlated with smaller tumour size ≤ 5 cm (62.7%; P < 0.001), tumours with mitotic index ≤ 5/50 high-power fields (60%; P < 0.001), and characterised by (very) low/moderate risk (70.2%; P = 0.006). Patients with GISTs bearing deletions encompassing KIT codons 557/558 had worse 5-year RFS rate (23.8%) than those with any other KIT exon 11 mutations (41.8%; P < 0.001) or deletions not involving codons 557/558 (33.3%; P = 0.007). Better 5-year RFS characterised patients with KIT exon 11 point mutations (50.7%) or duplications (40%). By multivariate analysis, tumours with PDGFRA mutations and KIT exon 11 point mutations/other than 557/558 deletions had lower risk of progression than with KIT exon 11 557/558 deletions (both Ps = 0.001).

CONCLUSIONS

KIT/PDGFRA mutational status has prognostic significance for patients' outcome and may help in management of patients with GISTs.

The Influence of Older Age on Physician and Patient Decision-Making Regarding Enrollment to Breast Cancer Clinical Trials

Background: More than 50% of breast cancers occur in women ≥65 years. Clear guidelines for treatment do not exist for this population, however, due to underrepresentation of older patients on clinical trials. We reported that patients 65 and older are significantly underrepresented in Southwest Oncology Group (SWOG) trials, particularly in breast cancer. (Hutchins, 1999) We conducted a prospective study (S0316) to determine physician- and patient-perceived barriers to breast cancer clinical trial enrollment in older versus younger patients.Methods: Eight geographically diverse SWOG institutions, 5 academic and 3 community, participated in S0316. Breast cancer patients were registered at time of systemic treatment decision-making. The study prospectively assessed reasons behind patients' and physicians' decisions to either enroll in or decline clinical treatment trials, including demographics, return rates to the institution, trial availability, and eligibility. Patient questionnaires elicited concerns about treatment toxicities, confidence in medical staff or institution, opposition or support by family/friends, and financial or time commitment concerns. Physician questionnaires elicited factors influencing decisions either not to discuss a trial or not to enroll the patient, including treatment toxicities, patient age or medical status, demands on personal or staff time, and reimbursement issues. Results were compared between patients &lt;65 vs. ≥65 years.Results: 1,079 patients were registered and eligible, and 909 (84%) returned for follow-up. Clinical trial participation was 16%. The major reason for non-accrual was either trial unavailability or ineligibility (60%). Older patients were less likely to be eligible for trials (65% vs. 78%, p=.004). If eligible, trial participation rates did not differ significantly by age (34% vs. 40%, p=.32). Treatment-specific issues were the most common reasons cited by all patients for non-participation. Patients ≥65 more often were concerned about side effects (p=.02), had friends opposed to participation (p=.001), or believed that participation would not benefit other generations (p=.009). Concerns about transportation, time commitment, or posing a burden to family were similar between age groups. Physicians discussed trial participation when trials were available and patients were eligible with 76% &lt;65 years versus 58% ≥65 years (p=.008). The study regimen and toxicity were the most common reasons influencing physician decisions not to discuss a trial, but did not differ between age groups. For patients ≥65 years, 14% of physicians indicated age as a reason the patient did not participate vs. 3% for patients &lt;65 years (p=.002).Conclusions: Trial unavailability or patient ineligibility are major reasons for lack of enrollment on breast cancer clinical trials for patients of all ages in this prospective study. Older patients were less likely to be eligible for trials, but if eligible participated at similar rates to younger patients. Older age should not deter physicians in recommending clinical trials. Addressing stringent eligibility criteria may improve accrual rates of older patients.Supported by the Breast Cancer Research Foundation and the SWOG Hope Foundation

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3077.

Single-molecule force spectroscopy using the NanoTracker optical tweezers platform: from design to application

Since the development of detection and analysis techniques for optical tweezers setups, there has been an ever-increasing interest in optical tweezers as a quantitative method, shifting its applications from a pure manipulation tool towards the investigation of motions and forces. With the capability of manipulation and detection of forces of a few hundred picoNewtons down to a fraction of a picoNewton, optical tweezers are perfectly suitable for the investigation of single molecules. Accordingly, the technique has been extensively used for the biophysical characterization of biomolecules, ranging from the mechanical and elastic properties of biological polymers to the dynamics associated with enzymatic activity and protein motility. Here, the use of state-of-the-art optical tweezers on the elasticity of single DNA molecules is presented, highlighting the possibilities this technique offers for the investigation of protein-DNA interaction, but also for other single molecule applications. Technical in nature, design aspects of the NanoTracker optical tweezers setup are addressed, presenting the recent advances in the development of optical tweezers, ranging from noise reduction to detection and calibration methodology.

SWOG S0509: A phase II study of novel oral antiangiogenic agent AZD2171 (NSC-732208) in malignant pleural mesothelioma

7511

Background: Preclinical studies suggest the autocrine growth loop involving VEGF and its receptors is a relevant therapeutic target for malignant pleural mesothelioma (MPM). We evaluated AZD2171, a potent tyrosine kinase inhibitor (TKI) of VEGFR1/2 in MPM. Methods: MPM patients (pts) after platinum-based chemotherapy, with PS 0–2, measurable disease and adequate organ function were treated with oral daily dosing of AZD2171 45 mg. Study endpoints were response rate, progression free survival (PFS), overall survival (OS), frequency/severity of toxicities, and correlation of clinical outcomes with tumor and serum biomarkers. Results: 54 pts were registered between November 2005 and April 2008; 45 pts are eligible for response and 46 for toxicity analysis. Median age was 66.8 yrs; M/F: 37/9. Tumor response by RECIST was seen in 4/45 (9%) of pts; of these responders, 2 pts with bulky disease had 56% and 91% tumor shrinkage, respectively. 15/45 (33%) had SD; 21/45 (47%) had PD; 1/45 (2%) had early death. Thirty-five pts have died. For 46 pts, median PFS is estimated at 3 months; median OS is estimated at 10 months. For 46 pts, frequent grade 1–3 toxicities included anorexia (30%), diarrhea (63%), fatigue (60%), hypertension (67%), and proteinuria (28%). There were 8 grade 4 events: Cognitive disturbance, colitis, confusion, ileal perforation, hypertension, hyponatremia, hypotension, and renal failure. Conclusions: AZD2171 has antitumor activity in MPM, with a DCR (CR/PR/SD) of 42% by RECIST, which has limitations in measuring response in pleural tumors. Notably, 2 pt tumors were exquisitely sensitive to this drug. Toxicities were consistent with those of the anti-angiogenic TKI class of drugs. Studies correlating outcome measures with tumor hypoxia- and angiogenesis-related gene expression and circulating endothelial cells are underway. Based on these data, we are proceeding in SWOG with a study of pemetrexed/cisplatin ± AZD2171 (S0905). This investigation was supported in part by the following PHS Cooperative Agreement grant numbers awarded by the National Cancer Institute, DHHS: CA32102, CA38926, CA14028, CA46441, CA105409, CA13612, CA45808, CA20319, CA86780, CA35090, CA67663, CA46282, CA42777, CA76448, CA04919, CA35176, CA63848, CA27057, CA16385.

[Table: see text]

Assessment of the heat shock protein 90 (HSP90) inhibitor IPI504 alone or in combination with the tyrosine kinase inhibitor (TKI) imatinib in mice carrying xenografts of human gastrointestinal stromal tumors (GIST)

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Background: Inhibition of HSP90 is a new strategy for treatment of GIST. IPI-504 is a potent i.v. HSP90 inhibitor. We assessed the activity of IPI-504 in imatinib-sensitive GIST xenografts, alone/combined with the TKI. Methods: Human GIST882 cells (KIT exon 13 mut.) were grafted in 43 nude mice, who were randomized to 4 groups: A (n=13; control); B (n=18; IPI-504 100 mg/kg 3x/wk p.o.); C (n=8; imatinib 50 mg/kg 2x/d p.o.); D (n=4; IPI-504+imatinib, dose/schedule as above) for 2 weeks. Histopathological assessment was done by H&E and KIT immunostaining, histological response (HR) was defined by magnitude of necrosis and myxoid degeneration [grade 1 (0–10%), 2 (>10% - ≤ 50%), 3 (> 50% - ≤90%), 4 (>90%)]. Expression/activation of KIT and its signaling (AKT, S6, MAPK) was assessed by Western blot. Results: IPI-504 alone significantly reduced tumor volume (41%) at day 14, further enhanced by adding imatinib (58%). Imatinib alone led to only a 5% reduction. IPI-504 induced grade 2 HR in 17/36 tumors, while the majority of tumors (13/15) treated with imatinib showed grade 1 HR. Grade 3/4 HRs were only seen with the combination. Mitosis decreased 3.3-fold, apoptosis increased 1.3-fold with IPI-504. Despite substantial reduction in mitotic activity in C and D (8.2- and 82-fold), apoptosis was virtually unaffected. In the IPI-504 arm, KIT levels were partially downregulated. Imatinib alone had no effect on KIT expression, while the combination produced a marked suppression of total KIT, accompanied by complete downregulation of the signaling. Loss of KIT in the combination arm was confirmed by immunostaining. Although KIT was not completely degraded with IPI-504, measurable effects on activation of AKT, S6 and MAPK were observed. Conclusions: IPI-504 has consistent antitumor effects in GIST xenografts, both histologically and on the molecular level. Combining IPI-504 with imatinib substantially enhances anti-tumor activity, providing a strong rationale for clinical trials of IPI-504 in GIST as single agent and in combination.

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