Pharmacokinetic (PK) and phase I study of sorafenib (S) for solid tumors and hematologic malignancies in patients with hepatic or renal dysfunction (HD or RD): CALGB 60301

3538

Background: We sought to characterize the PK and determine a tolerable dose of S in patients with HD or RD. Methods: Patients with performance status 0–2 and pathologically proven solid tumors, multiple myeloma, or non-Hodgkin’s lymphoma, for whom standard therapy was exhausted, were assigned to one of 9 cohorts: [1] Bilirubin (B) =ULN and SGOT =ULN and creatinine clearance (CC) =60 ml/min; [2] B > ULN but = 1.5 x ULN and/or SGOT > ULN; [3] CC between 40 and 59 mL/min; [4] B > 1.5 x ULN to = 3 x ULN (any SGOT); [5] CC between 20 and 39 mL/min; [6] B > 3 x ULN to 10 x ULN (any SGOT); [7] CC < 20 mL/min; [8] albumin < 2.5 mg/dL (any B/ SGOT); and [9] hemodialysis. S was administered po as a 400 mg test dose on day 1 with blood sampled before and 1, 2, 3, 4, 6, 24, and 168 hrs afterwards for PK. Total S concentrations were fit to a 2-compartment model and population parameters from previous studies were utilized. On day 8, continuous daily po S started with dose escalation in groups of at least 3 evaluable patients. Dose-limiting toxicity (DLT) by day 29 was defined as: grade 4 neutrophils or platelets; B = 1.5 x baseline in HD and = 2.5 x ULN in RD; CC reduction by > 20 mL/min in RD and >10 mL/min in HD; grade = 3 nausea/vomiting/diarrhea despite optimal supportive care; or any other grade = 3 non-hematologic toxicity. Results: Between 1/05 and 12/06, 146 patients (target 150) were registered but 12 never started therapy. With the exception of cohorts 6 and 7, at least 12 patients per cohort were evaluable. The dose level in each cohort with DLT in less than one third of patients was: [1] 400 mg bid; [2] 400 mg bid; [3] 400 mg bid; [4] 200 mg bid; [5] 200 mg bid; [6] not even 200 mg every third day tolerable; [7] n/a; [8] 200 mg qd; and [9] 200 mg qd. All DLT was non-hematologic: 9 of 12 events in patients with HD were increase in B; other DLT included abdominal pain, rash, fatigue, nausea/vomiting, hand-foot syndrome, congestive heart failure, diarrhea, hemorrhage, and hypertension. PK data are available for 51 patients. Apparent S clearance was: highly variable, median 5.69 (range 1.27 - 19.98) L/hr; not related to age, body weight, or sex; and not different among cohorts. Conclusions: Apparent S clearance does not depend on cohort. We propose the above empiric starting doses by cohort.

No significant financial relationships to disclose.

Phase I and pharmacokinetic (PK) study of PTK787/ZK222584 (PTK/ZK) plus capecitabine (cape) in patients (Pts) with advanced cancer

3595

Background: PTK/ZK is a small molecule inhibitor of the vascular endothelial growth factor receptor family. Cape is a standard treatment for pts with breast and colon cancer, tumors for which angiogenesis inhibition is beneficial. Therefore, we conducted a phase I study of the combination to determine the maximally tolerated doses (MTD), toxicities and PK interactions. Methods: Eligible pts had advanced cancer with no standard treatment option, Karnofsky performance status (KPS) > 70, and normal organ function. Pts with bone marrow or CNS involvement or who had more than 4 prior chemotherapy regimens were excluded. A dose escalation (dosesc) phase was conducted to determine the MTD followed by a dose expansion (dosexp) phase to assess PK interactions. PTK/ZK was given as a single oral daily doser without interruption and cape was given orally twice daily for 14 of 21 days. Results to Date: 43 pts (30 male, 13 female), median age 61 y (34–78 y) and median KPS 95 (70–100) were enrolled in the dosesc phase. 37 had prior chemotherapy; 5 had radiation only. Diagnoses included colorectal cancer (10), head/neck (7), sarcoma (5), renal (4), stomach/pancreas (3 each) and others (11). 29/43 pts were evaluable for MTD determination and received a total of 145 cycles. Doses of PTK/ZK-cape (mg-mg/m2) were: 750/2,500; 1,000/2,500; 750/2,000; 1,000/2,000; 1,250/2,000. DLT occurred in 1/6 pts (gr 3 fatigue) at 750/2,500; 2/2 pts (≥gr 3 fatigue, hypertension [HTN]) at 1,000/2,500; 0/3 pts at 750/2,000; 2/12 pts (≥ gr 3 dizziness, HTN and seizure) at 1,000/2,000 and in 1/6 (gr 3 proteinuria) pts at 1,250/2,000. 1,250 mg was the highest PTK/ZK dose planned. Other common toxicities in the dosesc phase were hand-foot syndrome (HFS, 93%) and HTN (28%). In the dosexp phase 26 pts (14 M, 12 F) have thus far received 73 cycles at the MTD (1,250/2,000). Median age is 65 y (26–79 y) and median KPS is 80 (70–100). 28/73 cycles were delayed or interrupted for toxicity with gr ≥3 toxicities (# cycles): HFS (7), fatigue (5), increased LFTs (5), HTN (3), DVT/PE (4). 23 pts (17 in dosesc and 6 in dosexp) had response or stable disease longer than 12 weeks. Final results and PK data will be presented. Conclusion: PTK/ZK and cape can be combined without unexpected toxicities.

No significant financial relationships to disclose.

Negative pressure ventilation in pediatric critical care setting

Invasive ventilation is associated with both pulmonary and non-pulmonary complications. There has been a renewed interest in the use of negative pressure ventilation (NPV) for various medical conditions to minimise the complications associated with positive pressure ventilation. The routine use of NPV in an ICU setting still requires further studies and research. In this article, the authors review the clinical applications of NPV together with associated risks and limitations. Case reports of patients with cardiac, neuromuscular and respiratory diseases managed with NPV on our unit are described. NPV improved the clinical condition in each of these patients and decreased the requirement for invasive therapy.

Inflammation of actinic keratoses subsequent to therapy with sorafenib, a multitargeted tyrosine-kinase inhibitor

The Ras-Raf-MEK-ERK signalling pathway is frequently dysregulated in human malignancies, as is angiogenesis and the vascular endothelial growth factor receptor (VEGF/VEGFR) pathway. These kinases are therefore important anticancer targets. The novel, oral treatment sorafenib (BAY 43-9006), has been shown to be an inhibitor of VEGFR, Raf and platelet-derived growth factor in clinical trials against a variety of cancers, with the greatest activity to date observed in metastatic renal cancer. Although side-effects with this targeted therapy are usually not dose-limiting, they frequently involve the skin, and consist of a maculopapular rash, palmar-plantar dysaesthesia, alopecia and xerosis. In this report, we present two patients in whom treatment with sorafenib resulted in inflammation of actinic keratosis, which in some cases progressed to invasive squamous cell carcinoma. This side-effect is of clinical importance, as early recognition is critical for early treatment and may represent a source of additional morbidity to these patients.

Adenosine A2A receptors in diffuse dermal fibrosis: pathogenic role in human dermal fibroblasts and in a murine model of scleroderma

OBJECTIVE

Adenosine regulates inflammation and tissue repair, and adenosine A2A receptors promote wound healing by stimulating collagen matrix production. We therefore examined whether adenosine A2A receptors contribute to the pathogenesis of dermal fibrosis.

METHODS

Collagen production by primary human dermal fibroblasts was analyzed by real-time polymerase chain reaction, 14C-proline incorporation, and Sircol assay. Intracellular signaling for dermal collagen production was investigated using inhibitors of MEK-1 and by demonstration of ERK phosphorylation. In vivo effects were studied in a bleomycin-induced dermal fibrosis model using adenosine A2A receptor-deficient wild-type littermate mice, C57BL/6 mice, and mice treated with adenosine A2A receptor antagonist. Morphometric features and levels of hydroxyproline were determined as measures of dermal fibrosis.

RESULTS

Adenosine A2A receptor occupancy promoted collagen production by primary human dermal fibroblasts, which was blocked by adenosine A2A, but not A1 or A2B, receptor antagonism. Adenosine A2A receptor ligation stimulated ERK phosphorylation, and A2A receptor-mediated collagen production by dermal fibroblasts was blocked by MEK-1 inhibitors. Adenosine A2A receptor-deficient and A2A receptor antagonist-treated mice were protected from developing bleomycin-induced dermal fibrosis.

CONCLUSION

These results demonstrate that adenosine A2A receptors play an active role in the pathogenesis of dermal fibrosis and suggest a novel therapeutic target in the treatment and prevention of dermal fibrosis in diseases such as scleroderma.

Presence of rabies specific immune complexes in cerebro-spinal fluid can help in ante-mortem diagnosis of human paralytic rabies

BACKGROUND

Human rabies presents in two clinical forms, viz. furious or encephalitic and paralytic. Clinical diagnosis of paralytic form is difficult and requires laboratory confirmation. Presently available diagnostic techniques are not very sensitive for ante-mortem confirmation of rabies.

OBJECTIVE

In the present study, we investigated whether presence of rabies specific immune complexes in cerebro-spinal fluid (CSF) of paralytic rabies patients could help in ante-mortem diagnosis of rabies.

STUDY DESIGN

A capture ELISA based on monoclonal antibodies to rabies nucleoprotein (N) and glycoprotein (G) was developed to detect immune complexes to rabies N and G proteins. We studied CSF samples collected ante-mortem from 30 suspected paralytic rabies patients in whom diagnosis was later confirmed by autopsy. We included 30 CSF samples from people undergoing spinal anesthesia as negative controls and 30 CSF samples from other viral encephalitis as disease controls.

RESULTS

Twenty-three out of 30 CSF samples (76.6%) showed presence of immune complexes to both rabies N and G proteins. None of the negative controls and CSFs from other confirmed viral infections were positive. Thus, the results were 100% specific and the sensitivity of this test was 76.6%.

CONCLUSIONS

Detection of immune complexes to rabies antigens may be used as one of the techniques for rapid ante-mortem diagnosis of human rabies.

Feasibility of day-case vitreoretinal surgery

PURPOSE

The indications for vitreoretinal (VR) surgery are increasing as equipment and techniques available improve. In order to decrease demand on limited health resources, day-case surgery would be beneficial in many cases. This study combines a retrospective and prospective arm to examine the feasibility and safety of routine day-case VR surgery.

METHODS

One hundred consecutive patients (50 retrospective and 50 prospective) undergoing VR surgery within the Royal Berkshire NHS trust were included. The retrospective arm aimed to identify the frequency and type of acute ophthalmic or medical intervention during postop overnight stay and the results were used to alter management in the prospective group. The prospective group consisted of patients undergoing a mixture of overnight stay and day-case surgery. All patients in the prospective group had routine subtenon marcaine anaesthesia together with prophylactic pre-operative intravenous acetazolamide. Patients deemed fit postoperatively were offered overnight ward discharge, with obligatory next-day review.

RESULTS

In the retrospective arm, 56% required oral nonsteroidal analgesia on the day of surgery and one patient required narcotic analgesia. Twenty-two per cent patients required intraocular pressure (IOP) control on the day of surgery and one patient required medical intervention in the form of urinary catheterisation. Nineteen patients required intervention on next-day review. In the prospective arm, 86% preferred day case and were suitable, 6% were suitable for day-case but preferred overnight stay and 8% were deemed not fit for discharge. No patient required narcotic analgesics. No patient discharged returned as a casualty overnight. Only one patient required topical beta-blocker for the control of IOP on next-day review.

CONCLUSIONS

These data suggest that many patients who are hospitalised overnight for VR surgery could be safely treated as day cases. Such a shift in the pattern of care for VR surgery could provide a significant improvement in health-care efficiency and minimise patient inconvenience.

A phase 1, dose-escalation trial of STA-5312, a microtubule inhibitor with a novel binding site, in advanced or metastatic solid malignancies

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Background: STA-5312 is a novel microtubule inhibitor with a distinct binding site from other agents such as vincristine, colchicine, or paclitaxel, which has demonstrated antitumor activity against a range of solid tumors in chemotherapy-resistant cancer. Methods: The trial assessed the safety, toxicity, pharmacokinetics (PK) and maximum tolerated dose (MTD) level of STA-5312 when administered as an IV infusion weekly for the first 3 weeks of a 4 week cycle. Assessment of activity is a secondary objective. The starting dose level was 6mg/m2. Dose escalation was based on evaluation of toxicity through the first cycle, with dose doubling in cohorts of 1–2 patients (pts) until a grade (gr) 2 or greater toxicity occurred, followed by at least 3 pts/cohort and 50% dose escalations. After a dose limiting toxicity (DLT), cohorts were expanded to at least 6 pts and subsequent escalations limited to 33%. The dose below the lowest dose at which 1/3 of 6 or more patients show DLT will be declared the MTD. PK sampling was performed during cycle 1. Results: To date, 25 pts have been treated: median age 58 years (35–77), ECOG performance status of 0–2, and median treatment duration 43 days. No serious drug-related toxicity was observed until a DLT (ataxia) was reported in the only patient treated at 64mg/m2, leading to de-escalation to 48 mg/m2, where the only patient experienced aphasia and ataxia. Enrollment is being expanded at a lower dose level of 32 mg/m2. Other adverse events attributable to STA-5312 include (>10%) anemia, fatigue, constipation, nausea, and anorexia. Exposure (AUC) was linear with respect to dose. Five patients have had disease stabilization. Conclusions: STA-5312 appears to be well tolerated when given weekly in doses up to 32mg/m2. The MTD has not been determined and enrollment is ongoing.

[Table: see text]

Lysozyme refolding with cyclodextrins: structure-activity relationship

Cyclodextrins (CDs), in the presence or absence of detergents, have been reported to suppress aggregate formation during the refolding of a number of proteins. A structure-activity relationship study between CD chemistry and refolding of lysozyme was performed and compared to carbonic anhydrase, in order to better understand the mechanism of CD-assisted protein refolding and to identify CDs that could function as good protein folding agents. Among the natural CDs, which have only hydroxyl groups, alpha-CD, with a smaller cavity size was more effective than the oligosaccharide with a larger cavity, gamma-CD. Replacement of the hydroxyls with other functional groups did not improve, but could seriously interfere, with the lysozyme refolding ability of alpha-CD. In case of gamma-CD, substitution of its hydroxyls with other groups either enhanced or diminished its refolding capability towards lysozyme. In general, neutral CDs were better refolding agents than the charged sugars. The presence of anionic substituents like carboxyl and phosphate groups actually promoted aggregate formation and completely abolished the sugar's refolding ability. This effect was more pronounced with lysozyme than with carbonic anhydrase. CDs with cationic functional groups did not show any significant effects on lysozyme refolding. The presence of both anionic and cationic substituents on the same CD molecule was found to partially restore its renaturation ability. Electrophoresis data indicate that CDs, which promoted lysozyme refolding, arrested aggregation at the stage of smaller soluble aggregates. Interestingly, the structure-activity relationship observed with lysozyme was quite similar to that reported for a non-disulfide protein, carbonic anhydrase. These results suggest that the effects of CDs on protein refolding are attributed to their ability to suppress aggregation of proteins. CDs may show properties similar to chaotropic agents, which may help explain their anti-aggregation and protein refolding ability. Besides alpha-CD, a number of other neutral CDs were found to be effective protein folding aids.

Development and evaluation of a rapid IgM capture ELISA (JEV-Chex) for the diagnosis of Japanese encephalitis

BACKGROUND

The IgM capture ELISA has been the most widely used diagnostic method for Japanese encephalitis. However, the lack of availability of validated commercial kits as well as the short shelf life of the kit reagents has limited the use of this technique to very few centres in Asia.

OBJECTIVES

Development and evaluation of a rapid IgM capture ELISA (JEV Chex) in comparison to the conventional IgM capture ELISA. Produce key reagents such as cell culture derived JEV antigen and biotinylated monoclonal antibody which are stable at room temperature.

STUDY DESIGN

The conventional IgM capture ELISA was modified to reduce the total assay time and two key reagents used in the assay JEV antigen and biotinylated anti-JEV monoclonal antibodies were rendered stable at room temperature using a special procedure. A multi-centric evaluation of this rapid ELISA was carried out using well characterized stored CSF and serum samples. Long term stability of the key reagents was also assessed over a period of 6 months.

RESULTS

The rapid IgM capture ELISA developed by us showed complete concordance with the results obtained using the conventional ELISA at all the three centres where it was evaluated. In addition, the stability studies carried out with the inactivated cell culture antigen and the biotinylated monoclonal antibodies stored at room temperature for a period of 180 days revealed that both these reagents yielded consistent optical density values in the ELISA.

CONCLUSIONS

The rapid ELISA format of the IgM capture ELISA (JEV-Chex) developed by us as well as the stability of reagents achieved by us in this study is what renders this rapid IgM capture ELISA very robust and user friendly since reagents can be stored at 4 degrees C by peripheral labs.

Changing trends in US injury profiles: revisiting non-fatal occupational injury statistics

The purpose of this paper is to review the current trends in non-fatal injury profiles of workers in the United States. It is generally accepted that occupational injury and illness rates are affected by many factors, such as the amount and quality of training, employee turnover rates, work experience, extent of mechanization and automation, job-related parameters, and worker gender. In the last decade, not only have the technologies used in the workplace changed significantly, there has been a greater awareness among employers and employees as to the importance of containing work injuries. Additionally, the extent of outsourcing for labor-intensive jobs has increased dramatically owing to cheaper labor costs in places such as China and Mexico. These changes have affected the manufacturing sector of US industry more than any other sector. How these changes have influenced the injury and illness profiles of the American worker is of considerable interest given the increased attention paid to work-workplace design, injury hazard control, and ergonomics in general. In this paper, we compare the injury and illness profiles of US workers separated by nearly a decade. The trends from early 1990s are compared to those from early 2000s. Data from the Bureau of Labor Statistics were used to compile the injury statistics. The results of our comparison show that while the absolute numbers of work-related injuries and illnesses have declined over the last 10 years, the basic trends associated with different factors remain almost unchanged. The reasons for this decline are discussed in this paper.

Fluorometric assay for detection and quantitation of polyamidoamine dendrimers

Polyamidoamine dendrimers are protein-like nanomaterials that have many potential biological applications. Research studies using dendrimers often require their detection and quantitation. This article describes a simple, inexpensive, and rapid fluorometric assay based on the ability of dendrimers to bind the fluorescent probe, 8-anilino-1-naphthalene-sulfonic acid. This interaction leads to an enhanced fluorescence intensity of the dye that shows a linear relationship with dendrimer concentration. The procedure is applicable to dendrimers that have various surface functional groups and internal cores. Amine- and hydroxyl-terminated dendrimers gave the best calibration curves under alkaline conditions (pH 7.4). Carboxyl-terminated dendrimers required acidic conditions for their measurement. The assay for dendrimers with an amine surface and an ethylene diamine core was accurate between 0 and 100 microM and produced a within-run coefficient of less than 5%. Under the assay conditions used, the fluorescence signal strength was dependent on type of surface group and core length of the dendrimer.

"Myocardial infarction" in adolescents: do we have the correct diagnosis?

The evaluation of adolescents with chest pain, elevated cardiac enzymes, and abnormal electrocardiograms (ECGs) continues to pose diagnostic and management dilemmas. Myocardial infarction is an uncommon finding in this population and alternative diagnoses must be considered. Our database was retrospectively reviewed for adolescents age 16-18 years without prior cardiac history who underwent cardiac catheterization. Patients who presented with chest pain, elevated cardiac enzymes, normal ejection fraction, and abnormal ECGs were included. Management, diagnostic testing, and final diagnosis were reviewed. Nine adolescents (eight males and one female) without prior cardiac history were identified. The ECG findings in all patients were consistent with myocardial ischemia in a coronary distribution. Thrombotic coronary occlusion was not found in any patient. In adolescents without prior cardiac history of risk factors for myocardial infarction such as Kawasaki disease, familial hypercholesterolemia, or drug use who present with chest pain, multiple diagnoses must be considered even in the presence of focal ischemic ECG changes and elevated cardiac enzymes. Thrombolytic therapy or anticoagulation should be withheld until a definitive diagnosis of myocardial infarction has been made. Magnetic resonance imaging is the most useful tool to differentiate focal myocarditis from myocardial infarction.

Roles of polymerization dynamics, opposed motors, and a tensile element in governing the length of Xenopus extract meiotic spindles

Metaphase spindles assemble to a steady state in length by mechanisms that involve microtubule dynamics and motor proteins, but they are incompletely understood. We found that Xenopus extract spindles recapitulate the length of egg meiosis II spindles, by using mechanisms intrinsic to the spindle. To probe these mechanisms, we perturbed microtubule polymerization dynamics and opposed motor proteins and measured effects on spindle morphology and dynamics. Microtubules were stabilized by hexylene glycol and inhibition of the catastrophe factor mitotic centromere-associated kinesin (MCAK) (a kinesin 13, previously called XKCM) and destabilized by depolymerizing drugs. The opposed motors Eg5 and dynein were inhibited separately and together. Our results are consistent with important roles for polymerization dynamics in regulating spindle length, and for opposed motors in regulating the relative stability of bipolar versus monopolar organization. The response to microtubule destabilization suggests that an unidentified tensile element acts in parallel with these conventional factors, generating spindle shortening force.